Table of Content

15 December 2002, Volume 13 Issue 12

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Early diagnosis of low-value forest: An approach of ecological factors

DU Xiaojun, JIANG Fengqi, SHEN Hui, LIN Heming

2002, (12):  1523-1528. 

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The management and improvement of low-value forests is an important issue of forestry in China. This paper put forward a new thought of early diagnosis for low-value forest. By applying this method,the forest growth trend before the explosion of the state of low-value forest was diagnosed according to the formation rule of low-value forest,and so,managers could adopt corresponding management measures in time. Taking a case study of Chinese pine plantations in western Liaoning Province,the early diagnosis of low-value forest was studied,and set up early diagnosis techniques of ecological factor approach based on single factor experiment and discriminant analysis: 1) following discriminant indices were selected: soil thickness (X₁),organic matter (X₂),soil nitrogen content (X₃),soil water content (X₄),and soil microbic quantity (X₅);2)discriminant function could be expressed as: Y=1.596X₁- 0.51 X₂-3.196X₃+1.622X₄+1.898X₅ ;3)early diagnosis of low-value forest was carried out by discriminant function and the value of each discriminant index. For early diagnosis of low-value forest,this paper is a pilot study. It is suggested that the forming mechanism of low-value forest and their related study should be strengthened.

Ecological and biological characteristics of Wikstroemia indica

REN Hai, PENG Shaolin, DAI Zhiming, LIANG Xiaodong, CAI Xi'an, LIN Rongbiao

2002, (12):  1529-1532. 

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Wikstroemia indica was the common shrub with medicine use in subtropical and tropical zones. The studies on the biological and physiological characteristics, population dynamics,biomass,nutrient composition of Wikstroemia indica showed that Wikstroemia indica was widely dispersed over hilly lands and opened forests. It was heliophytes and grew well on impoverished soil. Its average photosynthetic rate and conductance were 7.33 μmol CO₂·m^-2 ·s^-1 and 0.042 molH₂O·m^-2 ·s^-1,respectively. The weighted nutrient concentration of Wikstroemia indica were N 0.667%,P0.081%,K0.540%,Ca 0.776%,and Mg0.259%,respectively,and the medicine ingredient was Wikstroemine C₁₆H₁₂O₅. Due to morphological difference,the competitive power on energy and nutrient of Wikstroemia indica was less than that of Rhodomyrtus tomentosa . Wikstroemia indica population decreased,while Rhodomyrtus tomentosa increased on shrubby grass land during early successional stage. Wikstroemia indica could be planted to increase its biomass to exploit medicine use.

Ecological restoration of Castanopsis carlesii forest in Wupin, Fujian

YOU Shuisheng

2002, (12):  1533-1536. 

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Analyses on the effects of the different scales of human disturbance on restoration of Castanopsis carelesii forest in Wupin,Fujian indicated that with increasing degrees of the scales of human disturbance (A class, regeneration by selected cutting; B class, natural regeneration;Cclass,natural regeneration promoted by artificial tending;D class,Chinese fir forest),the important value of Castanopsis carlesii and the similar index between the communities decreased,and the assembling and abundance degrees of species increased under disturbance of B or C class,and decreased under D class.It could be concluded that the disturbance of A class was light,that of B class was medium and could be restored rapidly,disturbance of C class was also medium but would be restored in a longer period,and that of D class w as difficult to be restored due to the intense disturbance.

Soil moisture dynamics under artificial Caragana microphylla shrub

Alamusa, JIANG Deming, FAN Shixiang, LUO Yongming

2002, (12):  1537-1540. 

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Applying the methods of deducing time series from vegetation space alignment,we analyzed the spatial and temporal variation features of soil moisture under artificial Caragana microphylla shrubs built in1984,1987,1995,1999. The results showed that affected by mechanical composition of mobile sandy dunes,the soil of sandy land was mainly composed of sandy particle,and the particles of >0.01 mm were accounted for 97%. The withered moisture was 1.55%. The field waterhold capacity was 5.5%,and the available moisture storage was 3.95%. With the increase of the dominance of fix sand vegetation,the moisture content of soil under artificial Caragana microphylla shrubs was decreased. The soil moisture of vegetation built in1984 was lower than that built in1999. The soil moisture conditions of four stages vegetation were continued depressing from April to June in a year,the lowest point presenced in June,and then gradually increased from July to October. The vertical change of soil moisture showed the tendency of increasing with soil depth. The soil moisture decreased by the degrees of early built vegetation (1984,1987). Especially in70 cm soil depth,the moisture content of soil decreased obviously. Caragana microphylla shrubs absorbed water and aggravated the shortage of soil moisture content near the root system,which affected the component of vegetation in Caragana microphylla shrubs .The species of herbaceous plants and annual plants increased during the growth of Caragana microphylla shrub.

Characteristics of canopy patches related to natural regeneration of broad-leaved Korean pine forest

GUO Qingxi

2002, (12):  1541-1543. 

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The characteristics of canopy patches of dominant tree species in a broad-leaved Korean pine forest at an elevation of 740 m in north slope of Changbai mountain was investigated to understand the effects of canopy patch on the structure and regeneration of the forest. The results showed that the main species that constituted the canopy patches were Pinus koraiensis,Tilia amurese,Acer mono and Quercus mongolica,their canopy patches covered 57.1 % of the forest,and 87 % of the total area of the canopy. Most canopy patches were less than100 m², with irregular shapes. The seedlings and saplings of Acer mono were distributed under almost all canopy patches of Tilia amurense and Pinus koraiensis,and reached the maximum densities under canopy patch of Tilia amurense of 32 m²,and patch of Pinus koraiensis of 28 m². However,the seedlings and saplings of Tilia amurense were distributed only under a few canopy patches of Tilia amurense and Pinus koraiensis .

Reflectivity of broad-leaved Korean pine forest in growing season on Changbai Mountain

GUAN Dexin, JIN Mingshu, XU Hao

2002, (12):  1544-1546. 

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The hourly reflectivity of broad-leaved Korean pine forest on Changbai Mountain from 22 May to 14 October 2001 was calculated based on total solar radiation and reflect radiation. The results showed that: the reflectivity of the forest was related to solar altitude. It was generally high just after sunrise or before sunset,but was relatively stable as solar altitude was higher than 30?. The diurnal curves of reflectivity took Ushape. The reflectivity of the forest was also related to sky conditions. In clear days,the Ushape was quite clear. In scattered days,the reflectivity just after sunrise and before sunset was not as high as in the clear days,and the Ushaped curve was shallow. In overcast days, the reflectivity fluctuated. In terms of dynamic variation in the measured period,the reflectivity was relatively high in early June,decreased a little in late June,kept stable from July to September,and dropped gradually in the first half of October. The variation was related to the phenology of the forest canopy.

Determination and calculation of evapotranspiration of broad-leaved Korean pine forest on Changbai Mountain

WANG Anzhi, PEI Tiefan

2002, (12):  1547-1550. 

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.In this paper,the E_t of broad-leaved Korean pine forest on Changbai Mountain was determined by water balance method,and calculated by Bowen ratio energy balance (BREB) method in July,August and September,2001. The total E_t was 288.18 mm and 214.94 mm,respectively,and the daily average E_t in each month was gained,while the rainfall is 301.9 mm. Furthermore,the daily E_t and hourly E_t rate were computed by BREBmethod,and the availability and precision of the E_t determined by water balance and calculated by BREBmethod was discussed.

Introduction and selection of new poplar clones in shelterbelts/windbreaks in northern Liaoning

LIN Heming, FAN Zhiping, ZENG Dehui, JIANG Fengqi

2002, (12):  1551-1554. 

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Six new poplar clones were introduced in Qianshuangjing township of Changtu county,Liaoning Province as experiment materials,and their indeces in growth,cold resistance,disease infection,and insect infection were evaluated and compared to the locally grown Fuzha Ⅱ poplar. According to the comparison of the 4 indices,the study found that N 119 poplar showed all the scores obviously better than those of CKand other poplars,and was recommended for the area. The growth of Zhonglin 95 was higher,and its disease and pest infection was equal or near to the CK. So,the poplar Zhonglin 95 is also worthy to be recommended.

Freezing injury of plant and oxidative stress-Superoxide generation in freeze-thaw cycles of Cabbage leaf tissues

JIN Yuehua, TAO Dali, DU Yingjun

2002, (12):  1555-1558. 

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To test the hypothesis that oxidative stress is involved in inducing freezing injury of plants,nitroblue tetrazolium (NBT) was infiltrated into cabbage leaf tissues before they were frozen. NBTwas reduced to formazans in freeze thaw cycles. The ethanol-extractable mono-formazan was measured by a spectrophotometer,and used as a quantitative indicator of oxidative stress that developed during a freeze-thaw cycle. NBT perse as an oxidant increased the freezing injury slightly. When Me₂SO as a cryoprotectant was infiltrated into leaf tissue,it apparently enhanced the freezing tolerance,and this is correlated to its ability in ameliorating oxidative stress,as indicated by the partial inhibition of NBTreduction.The results supported the hypothesis that freezing injury of plants is related to oxidative stress. The experiments indicated that it was possible that the reductant of NBTin the freeze thaw cycle was superoxide anion free radical.

Effects of simulated acid rain on chloroplast activity in Dimorcarpus longana Lour cv wulongling leaves

QIU Dongliang, LIU Xinghui

2002, (12):  1559-1562. 

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Adecreased content of chlorophyll (Chl) and carotenoid (Car) was found in the Dimorcarpus longana Lour. cv. wulongling leaves when treated with <pH3.5 acid rain. The decline of Chl content was caused by the reduction of Chla,while Chlb was less sensitive to the acid rain,which resulted in a decrease of Chla/Chlb ratio. The content of Car and the ratio of Chla to Chlb reduced with the duration of stress time. The injury of acid rain to photosynthetic pigments was intensified by illumination. The activities of photoreduction,photophosphorylation and H⁺ ATPase activity decreased with the reduction of pHvalue under the simulated acid rain. Therefore,the injury of electron transport chain and the uncoupling of photophosphorylation might lead to the ineffective absorption,transportation and transformation of light energy. In our study,the process of photophosphorylation was more sensitive to acid rain than that of photoreduction.

N₂O emission from trees under different light irradiances

ZHANG Xiujun, CHEN Guanxiong, XU Hui

2002, (12):  1563-1565. 

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This paper firstly measured in situ N₂O emission from branches and leaves of sun plants (Fraxinus mandshurica,Pinus koraiensis,Alnus hirsuta) and shade tolerant plants (Tilia amurrensis) under different light irradiances in closed chamber. Light irradiance had contrast effects on N₂O emission flux from sun and shade tolerant tree species. In the test sun plants,more N₂O was emitted under weak light than under strong light. The emission rates decreased with increasing irradiances,and even absorption instead of emission of N₂O was detected under strong light. In contrast to sun plants,in the shade tolerant plant T.amurrensis,there was more N₂O emission under strong light than under weak light,and N₂O absorption from environment was detected under weak light.

