Gene introgression usually results from spontaneous hybridization occurring among closely related species in sympatric populations and thus has great impact on the genetic structure of natural populations. This phenomenon has recently become one of the most active subjects in study of evolutionary and conservation biology. In the present study, eight chloroplast microsatellite (cpSSR) primers were used to examine genetic diversity, population genetic structure and hybridization introgression among seven Actinidia species with overlapping distributions in transitional regions ranging from the western China plateau to the middle-eastern China hilly mountains. The results showed: (1) A total of 42 haplotypes designated by 18 alleles at six polymorphic loci were detected across 655 individuals of the ten sympatric populations sampled. Although a reticulate evolutionary relationship was revealed among cpSSR haplotypes, there existed a strong species-specific tendency. (2) The intra-specific genetic diversity was generally high but varied greatly among different species. A. fulvicoma var. lanata showed the highest genetic diversity (P = 62.50%, h_T = 0.173, H_T = 0.897) whereas A. deliciosa exhibited the lowest (P = 37.5％, h_T = 0.041, H_T = 0.516). (3) High level of inter-population genetic differentiation (G_ST and F_ST varied from 0.319 to 0.780 and 0.40 to 0.695, respectively) and limited gene flow (N_m ranged from 0.219 to 0.747<1) were detected among the different species, of which A. deliciosa showed the highest inter-population genetic differentiation (G_ST = 0.780, F_ST = 695). (4) No significant difference was found between Gst (unordered alleles) and Nst (ordered alleles), sug-gesting a lack of phylogeographical structure for most Actinidia species. This is consistent with the Mantel test which revealed no significant relationship between genetic distance and geographical distance. (5) Inter-estingly, a relatively high level of inter-specific genetic differentiation was detected among species in sym-patric populations (F_ST ranged from 0.476 to 0.990), except for two populations (HW and GZ) of the A. chinensis/A. deliciosa complex. The result was also well in accordance with UPGMA analysis, which re-vealed that the populations tended to cluster together into the same species. Further analysis indicated that the A. chinensis/A. deliciosa complex was probably highly influenced by both shared ancestral chloroplast polymorphism and recent hybridization introgression. However, hybridization introgression rarely occurred between less related species, suggesting homoplasy events may have also played an important role in shaping phylogenetic relationships in the genus. The results have important implications for understanding population genetics and evolutionary patterns in the genus Actinidia and provide baseline data for formulating conserva-tion and management strategies.

The phytoplankton community in the southern waters of Hainan Island was characterized based on four cruise surveys carried out in 1998 and 1999. A total of 290 species (including 23 varieties and 5 forms) were identified by microscope, and species composition, richness and community structure were analyzed using statistical and clustering methods. The results showed that phytoplankton species were abundant in the study area, and were mainly composed of diatoms and dinoflagellates. The species composition showed a significant spatio-temporal variation. In general, the dominant species were characterized by warm water and halophilous or euryhalinous affinities. In the cool seasons, Navicula subminuscula, a eurythermal species, was the major dominant species, while warm water species in-creased rapidly with increasing air temperature. Phytoplankton richness showed no remarkable seasonal variations, and diatoms were the most abundant group throughout the year. However, the richness of dinoflagellate and blue-green algae increased significantly in warm seasons. The center of phytoplank-ton richness occurred in the western waters around the mouth of the Beibu Bay in April and September, and then shifted to the middle-eastern waters in December and January. A clustering diagram indicated that the phytoplankton community had no obvious block distribution. The diversity index of the phyto-plankton community was relatively low in December, at which time the community was unstable in middle-southern waters. In conclusion, this phytoplankton community comprised a unique tropical open sea biota, showing significant seasonal variation, and influenced by hydrologic features.

Integrating research on phytoplankton of the Taiwan Strait by scholars from the Chinese mainland and Taiwan, we proposed a list of 620 phytoplankton species. We also identified their ecological groups and distinguished red tide species. Furthermore, based on 344 samples collected from the Taiwan Strait in four seasons from May 1984 to February 1985, we analyzed the distribution pattern of species and the spa-tio-temporal variation of species abundance. Of the 299 species identified in this survey, 199 species be-longed to Bacillariophyta, whose abundance accounted for 99.25% of the total. The maximum species num-ber and abundance of phytoplankton both occurred in August, while the minimum appeared in February. Compared with coastal waters, strait waters had more phytoplankton species but lower abundance. The rela-tionships between the distribution of phytoplankton and environmental factors are also discussed.

