Table of Content

15 October 2005, Volume 16 Issue 10

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Population dynamics of endangered plant species Abies chensiensis

ZHANG Wenhui, XU Xiaobo, ZHOU Jianyun, XIE Zongqiang

2005, 16(10):  1799-1804. 

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In order to know the endangered status and causes of Abies chensiensis in Qinlin Mountains,a field investigation on 18 plots was conducted on its age structure,life table and fecundity,and its population dynamics were predicted by time sequence model.The analysis on the age structure of Abies chensiensis populations showed that there were fewer young individuals,but middle-aged and old individuals were relatively rich.The population D in Abies chensiensis-Indigofera amblyantha-Carex lanceolata association showed a relatively stable development tendency,while other four populations (A,B,C and E) in Abies chensiensis-Pinus tabulaeformis-Sinarundinaria nitida-Carex lanceolata association,Abies chensiensis-Quercus aliena var.acutserrata-Litsea pungens-Carex lanceolata association,Abies chensiensis-Betula albo-sinensis-Sinarundinaria nitida-Duchesnea indica association,and Abies chensiensis-Pinus tabulaeformis-Smilax stans-Carex lanceolata association all showed an obviously declining tendency.The analysis on the life tables and survival curves showed that the survival curve of Abies chensiensis populations belonged to Deevey Ⅲ,and the death peak of different populations was in the period of 60～100 years old.The number difference among populations reflected the population habitat.Time sequence prediction indicated the numbers of old individuals would be increased at the beginning,and decreased finally in 20,40,and 80 years.It was difficult to maintain the population stability.Analysis on 10 ecological factors showed that tree coverage,soil organisms and air humidity influenced population positively,and human disturbance and sunlight influenced population negatively.In situ conservation should be taken as the most important management countermeasure,and natural regeneration should be promoted.At the same time,artificial population should be expanded.

Application of GIS and integrated mathematic models on estimating forest land wood productiveness and solar energy use efficiency

XING Shihe, LIN Dexi, SHEN Jinquan, CAO Rongbin

2005, 16(10):  1805-1811. 

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Based on the meteorological elements observation and mountain soil survey in Fujian Province,this paper approached the application of geographic information system (GIS) and integrated mathematic models on estimating the grid wood productiveness and solar energy use efficiency(SEUE) of regional forest land.The results showed that there was a significant quadratic correlation of annual mean temperature,precipitation and total solar radiation energy(TSRE) with longitude,latitude and altitude, and their multiple correlation coefficients ranged from 0.692 to 0.981.The regional annual mean TSRE,temperature and precipitation could be well estimated by GIS and integrated models of quadratic tendency curve,and linear,quadratic and quartic inverse distance weighted interpolation.These annual means estimated by the models did not differ greatly from observed data,and the t test values were 1.29,0.12 and 0.06,respectively.The grid wood productiveness and SEUE of regional forest land in Fujian could also be well estimated with the aid of GIS and integrated models, which ranged from 2.32 m³穐m^-2穣r^-1 to 18.61 m³穐m^-2穣r^-1 and from 0.11% to 0.91%, respectively.

Energy characteristics of Casuarina equisetifolia ecosystem on coastal sand in Dongshan County,Fujian Province

YE Gongfu, ZHANG Qinghai, LU Changyi, LIN Yiming, WU Xilin

2005, 16(10):  1812-1816. 

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The study on the energy characteristics of Casurina equisetifolia community on red earth eolian sandy soil and homogeneous eolian sandy soil in Dongshan County of Fujian Province showed that the standing biomass and energy of Casurina equisetifolia community were 15 681.84 g·m^-2 and 317 795.31 kJ·m^-2 on red earth eolian sandy soil,and 5 129.87 g·m^-2 and 10 575.50 kJ·m^-2 on homogeneous eolian sandy soil,respectively.On homogeneous eolian sandy soil,the gross caloric value of the community ranged from 19.98 kJ·g^-1 to 21.39 kJ·g^-1,of which,dead branch was the highest while root was the lowest,and its percentage was 46.93%(truck)>16.44%(root)>13.92% (branch)> 12.28%(dead branch)>5.87%(bark)>3.90%(leaf)> 0.66%(fruit).The return amount of litter was 2 061.77 kJ·m^-2·yr^-1,and the net energy productivity was 12662.82 kJ·m^-2·yr^-1.On red earth eolian sandy soil,the gross caloric value was 19.84～21.70 kJ·g^-1,among which,leaf was the highest while root was the lowest,and its percentage was 38.09%(truck)>19.48%(branch)>17.09%(root)>16.86%(leaf)>6.83%(bark)>0.88%(dead branch)>0.77%(fruit).The returned amount of litter was 9 070.47 kJ·m^-2·yr^-1,and the net energy productivity was 31 298.70 kJ·m^-2·yr^-1.The standing biomass and energy of Casurina equisetifolia community were higher on red earth eolian sandy soil than on homogeneous eolian sandy soil, mainly because red earth eolian sandy soil had a thinner sandy layer(<20cm) and a stronger nutrient and water supplying ability.

Biomass and carbon storage of ground bryophytes under six types of young coniferous forest plantations

BAO Weikai, LEI Bo, LENG Li

2005, 16(10):  1817-1821. 

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This paper studied the biomass and carbon storage of the ground bryophytes under young Picea balfouriana (P),Pinus tabulaeformis (Y),Pinus armandii (H),Larix kaempferi (L),Picea balfouriana-Pinus tabulaeformis (P-Y),and Pinus tabulaeformis-Pinus armandii (Y-H) forest plantations in the upper reach of Minjiang River,Sichuan Province.The results showed that total biomass and carbon storage of ground bryophytes were relatively low,being 3.11～460.36 kg·hm^-2 and 1.12±0.03～168.95±0.92 kg·hm^-2,respectively.On plot level,only the bryophyte biomass between forest P and others,and the carbon storage between forest L and others were significantly different.The ground bryophyte had the highest biomass and carbon storage under forest P,while the lowest ones under forest H.Comprehensive analysis suggested that forest type and its structural feature might be the important factors determining the biomass and carbon storage of ground bryophytes,and thinning was an important measure to improve ground bryophyte growth and biomass production.

