Table of Content

18 March 2006, Volume 17 Issue 03

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Articles

Eco-value level classification model of forest ecosystem based on modified projection pursuit technique

WU Chengzhen;HONG Wei;HONG Tao

2006, 17(03):  357-361 . 

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To optimize the projection function and direction of projection pursuit technique,predigest its realization process,and overcome the shortcomings in long time calculation and in the difficulty of optimizing projection direction and computer programming,this paper presented a modified simplex method (MSM),and based on it,brought forward the eco-value level classification model (EVLCM) of forest ecosystem,which could integrate the multidimensional classification index into one-dimensional projection value,with high projection value denoting high ecosystem services value.Examples of forest ecosystem could be reasonably classified by the new model according to their projection value,suggesting that EVLCM driven directly by samples data of forest ecosystem was simple and feasible,applicable,and maneuverable.The calculating time and value of projection function were 34% and 143% of those with the traditional projection pursuit technique,respectively.This model could be applied extensively to classify and estimate all kinds of non-linear and multidimensional data in ecology,biology,and regional sustainable development.

Differences of δ¹³C annual series among报Cryptomeria fortunei tree rings at Tianmu Mountain

ZHAO Xingyun^1，2;WANG Jian¹;QIAN Junlong³;ZENG Zhaopeng²

2006, 17(03):  362-367 . 

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This paper determined the δ¹³C annual series of three Cryptomeria fortunei tree rings at West Tianmu Mountain,and analyzed their similarities and differences.In the period of 1837～1982,the correlations among the three δ¹³C series were significant,with r₁₂=0.47,r₁₃=0.65 and r₂₃=0.52 (P<0.001,n=146),respectively.After removing the high-frequencies from the original δ¹³C series by using polynomial function model,a significant correlation was observed among three low-frequencies,with the correlation coefficient varied from 0.95 to 0.998.A significant correlation was also observed between original low-frequencies and simulated high-frequencies,with the correlation coefficient being 0.79～0.84.The three δ¹³C annual series had similar high-frequency and low-frequency variations.High-frequency variation recorded similar climate variation information,while low-frequency reflected the information of atmospheric CO₂ changes.It was the common case for different individuals of trees that in the three δ¹³C annual series,climatic factors caused highfrequency change,while atmospheric CO₂ concentration caused low-frequency variation.The differences among the three δ¹³C annual series were mainly caused by the local environmental conditions at the growth sites of trees,while the individual difference among the three δ¹³C series caused by local environmental conditions had very small effects on the changes of the three δ¹³C series.It could be concluded that the differences among the three δ¹³C series did not affect the suitability of using tree ring’s δ¹³C annual series as the indirect evidence in climatic variation study,and the reliability and coherence of reconstructing historical climate changes.

Root exudates of potassiumenrichment genotype grain amaranth and their activation on soil mineral potassium

LI Tingxuan^1,2;MA Guorui²;ZHANG Xizhou¹

2006, 17(03):  368-372 . 

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With solution culture experiment,this paper studied the effects of two potassium supply levels on the root exudates content and its dynamics of two grain amaranth genotypes (potassium-enrichment K12 and ordinary M9),and the activation of root exudates on soil mineral potassium.The results showed that the root exudation rates of soluble sugar,amino acids and organic acids of these two genotypes were decreased with increasing potassium supply level,which was higher in K12 than in M9.The root exudation capability of the two genotypes was similar under normal potassium supply level,while that of K12 was significant higher than M9 under low potassium supply level.Organic acid was the main root exudate under two potassium supply levels,which was several decuples or hundreds times as much as that of soluble sugar and amino acids.Compared with those at the fortieth day,the exudation rates of soluble sugar,amino acids and organic acids at the fiftieth day decreased rapidly in M9,while decreased slowly in K12.At three growth phases,the contents of soluble sugar,amino acid and organic acid were higher in the root exudate of K12 than in that of M9,and the difference of the two genotypes became significant with time extended.The content of organic acid in root exudate was accounted for >93% in the two genotypes at three growth phases.Soil available potassium content after treated by the root exudates of grain amaranth was higher than that treated by pure water.Under low potassium stress,the content of soil available potassium treated by the root exudates of K12 was higher than that treated by those of M9.

Dynamic changes of morphological parameters of tobacco root in field

MA Xinming¹XI Lei1,XIONG Shuping1，YANG Juan2

2006, 17(03):  373-376 . 

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The study with rhizotron showed that the total length of tobacco’s second order lateral root had a much more increase than that of first order one,and the root length developed rapidly during 26～40 d and 56～70 d after transplanting for the second and first order lateral root,respectively.Before tip pruning,the branch root density of tobacco was decreased in order of 10～20＞0～10＞20～30＞30～40 cm soil layer.The branch density of main root was the highest in 7～21 cm soil layer.The deeper the soil layer,the bigger the ratio of dry weight and root length,but the distribution was reverse at 90 d after transplanting.The first order lateral root length density distributed in “S” curve in 0～10 cm soil layer and in double climax curve in 10～20,20～30 and 30～40 cm soil layers,while the second order lateral root length density became bigger with the course of growth period,which was in “S” curve in 0～10 cm soil layer and in single climax curve in other soil layers.

Plant diversity of different replaced communities after Eupatorium adenophorum removal

WANG Chongyun^1,2;LIU Wenyao^1,3;LIU Lunhui¹;CUI Jianwu^1,2　

2006, 17(03):  377-383 . 

