Based on investigation of moist evergreen broad-leaved forests in Anzihe Nature Reserve and Tiantai National Forest Park, located at the western edge of the Sichuan Basin, we studied the response of species diversity to different restoration phases using the technique of space-for-time substitution, the results were as follows: (1) During 350 years of restoration succession, we found a unimodal response of species diversity over time. Species richness and the Margalef index peaked 100 years after the onset of restoration succession, up to 130 and 21.49, respectively. There was a fast increase in arbor species within the first 50 years, and then in shrubs and herbs within 50–100 years phase. The species number and the Margalef index (y) varied according to a parabolic function with time (t): y = y₀+at+bt²+ct³. We recommend Lindera limprichitii and Machilus pingii as ideal tree species for afforestation in the study area because of their wide niche; (2) There were greater value of Simpson index during 30–50 years after restoration and value of Shannon-Wiener index during 30–100 years respectively. The variance coefficient of species diversity in the arbor layer was greater than that in the shrub layer. The shrub layer contributed greatly to species diversity of the whole community, therefore it should be given more concern in the restoration of secondary forests; (3)Species evenness index displayed a fluctuating increase with the restoration process. Pielou index reaching 2.0834 and the McIntosh index 2.4177 after 350 years of restoration; (4) The Whittaker index displayed a fluctuating increase through the whole restoration process, whereas the Sørenson index decreased. Although the restoration of the moist evergreen broad-leaved forest is a long-term process and it will take at least 300 years to recover to its climax community, there is strong resilience, implying that natural recovery is a very effective and efficient way to restore degraded moist evergreen broad-leaved forest and its biodiversity in the study area.

In order to provide a scientific basis for biodiversity protection on the Ordos Plateau, we compared plant community diversity in 1999 and 2000 with that in 1986 (Li, 1990). The results indicated that the 23 major types of plant communities showed significant differences in Simpson index, Shannon-Wiener index, and coverage, but similar richness. Higher diversity and higher coverage occurred in the typical steppe in the middle-eastern sector of the plateau, while higher diversity but lower coverage was found in the desert-steppe and steppe-desert in the west, and lower diversity but higher coverage was found in the communities of the Maowusu sandland. From 1986 to 2000, the biodiversity and coverage of the communities had changed ob-viously. The biodiversity of typical steppe, desert-steppe and sandland vegetation showed a decreasing trend, whereas coverage of typical steppe and steppe-desert increased, and the coverage of the desert-steppe de-creased. We recommend that great attention should be paid to the ecological conservation of the desert-steppe as well as to species diversity of sandland vegetation and steppe desert.

The relationship between plant species diversity and primary productivity has long been a hot topic in biodiversity research. We examined the relationship between species richness and productivity in four typical grasslands of northern China at different spatial scales. At the community scale, a positive correlation was found for six of seven communities, and a unimodal pattern was found only for one community (Stipa glareosa community). At large scale (vegetation type or landscape/region), a significant positive relationship was found. Species richness ranged from 4 to 35 species, and community above-ground productivity from 13 to 368 g·m^–2·yr^–1. The highest species richness and above-ground productivity were found in the alpine meadow community, followed by meadow steppe, typical steppe and desert steppe.

Fagus (Fagaceae) is a small genus with 11 monoecious tree species. Fagus lucida, occurring in high subtropical mountains, is an abundant deciduous species which forms an important component of mixed broad-leaved evergreen and deciduous forests. Using Braun-Blanquet and Fujiwara phytosociological meth-ods, we compared the F. lucida forests distributed in Mt. Nanshan，Mt. Fanjing，Kuankuoshui Nature Re-serve, and Mt. Badagong in order to protect remanet forests due to overexploitation. Based on data from 37 sites, three associations and six subassociations were identified. Comparing species composition and life-form structure of the associations, we found that the Yushanio basihirrsuto–Fagetum lucidae communi-ties in Mt. Nanshan and Sinarundinario chungii–Fagetum lucidae communities in Mt. Fanjing and Kuanku-oshui Nature Reserve had similar characteristics of mixed evergreen and deciduous broad-leaved forests,while Sinarundinario nitido–Fagetum lucidae communities in Mt. Badagong presented feature of deciduous broad-leaved forests. The DBH size classes of F. lucida in Mt. Nanshan and Mt. Badagong had an L-shaped distribution and a monomodal distribution, respectively. In Mt. Nanshan, F. lucida regeneration benefits from forest gaps but is hindered by dense bamboo. In Mt. Badagong, natural regeneration of F. lucida is poor although bamboo is scarce. Further researches is needed to explain this phenomenon.