Chemical components of volatiles from withered black poplar leaves with different physiological age

GUO Xianru, YUAN Guohui, JIANG Jinwei, LUO Meihao, MA Jisheng

2005, 16(10):  1822-1825. 

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By the methods of steam distillation and GC-MS,this paper analyzed the chemical components of the volatiles from withered black poplar leaves.The main components of the volatiles from young leaves were(Z)-3-hexenol(44.81%),4-methyl-1-pentanol(21.85%)and 2-hydroxy-benzaldehyde(15.19%),those from matured leaves were(Z)-3-hexenol(28.71%)and 2-hydroxy-benzaldehyde(10.35%),while in the volatiles from senescent leaves,the main components were 2-hydroxy-benzaldehyde(28.81%)and benzyl alcohol(15.06%).The(Z)-3-hexenol content in the volatiles was evidently decreased with increasing leaf age,while the species and contents of aromatic compounds were in adverse.

Allelopathy and chemical constituents of Ligularia virgaurea volatile

MA Ruijun, WANG Mingli, ZHU Xuetai, LU Xianwen, SUN Kun

2005, 16(10):  1826-1829. 

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Ligularia virgaurea is a noxious weed widely distributed on the psychro-grasslands of east Qinghai-Tibet Plateau of China,but the allelopathic effects of its volatile is less known.In this study,the allelopathy of L.virgaurea volatile to 5 kinds of grasses was examined,and its chemical constituents were analyzed by GC-MS.The results demonstrated that the volatile of growing L.virgaurea could inhibit the seed germination speed and germination rate of all tested grasses.The inhibitory effects on Elymus nutans and Bromus magnus were significant,while Poa annua and Festuca ovin were not very sensitive.18 major constituents were identified from the essential oil of L.virgaurea,accounted for 68.24% of the total.The main chemical components were 2-methyl-heptane (9.84%), 3-methyl-heptane(8.25%), heptane(7.93%),4-methyl-1-(methylethyl)-bicyclo[3,1,0]hex-2-ene(7.79%),3-methyl-hexane (6.38%),2-methyl-hexane(5.54%),and D-limonene(4.70%).Monoterpenoids accounted for 16.58%of the total,indicating that volatilization was one of the ways by which L.virgaurea released allelochemicals.The allelopathy of the volatile may play an important role in enhancing the competitive ability of the species,and be one of reasons of grassland degeneration.

Characteristic study on village landscape patterns in Sichuan Basin hilly region based on high resolution IKONOS remote sensing

LI Shoucheng, LIU Wenquan, CHENG Xu, Erle C.Ellis

2005, 16(10):  1830-1837. 

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To realize the landscape programming of agro-ecosystem management,landscape-stratification can provide us the best understanding of landscape ecosystem at very detailed scales.For this purpose,the village landscapes in densely populated Jintang and Jianyang Counties of Sichuan Basin hilly region were mapped from high resolution (1 m) IKONOS satellite imagery by using a standardized 4 level ecological landscape classification and mapping system in a regionally-representative sample of five 500?500 m² landscape quadrats (sample plots).Based on these maps,the spatial patterns were analyzed by landscape indicators,which demonstrated a large variety of landscape types or ecotopes across the village landscape of this region,with diversity indexes ranging from 1.08 to 2.26 at different levels of the landscape classification system.The richness indices ranged from 42.2% to 58.6%,except that for the landcover at 85%.About 12.5% of the ecotopes were distributed in the same way in each landscape sample,and the remaining 87.5% were distributed differently. The landscape fragmentation indices varied from 2.93 to 4.27 across sample plots,and from 2.86 to 5.63 across classification levels.The population density and the road and hamlet areas had strong linear correlations with some landscape indicators,and especially,the correlation coefficients of hamlet areas with fractal indexes and fragmental dimensions were 0.957^* and 0.991^**,respectively.The differences in most landscape pattern indices across sample plots and landscape classes were statistically significant,indicating that cross-scale mapping and classification of village landscapes could provide more detailed information on landscape patterns than those from a single level of classification.

Heat island effect and human body comfortable degree in Zhengzhou city

ZHENG Jinggang, ZHANG Jingguang, LI You

2005, 16(10):  1838-1842. 

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In this paper,the key factors of heat island effect in Zhengzhou city were monitored by grid method to study the diurnal and seasonal changes and the spatial distribution of the effect,and to evaluate the comfortable degree of human bodies at different sites of the city.The results showed that on the whole,the heat island effect had a unimodal diurnal change,while its intensity was distinctly different among seasons,being decreased in order of winter>spring>autumn>summer.The spatial distribution of heat island center was significantly related to its nearby industrial heat resources.As for the comfortable degree of human bodies,the People's Park was the best site because of its arbor virescence,while in the Xiliu Lake Park with lawn as its main greening type,its capability of improving microclimate was weaker.The railway station square still had 16% frequency of most comfortable degree,because of its open space and better air fluidity.

Assessment indicators of soil quality in hilly Loess Plateau

XU Mingxiang, LIU Guobin, ZHAO Yunge

2005, 16(10):  1843-1848. 

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By the methods of sensitivity analysis,main component analysis and discriminant analysis,this paper screened the sensitive indicators from 32 soil attributes to assess the productivity and erosion-resistance ability of the soils in hilly Loess Plateau.The results showed that soil available phosphorus content,anti-scouring ability,infiltration coefficient,labile organic carbon content,organic matter content and urease activity were the most sensitive indicators for soil quality assessment and the main targets for soil quality management and improvement,while soil biological indicators were with high and medium sensitivity.Five soil quality factors were summed up from 29 soil chemical,physical and biological attributes,i.e.,organic matter,texture,phosphorus,porosity and microstructure.Except the factor porosity,the other four factors were significantly different between different land use types.Eight indicators including soil organic matter content,infiltration coefficient,anti-scouring ability,CEC,invertase activity,mean weight diameter (MWD) of aggregates,available phosphorus,and MWD of micro-aggregate were identified as the assessment indicators of the soil quality in hilly Loess Plateau,with the organic matter content,infiltration coefficient and anti-scouring ability as the key indicators.