Calculation method of ecological water requirement for forestland and its application to Huang-Huai-Hai Region

ZHANG Yuan, YANG Zhifeng

2002, (12):  1566-1570. 

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The evapotranspiration and soil moisture content of forestland were studied in relation to free growth. It was found that when the soil moisture content was about 45～100 % of field capacity and the actual evapotranspiration came up to 60～100 % of potential evapotranspiration,the growth of trees could be sustained. On the basis of our research,the grading standard and calculation method of ecological water requirement of forestland were established. Moreover,the ecological water requirement for forestland in Huang Huai Hai area was estimated by GIStechnology,and its ecological water shortage was compared to its current water consumption. The results indicated of that the annual ecological water requirement of forestland in Huang Huai Hai region was 25.6～45.8 billion m³,and its current water consumption was approximately 2.8 billion m³ below the minimum of ecological water requirement,and 8.4 billion m³ below the optimal ecological water requirement.

Effect of different fertilization system on soil nutrient budget

YU Wantai, ZHANG Lu, YIN Xiuyan, MA Qiang, SHEN Shanmin

2002, (12):  1571-1574. 

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Along term experiment was carried out on a damp palm soil about ten years under the condition of nutrient recycling and reutilization. The quantity of crop nutrients transferred from the system,and the nutrient budget of N,Pand Kin soil were studied. The results of a ten-year field experiment indicated that the use of nutrients recycled in the farming systems with appropriate amount of fertilizers applied according to the soil nutrient supplying ability could not only produce high crop yield, but also balance the soil nutrient budget,so that,there were no significant surplus of nutrients (mainly inorganic nitrogen) which might emit or leach out of soil into environment.

Effect of combined application of bioorganic manure and inorganic nitrogen fertilizer on soil nitrogen supplying characteristics

ZHANG Yali, ZHANG Juan, SHEN Qirong, WANG Jinchuang

2002, (12):  1575-1578. 

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Pot experiment was carried out to study the effect of application bioorganic manure on soil nitrogen supplying characteristics. Compared with the application of raw rice straw,a combined application of bio organic manure and inorganic nitrogen fertilizer could boost the content of microbial biomass carbon and nitrogen,and the increased percentage could be 300～400 %. Astrong immobilization of nitrogen by microorganisms was always followed by a net Nmineralization, which was mostly favorable for the growth and development of plant,and improved the use efficiency of nitrogen fertilizer.

Effects of applying nitrogen fertilizer at different stages in ploughed furrow on dry matter production and yield of rice

SHI Kun, HAO Shufeng, XIE Hongtu, ZHANG Xudong

2002, (12):  1579-1581. 

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The effects of applying nitrogen fertilizer in ploughed furrow at different stages on dry matter production and yield of rice were studied in a field experiment in1999. The results showed that applying Nfertilizer at booting stage (BS) had better effects on dry weight (2.9 g·hill^-1) of leaf,stem and whole plant than at panicle primordia formation stage (PPFS),tillering stage (TS) and regular Nfertilization (RF). Meanwhile,the dry weight of leaf and sheath as well as the leaf area index (LAI,8.9) could be maintained at a high level for a relative long time in BStreatment,compared with PPFS,TSand RFtreatments. Similar phenomenon was observed in the growth velocity (0.73 g·d^-1 ·hill^-1) of stem and whole plant,and the dry weight (10434 kg·hm^-2) of seed. The grain yield of rice followed the sequence of BS≥PPFS>TS≥RF. Thus,the optimum stage of applying Nfertilizer in ploughed furrow was the booting stage.

Genetic ecology of rice allelopathy on receiver plant

HE Huaqin, LIN Wenxiong, DONG Zhanghang, GUO Yuchun, SHEN Lihua, LIANG Yiyuan, CHEN Fangyu, LIANG Kangjing

2002, (12):  1582-1586. 

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In this study, 5 parental rice lines with different allelopathic potential were employed in partial diallel cross (4?5) to get 10 groups of F 1 seeds. After testing the inhibitory effects of 5 parents and 10 F₁s under different environment at different leaf stage on the shoot length of receiver plant lettuce(Lactuca sativa L.),dynamic genetics of rice allelopathy and its genotype譭nvironment effects were analyzed by using additive-dominant developmental genetic models. The results showed that additive and dominant effect genes expressed alternatively during 3-leaf stage to 8-leaf stage in rice seedling. As additive effect genes were pronounced at 7-leaf stage,dominant effect genes appeared to play the most important role at 3-leaf stage and 6-leaf stage but the two effect genes were equally important at 5-leaf stage and 8-leaf stage. Heritabilities analysis indicated that the general heritability in the narrow sense(H_N²) was significant at 5-,7- and 8-leaf stage,and decreased with increasing leaf stage. Rice allelopathy was significantly affected by genotype譭nvironment(GE) interaction,suggesting that the environment of allelopathic rice development must be controlled for practical use.

Screening methodology for rice (Oryza sativa) genotypes with high phosphorus use efficiency at their seedling stage

GUO Yuchun, LIN Wenxiong, SHI Qiumei, LIANG Yiyuan, CHEN Fangyu, HE Huaqin, LIANG Kangjing

2002, (12):  1587-1591. 

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Under hydroponic culture,the responses of rice (Oryza sativa) genotypes to low Pstress were respectively evaluated by means of relatively-higher Pconcentration in a controlled system with insoluble phosphate source (Ca₃(PO₄)₂) and of relatively-lower concentration with 0.5 mg P/Lin which NaH₂PO₄ was the soluble phosphate. Relative indices such as relative dry weight of tillers (RTW),total relative plant dry weight (RPW),relative number of tillers (RTN),relative dry weight of root (RRW),relative dry weight of shoot (RSW),relative leaf age (RLA) and relative plant height (RPH) were used to screen as the tolerant indices to Pdeficiency,and the correlations among screening criteria per se were analyzed. The results showed that there were significant differences of tolerant indices to Pdeficiency in the test rice genotypes. When the rice cultivars were exposed to low Pstress with the relatively-higher Pconcentration to be screened,the relative tiller dry weight (RTW),relative shoot dry weight (RSW) and total relative plant dry weight (RPW) could be used as the better screening criteria,especially RTWwas considered as a sensitive and reliable screening criterion because its coefficient of variation (CV) and the variable range of data among the test varieties should be large. However,when rice genotypes were grown in the stress condition with relatively-lower Pconcentration,the screening criteria were diffenent,and it suggested that relative shoot dry weight (RSW) or total relative plant dry weight (RPW) was the best single screening criterion.

Application of latent root regression method in analysis of predation of predatory natural enemy in paddy field

TANG Jinlong, WU Jincai

2002, (12):  1592-1594. 

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Alatent root regression model was constructed for analyzing the predation quantity in a coexistence system of four spiders (Pirata subpiraticus,Oedothorax insecticeps,Clubiona japonicola, and Bianor hotingchiehi) with brown planthopper (Nilaparvata lugens). The predation quantity of the spiders in a multi species coexistence system could be predicted by y= 6.6600 +6.3399(-0.0138X₁^* +0.0895X₂^*+0.0078 X₃^* -0.1067X₄^* +0.6742X₅^*). The result showed that compared to LSregression, the accuracy of predation quantity predicted by the model increased by 10%.

Differences between barley cultivars in seedling growth and in uptake of cadmium and nutrients under various Cd levels

WU Feibo, ZHANG Guoping

2002, (12):  1595-1599. 

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Asolution culture experiment was carried out to examine the genotypic differences of barley in the uptake/accumulation of Cd and some mineral elements,plant development and biomass accumulation under different Cd levels. The results showed that the plant height,leaf number,SPADvalue and biomass accumulation of shoot/root were significantly reduced in the plant grown in1 μmol·L^-1 Cd nutrient solution compared to control,and the absorption of Zn,Mn and Cu was strictly retarded. There was a highly significant difference in the reduction of these growth parameters among cultivars. Mimai 114 and Zhenong1 showed the least reduction,suggesting its high tolerance to Cd toxicity,while Wumaoliuling with the greatest reduction. Significant cultivar difference in Cd concentration/accumulation was also found. Zhenong1 contained the highest Cd concentration in plant tissue,while Mimai 114 contained the lowest Cd concentration. Asignificantly negative correlation between biomass accumulation and Cd concentration/accumulation of shoot and Cd concentration of root was found,while no significant relationship with root Cd accumulation.

A comparative study on photosynthesis and transpiration of Kelimeris integrifolia in summer and autumn on Songnen grasslands of China

DU Hongmei, WANG Deli, SUN Wei

2002, (12):  1600-1604. 

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The diurnal changes in photosynthesis and transpiration of Kelimeris integrifolia in Summer and Autumn on Songnen grasslands were characterized as a two-peak curve,but with some differences between two seasons. It was shown that environmental conditions and plant internal factors had a strong effects on plant photosynthesis and transpiration. The net photosynthetic and transpiration rates of the leaves were positively correlated to photosynthetically active radiation (P<0.01),and negatively correlated to stomatal resistance as well as intercellular CO₂ concentration (P<0.05). The transpiration rate was positively correlated to leaf temperature and water saturation deficit of the air. Among the above factors,photosynthesis active radiation was the dominant factor,and stomatal resistance also played an important role in plant photosynthesis and transpiration.

Simulation alfalfa growth in Wulanbuhe sandy region

BAI Wenming, BAO Xuemei

2002, (12):  1605-1609. 

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Based on the theories of accumulated temperature and on the physio-ecological characteristics of Medicago sativa, a simulation model for its growth under soil water stress in arid sandy region was developed. The model was mainly composed of four modules: the stage module of growth, the dynamic module of leaf area index, the accumulated module of dry matter, and the distributive module of dry matter. After simulating and calculating, the model could be used to predict the growing progress and dynamic changes of leaf area and yield for herbage in sandy region. The result shows that the application of the model to production is usually effective.

On the safety threshold of wetlands based on water ecological element-Taking wetlands in Sanjiang Plain as an example

LIU Zhenqian, WANG Jianwu, LUO Shiming, LU Xianguo, LIU Zhaoli, LIU Hongyu, LI Xiujun

2002, (12):  1610-1614. 

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The lowest water requirement of the wetlands was demonstrated through different simulations. Based on the relationship between the area of wetlands and its effects on air temperature and humidity,some useful statistical models were established. According to the theory and principles of system dynamics (SD),a dynamic simulation model of the wetlands' retaining water was compiled in DYNAMOlanguage. Finally,the safety threshold of the wetlands was assessed based on its water ecological factors. The feasibility of the method was demonstrated by a case study on the wetlands in Sanjiang Plain of China.

Landscape ecological studies on autumnal Chinese cabbage fields in Shenyang city suburb Ⅰ Features of autumnal Chinese cabbage field patches

ZHANG Kai, WEN Dazhong, CAO Zhiqiang, LIANG Wenju

2002, (12):  1615-1618. 

