In recent years , taxonomic correlation between species richness of different taxonomic groups has been an active issue in biodiversity studies. However , there are cont radictory results. We collected species checklists from three geographic regions : zoogeographic regions , administ rative regions and nature reserves in China. We analyzed both correlation and ratio of avian and mammalian species richness in these regions. We also calculated the correlation and species ratios of bird and mammals in different latitudinal and longitudinal regions. Our result s showed that there were significant correlations ( p < 0.01) between the bird and mammal species richness in each of those regions. All avian and mammalian species richness correlation coefficients were higher than 0. 85 except that of nature reserves , 0. 818 , and that of the North China Region , 0. 768. Therefore , the high correlation between avian and mammalian species richness may have predictive values. There were no significant differences ( p > 0.20) among species ratios of birds and mammals except those of different zoogeographic regions ( p < 0.05) . The bird and mammal species ratio in China was lower in the central region but higher in the border regions with the highest value from northeast China. We also studied the difference in species richness and species ratios calculated with historically accumulated species checklists and modern species checklist . The correlation coefficient calculated with accumulated species checklists was less than that calculated with the modern species checklist , but the bird and mammal species ratio was higher than that calculated with modern data. Finally , we explored why the bird and mammal species richness are correlated. According to the species-area formula , S = CA^Z ,we deduced the correlation relationship of these taxonomic groups. When we analyzed all species richness data of bird and mammals , we found Z₁/ Z₂ = 0. 913 , thus , C₁/ C₂ approximates R_am . The study can be extended to other taxa. The species richness correlation provides us a means for rapid assessment of species diversity.

A survey of wild Chinese Alligator was conducted from July to August 1999 and from August to September 2000 by direct counting after dark (20 z00pm) using headlamps or a 12v portable spotlight. At each site visited , the authors mapped the ponds using laser rangefinder and compass , characterized the physical nature of the ponds and vegetation , and conducted interviews with local residents. The location of all sites was recorded using a hand2held GPS. There are 26 sites in 5 counties that were surveyed where wild Chinese Alligators still exist in Anhui province , including 13 designated conservation sites of the National Chinese Alligator Reserve. The current wild alligator populations mainly exist in the best type of habitat , which totals 17.4 ha with estimated populations of 50.7 % in 1999 and 40.0 % in 2000. This can be compared with the other two types of habitat , which total 22. 0 ha and 19. 0 ha , with their estimated population numbers of 24.0 % in 1999 and 30.9 % in 2000 , and 25.3 % in 1999 and 29.1 % in 2000 respectively. The average ecological densities of the alligators in the two years were 1.3 ind. / ha and 1.8 ind. / ha , with an estimated population of 145 individuals. However , the population has been evidently divided into 18 isolated small local populations with different numbers of individuals. We suggest that habitat should be restored and captive-reared alligators should be reint roduced into the area to rebuild a viable population.

The faunal composition of butterflies in different habitat types in the Qilian area of Qinghai Province , northwest China , was surveyed f rom 1997 to 1999. Five habitat types were classified based on altitude , climate , soil and vegetation differences : hilly cultivated land , mountain steppe , forest steppe , alpine shrub meadow and bare rock. Of the total collection of 4 ,367 specimens , 53 species of 35 genera in six families were identified. Species richness , species composition similarity (J accard index) and species diversity index ( Shannon-Wiener index , H′) were calculated for the five habitat types. The species richness increased in the following sequence : bare rock (6 spp. ) , mountain steppe (13 spp. ) , forest steppe (14 spp. ) , alpine shrub meadow (22 spp. ) and hilly cultivated land (23 spp. ) . In cont rast , the species diversity increased in a different sequence : bare rock ( H′= 1.4629) , forest steppe ( H′= 2.2398) , mountain steppe ( H′= 2.2676) , hilly cultivated land ( H′= 2.7071) and alpine shrub meadow ( H′= 2.7734) . The butterfly species composition between forest steppe and hilly cultivated land had the highest similarity (J accard index = 0.3704) , with the second highest similarity between mountain steppe and alpine shrub meadow (J accard index = 0.2500) , and the lowest similarity between bare rock and other habitat types.