Effects of land use type on soil nutrient distribution in northern agro-pasture ecotone

LIU Quanyou, TONG Yiping

2005, 16(10):  1849-1852. 

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Soil samples under five land use types were collected from Duolun County in the northern agro-pasture ecotone.Chemical analysis showed that soil nutrient content was the lowest in farmland,medium in grassland,and the highest in woodland,indicating that reclamation accelerated the decomposition of soil organic matter and the further loss of soil nutrients.To investigate the effects of land use type on soil organic matter,available phosphors,available nitrogen and total nitrogen,soils from four different land use types in the catchments with slopes steeper than 15? were sampled and analyzed.Vertically,the content of soil nutrients from slope bottom to its top was two times higher in land use type cropland-grassland-woodland than in grassland-woodland-cropland.Such a difference indicated the positive effects of the former land use type on soil nutrient retention.Therefore,selecting this optimal land use type in studied area could improve local eco-environment and economic benefits.

Water cycling characteristics of grassland and bare land soils on Loess Plateau

CHEN Hongsong, SHAO Mingan, WANG Kelin

2005, 16(10):  1853-1857. 

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The study under natural and simulated rainfall conditions showed that the variance coefficient of soil water in the grassland and bare land on Loess Plateau decreased with increasing soil depth,and the vertical change of soil water in drought year in the profile could be divided into four layers.In rainy year,the variance coefficient of soil water decreased first,increased later,and decreased lastly with the increase of soil depth,due to the continual rainfall infiltration and intensive evapotranspiration.The variance coefficient at surface soil layer was obviously smaller in rainy year than in drought year.Compared with that in bare land,the soil water cycling in grassland was deeper in depth and greater in intensity,as well as higher in evapotranspiration.The temporal change of soil water mostly depended on rainfall and evapotranspiration,especially in surface soil layer,and the change of soil water lagged behind gradually from low to deep layers in the profile.Soil water storage had a seasonal change,and could be divided into three main periods,i.e.,decreasing in spring,alternatively decreasing and increasing in summer and autumn,and relatively stable in winter.In drought year,soil water storage decreased,and infiltrated rainfall was all consumed by intensive evapotranspiration.In rainy year,soil water storage increased,but most infiltrated rainfall (more than 80%) was consumed by intensive evapotranspiration.

Research on mineralization process of organic phosphorus in black soil in Northeast China

ZHAO Shaohua, YU Wantai, ZHANG Lu, SHEN Shanmin

2005, 16(10):  1858-1861. 

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Buried bag and incubation experiments were conducted to study mineralization process of organic phosphorus in black soil in Northeast China under different time sequences.The results showed that both the content and mineralized velocity of organic P decreased gradually as time went on,the cumulative mineralized rate increased step by step,whether it was used by the method of incubation or buried bag.Under incubation,two treatments'mineralized velocity reached the maximum at first month (31.67,38.75 mg穔g^-1穖onth^-1,respectively),and their cumulative mineralized rate and mineralized velocity at six months were 7.94%,13.26 mg穔g^-1穖onth^-1 and 9.24%,17.99 mg穔g^-1穖onth^-1,respectively.Under buried bag,the mineralized velocity of five treatments all reached the maximum at first year (55.67,55.65,49.60,19.71,22.52 mg穔g^-1穖onth^-1,respectively),and the cumulative mineralized rate and mineralized velocity of maize root and wheat root treatments at three years both were approximately 50% and 35 mg穔g^-1穖onth^-1,which were higher than those under soybean root and grass root treatments.From two methods of studies on the mineralization process of organic P,it could be seen that the original content of organic P influenced its mineralized rate and mineralized velocity:the higher of the original content of organic P,the higher of its mineralized rate and mineralized velocity.

In vitro fermentation characteristics of crop straws and their combined utilization

ZHOU Chuanshe, TANG Shaoxun, JIANG Hailin, TAN Zhiliang

2005, 16(10):  1862-1867. 

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By the technique of in vitro gas production,this paper studied the in vitro fermentation characteristics of different kinds of crop straws and their combined utilization.The results showed that the theoretical maximum gas production and the gas production rate of silage corn were increased by 19.1% and 8.2 %,respectively,compared to corn stalk.These two indices of mixed crop straws were higher than those of single crop straw,and significant positive interactions in gas production were observed after 48 h of incubation.It was concluded that a combined utilization of silage corn with different kinds of crop straws could be an efficient way to improve the nutritional characteristics.The optimum ratio of the mixture was 25/75 or 50/50 when silage corn mixed with wheat or rice straw.

Nutrient use efficiency and yield-increasing effect of single basal application of rice-specific controlled release fertilizer

CHEN Jiansheng, XU Peizhi, TANG Shuanhu, ZHANG Fabao, XIE Chunsheng

2005, 16(10):  1868-1871. 

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A series of pot and field experiments and field demonstrations showed that in comparing with the commonly used specific-fertilizers containing same amounts of nutrients,single basal application of rice-specific controlled release fertilizer could increase the use efficiency of N and P by 12.2%～22.7% and 7.0%～35.0%,respectively in pot experiment,and the use efficiency of N by 17.1% in field experiment.In 167 field demonstrations successively conducted for 3 years in various rice production areas of Guangdong Province,single basal application of the fertilizer saved the application rate of N and P by 22.1% and 21.8%,respectively,and increased the yield by 8.2%,compared with normal split fertilization.