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Some typical patches of autumnal Chinese cabbage fields in the agricultural landscapes of Shenyang city suburb were investigated,and their basic features,such as areas,shapes,neighborings and connections,were recorded. Their mosaic features were also analyzed and discussed. In the region of less 5 km distance from city,many Chinese cabbage patches neighbored each other and connected to highways,while in the region of 5～10 km distance from city,they neighbored with corn patches and connected to countryside roads. In the region over 10 km distance from city,many Chinese cabbage patches are surrounded by corn patches and connected to countryside roads.

Landscape ecological studies on autumnal Chinese cabbage fields in Shenyang city suburb Ⅱ Relationship between Chinese cabbage field patches and their neighboring landscape elements

ZHANG Kai, WEN Dazhong, CAO Zhiqiang, LIANG Wenju

2002, (12):  1619-1623. 

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The relationship between autumnal Chinese cabbage patches and their neighboring other lanascape elements were studied in Shenyang suburb. The groups and quantities of arthropods moving through a boundary between a Chinese cabbage patch and its neighboring corn patch in certain period,were investigated and the 7 oders of arthropods moving through the boundary with an average flow of 10.3 indiviaduals穖_-1 穌^-1 were observed. The changes of falling dust rates on a Chinese cabbage patch near a countryside road are analyzed. Some principles of agroecosystems in an agricultural landscape were discussed on the basis of these observation results.

Oasis corridor landscape in arid regions:A case study of Jinta Oasis

MA Mingguo, CAO Yu, CHENG Guodong

2002, (12):  1624-1628. 

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In arid region oasis, the main corridor landscape types include river, ditch, shelterbelt and road. This paper introduced their basic ecological effects on transporting mass and energy and on obstructing desert landscape expansion and incursion. Using Geographic Information System (GIS), the corridor distribution and its spatial relationship with other landscape types in the Jinta Oasis were analyzed. Based on the dynamically monitoring on the landscape pattern change of the Jinta Oasis during the latter 10 years, the driving functions of the corridors on this change were analyzed in detail. The results showed that all kinds of corridors' characteristics could be quantified by the indexes such as length and width, ratio of parameter and area, density,and non heterogeneity. The total corridor length of Jinta Oasis is 1838.5 kilometers and its density is 2.1 km穔m^-2 .The corridor density of the irrigated land, forest and resident area is maximal,showing that the affection degree of the oasis corridors on them is the most. The improvement of the corridor quality is one of the important driving factors on the irrigated land.

Echolocation sound waves, morphological features and foraging strategies in Hipposideros pratti

CHEN Min, FENG Jiang, LI Zhenxin, ZHOU Jiang, ZHAO Huihua, ZHANG Shuyi, SHENG Lianxi

2002, (12):  1629-1632. 

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Studies on the echolocation sound waves in different states (flying and hanging),morphological features and ecological processes (foraging strategies,foraging habitat and diet type) of Hipposideros pratti showed that H.pratti had CF (constant frequency) FM (frequency modulated) echolocation sounds. There were some differences in dominant frequency (caused by Doppler compensating effect),pulse repetition rate,pulse duration and interpulse interval between the bats at flying and hanging. The dominant frequency, FMbandwidth,pulse duration and interpulse interval were lower,while the pulse repetition rate and duty cycle were higher at flying than at hanging. All the differences indicated that H.pratti could adopt specific echolocation sounds to adapt to specific environments and conditions to detect,approach and capture their preys successfully. On the basis of echolocation sound and field observation,it was concluded that H.pratti might search the preys at flying in the period of insect fastigium,and after the period,it might search the targets at hanging. The foraging habitat was near the tree crowns,and the preys consisted mainly of relatively large insects,such as beetles.

Effects of mating experience and temperature on sex pheromone production of beet armyworm, Spodoptera exigua

DONG Shuanglin, DU Jiawei

2002, (12):  1633-1636. 

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Mating experience could not affect the production of sex pheromone in the female glands 24 h later, which meant that the beet armyworm females might call and mate again in next scotophase. This result explained the phenomenon why the beet armyworm could mate several times in their life under field conditions. On the contrary, ambient temperature greatly influenced the pheromone biosynthesis in the beet armyworm females. The optimal temperature for the biosynthesis of sex pheromone was between 15～25 ℃. Under the temperature beyond this range,the biosynthesis of the pheromone components was disturbed in terms of absolute titers,proportions,and their CVs. The biosynthesis of component Bwas suppressed under 35 ℃,and the proportion of Ato Bwas significantly higher. In contrast,under 10 ℃,the titer of Aand the proportions of Ato Bwere disturbed significantly,and the proportions of Ain ABand ADbinary blends changed significantly. Furthermore,the CVs of the ratios of Ato Band Ato Dbecame larger than10 % under 10 ℃.

Effect of earthworm inoculation on soil carbon and nitrogen dynamics and on crop yield with application of corn residues

LI Huixin, HU Feng, SHEN Qirong, CHEN Xiaoyun, CANG Long, WANG Xia

2002, (12):  1637-1641. 

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This study was carried out in the Experimental Station of Nanjing Agricultural University,which is in a subtropical monsoon region characterized by a warm-wet spring and a hot-dry summer. The annual average temperature,precipitation and evaporation are 15.6℃,1010 mm and 1560 mm,respectively. In1999,the experimental plots (2.8 m×1.0 m×0.6 m) were established by concrete frame. Soil in the plots was orthic aquisols collected from Rugao County,Jiangsu Province. Crop rotation was upland rice and winter wheat. At the beginning of the first crop (rice) season,earthworms (Pheretima sp.) were inoculated at a density of 10·m^-2 and 20·m^-2,respectively,in the plots with an application of corn residues at the rate of 1500 g·m^-2 (750 g·m^-2 in the following seasons). The responses of soil carbon and nitrogen and crop yield to earthworm activity were investigated from 1999 to 2001. The results showed that earthworms had no significant influences on total soil carbon and nitrogen content,which implied that there was no depletion of soil carbon and nitrogen pools in the presence of earthworms. The maintenance of soil carbon might be explained by low assimilation efficiency of organic matter by earthworms,and by the compensation of carbon returning from plant production enhancement. Soil mineral nitrogen,soil microbial biomass carbon and microbial biomass nitrogen were increased,and nitrogen mineralization was strengthened by earthworm activities,which was more obvious at jointing/booting and heading stages. In comparison with no worm treatments,the yield of rice and wheat increased by 9.3% and 5.1%,respectively,in the treatments inoculated with earthworms. It was concluded that earthworm was very important in promoting nitrogen recycling of crop residues and plant productivity,and in keeping the balance of soil carbon pool as well.

Life table of natural population of banana pseudostem weevil, Odoiporus longicollis Oliver, in Spring

LU Yongyue, LIANG Guangwen, ZENG Ling

2002, (12):  1642-1644. 

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The active factor life tables of natural population of banana pseudostem weevil were built,and the controlling effect of active factors was evaluated by using exclusion index of population control (EIPC). The results showed that the population trend indices in growing and harvested banana trunks were 4.3481 and 3.6628,and the EIPCof predation and others were 1.9256 and 2.3577,respectively. The EIPCof natural death were 1.3607 and 1.3554,and that of parasitism and disease in growing and harvested banana trunks were 1.1988 and 1.1668, respectively. The factor of predation and others was important.

Geostatistical analysis on spatial patterns of Erythroneura sudra and Erigonidium graminicola

ZOU Yunding, BI Shoudong, ZHOU Xiazhi, LI Lei, GAO Caiqiu, DING Chengcheng

2002, (12):  1645-1648. 

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The spatial construction and distribution of Erythroneura sudra and Erigonidum gramimicola at different periods were investigated with geostatisics. The results showed that the semivariogram of Erythroneura sudra was described by spherical model,indicating an aggregated spatial arrangement. The range was 25.71～37.14 m. The semivariograms of Erigonidum graminicola was fitted by spherical model too,also indicating an aggregated spatial arrangement,and its range was 25.12～44.06 m. The amount and spatial distribution of Erigonidium graminicola was closely related to that of Erythroneura sudra. It reveals that Erigonidium graminicola is the dominant natural enemies influening the population of Erythroneura sudra.

Relationship between sexual reproduction, population growth and resting egg production of freshwater rotifer Brachionus calyciflorus

XI Yilong, CAO Ming, HUANG Xiangfei

2002, (12):  1649-1654. 

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Using exponential and logistic growth models,the effects of sexual reproduction frequency and the proportion of a female's daughters reproducing sexually on population growth rate and resting egg production of freshwater rotifer Brachionus calyciflorus were examined by computer simulation. Within the parameters of the simulation,the percentage of micitc females in the offspring required for maximum resting egg production increased from 9% to 69%,when the frequency of sexual reproduction decreased from 100% to 20%. The increase of density dependent limitation (the value of Kdecreased from 1000 to 100) made this percentage increase from 18% to 69%,and resting egg production decrease from 1072.10 to 133.67. The relationship between the population growth rate (r) and the optimum percentage of mictic females in the offspring required for maximum resting egg production was best described by curvilinear regression. When sexual reproduction became more frequent and density dependent decreased,The population with the percentage of mictic females in the offspring in10～30% had a bigger resting egg production.

Effects of 1, 2, 4-trichlorobenzene stress on active oxygen in germinated soybean seeds

LIU Wan, SUN Tieheng, LI Peijun, ZHOU Qixing, LIANG Wenqu, TAI Peidong, XU Huaxia, ZHANG Hairong

2002, (12):  1655-1658. 

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Pot culture experiment on the effects of 1,2,4 trichlorobenzene (TCB) stress on active oxygen metabolism of germinated soybean seeds indicated that during the beginning (1st～3rd day) of 100～300 μg·g^-1 TCB treatment,the respiratory peak appeared earlier,and the respiratory rate,the accumulation of superoxide radical (O₂^-) and H₂O₂,as well as the malondialdehyde (MDA) content were all enhanced. During 1～6 days of TCBstress,peroxidase (POD) activity gradually increased,and superoxide dismutase (SOD) activity increased firstly,and decreased afterward. These results suggested that the injury effects of TCBstress on germinated soybean seeds were achieved by excessive accumulation of active oxygen resulted from the degradation of active oxygen scavenging enzyme system.

Effects of organic manure on the conformation and biological availability of soil Cd

ZHANG Qiufang, WANG Guo, YANG Peiyi, FANG Ling

2002, (12):  1659-1662. 

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Pot experiments were conducted to investigate the effect of organic manure on the conformation and availability of both native and added Cd in red soil and moisture soil under rice planting. Most of the added Cd existed in exchangeable form, while the native Cd existed more evenly in four forms. The organic manure did not influence apparently on the forms of native Cd,whereas influenced significantly on those of the added Cd. From tillering to mature stage, the exchangeable form of the native Cd increased, while that of the added Cd decreased. The application of organic manure could promote the uptake of Cd under the treatments without adding Cd. Under the treatments of adding Cd,the application of the organic manure could depress the uptake of Cd,and the effect of applying pig's manure was stronger than that of applying peat. There existed a significant antagonism between the accumulation of Cd and Fe in rice roots.