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In this paper,an investigation on the structure,species composition and plant diversity of replaced communities after the removal of invasive E.adenophorum at the beginning of 1980s was made in the Shuangbo County of Yunnan Province,with local aged Pinus yunnanensis and unmanaged E.adenophorum forests as the reference.The results showed that in replaced communities,the richness,Shannon-Wiener,Simpson,and Pielou evenness indices values of woody species were 25～28,1.06～2.34,0.36～0.86 and 0.32～0.73,and those of herb species were 6～8,1.51～1.97,0.74～0.84 and 0.84～0.90,respectively.In unmanaged E.adenophorum community,the corresponding indices values of woody species were 3,0.14,0.10 and 0.13,and those of herb species were 3,0.09,0.03 and 0.08,respectively,being much lower than those of the replaced communities.The replaced communities dominated by fast-growing tree species in E.adenophorum forest developed through a 20 years rehabilitation period,under which,there was a clear understory layer dominated by native species.The density and growth rate of E.adenophorum was inhibited in the replaced communities.In comparison with the E.adenophorum community,the plant diversity of replaced communities was greatly increased.Among the replaced communities,P.yunnanensis + Schima wallichii + Eucalyptus globules community had the greatest plant diversity,but the replaced communities had lower plant diversity than the aged P.yunnanensis,with 42,2.88,0.92 and 0.77 for woody species,and 8,2.08,0.86 and 0.90 for herb species,respectively.It was suggested that more attention should be paid to conserve the rehabilitated communities,especially the P.yunnanensis plantation built on the degraded lands invaded by E.adenophorum.In addition,the introduction of local broadleaved species and some shade-loving herb plants into these plantations and its follow-up management were also important for the sustainable development of the revegetation.

Vertical distribution of soil organic carbon and total nitrogen in reed wetland

LU Guohong¹;ZHOU Li²;ZHAO Xianli¹;JIA Qingyu¹;XIE Yanbing¹;ZHOU Guangsheng^1,2

2006, 17(03):  384-389 . 

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With element analyzer,this paper measured the variation of organic carbon and total nitrogen in different soil depths of reed wetland.The results showed that soil organic carbon,total nitrogen,and C/N ratio were decreased gradually with increasing soil depth,and their accumulation peaks were differed with soil layers and months.Soil temperature and moisture and the growth status of reed were the main factors caused the differences.Soil organic carbon was strongly positively correlated with soil total nitrogen content in July,August and October,the R² being 0.73,0.73 and 0.71 respectively,but weakly correlated in September.Soil C/N ratio was negatively correlated to soil organic carbon and total nitrogen,but the correlativity was higher with soil total nitrogen than with soil organic carbon,suggesting that soil C/N ratio was more determined by the content of soil total nitrogen.

Responses of grafted eggplant seedling roots to low temperature stress

GAO Qinghai¹;WU Yan²;XU Kun¹;GAO Huiyuan¹

2006, 17(03):  390-394 . 

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The study on the changes of physiological and biochemical properties of grafted eggplant seedling roots under low temperature stress and the relationships between these changes and cold tolerance showed that at the initial stage of treating with 10 ℃(daytime) /3 ℃(night),eggplant seedling roots were most impressible to low temperature,with the MDA content,chilling injury index,POD activity,proline content and soluble protein content increased significantly,and root respiration rate,SOD activity and CAT activity decreased rapidly.With the extending of low temperature stress,root respiration rate and osmotic adjustment reduced continually,while chilling injury index increased.After 3 days recovery,the respiration rate,osmotic adjustment and SOD activity were increased.Among the test materials,T2 (with Hiranasu as rootstock) had the best recovery capability,followed by T1 (with Taibyo as rootstock) and CK (Jinong 2000).Grafting with stronger cold tolerance rootstock could improve eggplant root activity,and thus,its cold resistance markedly.

Effects of nitrogen topdressing at different growth stage on chlorophyll fluorescence of winter wheat flag leaves

JU Zhengchun;YU Zhenwen

2006, 17(03):  395-398 . 

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With field experiment,this paper studied the effects of nitrogen topdressing at different growth stage on the chlorophyll fluorescence and photosynthetic rate of winter wheat flag leaves,and on the grain yield of the wheat.Compared with that at gettingup and flagging stages,nitrogen topdressing at jointing stage improved the PSII (F_v/F_o) activity,maximum photochemical efficiency (F_v/F_m),PSII coefficient of photochemical fluorescence quenching (qP),actual quantum yield of PSII electron transformation (ΦPSⅡ),and photosynthetic rate of flag leaves,and made the dissipation of non-radiant energy lower at early and middle filling stage,and higher at late filling stage,which made it possible for flag leaves to absorb more light energy for photosynthesis at early and middle filling stage,and reduce the light inhibition extent and senescence at late filling stage.Nitrogen topdressing at jointing stag increased the spikes and grain weight per kernel,resulting in the highest grain yield.

Effects of salicylic acid on chlorophyll fluorescence and xanthophyll cycle in cucumber leaves under high temperature and strong light

SUN Yan;XU Weijun;FAN Aili

2006, 17(03):  399-402 . 

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In this study,cucumber leaves were under high temperature and strong light stress after two days of spraying with 50～400 μmol·L^-1 salicylic acid (SA) solution.The measurements showed that SA pretreatment could inhibit the decrease of intrinsic photochemical efficiency (F_v/F_m),quantum yield of PSII(ΦPSⅡ),maximum fluorescence value(F_m),and photochemical quenching (qP) by 16.1%～30.2%,11.9%～33.0%,7.2%～41.0% and 27.2%～160.8%,respectively,and promote the increase of non-photochemical quenching (NPQ) by 13.1%～62.9%,but had little effect on initial fluorescence value (F_o).SA pretreatment could also inhibit the decrease of xanthophyll cycle pool in cucumber leaves,and increase the deepoxidation extent of xanthophyll cycle (A+Z)/(V+A+Z),which was 29.5% and 24.6% higher than control,respectively.It was suggested that SA could protect the photosynthetic apparatus of cucumber leaves under high temperature and strong light through promoting non-radiative energy dissipation.

Effects of NO₃^-stress and recovery on chlorophyll fluorescence parameters and ATPase activities of cucumber seedling leaves

YANG Fengjuan¹;WANG Xiufeng¹;WEI Min¹;SU Xiurong²;YAN Tong¹

2006, 17(03):  403-407 . 