Soil C,N and P contents and their relationships with soil physical properties in wetlands of Dongting Lake floodplain

PENG Peiqin, ZHANG Wenju, TONG Chengli, QIU Shaojun, ZHANG Wenchao

2005, 16(10):  1872-1878. 

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Eight representative soil profiles were installed on three types of wetland (two profiles on Carex spp.-dominated floodplain,four on Phragmites-dominated floodplain,and two on paddy soil) in Dongting Lake floodplain of China in 2004,and their C,N and P contents,microbial biomass C,N and P,<0.001 mm clay particles,and bulk density were measured.The results indicated the spatial distribution of soil C and N and soil microbial biomass C,N,and P were very similar in the profiles (0～100 cm) of three types of wetland,being decreased gradually with depth,except for soil TP which was constant in the profiles.The percentages of soil microbial biomass C,N and P to soil organic C,total nitrogen and total phosphorus decreased gradually with depth.In top layer (0～10 cm),the contents of soil organic C and microbial biomass C and the percentage of soil microbial biomass C to organic C were 19.63～50.20 g·kg^-1,424.63～1 597.36 mg·kg^-1,and 3.17%～4.82%,respectively,the contents of soil total N and microbial biomass N and the percentage of soil microbial biomass N to total N were 1.85～4.45 g·kg^-1,57.90～259.47 mg·kg^-1,and 3.13%～6.42%,respectively,and the content of soil microbial biomass P and the percentage of soil microbial biomass P to soil total P was 24.16～200.99 mg·kg^-1 and 1.09%～11.20%,respectively.The bulk density of soil top layer (0～10 cm) was 0.65～1.04 g·cm^-3,and the content of <0.001 mm clay particles was 26.24%～39.48%.The contents of soil organic C and N and microbial biomass N and P in 0～10 cm layer were the highest in Carex spp.-dominated floodplain,followed by paddy soil,and Phragmites-dominated floodplain.Also in 0～10 cm layer,the soil microbial biomass C in Carex spp.-dominated floodplain and paddy soil was higher than that in Phragmites-dominated floodplain,while the soil bulk density in Phragmites-dominated floodplain was higher than that in paddy soil,and much higher than that in Carex spp.-dominated floodplain.The amount of soil <0.001 mm clay particles in Carex spp.-dominated floodplain and Phragmites-dominated floodplain was higher than that in paddy soil.In these three types of wetland,soil organic C and N and microbial biomass C,N and P had a significant logarithm correlation (P<0.01) with <0.001 mm clay particles,and a significant index correlation (P<0.01) with bulk density.

Effects of tillage method and herbicide on cornfield weed community

LIU Fangming, LIANG Wenju, WEN Dazhong

2005, 16(10):  1879-1882. 

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By the method of community ecology,this paper surveyed the weed community in a cornfield at the Shenyang Experimental Station of Ecology,CAS,and studied the effects of tillage method and herbicide on the weed composition,species diversity,and biomass at the experimental site.The results showed that the dominant weed species in the cornfield were Eriochloa villosa,Abutilon theophrasti,Bidens frondosa and Commelina communis,of which,Eriochloa villosa had the highest important value.In non-tillage field without herbicide application,the weed community had larger biomass,higher richness(S) and concentration(C),but lower species diversity(D) and species evenness(J).Herbicide could decrease weed species and inhibit biomass growth significantly in non-tillage field.It was clear that tillage method and herbicide could affect the weed composition,diversity and stability significantly.

Effects of nitrogen supply on flag leaf photosynthesis and grain starch accumulation of wheat from its anthesis to maturity under drought or waterlogging

FAN Xuemei, JIANG Dong, DAI Tingbo, JING Qi, CAO Weixing

2005, 16(10):  1883-1888. 

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In this paper,a cement pool culture experiment with three water treatments (waterlogging,drought,and moderate water supply) and two nitrogen levels (120 and 240 kg穐m^-2) was conducted to study the effects of nitrogen supply on the flag leaf photosynthesis and grain starch accumulation of two wheat varieties from anthesis to maturity under soil drought and waterlogging.In comparing with moderate water supply,soil drought and waterlogging reduced the photosynthesis rate (Pn) and SPAD of flag leaf and dry matter accumulation.Nitrogen supply under drought increased Pn and SPAD,while that under waterlogging was in adverse.The total soluble sugar content in grain was reduced under both drought and waterlogging,while that in leaf was decreased under waterlogging but increased under drought.Under waterlogging,increasing nitrogen application rate reduced starch accumulation.The unit grain weight and the yields of grain and starch were reduced under both drought and waterlogging,but nitrogen application favored them under drought while in adverse under waterlogging.It was indicated that both leaf photosynthesis and grain starch accumulation could be regulated by nitrogen supply under stress of soil drought or waterlogging from anthesis to maturity of wheat.

Genetic relationships among four Bactrocera cucurbitae geographic populations in Yunnan Province

ZHU Zhenhua, YE Hui, ZHANG Zhiying

2005, 16(10):  1889-1892. 

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In this study,the partial section of mitochondrial cytochrome b in 23 individuals of four Bactrocera cucurbitae geographic populations(Banna,Ruili,Yuanjiang,and Hekou)in Yunnan Province was sequenced,and the phylogenetic trees of all haplotypes were constructed by means of N-J method,using B.dorsalis,B.correct and B.tau as the out-group species.Of the 426 bp mitochondrial cytochrome b DNA sequences obtained,A%+T% was about 65.0%,four nucleotide sites were substituted,and no base composition of the sequences was inserted and lost.Five haplotypes were identified in all the sequences,with four showing polymorphism,and one shared.The genetic characters of the four populations were analyzed by Fst value and gene flow through Mega software.The Fst value was 0.16667～0.20000(P>0.05),and the Nm value was 2.00～2.50.The N-J tree suggested that four haplotypes constructed three clades.All results showed that the genetic differences presented among the four populations,but with low degrees.The main reason causing the genetic differences among the four populations was supposed to be related to genetic isolation and ecological adaptation.

