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    25 July 2001, Volume 12 Issue 4
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    Carbon equilibrium in Larix gmelinii forest and impact of global change on it
    JIANG Yanling, ZHOU Guangsheng
    2001, (4):  481-484. 
    Asbtract ( 0 )  
    In order to provide a methodological demonstration for the study of C cycle in forest,the CENTURY model was applied to simulate the C cycle in Larix gmelinii forest and to approach the impact of global change on it.The results showed that the Larix gmelinii forest served as a C sink, with an annual net absorption of 2.65t·hm-2.Cimate change and increased atmospheric CO2 concentration benefited for the net primary production(CNPP)and net C absorption capacity of forests in North China. When the atmospheric temperature was increased by 2℃,the gross biomass and NPP of Larix gmelinii forest increased, while soil C content decreased, and the variation of these three indices was bigger when the precipitation was decreased by 20% than increased by 20%, indicating that the limiting factor for the forest growth in this area is atmospheric temperature, while precipitation is abundant or even too much.
    Articles
    Gap formation features of humid evergreen broad-leaved forest in central subtropical Wawushan Mountain,Sichuan Province,China
    BAO Weikai, LIU Zhaoguang, YUAN Yafu, LIU Rendong, LIU Chaolu
    2001, 12(4):  485-490. 
    Asbtract ( 149 )  
    The primary and secondary subtropical evergreen broad-leaved forests at an altitude of 1720～1750m in Mt. Wawushan National Forest Park, southwestern China investigated to analyze their canopy gap formation characteristics.The sampling method and canopy formation causes were also discussed.In secondary evergreen broad-leaved fore- st,the gap density was surprisingly only 9 per hm2 and the size of all gaps was,no more than 10m2. Almost every gap had only one gap maker,and the gap makers often died standing by suppression. Accordingly successful natural regeneration is difficult in small gap,due to the rapidly lateral growth of canopy trees. In primary evergreen broad-leaved forest, the gap density was 15 per hm2, and 56% of the gaps had an area of no more than 40m2. The largest gap had an area of 256m2. The canopy gap accounted for 11.1% and expended gap occupied 19 8% of land area in the forest. Median area of canopy gaps and expended gaps was 59 and 105m2, respectively. Most gaps had more than one gap maker,and gap makers died falling and were often from mortality events separated in time. Most gaps aged over 10yr and a few were formed recently and the estimated gap formation rate was 0 01 per year. According to falling direction of trees and the relations with growth process, slope aspect and wind, we deduced gap-maker death resulted from integrated influence among topography,climate particular in wind, tree growth characteristics, and interactions of population under competition. Adapting method of plot sampling and projection drawing used in the paper can improve investigation accuracy and help improving comparison of results in different investigation area.
    AFLP analysis on genetic structure of planted Acacia auriculiformis population in Heshan
    ZHANG Junli, WANG Zhengfeng, WANG Bosun, LI Mingguang, ZHANG Weiyin
    2001, 12(4):  491-495. 
    Asbtract ( 232 )  
    AFLP analysis of Acacia auriculiformis populations in 3 different planted communities with the same provenance and same planting time indicated that the genetic heterozygosity was quite high in the plantation population.90.73% of total genetic variance distributed within a population,while only 9.27% among populations.The most distinct genetic structural difference was found between pure plantation and legume mixed plantation,next was between legume and non-legume mixed plantation,and the most similar was between pure and non-legume mixed plantation,which revealed that the genetic variation in this Acacia auriculiformis population was relatively higher than that from the natural forests by isoenzymic analysis data.The genetic differentiation was not the result of gene flow,but the result of the artificial selection and the microenvironmental changes.
    A preliminary study on ecological response of dominant tree species in Korean pine broadleaf forest at Changbai Mountain to soil water stress and their biomass allocation
    WANG Miao, DAI Limin, JI Lanzhu
    2001, 12(4):  496-500. 
    Asbtract ( 224 )   PDF (1KB) ( 137 )  
    Pot culture experiments were conducted to examine the ecological response and biomass allocation of Pinus koraienes,Fraxinus mandshurica,Juglans mandshurica,Tilia amurensis,and Quercus mongolica.The five dominant species in the Korean pine-broadleaf forest at Changbai mountain.Their seedlings were grown under three different soil moistures,e.g.,85%～100%(CK),65%～85%(MW)and 45%～65%(LW)of field water-holding capacity.The results showed that drought significantly decreased the individual leaf area,number of fine root,root length,and individual biomass of seedlings.The root proportions of T.amurensis and F.mandshurica increased with increasing soil water content,but the leaf proportion of J.mandshurica and Q.mongolica in MW treatment was higher than that of CK and LW.There was no significant difference in stem proportions of 5 tree species among different water stress treatments.The response of the biomass of 5 tree species to water stress was significant,the total biomass of T.amurensis,F.mandshurica,J.mandshurica and P.koraienes in MW and LW decreased by 32.8%,43.6%,26.2% and 23 8%,respectively,while that in Q.mongolica increased by 4.8%,indicating that Q.mogolica was the most drought-tolerent species among 5 tested species.
    Decomposition processes of Tilia amurensis leaves in the Changbai Mountain forest ecosystem
    XU Zhenbang, DAI Limin, ZHANG Yangjian, CHEN Hua
    2001, (4):  501-504. 
    Asbtract ( 0 )  
    A 4-year field experiment was carried out in the Changbai Mountain to study the decomposition process of Tilia amurensis leaf and its affecting environmental factors.The results reveal that the decomposition process of Tilia amurensis leaves could be expressed by an exponent equitation.With the increase of elevation and the change of vegetation types,the decomposition rate in 1～5 standard experimental fields was -0 391,-0 339,-0 257,-0 198 and -0 125,respectively,indicating that the decomposition rate was decreased with ascending elevation.The maximum decomposition took place when the environment was in the shadow of 60%～80%.The leaves were acceleratively decomposed when the tested moisture was increased.Moisture affected the decomposition process more strongly than light.