Effect of organophosphorus pesticide toxicity on soil animal

WANG Zhenzhong, ZHANG Youmei, LI Zhongwu, XING Xiejia

2002, (12):  1663-1666. 

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The test of organophosphorus pesticide on toxicity of soil animal showed that soil animal is sensitive to organophophorus toxicity,the species and quantities of soil animal treated by four kinds of pesticide are decreased. The species of soil animals was decreased with decreasing common population and rare population,while the amount change of soil animal was associated with the amount change of dominant populations of Acarina and Collembola. Toxicology and toxicity experiment showed that the pesticide has a deadly effect to earthworm,and its toxicity constrained the respiration intensity of big soil animals obviously,which weakened with the increasing pesticide concentration and prolonging poisoning time.

Application of turning band method in conditional simulation of soil heavy metals

WANG Xuejun

2002, (12):  1667-1670. 

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Geostatistical simulation techniques are widely used in studying spatial phenomena. The purpose of this study is to make an experimental study in applying this technique to understand the spatial distribution of copper and lead in wastewater irrigated agricultural soil in the eastern suburb of Beijing. The results showed that the simulation is efficient,because it fits to the main characteristics of the revealed reality of the spatial distribution of these elements. Geostatistical simulation could play an important role in regional environmental and ecological studies.

Vegetation distribution in coal cinder yard of Wuhu thermal power station

WANG Youbao, ZHANG Li, LIU Dengyi

2002, (12):  1667-1669. 

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There are 30 species of natural colonized plants in the coal cinder yard of Wuhu thermal power station,and they are subordinate to 14 families and 29 genera. The main families are Compositae (7 species),Gramineae (6 species) and Leguminesae,among which,18 species are annual plant,9 species are perennial plant,and 2 species are woody plants. The chief factors limiting the vegetation distribution are extreme infertility and high concentration of heavy metals.

A comprehensive model for assessing lake eutrophication

Qinghua CAI, Jiankang LIU, Lorenz King

2002, (12):  1674-1678. 

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The evaluation of eutrophication or trophic state of a lake is in fact a multivariate comprehensive decision making process quantifying the qualitative problem. Therefore,we should use a comprehensive method to assess lake eutrophication. On the basis of summarizing some comprehensive methods for assessing lake eutrophication reported in China and abroad,it is pointed out that the trophic state index (TSI) should be a major method for evaluating lake eutrophication, since it could provide a continuous numerical class of lake trophic state and a rigorous foundation of quantitative studies of eutrophication mechanism. Using analytic hierarchy process (AHP) to determine the weight attributions in the selected comprehensive indices,the authors,constructed a comprehensive assessment model as: TSI=W(Chla)?TSI(Chla)+W(Sd)?TSI(Sd)+W(TP)?TSI(TP) or TSI_M=W(Chla)?TSI_M(Chla)+W(Sd)?TSI_M(Sd) +W(TP)?TSI_M(TP) where W(X) were the weights for the above three parameters with value in percentage as 54.0,29.7 and 16.3,respectively. Additionally,the relations between comprehensive evaluation and other statistical methods such as cluster analysis were briefly discussed.

Basic theory and research method of urban forest ecology

HE Xingyuan, JIN Yingshan, ZHU Wenquan, XU Wenduo, CHEN Wei

2002, (12):  1679-1683. 

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With the development of world economy and the increment of urban population,the urban environment problem hinders the urban sustainable development. Now,more and more people realized the importance of urban forests in improving the quality of urban ecology. Therefore,a new subject,urban forest ecology,and correlative new concept frame in the field formed. The theoretic foundation of urban forest ecology derived from the mutual combination of theory relating to forest ecology,landscape ecology,landscape architecture ecology and anthrop ecology. People survey the development of city from the view of ecosystem,and regard the environment,a colony of human,animals and plants,as main factors of the system.The paper introduces systematically the urban forest ecology as follows:1) the basic concept of urban forest ecology;2) the meaning of urban forest ecology;3) the basic principle and theoretic base of urban forest ecology;4) the research method of urban forest ecology;5) the developmental expectation of urban forest ecology.

Progress in studies on an exotic vicious weed Mikania micrantha

ZHANG Weiyin, WANG Bosun, LIAO Wenbo, LI Mingguang, WANG Yongjun, ZAN Qijie

2002, (12):  1684-1688. 

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Mikania micrantha is a perennial weed of Astraceae native to south and central America. It has invaded Southeast Asia,Pacific region and South China. Because Mikania micrantha grows very fast and is hard to control,it has become one of the world's worst weed. In this paper,the history and status of the study on Mikania micrantha was reviewed. The research on Mikania micrantha was mainly focused on its biology,ecology,harm and control. Although some progress in the research was obtained,there is no dramatic breakthrough in the control of Mikania micrantha so far. There fore,it needs more work to solve the problems resulted from the invading Mikania micrantha .

A review on fundamental studies of secondary forest management

ZHU Jiaojun

2002, (12):  1689-1694. 

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Secondary forest is also called as natural secondary forest,which regenerates on native forest that has been disturbed by severe natural or anthropogenic disturbances.The structural and dynamic organizations,growth,productivity and stand environment of secondary forests are significantly different from those of natural and artificial forests. Such significant differences make secondary forests have their own special characteristics in forestry. Secondary forests are the main body of forests in China. Therefore,their management plays a very important role in the projects of natural forest conservation and the construction of ecological environment in China or in the world. Based on a wide range of literature collection on secondary forest research,the fundamental studies of secondary forest management were discussed. The major topics are as follows: 1) basic characteristics of secondary forest,2) principles of secondary forest management,3) types of secondary forest,4) community structure and succession dynamics of secondary forest,including niches,biodiversity,succession and so on,5) main ecological processes of secondary forest,including regeneration,forest soil and forest environment. Additionally,the research needs and tendency related to secondary forest in the future were also given,based on the analyses of the main results and the problems in current management of secondary forest. The review may be helpful to the research of secondary forest management,and to the projects of natural forest conservation in China.

Prospect of the study on desertification and its restoration of Keerqin sandy land

JIANG Deming, LIU Zhimin, KOU Zhenwu

2002, (12):  1695-1698. 

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In this paper,the study on desertification and its restoration of the Keerqin sandy land was briefly reviewed. With reference to the trends in related scientific fields and pressing demand in restoring existing desertified lands,several key aspects,including vegetation processes,eco-hydrological processes,landscape processes,and assessment of regional environmental state,prediction of desertification trends and exploration of restoration measures for the whole Keerqin sandy land,aimed to discover mechanisms leading to desertification and to restore desertified lands,were raised.

Ecological forecasting: A frontier in ecology

ZENG Dehui, JIANG Fengqi, FAN Zhiping, JI Lanzhu

2002, (12):  1699-1702. 

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An evolving science of ecological forecasting is beginning to emerge,and could have an increasingly important role in policy-making and management of natural resources and environment. The progress in computer science, quantitative analysis and ecological theory, together with the application of new high technology, will increase our ability to forecast ecosystem change. The authors introduced the connotation of ecological forecasting,relevant research advances,and some typical examples. Ecological forecasting is an important frontier in ecology, and also,would be an important direction for future ecological study.

Application and development of terrestrial biogeochemical model

WANG Xiaoke, BAI Yanying, OUYANG Zhiyun, MIAO Hong

2002, (12):  1703-1706. 

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Biogeochemical modeling plays a role as important as experimental measurement in ecosystem research. This paper analyzed the development of biogeochemical model using TEM and DNDC model as cases. Current biogeochemical models were classified according to modeling method, application purpose,element concerned, ecosystem type,and spatial scale. The basic framework (three component:plant,air and soil,and three interface:plant-air,plant-soil,and soil-air) and interior fundamental processes (physical,chemical and biological processes) of biogeochemical models were reviewed,and some important problems concerning biogeochemical modeling,such as scale upping,integrating GISand remote sensing,involved human activity,and comparison study were focused.

Advances in the research on sources and sinks of CH₄ and CH₄ oxidation （uptake） in soil

WANG Chenrui, HUANG Guohong, LIANG Zhanbei, WU Jie, XU Guoqiang, YUE Jin, SHI Yi

2002, (12):  1707-1712. 

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Methane (CH₄) is one of the main greenhouse gases contributing greenhouse effect,and its potential greenhouse effect is 21 times of CO₂. Therefore,to determine the sources and sinks of atmospheric CH₄ and to assess and forecast their amounts become and importand focus concerning the researches on global change and greenhouse effect. This paper summarized the researches on the cources and sinks of CH₄,and amplified on the influential factors (e.g.land use,ambient atmospheric CH₄ concentration,soil temperature,soil moisture content,soil pHand soil porosity) on atmospheric and interior CH₄ oxidation in soil. It is significant that studying CH₄ oxidation in vertical zonation soil in forests of Changbai Mountain to evaluate the CH₄ consumption in forest soil.

Diversity of the microorganisms degrading aromatic hydrocarbons

QIU Junshan, ZHU Keli, ZHANG Jie, ZHANG Zhongze

2002, (12):  1713-1715. 

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Aromatic hydrocarbons are biological xenobiotics. Indigenous microorganism groups turn from being unfamiliar with into active response to environmental changes by their adaptability to environment. There are changes in their genetic background, and then,the biodiversity turns into being. This paper reviewed the microorganism groups resources,biocharacters,genetic background,evolvement and their aptability to environment;described the genetic information,expression and regulatory for some species in detail;and pointed out that the degradation of aromatic hydrocarbons depended maily on new microorganisms formed by genetic engineering and on their highly efficient metabolic regulatory.

Effect of root cutting on leaf photosynthesis rate and water use efficiency of maize

CHAI Shiwei, LIU Wenzhao, LI Yangyang

2002, (12):  1716-1718. 

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Studies on the effect of different levels root cutting on the photosynthesis rate,stomata conductance,aboveground biomass,grain yield,and water use efficiency of maize showed that moderate root cutting could improve its photosynthesis ability,and increase its aboveground biomass and WUE. On the contrary,when the roots were cut severely,the photosynthesis ability was weakened,and the biomass was decreased. Moderate root cutting could increase maize grain yield,but the effect was not significant.

Endurance ability of transgenic Common carp under different environmental conditions

LIANG Liqun, SUN Xiaowen, CAO Dingchen, YAN Xuechun

2002, (12):  1719-1720. 

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This paper dealt with the endurance ability of transgenic Common carp F₃, and Common carp under different environmental factors such as temperature,alkaline,and pHvalue. The results showed that there was no obvious difference of endurance abilities between transgenic Common carp and Common carp under the different environmental factors.