Arthropod community structure and its fuzzy clustering analysis in jujube orchard

BI Shoudong, LIU Li, GAO Caiqiu, ZOU Yunding, CAO Chuanwang, DING Chengcheng, LI Changgen, MENG Qinglei

2005, 16(10):  1893-1897. 

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Based on the principles of community ecology and by the method of fuzzy clustering,this paper studied the temporal and quantitative dynamics of the arthropod community and sub-community in jujube orchard(Feidong 2003),aimed to utilize natural enemy resources for pest control.There were 52 species of arthropod belonging to 47 families in the orchard.Arachnida and Cecidomyidae had a higher relative abundance than other families being 0.3465 and 0.2309,respectively.The individuals of the arthropod community were the highest on 8 June and 21 September.The total community and pests-neutral insect sub-community could be clustered into 4 clusters,respectively.For total community,the clusters (T=0.92) were those on 22 March,6 April,22 November,and on other dates,and for pests-neutral insect sub-community,they (T=0.94) were those on 22 March,6 April,8 June,and on other dates.The natural enemy sub-community could be clustered into 3 clusters (T=0.94),i.e.,those on 22 March,on 6 April,and on other dates.The results of cluster analysis partly reflected the seasonal differences of total community and sub-community,while the temporal overlaps of cluster results reflected the complexity of community structure.

Effects of earthworm activity on phosphorus fraction and available phosphorus content in red soil

LIU Dehui, HU Feng, HU Pei, CHENG Jiemin

2005, 16(10):  1898-1902. 

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By the methods of incubation test and Hedley's phosphorus fractionation,this paper studied the effects of inoculating earthworm(Pheretima pingi) on the phosphorus fractions and available phosphorus contents in red soil.The results showed that during a 100-day incubation,earthworm inoculation combined with organic materials(rice straw RS,peanut residue PR,and rape residue RR) amendment increased significantly the content of soil available phosphorus.Statistics analysis showed that there was a significant difference in soil available phosphorus content between treatments PR or RR with and without earthworm inoculation.Compared with the contents of anion-exchange resin P(trace),NaCO₃-soluble P(14.5 mg·kg^-1) and microbial P(1.0 mg·kg^-1) in CK,those in treatments of earthworm inoculation plus organic materials amendment increased to 10.5～17.8 mg·kg^-1,23.5～35.6 mg·kg^-1,and 6.8～9.7 mg·kg^-1,respectively,organic phosphorus content enhanced from³7.9 mg·kg^-1 to 50.7～59.3 mg·kg^-1,whereas residual P was reduced.Earthworm performed an activated effect on the availability of phosphorus in red soil.

Effects of returning maize straw into field on dynamic change of soil microbial biomass C,N and P under different promoted decay condition

ZHANG Dianxue, HAN Zhiqing, LI Dongpo, LIU Wei, GAO Shuguo, HOU Dongjun, CHANG Liansheng

2005, 16(10):  1903-1908. 

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A 2-year field experiment of wheat-maize rotation was conducted on a cinnamon soil of east Hebei Province to study the effects of returning maize straw into field on the dynamics of soil microbial biomass C,N and P,and their relationships with soil nutrients and enzyme activities.The results showed that under the condition of returning maize straw combined with applying chemical fertilizer to adjust straw C/N,the application of effective microorganisms could increase soil microbial biomass C,N and P in each crop growth period,advance their peak time,and better regulate soil nutrient supply,compared with no application of effective microorganisms.Soil microbial biomass had a significantly positive correlation with soil enzyme activities,but its correlation with soil hydrolysable N and available P was strongly affected by crop growth and fertilization system.

Ecological effects of multifunctional micro-flora agent in environment

ZHANG Xin, ZHANG Bingxin, ZHAO Yuhua, YANG Li, YANG Chinghong, YU Jingquan

2005, 16(10):  1909-1912. 

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In this paper,strains ZJY-1(Brevibacillus brevis)and ZJY-116(Bacillus subtilis)with evident inhibitory effect on Fusarium oxysporum f.sp.cucumerinum and with promotion effect on plant growth were screened from cucumber rhizosphere,and the feasibility of exerting the ecological effects of multifunctional micro-flora agent was studied by treating cucumber seeds with the two strains singly or mixed with chlorpyrifos-degrading strain DSP3(Alcaligenes faecali).The results showed that the two strains could keep their functions in suppressing disease and promoting plant growth when mixed with DSP3,and the chlorpyrifos-degrading effect of DSP3 had no significant difference when DSP3 was applied singly or mixed with the two strains.This study testified the feasibility of applying multifunctional micro-flora agent in the environment.

Phosphorus removal efficiency of Yaonigou constructed wetland on Fuxian lakeshore

CHEN Yuangao, WU Xianhua, LI Wenchao, KONG Zhiming

2005, 16(10):  1913-1917. 

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To mitigate and control the eutrophication of the waters in Fuxian Lake bay,1 hm² Yaonigou constructed wetland was built on the north Fuxian lakeshore,and the P removal of the wastewater from Yaonigou River was investigated by the techniques of precipitation pond,oxidation pond,and subsurface-and surface flow constructed wetland.The results demonstrated that this constructed wetland had a very strong capacity (7.8%～81.1%) of total phosphorus (TP) removal.The average removal rate of TP was 54.9%,and the TP retention in the constructed wetland was 265mg·m^-2·d^-1,of which,plant assimilation was 26.1mg·m^-2·d^-1,about 10% of the total.The TP removal was mainly through adsorption and sedimentation,but the seasonal growth dynamics of main plant Oenanthe javanica could have a definite effect on the efficiency of TP removal.During the examination,the TP retention capacity was in order of subsurface flow constructed wetland>oxidation pond>precipitation pond>surface flow constructed wetland.