Vegetation restoration is one of the important methods of land reclamation in the field of mining. In order to study the interspecific associations of plants and soil factors affecting the stability of plant communities in the process of vegetation restoration, we surveyed plant communities as well as their habitats in Antaibao Mine, Shanxi. The communities and habitat were investigated at three different scales: 10 m×10 m quadrats for trees, 4 m×4 m for shrubs, and 1 m×1 m for grasses and herbs. Continuity corrected χ2 test, and Spearman rank correlation were employed to analyze the association among the common species in different plant communities, and grey incidence recognition was used to identify soil factors that affected community stability. The results showed that, dominated by xerophytes, this grassland community was poor in species richness. In this community, some species were associated, while others were independent. In the thicket community, which was also dominated by xerophytes, there was a positive association of overall species. The occurrence of some mesophytes as well as the positive association with the dominant species indicated that the community was in positive succession. In the forest community, there was also a positive association among overall species, indicating the community was in a relatively steady stage in recovering succession. The influence of soil factors ranked in the following order: soil organic matter > N > P> K> Cu> Mn > pH > Zn>EC. In conclusion, compared with shrubs and grasslands, the present forest community is better adapted to the special habitats in Antaibao Mine, and soil organic matter content is a key factor determining the stability of plant communities.

We surveyed the macrofauna diversity at five sampling stations of the Jiaozhou Bay during seven cruises from Sept. 2003 to Sept. 2004. The species diversity was studied based on quantitative investigations of species composition, biomass and secondary production. The results showed the following: stations D and S, located at Dagu River estuary and central channel respectively, had the lowest diversity indices. Diversity indices differed significantly between the stations inside and oustide the aquicultural area. The number of species (S) and Margalef’s richness index (D) demonstrated distinct seasonal variations: they were lower in spring and autumn and higher in winter and summer. Among all the environmental factors examined, only Shannon-Wiener diversity index (H′) and Margalef’s richness index had negative correlations with macro-faunal secondary production. Both the results of diversity indices and abundance/biomass curves indicated that the macrobenthic community in aquicultural areas was disturbed to a certain degree.

In order to inquire into the basic rules of the species richness and fauna of fleas along latitudinal gradient and the main ecological factors affecting their distribution, 153 flea species, belonging to 45 genera and 9 families, were collected in mountainous areas at northern latitudes from 21° to 28° in the Hengduan Mountains of western Yunnan, China. All the data were analyzed synthetically with statistics. The results showed that: (1) The richness of flea families, genera, species, endemic species, ratios of endemic species and species of different faunal realms increased first and then decreased with increasing latitude, peaking at 25° to 27°N. The unimodal pattern may be the result of an edge effect between two faunal regions. (2) The horizontal patterns of Oriental and Palaearctic elements were significantly different. A gradually decreasing tendency appeared in Oriental elements with increasing latitude, whereas there was an increasing tendency in Palaearctic. The transitional zone of the two realms ranged from 23º to 29º N and formed an overlap zone and divergence center at 25º to 27ºN. (3) Three main ecological types were identified in the Hengduan Mountains based on cluster analysis. The results reflected the influence of latitude, climate and vegetation on species distribution and community compositions, and also the concordance of flea species distribution and latitu-dinal gradient. (4) The horizontal distribution of β diversity showed two peaks, indicating the transition and transformation of flea species composition and distribution along different gradients, and thus was associated with climate and environmental change. (5) The horizontal patterns of species richness and fauna were simi-lar to the vertical pattern in the Hengduan Mountains. (6) The zones from 25º to 27ºN were the center of dif-ferentiation and overlap of the two realms. Because of the edge effect and complex landscape, the families, genera, species and endemic species of fleas here all showed high diversity, suggesting that this may be the core areas for diversity conservation, distribution and differentiation in China. We conclude that the main factors affecting flea diversity in the Hengduan Mountains are the edge effect in this transitional area of fauna and flora, and heterogeneity of climate, geographical condition and vegetation.

Farm animal genetic resources have been threatened over the past decades, therefore a scientific and efficient framework is critical to allocate limited funds to conserve maximal genetic diversity of farm animals. In this study, the marginal diversity method was exploited to set priorities for conservation of 18 Chinese pig breeds. Based on the analysis of their extinction probability, contribution rate, marginal diversity, and conservation potency, we evaluated the effectiveness of three models to gain the maximal expected diversity and optimal fund allocation. The additive model (model A) proved to be optimum for allocation of all the funds to 10 of the 18 Chinese pig breeds. The largest share of funds (16%) was allocated to the Hang pig, followed by the Ganzhongnan spotted pig/Wanan pig and Shengxian pig (which earned 14% each), the Yangxin pig and Leping pig (11% each), the Wuzhishan pig (10%), the Yushan black pig and Ganzhongnan spotted pig/Guanchao pig (9% each), and the Qingping pig, Wuyi pig and Jiaxing pig (2% each). The results indicate that the degree of endangerment, genetic diversity, economic importance and contribution of breeds to the species diversity should be taken into account when allocating conservation funds.