    Articles
    Influence of temperature and moisture on soil nitrogen mineralization under two types of forest in Changbai Mountain
    ZHOU Caiping, OUYANG Hua
    2001, 12(4):  505-508. 
    Asbtract ( 193 )  
    The effect of temperature(t)and soil water content(θ)on soil nitrogen mineralization under coniferous-broadleaved and spruce-fir coniferous forests was evaluated by using laboratory incubation method.Based on the analysis of inorganic nitrogen in soil extracts before and after incubation,it was showed that the net mineralization rate of soil nitrogen was positively related to t(α<0 001)from 5℃ to 35℃,and to water content when water contents was low,but there was a decrease in net mineralization rate when the water content was above an optimum value.The result suggested the interactive effect of temperature and moisture on the mineralization of soil nitrogen.Two dimensional(t,θ)equations to describe the effect were drawn up.
    Characteristics of litter and its contained water in three succession communities in Dinghushan Mountain
    YAN Junhua, ZHOU Guoyi, TANG Xuli, ZHANG Deqiang
    2001, (4):  509-512. 
    Asbtract ( 0 )  
    Studies on the characteristics of litter and its contained water in three succession communities in Dinghushan Mountain showed that the standing mass of litter was in the order of pine forest>mixed forest>broad-leaved forest,and the annual litterfall was broad-leaved forest>mixed forest>pine forest,indicating that the return rate of nutrients was lower in pine forest than in broad-leaved forest.The proportion of leaf litter decreased in the order of pine forest>mixed fo- rest>broad-leaved forest,and that of branch,flower,and fruit litter was on the contrary, because the broad-leaved fo- rest had the largest amount of branches and the biggest scope of canopy. The saturation water content of litter in pine forest, mixed forest and broad-leaved forest was 329.0%,313.0% and 295.0%,respectively,showing no significant difference,but the water content of litter in three communities differed significantly,followed the order of broad-leaved forest>mixed forest>pine forest.The evaporation ratio of litter water to free water in broad-leaved forest, mixed fo-rest and pine forest was 78.9%,82.45% and 91.22%,respectively.
    Articles
    Nourishing characteristic of geochemical elements in Antarctic mosses and lichens
    LI Xiaomei, ZHAO Junlin, SUN Liguang
    2001, 12(4):  513-516. 
    Asbtract ( 146 )   PDF (1KB) ( 161 )  
    Studies on the nourishing properties of geochemical elements in Antarctic mosses and lichens show that potassium and calcium were the most active elements,while phosphorous was accumulated in the middle part of lichen cells,and participated in organic synthesis.Mosses accumulated sulphur stressly,but took in iron and magnesium negatively.Aluminum and silicon were absorbed passively by lichens.It is concluded that potassium and calcium were the important nutrient elements for the growth of mosses and lichens,sulphur and phosphorous were the middle significant nutrients,while aluminum and silicon were the passively accumulated elements.
    Characteristics and quantitative simulation of stomatal conductance of Aneurolepidium chinense
    WANG Yuhui, HE Xingyuan, ZHOU Guangsheng
    2001, (4):  517-521. 
    Asbtract ( 0 )  
    Based on field measurements of stomatal conductance and photosynthesis of Aneurolepidium chinense,the dynamic characteristics and the relationship between stomatal conductance and environmental conditions were examined to develop a leaf stomatal conductance model for A. chinense. The results showed that the variation of stomatal conductance of A. chinense was closely correlated with environmental factors, such as physiologically active radiation(PAR), vapor pressure deficit(VPD)and air temperature(Ta). The daily variation of A. chinense stomatal conductance could be described as M-type curve at fair-weather, but⌒-type curve at cloudy weather.The value of stomatal conductance increased with the increase of PAR or Ta, but decreased with the increase of VPD. The relationship between stomatal conductance(gs)and environmental factors could be expressed as:gs=PAR(2.01Ta2+147.74Ta-2321.11)/((444.62+PAR)(-38.04+VPD))..This model would be helpful to simulate the dynamical photosynthesis of leaf and canopy and to further simulate the NPP of ecosystems and the exchange of water and heat among the soil-plant-atmosphere continum.
    Carbon equilibrium in Larix gmelinii forest and impact of global change on it
    JIANG Yanling, ZHOU Guangsheng
    2001, (4):  481-484. 
    Asbtract ( 877 )   PDF (217KB) ( 355 )  
    In order to provide a methodological demonstration for the study of C cycle in forest,the CENTURY model was applied to simulate the C cycle in Larix gmelinii forest and to approach the impact of global change on it.The results showed that the Larix gmelinii forest served as a C sink, with an annual net absorption of 2.65t·hm-2.Cimate change and increased atmospheric CO2 concentration benefited for the net primary production(CNPP)and net C absorption capacity of forests in North China. When the atmospheric temperature was increased by 2℃,the gross biomass and NPP of Larix gmelinii forest increased, while soil C content decreased, and the variation of these three indices was bigger when the precipitation was decreased by 20% than increased by 20%, indicating that the limiting factor for the forest growth in this area is atmospheric temperature, while precipitation is abundant or even too much.
    Articles
    Gap formation features of humid evergreen broad-leaved forest in central subtropical Wawushan Mountain,Sichuan Province,China
    BAO Weikai, LIU Zhaoguang, YUAN Yafu, LIU Rendong, LIU Chaolu
    2001, (4):  485-490. 