Corresponding analysis on rice grain heavy metal pollution in Fujian Province

KE Qingming, LIANG Kangjing, ZHENG Luduan, ZHU Yan, FANG Hui, LIANG Yiyuan, GUO Yuchun, LIN Wenxiong

2005, 16(10):  1918-1923. 

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By the methods of environmental statistics and corresponding analysis,this paper collected 38 early and late rice grain samples from the middle,southern,northern,western and eastern parts of Fujian Province to detect their Hg,As,Cr,Cd and Pb contents,and to search for the main factors resulting in the difference of rice cropping type in different regions,aiming at further understanding the relationships between heavy metal pollution and rice cropping type.The results showed that among the test heavy metals in grain,Pb had the highest percentage(100%) beyond the standard level,followed by Hg (78.95%),Cd (50.5%) and Cu (2.63%),while As did not surpass the standard level.It therefore could be concluded that Pb and Cd were the main factors resulting in the difference of rice cropping type in different regions.The results also showed that 38 rice grain samples could be clustered into 7 groups,indicating that different rice cropping types would significantly cause different degrees of heavy metal pollution,which suggested that the best way in controlling and preventing rice grain heavy metal pollution could be the approach of combining site-controlling with variety selection,based on the situation of different regions and rice cropping systems.

Cd,Cu,Zn and Pb contents and forms in soils and rapeseeds around Wuhu Plant

WANG Xingming, LIU Dengyi, TU Junfang, LI Zheng, WANG Youbao

2005, 16(10):  1924-1931. 

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The study showed that around Wuhu Plant,soil Cd,Zn and Pb mainly existed in Fe-Mn oxide form,and Cu in residual form,with the percentage of 31.81%,39.83%,53.79%,and 46.24%,respectively.Soil exchangeable Cd and Pb had a higher proportion (23.47% and 16.32%) than soil exchangeable Cu and Zn (3.14% and 0.54%).The correlations between soil heavy metals and their forms,as well as their transformation to available form were different.Different heavy metals had different accumulation trends in rapeseed and its hull.Cu easily accumulated in hull,while Cd,Zn and Pb had a higher accumulation in seed.The accumulation rate of heavy metals in rapeseed and hull was also different,being the highest for Cd.There was a significantly negative correlation (P<0.05) between the accumulation rate of heavy metals and their contents in soil.In rapeseed,Cd,Cu and Pb were mainly in sodium hydroxide form,with the percentage of 32.50%,22.94% and 34.69%,respectively,while Zn was mainly in EDTA form,with a percentage of 45.97.The existed forms of heavy metals in rapeseed probably affected their toxicity,but the toxicity to human food could not be inferred from this research,and needed to be studied further.There was a weak relation between heavy metals contents and their existed forms in rapeseed.

Enrichment characteristics of heavy metals in heron eggs

ZHOU Lizhi, LI Jinhua, YIN Huabao, CHANG Wei, WANG Xiang, LIU Qi, XU Siqi, GUI Xueqin, YAN Ruiwen

2005, 16(10):  1932-1937. 

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In this study,the eggs and tissues of black-crowned night heron,little egret,Chinese pond heron and cattle egret were sampled from the Dashu,Yuantong and Taizi mountains in Hefei areas of Anhui Province in April to June 2004,and the residual amounts of Cd,Pb and Cr in the samples were determined by atomic absorption spectrophotometry.The results showed that the test heavy metals could be detected at high levels in the eggshell,egg contents,and tissues of most samples.Eggshell and bone were the two main sites for heavy metals enrichment.Eggshell had significantly higher residues of the heavy metals than egg contents,implying that heavy metals could be excreted by eggshells.The residues of heavy metals in eggshell ranked as Cr>Pb>Cd,and had significant differences among species.Of the three heavy metals,Cr showed the most variation among species,being the highest in eggshell of Chinese pond heron and the lowest in that of cattle egret,but in egg contents,there was no significant difference among species.The variation of Cr residues among species was the second,being the highest in the egg contents of Chinese pond heron but not detected in that of cattle egret.The residues of Pb among species varied little.Since eggshell was easy to collect,it was practical to use it as the indicator to assess the pollution status of wetlands.

Effects of overlying water properties on sorption of organic pollutants in sediments

CHEN Hualin, CHEN Yingxu, XU Yuntai, SHEN Mengwei

2005, 16(10):  1938-1942. 

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By the method of orthogonal experiment,this paper studied the effects of overlying water temperature,pH,ion- ic strength,and dissolved organic carbon (DOC) on the sorption of phenanthrene and pentachlorophenol (PCP) in sediments.The results showed that temperature was the main factor affecting the sorption behavior of phenanthrene,with the trend of partition coefficient (Kd) decreased with temperature.For PCP,its Kd was the smallest at 20 ℃,and its sorption was decreased with pH.The DOC content of overlying water slightly decreased the Kd of phenanthrene and PCP,and ionic strength only increased the Kd of PCP slightly.The sorption capacity of organic pollutants in sediment was mainly determined by the properties of organic pollutants and sediments.

Effects of stress duration and non-toxic ions on heavy metals toxicity to Arabidopsis seed germination and seedling growth

LI Weiqiang, MAO Renzhao, LIU Xiaojing

2005, 16(10):  1943-1947. 

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The study on the toxicity of heavy metals Hg²⁺,Cd²⁺,Cu²⁺ and Pb²⁺ to Arabidopsis seed germination and seedling growth showed that the test heavy metals had a stronger toxicity on seedling growth than on seed germination.The toxicity on seedlings was in order of Cu²⁺>Hg²⁺>Cd²⁺/Pb²⁺,while on seeds was Hg²⁺>Cd²⁺>Pb²⁺/Cu²⁺.Seed germination rate was decreased with increasing stress duration,and different heavy metals showed different toxicity at different stress duration.For example,Hg²⁺ displayed a stronger toxicity at 12～24 h stress,while Cd²⁺ was at 0～12 h stress.It seemed that seed coat played an important role in seed tolerance to heavy metals.The interaction between non-toxic ions and heavy metal ions on seed germination showed that Ca²⁺,Mg²⁺,K⁺ and Na⁺ at 5 mmol·L^-1could enhance the toxicity of Hg²⁺,but did not affect Cd²⁺ toxicity.For seedling growth,Ca²⁺,Mg²⁺,K⁺ and Na⁺ might enhance the toxicity of Hg²⁺,Ca²⁺ might alleviate the toxicity of Cd²⁺ but enhance the toxicity of Cu²⁺,and K⁺ might alleviate Pb²⁺ toxicity.The mechanism of heavy metals injury was discussed in the paper.