Early diagnosis of low-value forest: An approach of ecological factors

DU Xiaojun, JIANG Fengqi, SHEN Hui, LIN Heming

2002, (12):  1523-1528. 

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The management and improvement of low-value forests is an important issue of forestry in China. This paper put forward a new thought of early diagnosis for low-value forest. By applying this method,the forest growth trend before the explosion of the state of low-value forest was diagnosed according to the formation rule of low-value forest,and so,managers could adopt corresponding management measures in time. Taking a case study of Chinese pine plantations in western Liaoning Province,the early diagnosis of low-value forest was studied,and set up early diagnosis techniques of ecological factor approach based on single factor experiment and discriminant analysis: 1) following discriminant indices were selected: soil thickness (X₁),organic matter (X₂),soil nitrogen content (X₃),soil water content (X₄),and soil microbic quantity (X₅);2)discriminant function could be expressed as: Y=1.596X₁- 0.51 X₂-3.196X₃+1.622X₄+1.898X₅ ;3)early diagnosis of low-value forest was carried out by discriminant function and the value of each discriminant index. For early diagnosis of low-value forest,this paper is a pilot study. It is suggested that the forming mechanism of low-value forest and their related study should be strengthened.

Ecological and biological characteristics of Wikstroemia indica

REN Hai, PENG Shaolin, DAI Zhiming, LIANG Xiaodong, CAI Xi'an, LIN Rongbiao

2002, (12):  1529-1532. 

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Wikstroemia indica was the common shrub with medicine use in subtropical and tropical zones. The studies on the biological and physiological characteristics, population dynamics,biomass,nutrient composition of Wikstroemia indica showed that Wikstroemia indica was widely dispersed over hilly lands and opened forests. It was heliophytes and grew well on impoverished soil. Its average photosynthetic rate and conductance were 7.33 μmol CO₂·m^-2 ·s^-1 and 0.042 molH₂O·m^-2 ·s^-1,respectively. The weighted nutrient concentration of Wikstroemia indica were N 0.667%,P0.081%,K0.540%,Ca 0.776%,and Mg0.259%,respectively,and the medicine ingredient was Wikstroemine C₁₆H₁₂O₅. Due to morphological difference,the competitive power on energy and nutrient of Wikstroemia indica was less than that of Rhodomyrtus tomentosa . Wikstroemia indica population decreased,while Rhodomyrtus tomentosa increased on shrubby grass land during early successional stage. Wikstroemia indica could be planted to increase its biomass to exploit medicine use.

Ecological restoration of Castanopsis carlesii forest in Wupin, Fujian

YOU Shuisheng

2002, (12):  1533-1536. 

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Analyses on the effects of the different scales of human disturbance on restoration of Castanopsis carelesii forest in Wupin,Fujian indicated that with increasing degrees of the scales of human disturbance (A class, regeneration by selected cutting; B class, natural regeneration;Cclass,natural regeneration promoted by artificial tending;D class,Chinese fir forest),the important value of Castanopsis carlesii and the similar index between the communities decreased,and the assembling and abundance degrees of species increased under disturbance of B or C class,and decreased under D class.It could be concluded that the disturbance of A class was light,that of B class was medium and could be restored rapidly,disturbance of C class was also medium but would be restored in a longer period,and that of D class w as difficult to be restored due to the intense disturbance.

Soil moisture dynamics under artificial Caragana microphylla shrub

Alamusa, JIANG Deming, FAN Shixiang, LUO Yongming

2002, (12):  1537-1540. 

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Applying the methods of deducing time series from vegetation space alignment,we analyzed the spatial and temporal variation features of soil moisture under artificial Caragana microphylla shrubs built in1984,1987,1995,1999. The results showed that affected by mechanical composition of mobile sandy dunes,the soil of sandy land was mainly composed of sandy particle,and the particles of >0.01 mm were accounted for 97%. The withered moisture was 1.55%. The field waterhold capacity was 5.5%,and the available moisture storage was 3.95%. With the increase of the dominance of fix sand vegetation,the moisture content of soil under artificial Caragana microphylla shrubs was decreased. The soil moisture of vegetation built in1984 was lower than that built in1999. The soil moisture conditions of four stages vegetation were continued depressing from April to June in a year,the lowest point presenced in June,and then gradually increased from July to October. The vertical change of soil moisture showed the tendency of increasing with soil depth. The soil moisture decreased by the degrees of early built vegetation (1984,1987). Especially in70 cm soil depth,the moisture content of soil decreased obviously. Caragana microphylla shrubs absorbed water and aggravated the shortage of soil moisture content near the root system,which affected the component of vegetation in Caragana microphylla shrubs .The species of herbaceous plants and annual plants increased during the growth of Caragana microphylla shrub.

Characteristics of canopy patches related to natural regeneration of broad-leaved Korean pine forest

GUO Qingxi

2002, (12):  1541-1543. 

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The characteristics of canopy patches of dominant tree species in a broad-leaved Korean pine forest at an elevation of 740 m in north slope of Changbai mountain was investigated to understand the effects of canopy patch on the structure and regeneration of the forest. The results showed that the main species that constituted the canopy patches were Pinus koraiensis,Tilia amurese,Acer mono and Quercus mongolica,their canopy patches covered 57.1 % of the forest,and 87 % of the total area of the canopy. Most canopy patches were less than100 m², with irregular shapes. The seedlings and saplings of Acer mono were distributed under almost all canopy patches of Tilia amurense and Pinus koraiensis,and reached the maximum densities under canopy patch of Tilia amurense of 32 m²,and patch of Pinus koraiensis of 28 m². However,the seedlings and saplings of Tilia amurense were distributed only under a few canopy patches of Tilia amurense and Pinus koraiensis .

Reflectivity of broad-leaved Korean pine forest in growing season on Changbai Mountain

GUAN Dexin, JIN Mingshu, XU Hao

2002, (12):  1544-1546. 

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The hourly reflectivity of broad-leaved Korean pine forest on Changbai Mountain from 22 May to 14 October 2001 was calculated based on total solar radiation and reflect radiation. The results showed that: the reflectivity of the forest was related to solar altitude. It was generally high just after sunrise or before sunset,but was relatively stable as solar altitude was higher than 30?. The diurnal curves of reflectivity took Ushape. The reflectivity of the forest was also related to sky conditions. In clear days,the Ushape was quite clear. In scattered days,the reflectivity just after sunrise and before sunset was not as high as in the clear days,and the Ushaped curve was shallow. In overcast days, the reflectivity fluctuated. In terms of dynamic variation in the measured period,the reflectivity was relatively high in early June,decreased a little in late June,kept stable from July to September,and dropped gradually in the first half of October. The variation was related to the phenology of the forest canopy.

Determination and calculation of evapotranspiration of broad-leaved Korean pine forest on Changbai Mountain

WANG Anzhi, PEI Tiefan

2002, (12):  1547-1550. 

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.In this paper,the E_t of broad-leaved Korean pine forest on Changbai Mountain was determined by water balance method,and calculated by Bowen ratio energy balance (BREB) method in July,August and September,2001. The total E_t was 288.18 mm and 214.94 mm,respectively,and the daily average E_t in each month was gained,while the rainfall is 301.9 mm. Furthermore,the daily E_t and hourly E_t rate were computed by BREBmethod,and the availability and precision of the E_t determined by water balance and calculated by BREBmethod was discussed.

Introduction and selection of new poplar clones in shelterbelts/windbreaks in northern Liaoning

LIN Heming, FAN Zhiping, ZENG Dehui, JIANG Fengqi

2002, (12):  1551-1554. 

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Six new poplar clones were introduced in Qianshuangjing township of Changtu county,Liaoning Province as experiment materials,and their indeces in growth,cold resistance,disease infection,and insect infection were evaluated and compared to the locally grown Fuzha Ⅱ poplar. According to the comparison of the 4 indices,the study found that N 119 poplar showed all the scores obviously better than those of CKand other poplars,and was recommended for the area. The growth of Zhonglin 95 was higher,and its disease and pest infection was equal or near to the CK. So,the poplar Zhonglin 95 is also worthy to be recommended.

Freezing injury of plant and oxidative stress-Superoxide generation in freeze-thaw cycles of Cabbage leaf tissues

JIN Yuehua, TAO Dali, DU Yingjun

2002, (12):  1555-1558. 

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To test the hypothesis that oxidative stress is involved in inducing freezing injury of plants,nitroblue tetrazolium (NBT) was infiltrated into cabbage leaf tissues before they were frozen. NBTwas reduced to formazans in freeze thaw cycles. The ethanol-extractable mono-formazan was measured by a spectrophotometer,and used as a quantitative indicator of oxidative stress that developed during a freeze-thaw cycle. NBT perse as an oxidant increased the freezing injury slightly. When Me₂SO as a cryoprotectant was infiltrated into leaf tissue,it apparently enhanced the freezing tolerance,and this is correlated to its ability in ameliorating oxidative stress,as indicated by the partial inhibition of NBTreduction.The results supported the hypothesis that freezing injury of plants is related to oxidative stress. The experiments indicated that it was possible that the reductant of NBTin the freeze thaw cycle was superoxide anion free radical.

Effects of simulated acid rain on chloroplast activity in Dimorcarpus longana Lour cv wulongling leaves

QIU Dongliang, LIU Xinghui

2002, (12):  1559-1562. 

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Adecreased content of chlorophyll (Chl) and carotenoid (Car) was found in the Dimorcarpus longana Lour. cv. wulongling leaves when treated with <pH3.5 acid rain. The decline of Chl content was caused by the reduction of Chla,while Chlb was less sensitive to the acid rain,which resulted in a decrease of Chla/Chlb ratio. The content of Car and the ratio of Chla to Chlb reduced with the duration of stress time. The injury of acid rain to photosynthetic pigments was intensified by illumination. The activities of photoreduction,photophosphorylation and H⁺ ATPase activity decreased with the reduction of pHvalue under the simulated acid rain. Therefore,the injury of electron transport chain and the uncoupling of photophosphorylation might lead to the ineffective absorption,transportation and transformation of light energy. In our study,the process of photophosphorylation was more sensitive to acid rain than that of photoreduction.

N₂O emission from trees under different light irradiances

ZHANG Xiujun, CHEN Guanxiong, XU Hui

2002, (12):  1563-1565. 

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This paper firstly measured in situ N₂O emission from branches and leaves of sun plants (Fraxinus mandshurica,Pinus koraiensis,Alnus hirsuta) and shade tolerant plants (Tilia amurrensis) under different light irradiances in closed chamber. Light irradiance had contrast effects on N₂O emission flux from sun and shade tolerant tree species. In the test sun plants,more N₂O was emitted under weak light than under strong light. The emission rates decreased with increasing irradiances,and even absorption instead of emission of N₂O was detected under strong light. In contrast to sun plants,in the shade tolerant plant T.amurrensis,there was more N₂O emission under strong light than under weak light,and N₂O absorption from environment was detected under weak light.