A study on community st ructure of zooplankton , including density diversity and biomass di2 versity , was carried out f rom J an. to Dec. of 1999 in Lake Qiandaohu , Zhejiang. The diversity index of rotifers was the highest observed. The result s show that the higher the t rophic level of the lake , the higher the density diversity index of rotifers in definite t rophic level range (f rom oligot rophic to mesot rophic) . Regression analysis among the two zooplankton diversity indices and community factor under variations in time and space demonst rate the following relationships : Monthly variation 　density diversity = - 0. 922 + 4. 521density evenness 　n = 12 , r = 0. 872 , p < 0. 001 biomass diversity = 1. 99 - 0. 348 Daphnia hyalina biomass 　n = 12 , r = - 0. 868 , p < 0. 01 Horizontal variation 　density diversity = 2. 35 + 0. 008 species number 　n = 10 , r = 0. 672 , p < 0. 05 biomass diversity = 2. 88 - 1. 739 biomass dominance 　n = 10 , r = - 0. 826 , p < 0. 01

An investigation on weed species biodiversity and host plants of vesicular arbuscular mycorrhiza fungi (VAMF) within weed communities in new developed f ruit gardens was conducted. Phosphorus content in various weed rhizospheric soils was analysed. There were 96 species belonging to 27 families in the weed community ,among which 39 species were tested to identify VAMF colonies. It was found that all the species tested were colonized by VAMF , but the percentage of colonization and the colonizing intensity were very different among the families and species. Correlation analyses showed that no significant correlation exists between phosphorus content in rhizospheric soil and VAMF colonization. VAMF colonization mainly depends on the characteristics of host plants and the selection of VAMF. This suggests that conservation of weed diversity in upland ecosystems will be favorable for conserving VAMF activities and diversity.

Partial nucleotide sequences (120 bp) of the 16S rRNA gene (rDNA) containing V22 variable region were compared in 357 strains of Streptomyces . Most of the Streptomyces strains fell into one large cluster-group. By sharing the same 16S rDNA sequences or very high similarity , they were clustered into five major , three middle and eight minor clusters , and 19 strains recovered as single member clusters. The result demonst rated that the phenotypic clusters , which contains st rains that are different in terms of morphologic characteristics , such as spore color and spore surface , is very heterogeneous from a molecular systematic stand point .

Genetic differentiation of 11 populations in Ranunculus ternatus Thunb. from Central China was detected by means of PAGE. Eight enzymes encoded by seventeen loci were assessed. Genetic diversity within populations was relatively low. The proportion of polymorphic loci ( P) ranged from 0 to 41. 2 % , the average number of alleles per locus ( A ) from 1 to 1. 647 , the mean expected and observed heterozygosity ( He , Ho) per locus were from 0 to 0. 108 and 0 to 0. 102 respectively. The genetic identities between populations were remarkably high ( I = 0. 9754～0. 9991) . According to the results of cluster analysis based on Nei′sgenetic distances , three populations dist ributed in the southern part of Henan Province were far from the populations in Wuhan , Hubei Province. In Wuhan , very high similarity appeared among populations situated north of the Yangtze River (Changjiang) , and among those on the area south of the river. Analysis based on the spatial distance measured by GPS indicated a relationship between genetic distances and geographical factors. The authors deduced that the genetic differentiation of populations was enhanced by the isolating effect of the Yangtze River. A population from Wuhan was found to be remarkably different from the others in both morphological characters and genetic st ructures. But this population was not suggested as a new species or a new variety because no unusual allele was found in the enzyme loci detected.

Thirty trees of Malus xiaojinensis randomly sampled from three natural populations in two distribution areas (about 50 kilometers apart) , i. e. Dengcun of Mopo and Lianghe townships , Xiaojin County , Sichuan Province , and thirty corresponding seedlings were analyzed using random amplified polymorphic DNA (RAPD) techniques. Based on statistical analysis of the 81 RAPD bands produced by 15 decamer primers in polymerase chain reactions (PCR) with all of the DNA samples studied , the number of polymorphic RAPD bands among all the individuals and different populations were counted. The genetic relationship among all the individual trees and between different populations were analyzed using Nei and Li (1979) genetic distance and neighbor-joining methods in the TREECON software package. Genetic variance analysis was carried out using the AMOVA method in Arlequin Ver. 2. 000 software package. From 15 random decamers , 81 polymorphic bands were produced in all the DNA samples studied , average 3. 8 bands per primer. The average polymorphic RAPD bands of both three existing populations and their corresponding descendent seedling populations were about 1. 5 per primer. Among them , the highest average polymorphic RAPD bands per population is 2. 5 and the lowest is 0. 7. The genetic relationship trees constructed by the TREECON computer program for all the individuals and different populations show that there is genetic differentiation among the populations of M. xiaojinensis . The AMOVA analysis indicates that the seedling population variances composed a large part of the species genetic variation of M. xiaojinensis .