    Asbtract ( 1232 )   PDF (689KB) ( 310 )  
    The primary and secondary subtropical evergreen broad-leaved forests at an altitude of 1720～1750m in Mt. Wawushan National Forest Park, southwestern China investigated to analyze their canopy gap formation characteristics.The sampling method and canopy formation causes were also discussed.In secondary evergreen broad-leaved fore- st,the gap density was surprisingly only 9 per hm2 and the size of all gaps was,no more than 10m2. Almost every gap had only one gap maker,and the gap makers often died standing by suppression. Accordingly successful natural regeneration is difficult in small gap,due to the rapidly lateral growth of canopy trees. In primary evergreen broad-leaved forest, the gap density was 15 per hm2, and 56% of the gaps had an area of no more than 40m2. The largest gap had an area of 256m2. The canopy gap accounted for 11.1% and expended gap occupied 19 8% of land area in the forest. Median area of canopy gaps and expended gaps was 59 and 105m2, respectively. Most gaps had more than one gap maker,and gap makers died falling and were often from mortality events separated in time. Most gaps aged over 10yr and a few were formed recently and the estimated gap formation rate was 0 01 per year. According to falling direction of trees and the relations with growth process, slope aspect and wind, we deduced gap-maker death resulted from integrated influence among topography,climate particular in wind, tree growth characteristics, and interactions of population under competition. Adapting method of plot sampling and projection drawing used in the paper can improve investigation accuracy and help improving comparison of results in different investigation area.
    AFLP analysis on genetic structure of planted Acacia auriculiformis population in Heshan
    ZHANG Junli, WANG Zhengfeng, WANG Bosun, LI Mingguang, ZHANG Weiyin
    2001, (4):  491-495. 
    Asbtract ( 1328 )   PDF (826KB) ( 281 )  
    AFLP analysis of Acacia auriculiformis populations in 3 different planted communities with the same provenance and same planting time indicated that the genetic heterozygosity was quite high in the plantation population.90.73% of total genetic variance distributed within a population,while only 9.27% among populations.The most distinct genetic structural difference was found between pure plantation and legume mixed plantation,next was between legume and non-legume mixed plantation,and the most similar was between pure and non-legume mixed plantation,which revealed that the genetic variation in this Acacia auriculiformis population was relatively higher than that from the natural forests by isoenzymic analysis data.The genetic differentiation was not the result of gene flow,but the result of the artificial selection and the microenvironmental changes.
    A preliminary study on ecological response of dominant tree species in Korean pine broadleaf forest at Changbai Mountain to soil water stress and their biomass allocation
    WANG Miao, DAI Limin, JI Lanzhu
    2001, (4):  496-500. 
    Asbtract ( 1323 )   PDF (700KB) ( 461 )  
    Pot culture experiments were conducted to examine the ecological response and biomass allocation of Pinus koraienes,Fraxinus mandshurica,Juglans mandshurica,Tilia amurensis,and Quercus mongolica.The five dominant species in the Korean pine-broadleaf forest at Changbai mountain.Their seedlings were grown under three different soil moistures,e.g.,85%～100%(CK),65%～85%(MW)and 45%～65%(LW)of field water-holding capacity.The results showed that drought significantly decreased the individual leaf area,number of fine root,root length,and individual biomass of seedlings.The root proportions of T.amurensis and F.mandshurica increased with increasing soil water content,but the leaf proportion of J.mandshurica and Q.mongolica in MW treatment was higher than that of CK and LW.There was no significant difference in stem proportions of 5 tree species among different water stress treatments.The response of the biomass of 5 tree species to water stress was significant,the total biomass of T.amurensis,F.mandshurica,J.mandshurica and P.koraienes in MW and LW decreased by 32.8%,43.6%,26.2% and 23 8%,respectively,while that in Q.mongolica increased by 4.8%,indicating that Q.mogolica was the most drought-tolerent species among 5 tested species.
    Decomposition processes of Tilia amurensis leaves in the Changbai Mountain forest ecosystem
    XU Zhenbang, DAI Limin, ZHANG Yangjian, CHEN Hua
    2001, (4):  501-504. 
    Asbtract ( 1339 )   PDF (229KB) ( 238 )  
    A 4-year field experiment was carried out in the Changbai Mountain to study the decomposition process of Tilia amurensis leaf and its affecting environmental factors.The results reveal that the decomposition process of Tilia amurensis leaves could be expressed by an exponent equitation.With the increase of elevation and the change of vegetation types,the decomposition rate in 1～5 standard experimental fields was -0 391,-0 339,-0 257,-0 198 and -0 125,respectively,indicating that the decomposition rate was decreased with ascending elevation.The maximum decomposition took place when the environment was in the shadow of 60%～80%.The leaves were acceleratively decomposed when the tested moisture was increased.Moisture affected the decomposition process more strongly than light.
    Articles
    Influence of temperature and moisture on soil nitrogen mineralization under two types of forest in Changbai Mountain
    ZHOU Caiping, OUYANG Hua
    2001, (4):  505-508. 
    Asbtract ( 1445 )   PDF (597KB) ( 446 )  
    The effect of temperature(t)and soil water content(θ)on soil nitrogen mineralization under coniferous-broadleaved and spruce-fir coniferous forests was evaluated by using laboratory incubation method.Based on the analysis of inorganic nitrogen in soil extracts before and after incubation,it was showed that the net mineralization rate of soil nitrogen was positively related to t(α<0 001)from 5℃ to 35℃,and to water content when water contents was low,but there was a decrease in net mineralization rate when the water content was above an optimum value.The result suggested the interactive effect of temperature and moisture on the mineralization of soil nitrogen.Two dimensional(t,θ)equations to describe the effect were drawn up.
    Characteristics of litter and its contained water in three succession communities in Dinghushan Mountain
    YAN Junhua, ZHOU Guoyi, TANG Xuli, ZHANG Deqiang
    2001, (4):  509-512. 