Calculation method of ecological water requirement for forestland and its application to Huang-Huai-Hai Region

ZHANG Yuan, YANG Zhifeng

2002, (12):  1566-1570. 

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The evapotranspiration and soil moisture content of forestland were studied in relation to free growth. It was found that when the soil moisture content was about 45～100 % of field capacity and the actual evapotranspiration came up to 60～100 % of potential evapotranspiration,the growth of trees could be sustained. On the basis of our research,the grading standard and calculation method of ecological water requirement of forestland were established. Moreover,the ecological water requirement for forestland in Huang Huai Hai area was estimated by GIStechnology,and its ecological water shortage was compared to its current water consumption. The results indicated of that the annual ecological water requirement of forestland in Huang Huai Hai region was 25.6～45.8 billion m³,and its current water consumption was approximately 2.8 billion m³ below the minimum of ecological water requirement,and 8.4 billion m³ below the optimal ecological water requirement.

Effect of different fertilization system on soil nutrient budget

YU Wantai, ZHANG Lu, YIN Xiuyan, MA Qiang, SHEN Shanmin

2002, (12):  1571-1574. 

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Along term experiment was carried out on a damp palm soil about ten years under the condition of nutrient recycling and reutilization. The quantity of crop nutrients transferred from the system,and the nutrient budget of N,Pand Kin soil were studied. The results of a ten-year field experiment indicated that the use of nutrients recycled in the farming systems with appropriate amount of fertilizers applied according to the soil nutrient supplying ability could not only produce high crop yield, but also balance the soil nutrient budget,so that,there were no significant surplus of nutrients (mainly inorganic nitrogen) which might emit or leach out of soil into environment.

Effect of combined application of bioorganic manure and inorganic nitrogen fertilizer on soil nitrogen supplying characteristics

ZHANG Yali, ZHANG Juan, SHEN Qirong, WANG Jinchuang

2002, (12):  1575-1578. 

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Pot experiment was carried out to study the effect of application bioorganic manure on soil nitrogen supplying characteristics. Compared with the application of raw rice straw,a combined application of bio organic manure and inorganic nitrogen fertilizer could boost the content of microbial biomass carbon and nitrogen,and the increased percentage could be 300～400 %. Astrong immobilization of nitrogen by microorganisms was always followed by a net Nmineralization, which was mostly favorable for the growth and development of plant,and improved the use efficiency of nitrogen fertilizer.

Effects of applying nitrogen fertilizer at different stages in ploughed furrow on dry matter production and yield of rice

SHI Kun, HAO Shufeng, XIE Hongtu, ZHANG Xudong

2002, (12):  1579-1581. 

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The effects of applying nitrogen fertilizer in ploughed furrow at different stages on dry matter production and yield of rice were studied in a field experiment in1999. The results showed that applying Nfertilizer at booting stage (BS) had better effects on dry weight (2.9 g·hill^-1) of leaf,stem and whole plant than at panicle primordia formation stage (PPFS),tillering stage (TS) and regular Nfertilization (RF). Meanwhile,the dry weight of leaf and sheath as well as the leaf area index (LAI,8.9) could be maintained at a high level for a relative long time in BStreatment,compared with PPFS,TSand RFtreatments. Similar phenomenon was observed in the growth velocity (0.73 g·d^-1 ·hill^-1) of stem and whole plant,and the dry weight (10434 kg·hm^-2) of seed. The grain yield of rice followed the sequence of BS≥PPFS>TS≥RF. Thus,the optimum stage of applying Nfertilizer in ploughed furrow was the booting stage.

Genetic ecology of rice allelopathy on receiver plant

HE Huaqin, LIN Wenxiong, DONG Zhanghang, GUO Yuchun, SHEN Lihua, LIANG Yiyuan, CHEN Fangyu, LIANG Kangjing

2002, (12):  1582-1586. 

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In this study, 5 parental rice lines with different allelopathic potential were employed in partial diallel cross (4?5) to get 10 groups of F 1 seeds. After testing the inhibitory effects of 5 parents and 10 F₁s under different environment at different leaf stage on the shoot length of receiver plant lettuce(Lactuca sativa L.),dynamic genetics of rice allelopathy and its genotype譭nvironment effects were analyzed by using additive-dominant developmental genetic models. The results showed that additive and dominant effect genes expressed alternatively during 3-leaf stage to 8-leaf stage in rice seedling. As additive effect genes were pronounced at 7-leaf stage,dominant effect genes appeared to play the most important role at 3-leaf stage and 6-leaf stage but the two effect genes were equally important at 5-leaf stage and 8-leaf stage. Heritabilities analysis indicated that the general heritability in the narrow sense(H_N²) was significant at 5-,7- and 8-leaf stage,and decreased with increasing leaf stage. Rice allelopathy was significantly affected by genotype譭nvironment(GE) interaction,suggesting that the environment of allelopathic rice development must be controlled for practical use.

Screening methodology for rice (Oryza sativa) genotypes with high phosphorus use efficiency at their seedling stage

GUO Yuchun, LIN Wenxiong, SHI Qiumei, LIANG Yiyuan, CHEN Fangyu, HE Huaqin, LIANG Kangjing

2002, (12):  1587-1591. 

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Under hydroponic culture,the responses of rice (Oryza sativa) genotypes to low Pstress were respectively evaluated by means of relatively-higher Pconcentration in a controlled system with insoluble phosphate source (Ca₃(PO₄)₂) and of relatively-lower concentration with 0.5 mg P/Lin which NaH₂PO₄ was the soluble phosphate. Relative indices such as relative dry weight of tillers (RTW),total relative plant dry weight (RPW),relative number of tillers (RTN),relative dry weight of root (RRW),relative dry weight of shoot (RSW),relative leaf age (RLA) and relative plant height (RPH) were used to screen as the tolerant indices to Pdeficiency,and the correlations among screening criteria per se were analyzed. The results showed that there were significant differences of tolerant indices to Pdeficiency in the test rice genotypes. When the rice cultivars were exposed to low Pstress with the relatively-higher Pconcentration to be screened,the relative tiller dry weight (RTW),relative shoot dry weight (RSW) and total relative plant dry weight (RPW) could be used as the better screening criteria,especially RTWwas considered as a sensitive and reliable screening criterion because its coefficient of variation (CV) and the variable range of data among the test varieties should be large. However,when rice genotypes were grown in the stress condition with relatively-lower Pconcentration,the screening criteria were diffenent,and it suggested that relative shoot dry weight (RSW) or total relative plant dry weight (RPW) was the best single screening criterion.

Application of latent root regression method in analysis of predation of predatory natural enemy in paddy field

TANG Jinlong, WU Jincai

2002, (12):  1592-1594. 

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Alatent root regression model was constructed for analyzing the predation quantity in a coexistence system of four spiders (Pirata subpiraticus,Oedothorax insecticeps,Clubiona japonicola, and Bianor hotingchiehi) with brown planthopper (Nilaparvata lugens). The predation quantity of the spiders in a multi species coexistence system could be predicted by y= 6.6600 +6.3399(-0.0138X₁^* +0.0895X₂^*+0.0078 X₃^* -0.1067X₄^* +0.6742X₅^*). The result showed that compared to LSregression, the accuracy of predation quantity predicted by the model increased by 10%.

Differences between barley cultivars in seedling growth and in uptake of cadmium and nutrients under various Cd levels

WU Feibo, ZHANG Guoping

2002, (12):  1595-1599. 

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Asolution culture experiment was carried out to examine the genotypic differences of barley in the uptake/accumulation of Cd and some mineral elements,plant development and biomass accumulation under different Cd levels. The results showed that the plant height,leaf number,SPADvalue and biomass accumulation of shoot/root were significantly reduced in the plant grown in1 μmol·L^-1 Cd nutrient solution compared to control,and the absorption of Zn,Mn and Cu was strictly retarded. There was a highly significant difference in the reduction of these growth parameters among cultivars. Mimai 114 and Zhenong1 showed the least reduction,suggesting its high tolerance to Cd toxicity,while Wumaoliuling with the greatest reduction. Significant cultivar difference in Cd concentration/accumulation was also found. Zhenong1 contained the highest Cd concentration in plant tissue,while Mimai 114 contained the lowest Cd concentration. Asignificantly negative correlation between biomass accumulation and Cd concentration/accumulation of shoot and Cd concentration of root was found,while no significant relationship with root Cd accumulation.

A comparative study on photosynthesis and transpiration of Kelimeris integrifolia in summer and autumn on Songnen grasslands of China

DU Hongmei, WANG Deli, SUN Wei

2002, (12):  1600-1604. 

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The diurnal changes in photosynthesis and transpiration of Kelimeris integrifolia in Summer and Autumn on Songnen grasslands were characterized as a two-peak curve,but with some differences between two seasons. It was shown that environmental conditions and plant internal factors had a strong effects on plant photosynthesis and transpiration. The net photosynthetic and transpiration rates of the leaves were positively correlated to photosynthetically active radiation (P<0.01),and negatively correlated to stomatal resistance as well as intercellular CO₂ concentration (P<0.05). The transpiration rate was positively correlated to leaf temperature and water saturation deficit of the air. Among the above factors,photosynthesis active radiation was the dominant factor,and stomatal resistance also played an important role in plant photosynthesis and transpiration.

Simulation alfalfa growth in Wulanbuhe sandy region

BAI Wenming, BAO Xuemei

2002, (12):  1605-1609. 

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Based on the theories of accumulated temperature and on the physio-ecological characteristics of Medicago sativa, a simulation model for its growth under soil water stress in arid sandy region was developed. The model was mainly composed of four modules: the stage module of growth, the dynamic module of leaf area index, the accumulated module of dry matter, and the distributive module of dry matter. After simulating and calculating, the model could be used to predict the growing progress and dynamic changes of leaf area and yield for herbage in sandy region. The result shows that the application of the model to production is usually effective.

On the safety threshold of wetlands based on water ecological element-Taking wetlands in Sanjiang Plain as an example

LIU Zhenqian, WANG Jianwu, LUO Shiming, LU Xianguo, LIU Zhaoli, LIU Hongyu, LI Xiujun

2002, (12):  1610-1614. 

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The lowest water requirement of the wetlands was demonstrated through different simulations. Based on the relationship between the area of wetlands and its effects on air temperature and humidity,some useful statistical models were established. According to the theory and principles of system dynamics (SD),a dynamic simulation model of the wetlands' retaining water was compiled in DYNAMOlanguage. Finally,the safety threshold of the wetlands was assessed based on its water ecological factors. The feasibility of the method was demonstrated by a case study on the wetlands in Sanjiang Plain of China.

Landscape ecological studies on autumnal Chinese cabbage fields in Shenyang city suburb Ⅰ Features of autumnal Chinese cabbage field patches

ZHANG Kai, WEN Dazhong, CAO Zhiqiang, LIANG Wenju

2002, (12):  1615-1618. 