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With water culture,this paper studied the effects of NO₃^- stress and recovery on the chlorophyll contents,chlorophyll fluorescence parameters,and ATPase activities of cucumber seedling leaves.The results showed that under stress for 7 days,the chlorophyll a,chlorophyll b,total chlorophyll and carotenoid contents,intrinsic fluorescence (F_o),and MgATPase and Ca-ATPase activities were increased significantly when the NO₃^- concentration was high (168 mmol ·L^-1),while the intrinsic photochemical efficiency (F_v/F_m),potential activities (F_v/F_o) and quantum yield (ΦPSⅡ) of PSⅡ were decreased with increasing NO₃^- concentration.After recovery for 7 days,the chlorophyll and carotenoid contents of all treatments with NO₃^- were lower than CK,while the intrinsic fluorescence,intrinsic photochemical efficiency and quantum yield of PSⅡ were similar to CK when the NO₃^- concentration was ≤ 84 mmol·L^-1,and the F_v/F_m and ΦPSⅡ were significantly lower than CK when the NO₃^- concentration was>84 mmol·L^-1.The potential activity of PSⅡ was similar to CK when the NO₃^- concentration was 42 and 126 mmol·L^-1,but significantly lower than CK in other treatments.The activities of Mg-ATPase and Ca-ATPase were decreased firstly but increased then when the NO₃^- concentration was>84 mmol·L^-1.

Leaf structure and some physiologic characteristics of low temperature wheat germplasm

MIAO Fang¹;ZHANG Songwu¹;WANG Changfa²;LIU Dangxiao²

2006, 17(03):  408-412 . 

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Through a longterm observation on wheat canopy temperature,it was found that in the nature,there existed low temperature wheat germplasm (LTWG) with constant low canopy temperature,and high temperature wheat germplasm (HTWG) with constant high canopy temperature.The study on the leaf structure and some physiologic characteristics of LTWG during its blooming and milk-filling stages showed that the canopy temperature of LTWG was 1～4 ℃ lower than that of HTWG.The mesophyll cells of LTWG functional leaves were smaller,more compact in cell arrangement,and 1～2 cell layers more than those of HTWG’s.The average thickness of three LTWG functional leaves was 166,192 and 165 μm,being 26 μm thinner than that of HTWG,average vein interval of three functional leaves was 257,231 and 245 μm,being 31 μm smaller than that of HTWG,average transverse area of big veins of three functional leaves was 5 961,6 580 and 5 603 μm²,being averagely 837 μm² more than that of HTWG,and average transverse area of small veins was 1 624,1 521 and 1 472 μm²,being averagely 246 μm² more than that of HTWG.The chlorophyll content of three LTWG functional leaves was 2.8749,2.8162,and 2.4129 g·100 g^-1 FW,net photosynthetic rate was 10.864,10.8003,and 10.1939 μmol·m^-2·s^-1,and transpiration rate was 0.0076,0.0074,0.0067 mol·m^-2·s^-1,respectively,which were all higher than those of HTWG.It was revealed that there were close relationships among canopy temperature,organ structure,and physiologic function.

Profit and loss of nutrients in crop-fruit ecosystems

WU Faqi¹;LIU Haibin¹;ZHOU Zhengli²

2006, 17(03):  413-416 . 

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The analysis on the balance of nutrient’s profit and loss in crop-fruit ecosystems of three villges in middle-south Loess Plateau showed that fertilization was the main input of nutrients,of which,chemical fertilizer occupied a larger proportion,while organic manure was relatively insufficient.The quantity of N,P and K spent in interior circulation was far less than that exported from the ecosystem.The ratio of nutrient’s output and input in three test villages was differed,but all at a low level.

Estimation parameters of nitrogen balance in stock farming system of China

LIU Xiaoli^1,2;XU Junxiang¹;WANG Fanghao²;ZHANG Fusuo²;MA Wenqi¹

2006, 17(03):  417-423 . 

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The study of nitrogen (N) balance in stock farming system is the basis of nutrient management in animal husbandry production,and the determination of N cycling parameters is the foundation of this study.Through documents checking and data collecting,this paper analyzed the items and values of input/output parameters of N cycling in stock farming system,and ascertained the estimation parameters of N balance in the system,which could offer the theoretical foundation for nutrient management in animal husbandry production.

Provincial ecological footprint of China in the year of 2002

CHEN Min^1，3;WANG Rusong¹;ZHANG Lijun²;HUAI Baoguang²

2006, 17(03):  424-428 . 

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Based on the calculation of actual yield per unit area in 2002,this paper analyzed the ecological footprint and its composition of each province in China.The results showed that there was a significant difference in the ecological footprint and its composition among different provinces,e.g.,cropland changed from 0.078 hm²·cap^-1 in Shaanxi to 0.126 hm²·cap^-1 in Beijing,grazing land changed from 0.020 hm²·cap^-1 in Jiangxi to 0.372 hm²·cap^-1 in Xizang,forestland changed from 0.020 hm²·cap^-1 in Guizhou to 0.209 hm²·cap^-1 in Beijing,fishery area changed from 0.001 hm·cap^-1 in Xizang to 0.011 hm²·cap^-1 in Shanghai,built-up area changed from 0.013 hm²·cap^-1 in Guizhou to 0.045 hm²·cap^-1 in Neimenggu,and fossil energy changed from 0.251 hm²·cap^-1 in Guangxi to 2.854 hm²·cap^-1 in Shanxi.The eastern and southern provinces were mostly in a state of ecological deficit,while the western and northern provinces were mostly in a state of ecological remainder.As for the relationships among ecological footprint,economic development and technological progress,great difference existed in different provinces,e.g.,the ecological footprint was about 1 hm²·cap^-1 in Fujian,Henan,Sichuan,Anhui,Yunnan,Shaanxi and Guizhou,while the GDP per capita changed from 1.35×10⁴ yuan in Fujian to 0.3×10⁴ yuan in Guizhou,and the ecological footprint per 1×10⁴ yuan GDP changed from 0.74 hm² in Fujian to 3.51 hm² in Guizhou.Therefore,to resolve the conflicts between the shortage of natural resources and the economic development of China,emphasis should be put on the provinces with big ecological footprint per capita,low GDP per capita,and high ecological footprint per 1×10⁴ yuan GDP.In these provinces,economic growth mode and industrial structure should be changed,dependence of economy on natural resources should be decreased,use efficiency and economic output of natural resources should be improved,and ecological,resources and economic sustainability should be realized.