Distribution of nekton stock density and its community structure in Taiwan Strait in Summer and Autumn

LIN Longshan, ZHENG Yuanjia, MA Chunyan

2005, 16(10):  1948-1951. 

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This research was conducted based on the bottom trawl surveys in Summer and Autumn.An analysis on the stock density and community structure of nekton in Taiwan Straits indicated that the average stock density was 8.50 kg穐^-1 in Summer and 6.94 kg穐^-1 in Autumn.The species number was 80 in Summer and 91 in Autumn,and the abundance,species diversity index,and evenness index were all higher in Autumn than in Summer.The average species diversity index was 2.0466 in Summer and 2.3964 in Autumn.The dominant species whose index of relatively importance (IRI) was >200 were hairtail (Trichiurus japonicus),lanternbelly (Acropoma japonicum),red bigeye (Priacanthus macracanthus),large-scale lizardfish (Saurida undosquamis) and common Chinese squid (Loligo chinensis) in Summer,and hairtail (Trichiurus japonicus),skinnycheek lanternfish (Benthosema pterotum),wart perch (Psenopsis anomala),squid (Loligo chinensis),white-tipped mackerel scad (Decapterus maruaelsi) and deep pugnose ponyfish (Secuter ruconius) in Autumn.As a whole,the aggregated intensity of dominant species in Summer was higher than that in Autumn.

Microecological distribution of toxin-producing bacteria in Fugu rubripes in Bohai Sea and biological characteristics of B3B

FAN Yanhui, HU Jiangchun, MA Chengxin, XUE Delin, LIU Li, LI Yanmao, WANG Shujin, ZHANG Rongqing

2005, 16(10):  1952-1955. 

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The study showed that toxin-producing bacteria were commonly existed in each part of Fugu rubripes body.19 strains of high poisonous bacteria were isolated from its ovary,liver and other tissues,among which,strain B3B was identified as genus Bacillus based on its physiological and biochemical characteristics and 16SrDNA sequence,and could produce tetrodotoxin through mouse test,thinner chromatography,and mass spectrography.

A comparative study on feeding intensity of two rotifer Brachionus calyciflorus strains

GE Yali, XI Yilong, CHEN Fang

2005, 16(10):  1956-1961. 

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The study on the feeding intensity and its relationships with food concentration,food quality and cultural duration of Guangzhou and Wuhu Brachionus calyciflorus strains showed that the filtration and ingestion rates of the rotifers decreased with their increasing cultural duration.Within 20 hours,there was a curvilinear relationship between the filtration rate of both the two strains and food concentration,but a linear relationship between the ingestion rate and food concentration.The filtration rate of Guangzhou and Wuhu strains was 0.0029?0.0001 ml穒nd.^-1穐^-1and 0.0039?0.0008 ml穒nd.^-1穐^-1,respectively,when fed on Chlorella pyrenoidosa,which were higher than fed on the other two types of food.The ingestion rate of Guangzhou strain fed on Chlorella pyrenoidosa (0.3992?10⁴?0.00850?10⁴ cell穒nd.^-1穐^-1) was higher than that fed on Scenedesmus obliquus (0.1670?10⁴?0.0370?10⁴ cell穒nd.^-1穐^-1),but each of them was similar with that on mixed algae.The ingestion rate of Wuhu strain was not significantly affected by food type.The filtration and ingestion rates between the two strains differed with food concentration,food type and culture duration.

Effects of heavy metal ions on SOD activity of Litopenaeus vannamei hepatopancreas,gill and blood

WU Zhongwang, PAN Luqing, ZHANG Hongxia

2005, 16(10):  1962-1966. 

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This paper studied the effects of Cu²⁺,Zn²⁺and Cd²⁺on the superoxide dismutase (SOD) activity of Litopenaeus vannamei hepatopancreas,gill and blood.The results showed that the SOD activity changed significantly with prolonged exposure of these ions (P<0.05).The SOD activity of all test objectives changed with a single peak under the exposure of 0.1～1 mg Cu²⁺·L^-1,that of hepatopancreas and of hepatopancreas and gills was inhibited obviously under 10 mg Zn²⁺·L^-1 and 0.5 mg Cd²⁺·L^-1,respectively,while 0.25 mg Cd²⁺·L^-1 had no significant effect on that of gill.The SOD activity of hepatopancreas,gill and blood all increased first and then decreased under the prolonged exposure of <10 mg Zn²⁺·L^-1and <0.25 mg Cd²⁺·L^-1.There was an obvious dose-time response relationship between test metal ions and SOD activity.The SOD activity was decreased in order of hepatopancreas>gill>blood,while the toxicity of test metal ions was in order of Cd²⁺>Cu²⁺>Zn²⁺.

Toxicity effects of pentachlorophenol on Brachydanio rerio

ZHENG Min, ZHU Lin

2005, 16(10):  1967-1971. 