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Some typical patches of autumnal Chinese cabbage fields in the agricultural landscapes of Shenyang city suburb were investigated,and their basic features,such as areas,shapes,neighborings and connections,were recorded. Their mosaic features were also analyzed and discussed. In the region of less 5 km distance from city,many Chinese cabbage patches neighbored each other and connected to highways,while in the region of 5～10 km distance from city,they neighbored with corn patches and connected to countryside roads. In the region over 10 km distance from city,many Chinese cabbage patches are surrounded by corn patches and connected to countryside roads.

Landscape ecological studies on autumnal Chinese cabbage fields in Shenyang city suburb Ⅱ Relationship between Chinese cabbage field patches and their neighboring landscape elements

ZHANG Kai, WEN Dazhong, CAO Zhiqiang, LIANG Wenju

2002, (12):  1619-1623. 

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The relationship between autumnal Chinese cabbage patches and their neighboring other lanascape elements were studied in Shenyang suburb. The groups and quantities of arthropods moving through a boundary between a Chinese cabbage patch and its neighboring corn patch in certain period,were investigated and the 7 oders of arthropods moving through the boundary with an average flow of 10.3 indiviaduals穖_-1 穌^-1 were observed. The changes of falling dust rates on a Chinese cabbage patch near a countryside road are analyzed. Some principles of agroecosystems in an agricultural landscape were discussed on the basis of these observation results.

Oasis corridor landscape in arid regions:A case study of Jinta Oasis

MA Mingguo, CAO Yu, CHENG Guodong

2002, (12):  1624-1628. 

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In arid region oasis, the main corridor landscape types include river, ditch, shelterbelt and road. This paper introduced their basic ecological effects on transporting mass and energy and on obstructing desert landscape expansion and incursion. Using Geographic Information System (GIS), the corridor distribution and its spatial relationship with other landscape types in the Jinta Oasis were analyzed. Based on the dynamically monitoring on the landscape pattern change of the Jinta Oasis during the latter 10 years, the driving functions of the corridors on this change were analyzed in detail. The results showed that all kinds of corridors' characteristics could be quantified by the indexes such as length and width, ratio of parameter and area, density,and non heterogeneity. The total corridor length of Jinta Oasis is 1838.5 kilometers and its density is 2.1 km穔m^-2 .The corridor density of the irrigated land, forest and resident area is maximal,showing that the affection degree of the oasis corridors on them is the most. The improvement of the corridor quality is one of the important driving factors on the irrigated land.

Echolocation sound waves, morphological features and foraging strategies in Hipposideros pratti

CHEN Min, FENG Jiang, LI Zhenxin, ZHOU Jiang, ZHAO Huihua, ZHANG Shuyi, SHENG Lianxi

2002, (12):  1629-1632. 

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Studies on the echolocation sound waves in different states (flying and hanging),morphological features and ecological processes (foraging strategies,foraging habitat and diet type) of Hipposideros pratti showed that H.pratti had CF (constant frequency) FM (frequency modulated) echolocation sounds. There were some differences in dominant frequency (caused by Doppler compensating effect),pulse repetition rate,pulse duration and interpulse interval between the bats at flying and hanging. The dominant frequency, FMbandwidth,pulse duration and interpulse interval were lower,while the pulse repetition rate and duty cycle were higher at flying than at hanging. All the differences indicated that H.pratti could adopt specific echolocation sounds to adapt to specific environments and conditions to detect,approach and capture their preys successfully. On the basis of echolocation sound and field observation,it was concluded that H.pratti might search the preys at flying in the period of insect fastigium,and after the period,it might search the targets at hanging. The foraging habitat was near the tree crowns,and the preys consisted mainly of relatively large insects,such as beetles.

Effects of mating experience and temperature on sex pheromone production of beet armyworm, Spodoptera exigua

DONG Shuanglin, DU Jiawei

2002, (12):  1633-1636. 

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Mating experience could not affect the production of sex pheromone in the female glands 24 h later, which meant that the beet armyworm females might call and mate again in next scotophase. This result explained the phenomenon why the beet armyworm could mate several times in their life under field conditions. On the contrary, ambient temperature greatly influenced the pheromone biosynthesis in the beet armyworm females. The optimal temperature for the biosynthesis of sex pheromone was between 15～25 ℃. Under the temperature beyond this range,the biosynthesis of the pheromone components was disturbed in terms of absolute titers,proportions,and their CVs. The biosynthesis of component Bwas suppressed under 35 ℃,and the proportion of Ato Bwas significantly higher. In contrast,under 10 ℃,the titer of Aand the proportions of Ato Bwere disturbed significantly,and the proportions of Ain ABand ADbinary blends changed significantly. Furthermore,the CVs of the ratios of Ato Band Ato Dbecame larger than10 % under 10 ℃.

Effect of earthworm inoculation on soil carbon and nitrogen dynamics and on crop yield with application of corn residues

LI Huixin, HU Feng, SHEN Qirong, CHEN Xiaoyun, CANG Long, WANG Xia

2002, (12):  1637-1641. 

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This study was carried out in the Experimental Station of Nanjing Agricultural University,which is in a subtropical monsoon region characterized by a warm-wet spring and a hot-dry summer. The annual average temperature,precipitation and evaporation are 15.6℃,1010 mm and 1560 mm,respectively. In1999,the experimental plots (2.8 m×1.0 m×0.6 m) were established by concrete frame. Soil in the plots was orthic aquisols collected from Rugao County,Jiangsu Province. Crop rotation was upland rice and winter wheat. At the beginning of the first crop (rice) season,earthworms (Pheretima sp.) were inoculated at a density of 10·m^-2 and 20·m^-2,respectively,in the plots with an application of corn residues at the rate of 1500 g·m^-2 (750 g·m^-2 in the following seasons). The responses of soil carbon and nitrogen and crop yield to earthworm activity were investigated from 1999 to 2001. The results showed that earthworms had no significant influences on total soil carbon and nitrogen content,which implied that there was no depletion of soil carbon and nitrogen pools in the presence of earthworms. The maintenance of soil carbon might be explained by low assimilation efficiency of organic matter by earthworms,and by the compensation of carbon returning from plant production enhancement. Soil mineral nitrogen,soil microbial biomass carbon and microbial biomass nitrogen were increased,and nitrogen mineralization was strengthened by earthworm activities,which was more obvious at jointing/booting and heading stages. In comparison with no worm treatments,the yield of rice and wheat increased by 9.3% and 5.1%,respectively,in the treatments inoculated with earthworms. It was concluded that earthworm was very important in promoting nitrogen recycling of crop residues and plant productivity,and in keeping the balance of soil carbon pool as well.

Life table of natural population of banana pseudostem weevil, Odoiporus longicollis Oliver, in Spring

LU Yongyue, LIANG Guangwen, ZENG Ling

2002, (12):  1642-1644. 

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The active factor life tables of natural population of banana pseudostem weevil were built,and the controlling effect of active factors was evaluated by using exclusion index of population control (EIPC). The results showed that the population trend indices in growing and harvested banana trunks were 4.3481 and 3.6628,and the EIPCof predation and others were 1.9256 and 2.3577,respectively. The EIPCof natural death were 1.3607 and 1.3554,and that of parasitism and disease in growing and harvested banana trunks were 1.1988 and 1.1668, respectively. The factor of predation and others was important.

Geostatistical analysis on spatial patterns of Erythroneura sudra and Erigonidium graminicola

ZOU Yunding, BI Shoudong, ZHOU Xiazhi, LI Lei, GAO Caiqiu, DING Chengcheng

2002, (12):  1645-1648. 

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The spatial construction and distribution of Erythroneura sudra and Erigonidum gramimicola at different periods were investigated with geostatisics. The results showed that the semivariogram of Erythroneura sudra was described by spherical model,indicating an aggregated spatial arrangement. The range was 25.71～37.14 m. The semivariograms of Erigonidum graminicola was fitted by spherical model too,also indicating an aggregated spatial arrangement,and its range was 25.12～44.06 m. The amount and spatial distribution of Erigonidium graminicola was closely related to that of Erythroneura sudra. It reveals that Erigonidium graminicola is the dominant natural enemies influening the population of Erythroneura sudra.

Relationship between sexual reproduction, population growth and resting egg production of freshwater rotifer Brachionus calyciflorus

XI Yilong, CAO Ming, HUANG Xiangfei

2002, (12):  1649-1654. 

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Using exponential and logistic growth models,the effects of sexual reproduction frequency and the proportion of a female's daughters reproducing sexually on population growth rate and resting egg production of freshwater rotifer Brachionus calyciflorus were examined by computer simulation. Within the parameters of the simulation,the percentage of micitc females in the offspring required for maximum resting egg production increased from 9% to 69%,when the frequency of sexual reproduction decreased from 100% to 20%. The increase of density dependent limitation (the value of Kdecreased from 1000 to 100) made this percentage increase from 18% to 69%,and resting egg production decrease from 1072.10 to 133.67. The relationship between the population growth rate (r) and the optimum percentage of mictic females in the offspring required for maximum resting egg production was best described by curvilinear regression. When sexual reproduction became more frequent and density dependent decreased,The population with the percentage of mictic females in the offspring in10～30% had a bigger resting egg production.

Effects of 1, 2, 4-trichlorobenzene stress on active oxygen in germinated soybean seeds

LIU Wan, SUN Tieheng, LI Peijun, ZHOU Qixing, LIANG Wenqu, TAI Peidong, XU Huaxia, ZHANG Hairong

2002, (12):  1655-1658. 

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Pot culture experiment on the effects of 1,2,4 trichlorobenzene (TCB) stress on active oxygen metabolism of germinated soybean seeds indicated that during the beginning (1st～3rd day) of 100～300 μg·g^-1 TCB treatment,the respiratory peak appeared earlier,and the respiratory rate,the accumulation of superoxide radical (O₂^-) and H₂O₂,as well as the malondialdehyde (MDA) content were all enhanced. During 1～6 days of TCBstress,peroxidase (POD) activity gradually increased,and superoxide dismutase (SOD) activity increased firstly,and decreased afterward. These results suggested that the injury effects of TCBstress on germinated soybean seeds were achieved by excessive accumulation of active oxygen resulted from the degradation of active oxygen scavenging enzyme system.

Effects of organic manure on the conformation and biological availability of soil Cd

ZHANG Qiufang, WANG Guo, YANG Peiyi, FANG Ling

2002, (12):  1659-1662. 

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Pot experiments were conducted to investigate the effect of organic manure on the conformation and availability of both native and added Cd in red soil and moisture soil under rice planting. Most of the added Cd existed in exchangeable form, while the native Cd existed more evenly in four forms. The organic manure did not influence apparently on the forms of native Cd,whereas influenced significantly on those of the added Cd. From tillering to mature stage, the exchangeable form of the native Cd increased, while that of the added Cd decreased. The application of organic manure could promote the uptake of Cd under the treatments without adding Cd. Under the treatments of adding Cd,the application of the organic manure could depress the uptake of Cd,and the effect of applying pig's manure was stronger than that of applying peat. There existed a significant antagonism between the accumulation of Cd and Fe in rice roots.