Characteristics of soil organic carbon and microbial biomass carbon in hilly red soil region

TANG Guoyong^1,2;HUANG Daoyou¹;TONG Chengli¹;ZHANG Wenju¹,XIAO Heai¹;SU Yirong¹;WU Jinshui¹　

2006, 17(03):  429-433 . 

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In this paper,535 soil samples (0～20 cm) were taken from the woodland,orchard,upland,and paddy field in the hilly red soil region of south China,and the quantitative characteristics of soil organic carbon (SOC) and soil microbial biomass carbon (SMB-C) were studied.The results showed that SOC content was the highest (16.0 g·kg^-1) in paddy field and the lowest (8.4 g·kg^-1) in woodland,while SMB-C content was the highest in paddy field (830 mg·kg^-1) and the lowest in orchard (200 mg·kg^-1).There was a highly significant positive correlation (P＜0.01) between the contents of SOC and SMB-C in the four landuse types.It was suggested that the changes of SMB-C content could sensitively indicate the dynamics of SOC.The transition from woodland to orchard or cultivated land in hilly red soil region would not decrease the SOC content.

Statistical properties of Markov chain in land use and landscape study

WU Qiong^1,2;WANG Rusong¹;LI Hongqing²;Juergen Paulussen¹;HE Yong³;WANG Bihui³

2006, 17(03):  434-437 . 

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Markov chain has been widely applied in the study of land use and landscape changes,but its statistical properties were less tested.Based on the land use change data monitored in Beijing,and with Pearson χ² goodnessoffit test,this paper examined the time stability and time independence of Markov chain of land use change.The results indicated that the hypothesis of time stationary and Markov property is not tenable,which meant that the land use change in Beijing was an un-stationary and highly order Markov chain.Pearson χ² test was not as restricted as the likelihood ratio test,its transitional probabilities being allowed to be greater than zero,and thus,could be more useful in testing the assumption of homogeneity and independence.

Assessment of giant panda habitat based on integration of expert system and neural network

LIU Xuehua¹;Andrew K.Skidmore²;M.C.Bronsveld²

2006, 17(03):  438-443 . 

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To conserve giant panda effectively,it is important to understand the spatial pattern and temporal change of its habitat.Mapping is an effective approach for wildlife habitat evaluation and monitoring.The application of recently developed artificial intelligence tools,including expert systems and neural networks,could integrate qualitative and quantitative information for modeling complex systems,and built the information into a GIS,which could be helpful for giant panda habitat mapping.This study built a mapping approach for giant panda habitat mapping,which integrated expert system and neural network classifiers (ESNNC),and used multi-type data within GIS.The giant panda habitat types and their suitability were mapped by ESNNC.The results showed that the habitat types and their suitability in Foping Nature Reserve were assessed with a higher accuracy (>80%) by ESNNC,compared with non-integrated classifiers,i.e.,expert system,neural network,and maximum likelihood.Z-statistic test showed that ESNNC was significantly better than the other three non-integrated classifiers.It was recommended that the integrated approach could be widely applied into wildlife habitat assessment.

Feeding habitat of red-crowned crane and white-napped crane during their courtship period in Zhalong Wetland.

ZOU Hongfei;WU Qingming

2006, 17(03):  444-449 . 

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By the methods of fixed-spot observation,GPS positioning,plot sampling measurement and factor analysis,a comparative study was made on the feeding habitat of red-crowned and white-napped crane during their courtship period (from March to April) in Zhalong Nature Reserve in 2003 and 2004. The results showed that red-crowned crane preferred unique habitat for feed,mostly focused on water field (e.g.,reed marsh). During its selection of microhabitat,food factor played a crucial role,followed by concealment factor,water factor,and identification factor. The feeding habitat of white-napped crane was of diversification,and dry field,e.g.,Carex-marsh,farmland and burned field,was the priority. White-napped crane had a strict requirement in selecting feeding microhabitat,with “valid food” factor as the most important ingredient,and disturbance and water factors as the subordinate one.

Structural characteristics of soil nematodes community under different land uses in Changchun City

WU Donghui^1,2;ZHANG Bai¹;CHEN Peng³

2006, 17(03):  450-456 . 

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In this paper,an investigation on the species richness and abundance of soil nematodes in farmland,natural secondary forest,shelter forest and green space was made in Changchun City in July and September,2003.Soil nematodes were extracted with Baermann extractor,and identified to the genus level with the aid of microscope.A total of 7 273 soil nematode individuals were captured,and fell into 2 classes,7 orders,20 families,and 27 genera.Aphelenchus,Tylenchus and Pratylenchus were the dominant genera,which accounted for 61.58% of total individuals.Land use type had a significant effect on the community structure of soil nematodes,and aboveground litter removal and cultivation activity were the main factors affecting soil nematodes community structure.Aboveground litter removal considerably decreased soil nematodes individual density and community diversity,while cultivation activity changed the vertical distribution of soil nematodes individual density in the soil profile.Aboveground vegetation structure and landscape pattern appeared to have little effect on the ecological structure of soil nematodes community.