The resource , the population ecology , structure and characters of seeds , pollination biology and the relationship between plumpness of seeds and environment were investigated in the rare plant Changium smyrnioides . The genetic diversity and genetic structure of the species were analysed by morphological characters of seeds , starch gel elect rophoresis and RAPD analysis. The studies revealed lack of coordination between the ripening of the seeds and the season of East China , which resulted in low ratio of seed germination and low rate of population renewal. As human activity has dest royed and disturbed suitable habitat for the species , the range of each population has decreased and the habitat has become f ragmented which has decreased gene flow between populations ( N_m < 1. 0) . The low gene flow suggests that genetic drift may play a prominent role in shaping the present-day genetic composition. Based on these result s , some management st rategies are proposed for protecting this species effectively.

Undergrowth of plants in a Chinese fir plantation in different growth stages and site indices has been quantitatively analysed by using β-diversity index formulas. The results showed that the values of β-diversity index of undergrowth plant in different growth stages and site indices are obviously different , in which the difference between 56-year-old and 32-year-old forestsis greatest , and the closer to 56-year-old in growth stages , the smaller in β-diversity index values , in each Chinese fir community , the difference of β-diversity index values of undergrowth plant between 14 and 18 site indices is also great .

The categorization of different habitat types was done with principal component analysis and dynamical clustering based on parameters of the habitat . In addition , the quantitative characteristics of tree organization in Chinese fir and broad-leaved forests in different habitat types were analyzed. The results showed that : the characteristics of main parameters of habitat were distinctly different in different habitat and the dominant species and relative importance values were also different . The total number of species , species diversity , and community evenness of tree organization were different . The influence of altitude on the total number of species and on their ecological dominance was highly significant . Slope-exposure influenced the number of unit more significantly in certain degree. Altitude and slope-exposure had no influence on the ecological dominance of trees in different habitats. The protection of diversity in Chinese fir and broad-leaved mixed forest in different habitats should be emphasized.

Since lake eut rophication was first taken into consideration , scientists had managed to simulate the appearance of lake eut rophication , predict the response of lakes to different management through mathematical models , thereby determining the propermeans for management . In general , three developing phases of models of lake eut rophication have been arisen : (1) Single limited factor models , such as the phosphorus model. (2) Models of multiple limited factors , such as models for predicting the primary production of phytoplankton. (3) Eco2dynamic models , which are the main developing t rend of lake models at present and for the future. With improvement of understanding of lake ecosystems and the development of computers , the coupled ecological and hydrodynamic model , the object-oriented model and the neural network model show promise.

It was found in radar observations and marine samples that the phenomena of accompanying migration by natural enemies (including aeronautic spiders) with their hosts was significant and spectacular. The phenomena shows that the interaction between different trophic levels of natural enemy-insect and pest-plant is undoubtedly of important ecological and behavioral significance. The great difference of natural enemy catches in aerial samples between different areas in the tropics and the temperate zone reflect s the different backgrounds of biodiversity. The long-term monitoring of bio-flux in the low-level atmosphere would provide reliable information on biodiversity.

In this review , we discuss two applications of mtDNA analysis in zoological conservation biology. One is to describe and manage genetic diversity , an issue more relevant to long2term planning for conservation. Another is its use as a tool for the short-term demographic management of populations. We emphasize its use in recognizing Evolutionary Significant Units ( ESUs) and Management Units (MUs) . ESUs are recognized to partition genetic diversity and assess conservation value and can be identified as populations having significant phylogenetic divergence of mtDNA from other populations , with corroborating divergence of allele frequencies at nuclear loci. MUs are defined as demographically independent breeding units and are identified as populations having distinctive allele frequencies , regardless of phylogenetic structure and the level of genetic divergence. ESUs and MUs are both important units in conservation biology. The use of mtDNA should be in concert with analysis of nuclear loci in order to obtain reliable data for conservation.

Exotic weeds have caused serious harm to crop production , orchards , lawns , natural environment and biodiversity in China. This is closely related to certain characteristics of the exotic weeds and to lack of environmental resistance. To manage exotic weeds , measures should be taken in two aspects : one is prevention of int roduction of exotic weeds , and the other is control of existing ones. In the former aspect , measures that should be taken include : 1) reinforcing plant quarantine ; 2) establishing a risk assessment system for int roduction of exotic plants , and 3) encouraging the utilization of native plant s. In the latter aspect , the following comprehensive measures should be taken : 1) cont rolling ecological dest ruction ; 2) conducting biological cont rol of exotic weeds ; 3) using economic plants as habitat displacement cont rol agent s , and 4) conducting utilization of exotic weeds.

The core projects of the International Biodiversity Observation Year ( IBOY) are int roduced in the present paper. These project s address the following questions : 1) What biodiversity do we have and where is it ? 2) How is biodiversity changing ? 3) What goods and services does biodiversity provide ? 4) How can we conserve biodiversity ?Based on the int roductions , the authors put forward some suggestions for development of biodiversity science in China.