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With embryo development technique,this paper determined the toxicity of pentachlorophenol (PCP) to Brachydanio rerio embryos.The results showed that the special effect duration of PCP on embryos was within 6 hours after embryos incubation.PCP could markedly inhibit the development of Brachydanio rerio embryos,and cause its malformation and even death.There were different toxicity endpoints which could be observed in embryos exposed to PCP with different time.The lethal effect sensitivity of embryos incubated after 48 hours was getting lower when the exposure time was getting shorter,the LC₅₀ being the minimum (70.8 μg·L^-1) for 0 hpf embryos,and the maximum (831.8 μg·L^-1) for 24 hpf embryos.The acute toxicological endpoint of Brachydanio rerio embryos was in order of edema,no blood-circulation and heartbeat>incubation rate>stopping growth,and the most sensitive endpoints of Brachydanio rerio embryos to pentachlorophenol were no blood-circulation and half lethal concentration at 48 hrs.

Regulation effects of tourmaline on seawater pH value

XIA Meisheng, ZHANG Hongmei, HU Caihong, XU Zirong

2005, 16(10):  1972-1975. 

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In this paper,chemical analysis,X-ray diffraction and atomic force microscopy were employed to examine the characteristics of tourmaline produced in east Inner Mongolia Autonomous Region,and batch experiments were conducted to study its regulation effects on seawater pH value.The factors affecting the regulation,such as the dosage of tourmaline and the salinity and initial pH value of seawater,were also studied.The results showed that tourmaline could regulate the seawater pH value from its initial 3 and 10 to 7.1 and 8.9,respectively,and the regulation effect was greater in the seawater with lower salinity,e.g.,after 120 minutes treatment,the initial pH value (5.0) of the seawater with a salinity of 5,10,15,20 and 35 was increased by 3.24,3.16,3.06,2.99 and 2.85 unit,respectively.Tourmaline had little effect on seawater conductivity.This study would provide an experimental base for the application of tourmaline in aquaculture.

Research advances in ecosystem flux

ZHANG Xudong, PENG Zhenhua, QI Lianghua, ZHOU Jinxing

2005, 16(10):  1976-1982. 

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To develop the long-term localized observation and investigation on ecosystem flux is of great importance.On the basis of generalizing the concepts and connotations of ecosystem flux,this paper introduced the construction and development histories of Global Flux Networks,Regional Flux Networks (Ameri-Flux,Euro-Flux and Asia-Flux)and China-Flux,as well as the main methodologies,including micrometeorological methods (such as eddy correlation method,mass balance method,energy balance method and air dynamic method)and chamber methods (static and dynamic chamber methods),and their basic operation principles.The research achievements,approaches and advances of CO₂,N₂O,CH₄,and heat fluxes in forest ecosystem,farmland ecosystem,grassland ecosystem and water ecosystem were also summarized.In accordance with the realities and necessities of ecosystem flux research in China,some suggestions and prospects were put forward.

Biological effects of rare earth elements and their action mechanisms

HE Yuejun, XUE Li

2005, 16(10):  1983-1989. 

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This paper reviewed the effects of rare earth elements on plant root development,biomass,quality,and resistance against stress.Applying appropriate amount of rare earth elements could not only promote seed germination and root development,increase plant biomass,but also improve harvest quality and plant resistance against stress.The plant uptake characteristics of rare earth elements,as well as their contents,distribution,existing forms,and cyto-localization in plants were discussed,with the focus on the effects of rare earth elements on photosynthesis and chlorophyll formation,nutrient uptake,relationships between rare earth elements and calcium,and action mechanisms of rare earth elements on cell membrane and enzymes.Rare earth elements could enhance chlorophyll content and improve photosynthetic rate,and thus,could increase plant biomass.When an appropriate amount of rare earth elements was applied,the uptake of nutrients by plant and their transformation and utilization were promoted.Rare earth elements could replace calcium ion to participate in enzymatic reactions,maintain the osmosis and stability of cell membrane,promote the protection function of cell membrane,and enhance the plant resistance capability against stress.In the end,further researches on rare earth elements were suggested.

Advances in research on in situ chemo-immobilization of heavy metals in contaminated soils

GUO Guanlin, ZHOU Qixing, LI Xiuying

2005, 16(10):  1990-1996. 

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In situ immobilization of heavy metals is a main method for decreasing the mobility and bioavailability of heavy metal ions through their immobilization by adding various amendments.Due to its easy operation and rapid efficiency,this method is becoming non-replaceable,especially for the remediation of non-point polluted arable soils.Natural materials and industrial by-products with high capacity of entrapping and fastening heavy metals,e.g.,phosphorite,peat,lime,and organic fertilizers,can be obtained and employed,and the immobilization efficiency of these amendments as well as the environmental risk of the ionic leaching,releasing,and biological toxicity of heavy metals could be evaluated in laboratory and field.In this paper,the resources and types of the amendments were classified,and the possible immobilization mechanisms for the remediation of heavy metals- contaminated soils were discussed.The assessment methods of this remediation in laboratory and field were formulized,its limitation was analyzed,and further development directions were put forward.

Application of chemical ecology in controlling marine fouling organisms

FANG Fang, YAN Tao, LIU Qing

2005, 16(10):  1997-2002. 

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Many marine organisms can produce secondary metabolites beneficial to the protection of marine environments against fouling,and thus,applying chemo-ecological methods to extract the natural antifoulants from marine organisms to resolve the problems relevant to marine fouling is a new thinking in resent years.Its aim is to search for high efficient and non-toxic antifoulants to replace the existing chemically synthetic ones which are unfortunately found to have widespread toxic effects on marine environment.Although we know few about the antifouling mechanisms of secondary metabolites,many natural products have been proved to have antifouling activity.Therefore,basic and applied researches on the ecological roles of these natural compounds,their action mechanisms,coating compatibility,controlled release,and field test are required in the future.

General principles of urban ecological land classification and planning

DENG Xiaowen, SUN Yichao, HAN Shijie

2005, 16(10):  2003-2006. 

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Urban ecological land planning is a difficult and urgent task in city layout.This paper presented the definition of urban ecological land,and according the definition,divided the urban ecological land into two groups,i.e.,ecological land for service,and ecological land for functioning.Based on the principles of city layout,some measures to plan these two urban ecological land groups were proposed.