Predation and dispersal of Lithocarpus glaber seeds by rodents in Tiantong National Forest Park, Zhejiang Province

ZHANG Tianshu;LI Kai;CAI Yongli;YANG Kun;HU Xingming;PENG Shiming;CHEN Liqiao

2006, 17(03):  457-461 . 

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This paper studied the predation and dispersal of Lithocarpus glaber seeds by rodents in the Tiantong National Forest Park (29°48′N,121°47′E) of Ningbo City,Zhejiang Province.Five seeds release transects (three in evergreen broad-leaved forest,one in Pinus messoniana forest,and one in shrub),and two seeds release states (covered/uncovered and tagged/untagged) were set up.Iron snare traps were baited to determine the effects of rodents on seeds disappearance.The results showed that two species of rodents,Niviventer confucianus and N.fulvescensi,were the potential predators and dispersers of the seeds.The lost seeds labeled with small piece of tin-tags could be classified into three categories,i.e.,1) seeds consumed by rodents,with tags stuck seed fragments;2) seeds cut off from tags,with tags kept only;and 3) both seeds and tags disappeared.The loss rate of seeds was high at the beginning of the observation,and then decreased gradually.The daily seeds disappearance rate (DSDR) was variable in different habitats,with the highest (1.03%) in evergreen broad-leaved forest and the lowest (0.32%) in shrub.The proportion of these three categories was different,and related with habitat types.The difference of DSDR between covered and uncovered states was statistically significant (P<0.05),with a higher DSDR under uncovered state.No significant difference was observed between the DSDR of tagged and untagged.The distance of seeds dispersal by rodents was within 6.7 m.

Screening of mixed crop disease-resistant bacterial inoculants from N₂-fixing and P-solubilzing bacterial isolates

TAO Guangcan¹;WANG Suying¹;GUO Xingqiang¹;LI Ji²;XIE Guanghui¹

2006, 17(03):  462-467 . 

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In this paper,a total of 22 bacterial isolates capable of fixing nitrogen and/or solubilizing phosphorus were inoculated,and mixed incubated in 15 liquid media.The isolates were obtained from soil with selective media,and not purified.After grown for 48 hours,the mixed cultures were continuously inoculated to the same media,and then incubated under the same conditions.The procedures were repeated for 12 times,and 15 stable bacterial mixtures (SBM) were obtained.Each SBM was purified,which contained two or three bacterial species.Agar plate bacteriostasis test showed that 6 mixed cultures of the SBM exhibited significant inhibition effects to one or more plant pathogens of Verticillium dahliae,Rhizoctonia solani,and Pseudomonas syringae.It was found that C₇ and C₁₅ were the two SBM with most obvious antibiological effect.SMB C₁₅ had the ability of nitrogen fixation,and C₄,C₅,C₇,C₉,C₁₄ and C₁₅ showed the ability of phosphorus solubilization.These results suggested a possible approach to develop stable,synergistic,and multi-functional antibiological agents.

Realized resistance heritability and resistance risk of Spodoptera exigua tocyhalothrin,fenvalerate and alpha-cypermethrin

LAN Yiquan;ZHAO Shixi;WU Gang

2006, 17(03):  468-471 . 

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In this paper,Spodoptera exigua from Fuzhou of Fujian Province was continuously selected and bred to test its resistance to cyhalothrin，fenvalerate and alpha-cypermethrin,and to evaluate its realized resistance heritability (h²) and resistance risk.The results showed that after 12,10,and 10 generations,the resistance of S.exigua to cyhalothrin,fenvalerate and alpha-cypermethrin was increased by 18.1,27.6,and 45.4 fold,and the realized resistance heritability was 0.2567,0.3571 and 0.4239,respectively.Assuming that the h² of field S.exigua population was half of these values,it required 9～20 generations for cyhalothrin,6～14 generations for fenvalerate,and 5～12 generations for alpha-cypermethrin to obtain 10-fold increase in resistance under selective pressure of 50%～90% mortality for each selective generation.Of the three pyrethroids,the resistance risk to cyhalothrin was smaller than that to fenvalerate and alpha-cypermethrin.

Insect community and its relationship with Ceroplastes japonicus occurrence in jujube orchards

LIANG Yinquan¹;GAO Baojia¹;ZHEN Zhixian¹;WANG Jiangzhu¹;LIU Zhiqun²;NIU Jianzhong²

2006, 17(03):  472-476 . 

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Employing community character indices and canonical correlation analysis,this paper studied the insect community structure and its relationship with the occurrence degree of Ceroplastes japonicus in jujube orchards.The results showed that based on the community discrepancy coefficient of 0.20,the insect community in various sampling fields could be categorized into two groups,i.e.,plain and hill.The occurrence of C.japonicus in plain region was heavier,with lower insect community diversity,smaller species number,and higher dominance of phytophagous insects,while that in hill region was lighter,with higher insect community diversity,more abundant species,and higher dominance of natural enemy insects.Canonical correlation analysis indicated that at the significant level of 0.05,the first and second pairs of canonical correlation coefficients of C.japonicus occurrence characters and insect community characters were 0.9904 and 0.8538,respectively,suggesting that the occurrence of C.japonicus was significantly correlated with the characters of insect community.Community diversity (with the coefficient of 3.4893),species number (with the coefficient of 5.8060),and dominance (with the coefficient of 6.9353) had most important effects on the occurrence of C.japonicus.

Spatial distribution pattern of Pontania dolichura larvae and sampling technique

ZHANG Feng^1,2;CHEN Zhijie²;ZHANG Shulian²;ZHAO Huiyan¹ 

2006, 17(03):  477-482 . 