    Asbtract ( 978 )   PDF (726KB) ( 371 )  
    Studies on the characteristics of litter and its contained water in three succession communities in Dinghushan Mountain showed that the standing mass of litter was in the order of pine forest>mixed forest>broad-leaved forest,and the annual litterfall was broad-leaved forest>mixed forest>pine forest,indicating that the return rate of nutrients was lower in pine forest than in broad-leaved forest.The proportion of leaf litter decreased in the order of pine forest>mixed fo- rest>broad-leaved forest,and that of branch,flower,and fruit litter was on the contrary, because the broad-leaved fo- rest had the largest amount of branches and the biggest scope of canopy. The saturation water content of litter in pine forest, mixed forest and broad-leaved forest was 329.0%,313.0% and 295.0%,respectively,showing no significant difference,but the water content of litter in three communities differed significantly,followed the order of broad-leaved forest>mixed forest>pine forest.The evaporation ratio of litter water to free water in broad-leaved forest, mixed fo-rest and pine forest was 78.9%,82.45% and 91.22%,respectively.
    Articles
    Nourishing characteristic of geochemical elements in Antarctic mosses and lichens
    LI Xiaomei, ZHAO Junlin, SUN Liguang
    2001, (4):  513-516. 
    Asbtract ( 1443 )   PDF (509KB) ( 268 )  
    Studies on the nourishing properties of geochemical elements in Antarctic mosses and lichens show that potassium and calcium were the most active elements,while phosphorous was accumulated in the middle part of lichen cells,and participated in organic synthesis.Mosses accumulated sulphur stressly,but took in iron and magnesium negatively.Aluminum and silicon were absorbed passively by lichens.It is concluded that potassium and calcium were the important nutrient elements for the growth of mosses and lichens,sulphur and phosphorous were the middle significant nutrients,while aluminum and silicon were the passively accumulated elements.
    Characteristics and quantitative simulation of stomatal conductance of Aneurolepidium chinense
    WANG Yuhui, HE Xingyuan, ZHOU Guangsheng
    2001, (4):  517-521. 
    Asbtract ( 960 )   PDF (820KB) ( 413 )  
    Based on field measurements of stomatal conductance and photosynthesis of Aneurolepidium chinense,the dynamic characteristics and the relationship between stomatal conductance and environmental conditions were examined to develop a leaf stomatal conductance model for A. chinense. The results showed that the variation of stomatal conductance of A. chinense was closely correlated with environmental factors, such as physiologically active radiation(PAR), vapor pressure deficit(VPD)and air temperature(Ta). The daily variation of A. chinense stomatal conductance could be described as M-type curve at fair-weather, but⌒-type curve at cloudy weather.The value of stomatal conductance increased with the increase of PAR or Ta, but decreased with the increase of VPD. The relationship between stomatal conductance(gs)and environmental factors could be expressed as:gs=PAR(2.01Ta2+147.74Ta-2321.11)/((444.62+PAR)(-38.04+VPD))..This model would be helpful to simulate the dynamical photosynthesis of leaf and canopy and to further simulate the NPP of ecosystems and the exchange of water and heat among the soil-plant-atmosphere continum.
    Distribution characteristics and seasonal dynamics of phosphorus and potassium in wetland ecosystem in the Sanjiang Plain
    YANG Yongxing, WANG Shiyan
    2001, (4):  522-526. 
    Asbtract ( 1168 )   PDF (794KB) ( 345 )  
    From May to October in 1997, the plant,soil and logging water in the wetlands were sampled monthly,and their P and K concentrations were measured.With the method of one-factor non-linear regression analysis,the seasonal dynamics of P and K in two types of wetland i.e.,in Carex lasiocarpa-Glyceria spiculosa wetland and in Deyeuxia angustifolia wetland were studied.The concentrations of P and K varied with different species of wetland plant and different organs of the same plant species.But their common property was that the concentration of K was higher than that of P,which shows that the mire-wetland plants had the property of enriching K element.The concentrations of P and K had an obvious seasonal dynamics in plant,soil and logging water,but the patterns were not the same.Some simulation models were obtained,which could be used to forecast the seasonal dynamics of P and K contents.
    Effect of forest patch size and isolation on reproductive success of Great Tit in fragmented secondary-forests
    DENG Wenhong, GAO Wei
    2001, (4):  527-531. 
    Asbtract ( 1234 )   PDF (739KB) ( 292 )  
    The effect of forest patch size and isolation on reproductive success of Great Tit(Parus major)in fragmented se-condary-forests was studied in Zuojia Natural Protection Area of Jilin Province by collecting data on breeding success,clutch-size,laying date,egg weight,brood-size and number fledged of Great Tit in 18 large(20～30hm2),medium(10～20hm2),and small(6～10hm2)patches,and two extensive forests(>100hm2).All the forest patches were GPS tested.The results showed that isolation had no effect on reproductive success of Great Tit,and Great Tit laid 7.2 days earlier in extensive forests than in all forest patches.Clutches in extensive forests and large forest patches were slightly larger than those in medium and small forest patches,and eggs were heavier in extensive forests than in the patches.Patch size had no effect on brood-size and number fledged.The lost rate of the nests was high in medium and small fo- rest patches because of intense competition.
    Articles
    Spatial pattern and temporal dynamics of Atylotus pallitarsis population in Songnen Plain
    JIN Wei, SHENG Lianxi, GAO Wei, ZHANG Dongmei
    2001, 12(4):  532-534. 
    Asbtract ( 1484 )   PDF (974KB) ( 448 )  
    The spatial pattern and its time series dynamics of Atylotus pallitarsis population were examined in this paper.The results showed that the amount of this population was closely related to temperature and humidity,and its blood peak time appeared at about 14∶00 o’clock in the afternoon.The population cattles was aggregated distribution and emigration thoroughout the day,the aggregated distribution pattern was loose mass community,the distribution of insects in the community was at random.
    Characteristics and distribution pattern of farmland patch in river valley in middle and low Taihang mountain area-A case study in Yanzhi river in Fuping county, Hebei Province
    WANG Cheng, WU Hong, XU Huacheng
    2001, (4):  535-540. 