In order to explore the effect of human activities such as vegetation restoration and reconstruction on plant communities, we compared species diversity of eight major land-use types in Changchuan watershed with that of Aguimiao Nature Reserve, a control of natural background, 40 km away from Changchuan. The results showed that seabuckthorn brushwood (dominated by Hippophae rhamnoides), grassland, Chinese pine woodland (dominated by Pinus tabuliformis)，and intermediate peashrub brushwood (dominated by Caragana intermedia) supported relatively high species diversity. Intermediate peashrub brushwood, grass-land and Chinese pine woodland had comparatively high similarity with controls, with Sørensen indices at about 40%, indicating that the plant diversity of those three land-use types were more similar to the natural vegetation in this region. Synthetic Evaluation Indices (SEI) for land-use impact on biodiversity can be ob-tained by integrating Shannon-Wiener and Sørensen indices. The values of SEI of each land-use type ranked in the following order: grassland > Chinese pine woodland > intermediate peashrub brushwood > waste land > hankow willow brushwood > seabuckthorn brushwood > simon poplar woodland > crop land. Grassland, intermediate peashrub brushwood, and Chinese pine woodland should be adopted in the processes of vegeta-tion restoration and reconstruction, due to their functions of conserving local species diversity.

Brachymystax lenok (Salmonidae) is an economically important fish species in China whose population is currently declining due to overexploitation and environmental pollution. Recently it has been listed as a threatened species in the China Red Data Book of Endangered Animals. To study the genetic structure and phylogeographic pattern of its populations is important for addressing the systematics, evolution, and effective conservation of this species. Partial sequences of the mitochondrial control region (835 bp) were obtained by PCR amplification of 71 individuals of Brachymystax lenok from seven populations in China’s eastern river systems. A total of 43 (5.1%) nucleotides were variable, resulting in a total of 15 haplotypes. Analysis of molecular variance indicated that a high proportion of the total genetic variance was attri- butable to variations among regions (63.55%), whereas 24.17% and 12.28% occurred among populations within regions and within populations, respectively. A molecular phylogenetic tree constructed using the neighbor-joining (NJ) method suggested that the 15 haplotypes were assigned to three clades associated with geographic regions. There were no shared haplotypes found among regions. The pattern of phylogenetic dis-continuity, which is associated with spatial separation, is a result of both historical (long-term, zoogeographic barriers to gene flow) and contemporary (limited dispersal and gene flow capabilities) factors. Based on these results, we propose that each of the three evolutionarily distinct groups of lenok populations should be protected from loss of biodiversity. It is highly recommended that management efforts should be focused on riv-erine conservation, avoiding translocations from the populations of different regions.

Fanjing Mountain is situated in Guizhou Province, southwestern China. Having the best preserved ecological system in the region, it has been designated as a national nature reserve. From 2001 to 2003, to explore the status and dynamics of the species diversity of fishes, we conducted three surveys in both the Wujiang River and the Yuanjiang River systems in the area around Fanjing Mountains. A total of 3,614 specimen were collected from 19 sites, belonging to 85 species/subspecies, 61 genera, 14 families, and 5 orders. Of these, Clarias fuscus is an introduced species while the others are indigenous. Pseudohemiculter hainanensis, Metahomaloptera omeiensis omeiensis, and Glyptothorax fukiensis fukiensis were newly recorded in this area. The fish fauna mainly comprised members of the family Cyprinidae of the order Cypriniformes, and fishes living in swift-flowing streams and small-sized species were dominant. Our study, combined with literature review, showed that indigenous fish species had decreased. Additionally, the species in Cypriniformes decreased much more than those in other orders in the area. The rapid decrease of species richness of indigenous fishes probably resulted from over-fishing and destruction of the river environment. Measures for protection of indigenous fish in this area are also discussed.