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In this paper,the spatial distribution pattern of Pontania dolichura larvae was analyzed with Taylor's power law,Iwao's distribution function,and six aggregation indexes.The results showed that the spatial distribution pattern of P.dolichura larvae was of aggregated,and the basic component of the distribution was individual colony,with the aggregation intensity increased with density.On branches,the aggregation was caused by the adult behavior of laying eggs and the spatial position of leaves,while on leaves,the aggregation was caused by the spatial position of news leaves in spring when m＜2.37,and by the spatial position of news leaves in spring and the behavior of eclosion and laying eggs when m＞2.37.By using the parameters α and β in Iwao's m*-m regression equation,the optimal and sequential sampling numbers were determined.

Effects of environmental temperature on Dendrolimus punctatus development and survival

HE Zhong;HAN Ruidong;LIU Xianghui;GE Feng

2006, 17(03):  483-488 . 

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In a simulation test,three treatments of low,normal and high temperature were designed to examine the effects of environmental fluctuant temperature on the development and survival of second generation Dendrolimus punctatus larvae.The results showed that under different temperature but same light and dark cycle,the mortality of 1st～3rd instar was apparently different.Under long photophase,the larval mortality of 1st～3rd instar was 25.55%,55.13% and 58.23% at low,normal and high temperature,while under short photophase,the mortality was 32.67%,64.67% and 94.32%,respectively.High temperature resulted in the diapause of larvae.Under the same short photophase,the larvae exposed to high temperature could develop to 5th instar by 40%,while those exposed to normal and low temperature kept diapause,and could not develop to 5th instar after 20 days.After 48 days,the larvae exposed to high temperature became cocoons,while those exposed to normal and low temperature still diapaused.It was suggested that if the second generation larvae of D.punctatus encountered consecutive high temperature,most of them could develop to third generation.

Biodegradation of acetochlor in soil and its persistence against Echinochloa crusgalli

ZHU Jiusheng;QIAO Xiongwu;WANG Jing;QIN Shu

2006, 17(03):  489-492 . 

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Gas chromatograph and bioassay were used to study biodegradation of acetochlor and its influence on the persistence against Echinochloa crusgalli in soil.The results showed that halflife of degradation of acetochlor was significantly shorter in unsterilized soil than that in sterilized soil under the same experimental conditions of concentrations,water content and temperature,when acetochlor was added to the soil with concentrations of 1.25,2.5 and 5.0 mg·kg^-1 respectively,which demonstrated that microorganisms could evidently degrade acetochlor in soil.The experiment on degradation of three main kinds of microorganism cultivated in liquid culture medium gave same results above.The bioassay’s result showed that the period of acetochlor persistence against Echinochloa crusgalli was shorter in unsterilized soil than that in sterilized soil,which indicated that existence of microorganism could accelerate the degradation of acetochlor and shorten remaining time of the herbicide in soil,consequently reduce its persistence against the weed.

N₂O flux in typical wetlands of Sanjiang Plain

WANG Yiyong^1,2;ZHENG Xunhua²;SONG Changchun¹;ZHAO Zhichun¹

2006, 17(03):  493-497 . 

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By the method of static chamber-gas chromatography,this paper studied the nitrous oxide flux in three typical wetlands (perennial waterlogged Carex lasiocarpa marsh,seasonal waterlogged Deyeuxia angustifolia wet meadow,and perennially over-wet brushwood wetland) of Sanjiang Plain from 2002 to 2004.The results showed that the nitrous oxide flux in test wetlands presented obvious seasonal and annual variation,suggesting that these three typical wetlands were all the sources of atmosphere nitrous oxide during plant growth season,and the weak sink in winter.The annual average flux in C.lasiocarpa marsh,D.angustifolia and brushwood wetland was 53.928,21.408 and 657.120 mg·m^-2·yr^-1,respectively.No diurnal variation of nitrous oxide flux was observed in three typical wetlands,and there was no significant correlation between nitrous oxide flux and temperature.

Physiological metabolism and protective enzyme activity of Equisetum ramosissimum under Cu stress

LI Ying;LIU Dengyi

2006, 17(03):  498-501 . 

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The study with pot culture experiment showed that Equisetum ramosissimum did not appear obvious poisoning symptoms when treated with low concentration Cu (500 mg·kg^-1),while serious injuries were found when treated with high concentration Cu (1 000～3 000 mg·kg^-1),which reflected in the severe damage of cell membrane and cytoarchitecture as well as the structure and function of main organelles,and the significant decrease of the contents of leaf chlorophyll a and b and stem soluble monosaccharose.The cell membrane osmolarity and the average MDA content of the plant exposed to heavy copper pollution was 1～2 and 1～3 times greater than the control,respectively.It could be concluded that high concentration Cu disturbed the physiological metabolism,and critically threatened the normal growth of E.ramosissimum.The activities of protective enzyme,especially of SOD and POD,were enhanced with increasing Cu concentration,and had a positive correlation with Cu concentration (r_POD=0.978,r_SOD=0.926,P<0.05).

Effects of different concentration copper on pigment content and antioxidase system of Spirodela polyrrhiza and Lemna minor

TU Junfang;WANG Xingming;LIU Dengyi;LI Jing;LI Zheng

2006, 17(03):  502-506 . 

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The study with water culture showed that when treated with 0.056 mg Cu·L^-1,the chlorophyll a,b and (a+b) contents in Spirodela polyrrhiza and Lemna minor were increased by 11%,46% and 22%,and 8%,15% and 11%,while under 0.15～5.6 mg Cu·L^-1,the contents were decreased by 63%,62% and 63%,and 46%,45% and 45%,respectively,compared with no copper added.The malondialdehyde (MDA) content in S.polyrrhiza was 2.75 times higher than that in L.minor averagely.The superoxide dismutase (SOD),catalase (CAT) and peroxidase (POD) activities in both S.polyrrhiza and L.minor all increased first,but decreased then with increasing copper concentration.For S.polyrrhiza,the activities of test enzymes were the highest at 0.18 mg Cu·L^-1,but for L.minor,only when the Cu concentrations were up to 0.56,1.0 and 1.0 mg·L^-1,the activities of SOD,CAT and POD got to their peak values,respectively.It was concluded that higher concentrations of copper caused more damage to S.polyrrhiza than to L.minor,and the antioxidase system of the former was much more sensitive to the copper stress than that of the latter.