    Asbtract ( 1210 )   PDF (1088KB) ( 235 )  
    Based on the investigations in the main valley of Yanzhi river in Fuping county of Hebei Province,the characteristics and distribution patterns were analyzed. The results indicated that farmland patches were distributed in the whole valley,except the headstream reach. With the increase of human disturbances, the proportion of farmlands increased along the river from upstream to downstream, while in natural landscapes, the environmental heterogeneity and fragmentation of farmlands decreased.The area of Yanzhi river valley totaled 2297.09hm2,mainly composed by farmland.There were 117 farmland patches mainly distributed along the riverbank in the valley, totalling 1027.78hm2 and occupying 44 74% of the valley,which were very well irrigated,but always endangeed by flood. The farmland patches were not symmetrically distributed along river, with 57.17% of farmland located on the left side of bank. The width of farmland patch presented an increasing trend, with a remarkable variation.The farmland patches were mainly strip-shape.
    Enrichment of organic matter and nitrogen in eroded bedloads
    ZHANG Xingchang, SHAO Mingan
    2001, (4):  541-544. 
    Asbtract ( 1230 )   PDF (561KB) ( 278 )  
    Under natural rainfall,the influences of rainfall,slope gradient,tillage and fertilization on the enrichment ratio(ER)of organic matter(OM)and total nitrogen(TN)in eroded bedloads and the relationship between the ER and the composition of eroded bedloads was analyzed.The results showed that the enrichment of clay(ERclay)resulted in the enrichment of OM and TN,and the average value of ERclay,EROM and ERTN under different slope gradients was 1.77,2.09 and 1.61,respectively.The soil erosion module was negatively correlated with EROM and ERTN.The measures for soil erosion may increase the EROM and ERTN affected by rainfall,slope gradient,tillage and fertilization.
    Articles
    Influence of rare earth elements on chemical transformation of nitrogen in agricultural soil
    LIU Dingfang, WANG Zijian
    2001, 12(4):  545-548. 
    Asbtract ( 1588 )   PDF (229KB) ( 494 )  
    Soil available N,NH4+-N and NO3--N contents and soil urease activity were measured after application of rave earth elements(REEs).The results showed that the contents of soil available N and NH4+-N were affected by application of REEs,being significantly differed from those in the control when the dosage was higher than 5mg·kg-1 dry soil.However,soil NO3--N content in treated plots did not differed from that in the control.No observed effect concentration(NOEC)for the potential influnence of REEs on the chemical transformation and availability of soil available nitrogen was found to be 5mg·kg-1 dry soil.The decrease of soil available N concentration was found closely correlated to the inhibition of soil urease activity(R 2=0.87).It was suggested that the inhibition effect of REEs on the enzymatic nitrogen mineralization should be one of the major causes for the decline of soil available nitrogen concentration.The decrease of available nitrogen concentration occured shortly after REEs application,indicating that there should be a self-regulation process to maintain the available nitrogen concentration in soil.
    Indexing system and its quantitative expression for soil quality evaluation in Hainan island
    ZHANG Xuelei, ZHANG Ganlin, GONG Zitong
    2001, (4):  549-552. 
    Asbtract ( 1222 )   PDF (868KB) ( 284 )  
    Based on the SOTER database and some FAO frameworks, a soil quality indexing system was established, and some evaluation results were presented for some selected GIS photo spot of tropical cropland in Hainan island. With connection to the spatial database, this system could perform the output of evaluation results. The performance and evaluation results were approved by the local expertise. It is suggested that the established models should be modified by the local practice.
    Effect of different tillage methods on rice growth and soil ecology
    LI Huaxing, LU Weisheng, LIU Yuanjin, ZHANG Xinming
    2001, (4):  553-556. 
    Asbtract ( 1396 )   PDF (997KB) ( 421 )  
    Field experiments were conducted in double-cropping rice field in South China during 1998～1999 to study the effect of different tillage methods on rice growth and soil ecology. The results showed that with rice scattering planting, no-tillage method caused a reduction of rice tillering, effective panicle, and filled grains of rice. Grain yield under no-tillage was 13.40% lower than that under conventional tillage,and the economic benefits decreased by 10.9%. Soil analysis showed that in no-tillage fields, soil bulk density and hardness were increased, soil porosity and available P and K were decreased,the amount of actinomyces and fungi was reduced,while that of soil bacteria was increased, and the enzyme activity was promoted. Minimum tillage and conventional tillage had similar soil physical and chemical properties, soil microbial quantity and enzyme activity. Minimum tillage could produce a 2.1% higher grain yield than conventional tillage, and increase the economic benefits by 11.0%.
    Effect of HCO3- on root growth and nutrient absorption of different rice genotypes
    XU Xiaoyan, YANG Xiaoe, YANG Yuai
    2001, (4):  557-560. 
    Asbtract ( 1226 )   PDF (224KB) ( 223 )  
    Solution culture experiments with Zn-inefficient cultivar(IR26)and the Zn-efficient cultivar(IR8192-31-2)were conducted to study the effect of HCO3- on the root growth and nutrient absorption of different rice cultivars.The results showed that HCO3- strongly inhibited the root growth of Zn-inefficient cultivar especially at low Zn concentration.In contrast,that of Zn-efficienct cultivar was slightly stimulated by HCO3- at low Zn concentration.HCO3- not only inhibited Zn absorption of Zn-inefficient cultivar,but also inhibited its absorption of Fe,Mn,Cu,implying that there was no specific inhibition of HCO3- on Zn absorption.These results demonstrated that the inhibition of root growth by HCO3- was likely to be the initial action of HCO3- in inducing Zn deficiency in lowland rice.With treatment of bicarbonate,Zn concentrations in upper and lower leaves of the Zn-efficient cultivar and their ratios were higher than those of the Zn-inefficient cultivar.The results showed that the Zn-efficient cultivar could transport more zinc from lower leaves to upper leaves,which might be one of mechanisms that the Zn-efficient cultivar adapted to zinc deficiency in calcareous soil.