Effect of organophosphorus pesticide toxicity on soil animal

WANG Zhenzhong, ZHANG Youmei, LI Zhongwu, XING Xiejia

2002, (12):  1663-1666. 

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The test of organophosphorus pesticide on toxicity of soil animal showed that soil animal is sensitive to organophophorus toxicity,the species and quantities of soil animal treated by four kinds of pesticide are decreased. The species of soil animals was decreased with decreasing common population and rare population,while the amount change of soil animal was associated with the amount change of dominant populations of Acarina and Collembola. Toxicology and toxicity experiment showed that the pesticide has a deadly effect to earthworm,and its toxicity constrained the respiration intensity of big soil animals obviously,which weakened with the increasing pesticide concentration and prolonging poisoning time.

Application of turning band method in conditional simulation of soil heavy metals

WANG Xuejun

2002, (12):  1667-1670. 

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Geostatistical simulation techniques are widely used in studying spatial phenomena. The purpose of this study is to make an experimental study in applying this technique to understand the spatial distribution of copper and lead in wastewater irrigated agricultural soil in the eastern suburb of Beijing. The results showed that the simulation is efficient,because it fits to the main characteristics of the revealed reality of the spatial distribution of these elements. Geostatistical simulation could play an important role in regional environmental and ecological studies.

Vegetation distribution in coal cinder yard of Wuhu thermal power station

WANG Youbao, ZHANG Li, LIU Dengyi

2002, (12):  1667-1669. 

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There are 30 species of natural colonized plants in the coal cinder yard of Wuhu thermal power station,and they are subordinate to 14 families and 29 genera. The main families are Compositae (7 species),Gramineae (6 species) and Leguminesae,among which,18 species are annual plant,9 species are perennial plant,and 2 species are woody plants. The chief factors limiting the vegetation distribution are extreme infertility and high concentration of heavy metals.

A comprehensive model for assessing lake eutrophication

Qinghua CAI, Jiankang LIU, Lorenz King

2002, (12):  1674-1678. 

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The evaluation of eutrophication or trophic state of a lake is in fact a multivariate comprehensive decision making process quantifying the qualitative problem. Therefore,we should use a comprehensive method to assess lake eutrophication. On the basis of summarizing some comprehensive methods for assessing lake eutrophication reported in China and abroad,it is pointed out that the trophic state index (TSI) should be a major method for evaluating lake eutrophication, since it could provide a continuous numerical class of lake trophic state and a rigorous foundation of quantitative studies of eutrophication mechanism. Using analytic hierarchy process (AHP) to determine the weight attributions in the selected comprehensive indices,the authors,constructed a comprehensive assessment model as: TSI=W(Chla)?TSI(Chla)+W(Sd)?TSI(Sd)+W(TP)?TSI(TP) or TSI_M=W(Chla)?TSI_M(Chla)+W(Sd)?TSI_M(Sd) +W(TP)?TSI_M(TP) where W(X) were the weights for the above three parameters with value in percentage as 54.0,29.7 and 16.3,respectively. Additionally,the relations between comprehensive evaluation and other statistical methods such as cluster analysis were briefly discussed.

Basic theory and research method of urban forest ecology

HE Xingyuan, JIN Yingshan, ZHU Wenquan, XU Wenduo, CHEN Wei

2002, (12):  1679-1683. 

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With the development of world economy and the increment of urban population,the urban environment problem hinders the urban sustainable development. Now,more and more people realized the importance of urban forests in improving the quality of urban ecology. Therefore,a new subject,urban forest ecology,and correlative new concept frame in the field formed. The theoretic foundation of urban forest ecology derived from the mutual combination of theory relating to forest ecology,landscape ecology,landscape architecture ecology and anthrop ecology. People survey the development of city from the view of ecosystem,and regard the environment,a colony of human,animals and plants,as main factors of the system.The paper introduces systematically the urban forest ecology as follows:1) the basic concept of urban forest ecology;2) the meaning of urban forest ecology;3) the basic principle and theoretic base of urban forest ecology;4) the research method of urban forest ecology;5) the developmental expectation of urban forest ecology.

Progress in studies on an exotic vicious weed Mikania micrantha

ZHANG Weiyin, WANG Bosun, LIAO Wenbo, LI Mingguang, WANG Yongjun, ZAN Qijie

2002, (12):  1684-1688. 

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Mikania micrantha is a perennial weed of Astraceae native to south and central America. It has invaded Southeast Asia,Pacific region and South China. Because Mikania micrantha grows very fast and is hard to control,it has become one of the world's worst weed. In this paper,the history and status of the study on Mikania micrantha was reviewed. The research on Mikania micrantha was mainly focused on its biology,ecology,harm and control. Although some progress in the research was obtained,there is no dramatic breakthrough in the control of Mikania micrantha so far. There fore,it needs more work to solve the problems resulted from the invading Mikania micrantha .

A review on fundamental studies of secondary forest management

ZHU Jiaojun

2002, (12):  1689-1694. 

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Secondary forest is also called as natural secondary forest,which regenerates on native forest that has been disturbed by severe natural or anthropogenic disturbances.The structural and dynamic organizations,growth,productivity and stand environment of secondary forests are significantly different from those of natural and artificial forests. Such significant differences make secondary forests have their own special characteristics in forestry. Secondary forests are the main body of forests in China. Therefore,their management plays a very important role in the projects of natural forest conservation and the construction of ecological environment in China or in the world. Based on a wide range of literature collection on secondary forest research,the fundamental studies of secondary forest management were discussed. The major topics are as follows: 1) basic characteristics of secondary forest,2) principles of secondary forest management,3) types of secondary forest,4) community structure and succession dynamics of secondary forest,including niches,biodiversity,succession and so on,5) main ecological processes of secondary forest,including regeneration,forest soil and forest environment. Additionally,the research needs and tendency related to secondary forest in the future were also given,based on the analyses of the main results and the problems in current management of secondary forest. The review may be helpful to the research of secondary forest management,and to the projects of natural forest conservation in China.

Prospect of the study on desertification and its restoration of Keerqin sandy land

JIANG Deming, LIU Zhimin, KOU Zhenwu

2002, (12):  1695-1698. 

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In this paper,the study on desertification and its restoration of the Keerqin sandy land was briefly reviewed. With reference to the trends in related scientific fields and pressing demand in restoring existing desertified lands,several key aspects,including vegetation processes,eco-hydrological processes,landscape processes,and assessment of regional environmental state,prediction of desertification trends and exploration of restoration measures for the whole Keerqin sandy land,aimed to discover mechanisms leading to desertification and to restore desertified lands,were raised.

Ecological forecasting: A frontier in ecology

ZENG Dehui, JIANG Fengqi, FAN Zhiping, JI Lanzhu

2002, (12):  1699-1702. 

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An evolving science of ecological forecasting is beginning to emerge,and could have an increasingly important role in policy-making and management of natural resources and environment. The progress in computer science, quantitative analysis and ecological theory, together with the application of new high technology, will increase our ability to forecast ecosystem change. The authors introduced the connotation of ecological forecasting,relevant research advances,and some typical examples. Ecological forecasting is an important frontier in ecology, and also,would be an important direction for future ecological study.

Application and development of terrestrial biogeochemical model

WANG Xiaoke, BAI Yanying, OUYANG Zhiyun, MIAO Hong

2002, (12):  1703-1706. 

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Biogeochemical modeling plays a role as important as experimental measurement in ecosystem research. This paper analyzed the development of biogeochemical model using TEM and DNDC model as cases. Current biogeochemical models were classified according to modeling method, application purpose,element concerned, ecosystem type,and spatial scale. The basic framework (three component:plant,air and soil,and three interface:plant-air,plant-soil,and soil-air) and interior fundamental processes (physical,chemical and biological processes) of biogeochemical models were reviewed,and some important problems concerning biogeochemical modeling,such as scale upping,integrating GISand remote sensing,involved human activity,and comparison study were focused.

Advances in the research on sources and sinks of CH₄ and CH₄ oxidation （uptake） in soil

WANG Chenrui, HUANG Guohong, LIANG Zhanbei, WU Jie, XU Guoqiang, YUE Jin, SHI Yi

2002, (12):  1707-1712. 

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Methane (CH₄) is one of the main greenhouse gases contributing greenhouse effect,and its potential greenhouse effect is 21 times of CO₂. Therefore,to determine the sources and sinks of atmospheric CH₄ and to assess and forecast their amounts become and importand focus concerning the researches on global change and greenhouse effect. This paper summarized the researches on the cources and sinks of CH₄,and amplified on the influential factors (e.g.land use,ambient atmospheric CH₄ concentration,soil temperature,soil moisture content,soil pHand soil porosity) on atmospheric and interior CH₄ oxidation in soil. It is significant that studying CH₄ oxidation in vertical zonation soil in forests of Changbai Mountain to evaluate the CH₄ consumption in forest soil.

Diversity of the microorganisms degrading aromatic hydrocarbons

QIU Junshan, ZHU Keli, ZHANG Jie, ZHANG Zhongze

2002, (12):  1713-1715. 

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Aromatic hydrocarbons are biological xenobiotics. Indigenous microorganism groups turn from being unfamiliar with into active response to environmental changes by their adaptability to environment. There are changes in their genetic background, and then,the biodiversity turns into being. This paper reviewed the microorganism groups resources,biocharacters,genetic background,evolvement and their aptability to environment;described the genetic information,expression and regulatory for some species in detail;and pointed out that the degradation of aromatic hydrocarbons depended maily on new microorganisms formed by genetic engineering and on their highly efficient metabolic regulatory.

Effect of root cutting on leaf photosynthesis rate and water use efficiency of maize

CHAI Shiwei, LIU Wenzhao, LI Yangyang

2002, (12):  1716-1718. 

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Studies on the effect of different levels root cutting on the photosynthesis rate,stomata conductance,aboveground biomass,grain yield,and water use efficiency of maize showed that moderate root cutting could improve its photosynthesis ability,and increase its aboveground biomass and WUE. On the contrary,when the roots were cut severely,the photosynthesis ability was weakened,and the biomass was decreased. Moderate root cutting could increase maize grain yield,but the effect was not significant.

Endurance ability of transgenic Common carp under different environmental conditions

LIANG Liqun, SUN Xiaowen, CAO Dingchen, YAN Xuechun

2002, (12):  1719-1720. 

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This paper dealt with the endurance ability of transgenic Common carp F₃, and Common carp under different environmental factors such as temperature,alkaline,and pHvalue. The results showed that there was no obvious difference of endurance abilities between transgenic Common carp and Common carp under the different environmental factors.