Petridium revolutum,a promising plant for phytoremediation of Cu-polluted soil

ZHENG Jiemin^1,2;LOU Liping¹;WANG Shiheng²;TANG Shirong^1，3 

2006, 17(03):  507-511 . 

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A field survey on the Petridium revolutum growing on the Cu mining spoils in Yunnan Province and related greenhouse hydroponic sand culture experiment showed that when growing on the soil with an average Cu concentration of 2 432 mg·kg^-1 DW and the maximum Cu concentration of 7 554 mg·kg^-1 DW,P.revolutum had a large amount of aboveground biomass,with the maximum dry weight of 40.05 g·plant^-1 DW and the average dry weight of 18.33 g·plant^-1 DW.The average and maximum Cu contents were 201 and 567 mg·kg^-1 DW in aboveground biomass,and 346 and 1 723 kg^-1 DW in underground biomass,respectively.The transfer factor of Cu reached a maximum of 3.88,with an average of 0.81.Under quartz sand culture condition,P.revolutum could grow well when the Cu concentration in nutrient solution was 7 mg·L^-1.The accumulation of Cu by P.revolutum plant increased significantly with increasing Cu concentration,with the most of absorbed Cu concentrated in underground biomass.It was suggested that P.revolutum had a remarkable tolerance to Cu and a potential capacity of Cu accumulation,and could be used in the phytoremediation of Cu-polluted soils.

Absorption and accumulation of heavy metals by plants around a smelter

CUI Shuang^1,2;ZHOU Qixing^1,3;CHAO Lei^1,2

2006, 17(03):  512-515 . 

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The study on the absorption and accumulation of heavy metals lead,zinc,copper and cadmium by 8 plant species around a smelter showed that the metals accumulation by plants differed with plant species,their parts,and kinds of metals.Abutilon theophrasti had a higher capability of absorbing and accumulating Pb,Conyza canadensis,Ambrosia trifida,Polygonum lapathifolium,A.theophrasti,Solanum nigrum,Chenopodium acuminatum and Helianthus tuberosus had a higher capability of absorbing and accumulating Zn,C.acuminatum and A.theophrasti had a higher capability of absorbing and accumulating Cu,and S.nigrum,C.acuminatum,A.theophrasti,P.lapathifolium and C.canadensis had a higher capability of absorbing and accumulating Cd.These plants had TF values higher than 1,and were suitable for phytoextraction to remedy polluted soil.As for the plants with TF values lower than 1,they were suitable as the phytostabilizers of heavy metals-contaminated lands.

Lysosome of Eisenia fetida as biomarker of soil pollution

XIAO Nengwen;LIU Xianghui;LI Wei;GE Feng

2006, 17(03):  516-519 . 

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The lysosome of Eisenia fetida can accumulate neutral red dye rapidly.When exposed to environment pollution,the membrane of the lysosome is easily to be cracked,and the dye shall leak to the cytoplasm gradually,making the cell red.Therefore,neutral red retention time (NRRT) can reflect the damaged degree of lysosome.In this paper,the NRRT of the lysosome in coelomocytes of E.fetida was determined after exposed to different concentrations of acetochlor and selenium.The results showed that with increasing exposure time and increasing concentration of acetochlor and Se,the NRRT was decreased significantly,and had significant correlations with the concentrations of acetochlor in soil and of accumulated Se in E.fetida’s body.NRRT could be served as a biomarker of soil pollution,and a promising tool for the early warning of potential danger.

Performance of leachate nitrogen removal in bioreactor landfill system

HE Ruo;SHEN Dongsheng;ZHU Yinmei

2006, 17(03):  520-524 . 

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Utilizing the unique vertical aerobic-anoxic-anerobic ecological enviornment of landfills and adopting intermittent aeration at the top of landfilled refuse,this paper studied the performance of leachate nitrogen removal in the bioreactor landfill system.The results showed that intermittent aeration at the top of landfilled refuse could stimulate the growth of nitrifying and denitrifying bacteria.The population of denitrifying bacteria was 4～13 orders of magnitude higher than that in conventional landfilled waste layers,and the maximal value of nitrifying bacteria population reached 10⁹ cells·g^-1.The bioreactor landfill system with intermittent aeration at the top of landfilled refuse increased the potential of nitrogen removal from re-circulated leachate in the landfill bioreactor.By the end of the experiment，the concentrations of leachate NH₄⁺-N and total nitrogen (TN) decreased to 186 mg·L^-1 and 289 mg·L^-1,being only 18% and 26% of control,respectively.Intermittent aeration at the top of landfilled refuse also accelerated refuse decomposition,and increased the degree of waste stabilization.

Research advance in antibacterial immunity ecology of earthworm

WANG Chong;SUN Zhenjun;ZHENG Dongmei

2006, 17(03):  525-529 . 

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Earthworm lives in the environment flocked with pathogens,but few are infected due to the earthworm’s unique antibiotic and immune system.In this paper,the research advance in this domain was reviewed from the aspects of antibiotic barrier,cell immunity,and humoral immunity.Antibiotic barrier mainly includes body wall,alimentary canal and parietal mucus,cell immunity represents phagocytosis and encapsulation responses,while humoral immunity gives priority to unspecific immune system.The main antibacterial materials in the coelomic fluid of earthworm are antigen-binding proteins,agglutinins,antibacterial proteins,and lysozyme.

Research advance in characteristics and mechanisms of Nereis diversicolor endurance against environmental pollution

SUN Fuhong^1,2;ZHOU Qixing^1,3

2006, 17(03):  530-534 . 