In order to understand the distribution pattern of the resources of arbuscular mycorrhizal (AM) fungi in arid zones in northwestern China, we investigated AM fungal diversity in five vegetation types: desert, grassland, forest, meadow, and oasis farmland. Forty AM fungal species belonging to six genera were identified from the rhizospheres of 60 plant species. Of these fungi, 35 were identified to species and five were identified to genus. Glomus claroideum was the dominant species throughout the sampling area, but the occurrence and distribution pattern of AM fungi in the five vegetation types were quite different. Entrophospora was only observed in desert while Paraglomus was found in oasis farmland and desert, Archaeospora existed in grassland, desert and oasis farmland, and Scutellospora existed in meadow, forest and grassland. The biodiversity index in oasis farmland and meadow were higher than other vegetation types, indicating soil moisture may be the most important factor affecting the distribution of AM fungi in arid zones.

Phyllanthus emblica (Euphorbiaceae) is one of the dominant species distributed in dry-hot valleys of southwestern China. Besides its function in ecology, environment and reforestation, it is also an important medicinal plant. We studied the genetic diversity in four populations of P. emblica sampled from dry-hot valleys of Yunnan using ISSR (inter-simple sequence repeats) markers. Based on 12 primers, 135 clear and reproducible DNA fragments were generated, of which 115 were polymorphic, accounting for 85.19%. The coefficient of genetic differentiation (G_ST) equaled 0.1222. Such a high level of genetic diversity and low level of population genetic differentiation might result from the breeding system of this species. There was a lack of significant association between genetic and geographical distances (r=0.19798, P=0.6513>0.05) among P. emblica populations. The results suggest some important recommendations about sampling meth-ods to be used in ecological reforestation of dry-hot river valleys.

The Chinese egret (Egretta eulophotes) is a globally endangered species. During July in 2005, we studied nest selection of Chinese egret in Wuzhishan Archipelago of Zhejiang Province. A total of 74 nests were recorded. The results showed that the nests of Chinese egrets were aggregated in space on Mantoushan Islet (0.99 hm2) with an average distance of 119.6 cm between nests, and a minimum of 15 cm. Chinese egrets showed significant preference for the ground under shrubs as their nest site, especially below shrubs higher than 50 cm, followed by sites inside shrubs lower than 64 cm and on top of tussocks. Most nests were sheltered. When selecting nest sites, Chinese egrets chose sites that maximized shelter from typhoon and di-rect sun. Typhoon exposure was the most important factor influencing nest site selection of Chinese egrets, while the amount of high shrubs determined the reproductive success and the future status of Chinese egrets in Wuzhishan Archipelago Nature Reserve.

The six meetings of the Conference of the Parties to the Convention on Biological Diversity held in 2002 adopted the goal of “significantly reducing the rate of biodiversity loss worldwide by 2010”, and requested Parties to develop biodiversity assessment indicators and to conduct biodiversity assessment. This paper puts forward five indicators for comprehensive biodiversity assessment, i.e. species richness, diversity of ecosystem types, completeness of vertical stratification of vegetation, endemism, and extent of biological invasions, based on the principles of scientific approach, representativeness, and practicality. Methods for comprehensive biodiversity assessment were established, and a national biodiversity assessment was con-ducted by taking 31 provinces (including municipalities and autonomous regions) as the basic assessment units. Biodiversity of provinces was classified into four grades. Yunnan, Sichuan and Guangxi boast highly rich biodiversity. Guizhou, Hubei, Guangdong, Hunan, Chongqing, Fujian, Tibet, Jiangxi, Zhejiang, Hainan, Gansu, Xinjiang, and Shaanxi boast quite high biodiversity. Henan, Anhui, Shandong, Shanxi, Hebei, and Beijing have moderate biodiversity. Jilin, Inner Mongolia, Shanghai, Liaoning, Ningxia, Qinghai, Jiangsu, Heilongjiang, and Tianjin have poor biodiversity.

According to the English version of IUCN Red List Categories and Criteria (Version 3.1), the current Chinese translations of Vulnerable are not appropriate, which may mislead the public. We propose that the Vulnerable in this context means vulnerable to extinction, which means that a taxonomic unit already has a risk of extinction in the wild, but the risk is the lowest among the three threatened categories.