    Growing degree-days requirements for plant and leaf development of summer maize(Zea mays)-An experimental and simulation study
    ZHANG Yinsuo, YU Zhenrong, P. M. Driessen
    2001, (4):  561-565. 
    Asbtract ( 1374 )   PDF (678KB) ( 347 )  
    A growing degree-day(GDD)calculation method was recommended by comparing several popular used GDD calculation equations. The GDD between different development stages, from emergence to each leaf appearance and during the lifetime of each leaf,were calculated for summer maize with the field treatments differed in cultivars, plant density, sowing dates, water and fertilizer supplying levels. Factors influencing the stability of GDD were discussed,and simulation equations to predict the leaf development were fitted based on the field observed data.
    Articles
    Changes of photosynthetic characteristics of strawberry leaf under shading
    CHI Wei, WANG Rongfu, ZHANG Chenglin
    2001, 12(4):  566-568. 
    Asbtract ( 1632 )   PDF (205KB) ( 545 )  
    Studies on the photosynthetic characteristics of two strawberry varieties(Baojiaozaosheng and Shuofeng)under shading showed that the photosynthesis rate decreased by 20% and 47%,when the apparent quantum efficiency increased by 13% and 8%,respectively.The chlorophyll content was enhanced slightly,while the insoluble protein content in leaf decreased drastically.The results also showed that the PSⅡ activity decreased by 22.5% and 53.7%,and the activity of Rubisco, the key enzyme of Calvin cycle, decreased by 19.6% and 35.5%,respectively. The reason of photosynthesis rate descent in light saturation point was also discussed.
    Effect of long-term single application of chemical fertilizer on soil properties and crop yield
    Lü Jialong, ZHANG Yiping, WANG Xudong, ZHAO Gaoxia, ZHANG Chunhui
    2001, 12(4):  569-572. 
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    A long-term located experiment showed that single application of chemical fertilizer basically sustained the quantity le- vel of soil organic matter,nitrogen and phosphrous,reduced the energy level of soil humus and inhanced its condensation degree,aromaticity and aging function.The corp yield was basically the same as that of combined application with organic manure.
    Influence of fertilization depth on root system senescence of upland wheat after anthesis
    SHI Yan, WEI Dongbin, YU Zhenwen, YU Songlie
    2001, (4):  573-575. 
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    A soil column study showed that fertilization in a depth of 20～40cm sustained the activities of superoxide dismatase(SOD)and catalase(CAT)in root system at a high level,meanwhile the root system vigor,the soluble protein content in root system decreased slowly, and the content of malondiadehyde(MDA)in wheat root system decreased,which delayed its senescence.It is considered that the depth(20～40cm)of fertilization could be used as an index for delaying senescence.
    Arthropod community structures in transgenic Bt cotton fields
    WEI Guoshu, CUI Long, ZHANG Xiaomei, LIU Shun, L? Nan, ZHANG Qingwen
    2001, (4):  576-580. 
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    Arthropod community structures were investigated in transgenic Bt cultivars, Bollgard ®(B)and Chinese cotton 30(CC30), and common cultivars, control(C)and no control(NC)cotton field in North China in 1998.The results showed that compared with common cultivars,the species richness and the number of total individual of arthropod community in transgenic Bt cultivars field were reduced 2.4～16.3% and 71.0～78.3% respectively, in which dominant species in phytophagous subcommunity varied. The number of individual of predatory and parastic subcommunity were all increased. The similarity coeficient between CC30 and NC was 0.8243, B and NC 0.7320, B and C 0.3380,C and NC 0.3128, CC30 and C 0.2665. The order of diversity and evenness value of these were CC30(2.3712 and 0 6428), NC(2.3654 and 0.6251), B(2.1364 and 0.5791),and C(1.0877 and 0.2949), their dominant value was 0.8726(C), 0.3528(B),0.1178(NC)and 0.1048(CC30)respectively. It was concluded that different integrated pest management(IPM)strategy should be implemented in transgenic Bt cotton instead of common variety cotton field.
    Effects of volatiles from different trophic level on foraging behavior of Aphidius avenae
    LIU Yong, HU Cui, NI Hanxiang, SUN Jingrui
    2001, (4):  581-584. 
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    The responses of female Aphidius avenae to volatiles from undamaged wheat plant,Sitobion avenae and Rhopalosiphum padi,aphids-plant complexes and aphids damaged plant were investigated in wind tunnel and Y-tube olfactometer.The volatiles from undamaged wheat plant, S. avenae and R. padi were much less attractive to A. avenae than those from aphids-plant complexes and aphids-damaged plant.Although the parasitic rate was much lower,the R. padi-plant complexes and R. padi damaged plant were also attractive to A. avenae. Identification of volatiles by GC-MS showed that the main volatiles induced by aphids feeding were 2-camphene, 6-methyl-5-hepten-2-one, 6-methyl-5-hepten-2-ol, Z-3-hexenyl-acetate,and methyl salicylate,among which, 6-methyl-5-hepten-2-one and 6-methyl-5-hepten-2-ol were more attractive to A. avenae, while methyl salicylate was not attractive.
    Influence of temperature and relative humidity on epizootiological features of Zoophthora anhuiensis in Myzus persicae colonies
    LI Huiping, FENG Mingguang
    2001, (4):  585-589. 