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Nereis diversicolor is an ecologically keystone species of invertebrate that lives in the mud of marineterrestrial interlaced zone.This species can accumulate a large number of toxic heavy metals such as copper,cadmium and zinc in its body,and thus,shows a high endurance against toxic heavy metals.This paper summarized the latest research advance at home and abroad in the characteristics and mechanisms of N.diversicolor endurance against heavy metals and organic contaminants.N.diversicolor could achieve its heavy metals-endurance through several eco-chemical processes,e.g.,mucus secretion and contaminants excretion.The former could form a protective layer or integrate with dissolved ions of pollutants,and thus,decrease the bioavailability of pollutants,while the latter could lessen the pollutants^,bio-toxicity.More researches believe that the toxic heavy metals in N.diverdicolor body are stored in non-toxic physicochemical forms,i.e.,bound to metalbinding protein,such as metallothionein (MTs),metallothionein-like proteins (MTLP) and cytosolic heat-stable thiolic compounds (CHSTC),or incorporated into insoluble deposits or granules.The pivots of future researches on the ecotoxicology of N.diversicolor and its endurance mechanisms against pollutants were proposed.

Environmental regulation of Citrus photosynthesis

HU Meijun¹;GUO Yanping¹;SHEN Yungang²;ZHANG Liangcheng¹

2006, 17(03):  535-540 . 

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Recent researches on the mechanisms of environmental regulation of citrus photosynthesis showed that the photoinhibition of photosynthesis induced by strong light or ultraviolet radiation was related to the inactiveness of PSⅡ reaction center,and photorespiration and xanthophyll cycle played a pivotal role in protecting photosynthetic apparatus.Under temperature stress,lower CO₂ assimilation was mainly due to the decrease of RuBPCase activity and the inactiveness of PSⅡreaction center,and species sensitivity existed.The decline of photosynthetic CO₂ assimilation under high water stress was due to non-stomatal limitation,while that under low water stress was due to stomatal limitation.The citrus growth,yield and quality could be increased by increasing photosynthesis under elevated CO₂ concentration.The mechanisms of photosynthesis regulation by minerals such as nitrogen,phosphorus,sulfur and iron,as well as the effects of salt stress on photosynthesis were discussed,and the directions for future research were suggested.

Research advances in plant phenology

LI Rongping¹;ZHOU Guangsheng^1,2;ZHANG Huiling³

2006, 17(03):  541-544 . 

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Plant phenology can directly reflect the effects of climate change,and is the key for vegetation dynamics modeling.With the development of remote sensing and modeling techniques,the relationships between plant phenology and global climate change have been increasingly concerned by scientists.From the aspects of the relationships between plant phenology and environmental factors,the responses of plant phenology to global change,and the remote sensing monitoring of plant phenology,this paper reviewed the research advances in plant phenology,with the shortages of plant phenology research and the trends for future research put forward.

Research advance in potassium cycling in agroecosystems

JIANG Zishao;YU Wantai

2006, 17(03):  545-550 . 

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This paper reviewed the research advance in the budget of potassium in agroecosystems and the reuse of recycled potassium.Some strategies were brought forward to solve the problems in potassium cycling.In China,the amount of applied fertilizer potassium was far less than that of the potassium carried off by crops from soil,and thus,potassium was of negative balance all along.Soil potassium fertility was decreased continually,and the areas available to potassium application was extending.Though the application rate of potassium was increasing,the potassium balance was still of negative.To maintain and improve soil potassium fertility and to obtain high and stable crop yield,enough attention should be paid on soil potassium balance,structural optimization of agroecosystems,regulation of water and fertilizer,and combined application of organic and chemical fertilizers.

Anti-freezing proteins and plant responses to low temperature stress

WANG Ruiyun¹;LI Runzhi¹;SUN Zhenyuan²;REN Youshe¹;YUE Wenbin¹

2006, 17(03):  551-556 . 

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Anti-freezing proteins (AFPs) are the new type of proteins isolated from overwintering plants,which involve in the plant responses to low temperature stress.AFPs have multiple hydrophilic icebinding domains,which can inhibit the growth and recrystallization of ice in intercellular spaces.Some AFPs are homologous to the pathogenesis-related proteins,and function with two activities,i.e.,anti-freezing and diseaseresistance.The expression and accumulation of AFPs are controlled by developmental regulation and transcriptional factors,and affected by low temperature,short day length,dehydration,and ethylene.The heterologous over-expression of genes encoding AFPs in freezing-sensitive plants can enhance the freezing resistance of host plants.In this paper,the research advances in plant AFPs’ characters and their identification,mechanisms of freezing resistance and their regulation,and genetic modification were reviewed.

Effects of nutrients nitrogen and phosphorus on Heterosigma akashiwo growth

JIANG Yan¹;GAN Xuhua¹;TANG Xinyun¹;CHEN Xiaolin¹;YU Rencheng²

2006, 17(03):  557-559 . 

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The study showed that the relationships between the specific growth rate (μ) of Heterosigma akashiwo and the concentrations of nutrients nitrogen and phosphorus in water body accorded with Monod equation.H.akashiwo started to grow when the concentration of NO₃^--N was higher than 7.5 mg·L^-1,and the specific growth rate (μ) of the algae was proportional to the concentration of NO₃^--N between 3.75～75 mg·L^-1.The maximum growth rate of H.akashiwo(μ_m-n) was 0.3475·d^-1,and the half saturated constant (K_s-n) was 18.91 mg·L^-1.The specific growth rate of the alga was proportional to the concentration of PO₄^--P between 0～1.0 mg·L^-1.The maximum growth rate of H.akashiwo (μ_m-p) was 0.3024·d^-1,and K_s-n was 0.4086 mg·L^-1.The most suitable growth conditions for H.akashiwo were 37.5～225.0 mg·L^-1 NO₃^--N,5.0～500 mg·L^-1 PO₄^--P,and N/P 25.