Tacca integrifolia is a tropical herb with a core distribution in southeast Asia and disjunct populations in the Brahmaputra valley in China. Significant morphological differences exist between the two regions. Genetic variation within and among four populations, three from the Brahmaputra valley, and one from Malaysia, was assessed using 19 Inter-Simple Sequence Repeat (ISSR) primers. The Malaysian population was more than 2,000 km from the other populations. A total of 165 discernible loci were obtained, of which 111 were polymorphic (67.68%). Genetic diversity was relatively high at the species level (PPB = 67.68%, H_T =0.185, and H_sp = 0.292), but was low within populations (PPB = 12.81%, H_E = 0.065 and H_pop = 0.044). Extremely high levels of population genetic differentiation were detected based on Nei’s genetic diversity analysis (G_ST = 0.777) and AMOVA analysis (F_ST =0.9206). Genetic differentiation among the three Brahmaputra populations (0.28%) and within these populations (7.94%) was low (P < 0.001). Restricted gene flow (N_m = 0.1435) among populations may result from self-pollination, inefficient seed dispersal, populationisolation, and habitat fragmentation. The extremely low genetic diversity in Brahmaputra populations was probably due to the unique landforms and vicariance of the Brahmaputra valley.

We studied the species diversity of Curculionidae in seasonal rain forest，mountain rain forest，semi-evergreen monsoon forest，deciduous monsoon forest，karst monsoon forest，monsoon evergreen broad-leaf forest，warm deciduous broad-leaf forest，warm pine forest, and hot bamboo forest in Xishuangbanna Nature Reserve, Yunnan. A total of 853 weevils were captured by shaking-off collection, be-longing to 96 species, 52 genera, and 18 subfamilies. Among the subfamilies, Cryptorrhychinae, Otior-rhynchinae, Rhynchaeninae, Tychiinae, Curculioninae, Barinae, and Conoderinae contributed more than five species. Cryptorrhychinae, the most abundant subfamily, was represented by 21 species occupying 21.9% of the total. Rhynchaeninae, Curculioninae, Cryptorrhychinae, Otiorrhynchinae, Anthonomnae, Conoderinae, Barinae, Tychiinae, and Cioninae were represented by more than 10 weevil individuals, of which Rhyn-chaeninae had 394，comprising 46.2% of the total number. The greatest densities of individuals occurred in the warm deciduous broad-leaf forest and the seasonal rain forest, while relatively less occurred in the de-ciduous monsoon forest and the semi-evergreen monsoon forest. Every weevil community in the nine vegeta-tion subtypes had its own stenoecious and rare species. Seasonal rain forest was the richest in stenoecious and rare species, while semi-evergreen monsoon forest ranked second. Considering species richness, seasonal rain forest was the richest, whereas warm deciduous broad-leaf forest was the poorest. The weevil communi-ties in the nine vegetation subtypes are very dissimilar. More attention should be paid to seasonal rain forest and semi-evergreen monsoon forest for their important roles in biodiversity conservation.

Coptis teeta is an economic medicinal plant which is well protected in Yunnan. Based on ethnobotanical theory, combined with field study, community survey, and literature study, we investigated the history of cultivation and traditional management of C. teeta by local Lisu people in the Gaoligong Mountain region, Yunnan. We studied the local people’s knowledge and experiences in cultivating and utilizing this plant and its significance for biodiversity protection. The results showed that, since 130 years ago, in order to sustain this important economic plant, Lisu people have developed a set of effective methods to cultivate, manage and harvest it, and thus have formed a harmonic agroforestry system with higher species diversity than other land-use types. In return, the cultivation of C. teeta has benefited local Lisu people, providing over 50% of their cash income. This kind of land-use provides a good example of effectively protecting ecosystems without ruining local people’s profit.