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    The colony of green peach aphid,Myzus persicae(Sulzer),which was initiated with 3 pathogen-free apterae and another 3 ones inoculated with the conidia of the entomophthoraceous fungus,Zoophthora anhuiensis(Li)Humber,was maintained on detached cabbage leaves at the regimes of 10～25℃ and 90～100% of relative humidity(RH),and allowed for free reproduction and fungal infection.Based on 26 day observations,it was showed that the development of Z.anhuiensis in the colony was rapid at 15 or 10℃,regardless of the humidity range concerned.The cumulative mortality of the aphids attributed to Z.anhuiensis infection was 72.9～98.2% at 10℃ on day 26,and 78.7～94.4% at 15℃ on day 24,indicating the occurrence of epizootic in the colony.At 20℃,a high-level epizootic occurred only at 100% RH,with a cumulative mortality of 71.6% on day 24,contrasting to a much lower mortality(5.1～12.8%)at the other three humidity regimes.However,the maximal mortality at 25℃ on day 20 was only 27.2% even at 100% RH.Obviously,Z.anhuiensis caused aphid epizootic more easily at lower temperature,and to less degree was affected by the humidity.The disease prevalence(represented by the cumulative mortality)was correlated well to temperature,its interaction with relative humidity,and the days from initiation(r2=0 82,α<0 01).
    Ecological engineering for eutrophication control in lake
    SUN Gang, SHENG Lianxi
    2001, (4):  590-592. 
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    An ecological engineering was conducted for eutrophication control in the Nanhu Lake of Changchun.In 1996,the removal of phosphorus by harvesting aquatic macrophytes and fishes was 149.6kg and 189.9kg,respectively,and the phosphorus fixed in molluscs was 153.4kg.The total output was 492.9kg,which amounted approximately to the annual phosphorus input of the lake.After ecological engineering,the water quality turned better,the TP concentration in lake water decreased,the phytoplankton density reduced,and the number of phytoplankton species increased.The roles of molluscs and fish in controlling lake eutrophication should be further studied.Ecological engineering is an ideal method to control the eutrophication of urban lakes.
    Effect of VAM fungi on phosphatase activity in maize rhizosphere
    SONG Yongchun, LI Xiaolin, FENG Gu
    2001, (4):  593-596. 
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    The effect of VAM fungi on phosphatase activity in maize rhizosphere was examined by pot culture experiment,in which,three-compartment-pots were used,the central compartment being separated from the outer two by a nylon net with 30μm mesh.Plants were harvested 70 days after planting.Soil acid and alkaline phosphatase were measured at different distances from root surface.The results showed that VAM increased the activities of soil acid and alkaline phosphatase in the rhizosphere.It was found that different phosphorous sources had different effects on phosphatase activity.
    Articles
    Diversity of Sinorhizobium fredii strains
    CHEN Mingzhou, XIE Fuli, ZHOU Junchu
    2001, 12(4):  597-600. 
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    Rhizobial strains were isolated from soils growing with soybean cultivar Heilong 33 and Willimas.Fifty Sinorhizobium fredii strains were chosen,and their biological characteristics including growth velocity,acid-alkali endurance,resistance of intrinsic antibiotics,utilization of carbon and nitrogen sources,absorption of congo red,ability of melanin production,and plasmid profiles were comparatively researched.The dendrogram was described using the method of cluster analysis,and the biodiversity of Sinorhizobium fredii from different soils was proved.
    Land degradation and landscape ecological construction in Liaoning Province
    LI Yuehui, ZHAO Yi, GUAN Dexin
    2001, 12(4):  601-604. 
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    The degradation degree,area and distribution of three types of degraded land caused by erosion,desertification and salinization were investigated in Liaoning Province by using landsat TM 1∶250000 and GIS Data.The area of eroded,desertificated and salinized land occupied 92.5%,3.39% and 2.22% of the total provincial land area,respectively.Therefore,the land in this province was classified into three degradation regions:contemporary erosion degradation,geological erosion degradation,and desertification and salinization degradation region.The characteristics and the cause of degradation for each region were also analyzed.According to the local situation and the theory of landscape ecology,some landscape construction and restoration models were proposed.
    Landscape dynamics of two-side lands-along main urban roads in southwestern Shanghai
    GAO Jun, SONG Yongchang
    2001, 12(4):  605-609. 
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    Based on the aerial photos of Shanghai in 1984,1989 and 1994,the landscape databank of southwestern Shanghai was set up.According to the analysis of the landscape dynamics of three two-side belts along the main urban roads in southwestern Shanghai,it was showed that there was a great difference in the landscape succession of these belts with various functions.The main urban roads trended to multi-serving function with the expansion of the city.The change from increase to decrease in the diversity and evenness of landscape and the decline in landscape fragmentation were the major symbols of the landscape dynamics.
    Effect of Shajiang black soil amended by coal fly ash on ecological factors and residue of heavy metal in wheat field
    MA Xinming, WANG Xiaochun, DING Jun, GAO Erming, YANG Qinghua
    2001, 12(4):  610-614. 
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    The effect of Shajiang black soil amended by coal fly ash on ecological factors in wheat field and residua of Cd,Cr,Pb,Hg and As were studied by pot experiment. The results showed that applying coal fly ash into Shajiang black soil could decrease soil density, soil proportion and clay content,but increase soil porosity,filtration coefficient and soil temperature.Moreover,it could promote water evaporating when soil moisture was high and keep soil water when lower than 10%. It also could facilitate activity of soil micro-organism and promote soil nutrient transforming.With(6～18)×104kg·hm-2 coal fly ash applied in Shajiang black soil,the accumulated quantity of Cd,Cr,Pb,Hg and As in soil and in wheat grain were lower than international standard index of pollution. Therefor, Shajiang black soil amended by coal fly ash was safe and reliable within the above range.
    A comparative study on the sensitivity and specificity of cholinesterase and glutathione s-transferase in Gammarus pulex L
    YIN Daqiang, JIN Hongjun, YU Hongxia, CHEN Liangyan
    2001, 12(4):  615-618. 
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    Studies on the influences of lindane,pirimiphos methyl,permethrin,zinc and dodecyl linear alkybenzene sulfonate(LAS)on the activity and toxicity of cholinesterase(ChE)and glutathione s-transferase(GST)in Gammarus pulex L. showed that only pirimiphos methyl caused a change in ChE activity in Gammarus,with a significant reduction in enzyme activity after24h and 48h exposure.Both lindane and permethrin caused a change in GST activity in Gammarus,with a significant increase in enzyme activity after 48h exposure.Lindane alos caused a significant increase in GST activity after24h exposure.Biomarkers ChE and GST were demonstrated a high degree of specificity and sensiti- vity in comparison to the lethality assay,but GST activity was less specific than ChE activity.
    Effect of organic acids on soil chemical behavior of lead and cadmium and their toxicity to plants
    LIN Qi, CHEN Yingxu, CHEN Huaiman,ZHENG Chunrong
    2001, 12(4):  619-622. 
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    The interaction between organic acids(citric and oxalic acids)and heavy metals was examined in this paper.Equilibrium dialysis showed that the extent organic acids bound metals depended on the metal involved,and their binding pro- perties affected the adserption of Pb and Cd by soil,which was increased in the presence of oxalic acid,and decreased in the presence of citric acid.The effect of citric acid on the behavior and toxicity of Pb and Cd to plants was also studied.The presence of citric acid could reduce the toxicity of Pb,and inhibit the uptake of Cd in shoots and roots.However,there was no significant effect on the apparent toxicity of Cd.The interaction between Pb and Cd was found to be complicated.The Pb content in rice was higher in the presence of Cd,while the content of Cd is lower in the presence of Pb.
    Relationships between soil-plant nutrition,quality of agricultural products and human and livestock health
    LIU Qin, ZHANG Xin, ZHAO Yanwen, HU Zhengyi, WANG Xiaochang, CAO Zhihong
    2001, 12(4):  623-626. 
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    The abundant and insufficient situation of essential elements such as calcium magnesium,sulphur,zinc and iron and beneficial elements such as selenium and iodine in soils was reviewed, and the influences of these elements and organic matter on the quality of agricultural products and human and livestock health were discussed.The trends of future research in the field of soil element science and plant nutrition,in particular,the quality of agricultural products were prospected.
    Assessment of ecosystem health - concept framework and indicator selection
    YUAN Xingzhong, LIU Hong, LU Jianjian
    2001, 12(4):  627-629. 
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    Based on the concept framework of ecosystem health,this paper discussed the suitable indicators to synthetically assess the ecosystem health in governed landscape.Healthy ecosystem means not only ecological health itself,but also the long-term maintenance of healthy human population and the beneficial promotion of social and economic development.Resilience,biodiversity and productivity are the characteristics of healthy ecosystem.The first step in the structure of indicators to assess ecosystem health should be the determination of precise indicator principles.According to the purpose of assessment and the principles of selecting indicator,the indicator system for assessing ecosystem health can be divided into three categories,namely,biophysical indicators,ecological indicators,and social and economic indicators.
    Gene dispersal risk of transgenic plants
    FAN Longjang, ZHOU Xueping, HU Bingmin, SHI Chunhai, WU Jianguo
    2001, 12(4):  630-632. 
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    Gene flow is a key problem and top topic in risk assessment and management of transgenic plants.Five major study a- reas of gene dispersal in transgenic plants were reviewed in this paper,which include gene flow from transgenic plant to its wild species,characteritics of gene flow based on pollen,methods of doing experiment and risk assessment for gene flow,safety standards of risk assessment of transgenic plants,and long-term ecological impact of gene flow in the future.Some areas needed to be studied further were also proposed.
    Allelopathy in sustainable development of agriculture
    YAN Fei, YANG Zhenming, HAN Limei
    2001, 12(4):  633-635. 
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    Allelopathy in agriculture was summarized. For sustainable development of agriculture,inhibitions and simulations of allelopathy as some new measures were put forward and suggested to apply resonablely and effectively, so as to improve some techniques about crop straws returnning into soil, cultivation measure, crop rotation and bio-control of weeds and insect pests.
    Degradation of phenanthrene and pyrene in contaminated soil by immobilized Zoogloeasp and Fusarium sp
    WANG Xin, LI Peijun, GONG Zongqiang, LI Bin, JU Jingli, HE Xiuliang, TAI Peidong
    2001, 12(4):  636-638. 
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    Immobilized with PVA,sodium alginate and activated carbon,both Zoogloea sp. and Fusarium sp.strains could degrade phenanthrene and pyrene efficiently.The optimal carrier was made of 100ρ·g-1 L PVA,5 sodium alginateρ·g-1 L and 50 activated carbon ρ·g-1 L.The degradation rates of phenanthrene and pyrene in 10 days were 87.48% and 75.34% by the immobilized bacterium,37.04% and 20.85% higher than those by the free bacterium,and the rates in 15 days were 84.36% and 74.87% by the immobilized fungus,5.35% and 11.23% higher than those by the free fungus.
    Effect of pH on nodulation of soybean rhizobia from Weifang and Huayuankou soils
    YANG Jiangke, ZHOU Qin, ZHOU Junchu
    2001, 12(4):  639-640. 
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    The effect of pH on the nodulation of Sinorhizobium fredii and Bradyrhizobium japonicum was examined by analy- zing the indigent soybean rhizobia,predominant indigent rhizobia,and specific rhizobia,respectively.The results showed that very acid and very alkaline environment could retard the nodulation and inhibit the growth of the rhizobia.Sinorhizohium fredii could endure environment more strongly than Bradyrhizobium japonicum,and had a high competitive nodulation capacity.Bradyhizobium japonicum could endure acid environment more strongly than Sinorhizobium fredii.In very acid and very alkaline environment,the nodulation capacity of S.fredii and B.japonicum was mainly determined by their physiological characteristics.