Kadoorie Farm and Botanical Garden is located in the New Territories, on the mainland of Hong Kong. During 1990-1995 impact flight (IM) and ultraviolet light (UV) traps were set for several consecutive periods to study abundance, diversity, and phenology of the Class Insecta. We report here these features for the Order Coleoptera and some major beetle families, and compare variation in these features for beetles between IM and UV traps. About 13 000 specimens were collected belonging to 45 families (subfamilies) and 231 species. About 25% of these families are recorded from Hong Kong for the first time: Alleculidae, Biphyllidae, Byrrhidae, Colydiidae, Corylophidae, Cryptophagidae, Hydroscaphidae, Lagriidae, Lathridiidae, Limnichidae, and Zopheridae.Most of the beetles collected in the secondary forest are woodborers both in number and kind (either xylophagous or saprophytophagous), in contrast with the majority of phytophagous beetles collected by sweep nets in a nature reserve across the border in nearby mainland China. The Margalef (1958) richness index indicates that Mordellidae, Coccinellidae, Curculionidae, Cerambycidae, Chrysomelidae, Elateridae, Carabidae, Staphylinidae, Corylophidae, Buprestidae, Nitidulidae, Scolytidae, and Tenebrionidae are the richest families in species in decreasing order (d>1.5). The ShannonWiener (1949) diversity index indicates that Mordellidae, Coccinellidae, Curculionidae, Staphylinidae, Elateridae, Chrysomelidae, Cerambycidae, Carabidae, Nitidulidae, and Buprestidae are the most diverse families in decreasing order (H′>1.5). The Pielou (1975) evenness index indicates that Mordellidae, Coccinellidae, Curculionidae, Staphylinidae, Elateridae, Chrysomelidae, and Cerambycidae are the most balanced families in diversity and abundance in decreasing order (J>0.3). The BergerParker (1970) dominance index indicates that Scolytidae, Cerambycidae, Bostrichidae, Scarabaeidae, and Curculionidae are the most abundant families in number of individuals in decreasing order (D>1.5%). Overall, Cerambycidae, Coccinellidae, Curculionidae, Mordellidae, Scarabaeidae, and Scolytidae are the major families in the secondary forest with number of species 15 or number of individuals 200. Over 85% of all specimens were bark beetles during the study period, suggesting an outbreak of Scolytidae in the secondary forest.Seasonal patterns of the Coleoptera are conspicuous. Abundance of beetles began to increase in February and drastically decreased in August, but peak occurrence differed between IM and UV traps. Those caught by UV had a distinct peak in June, while those caught by IM peaked in July. Beetles in each of the major families also showed different seasonal patterns of abundance.Families with one single species comprise over 50% of the beetle families. Captures by different traps are often mutually exclusive. About 30% of the beetle families were caught by only IM traps, while 10% were caught by only UV traps. Of the remaining 26 families, 11 had at least one species that was mutually exclusively captured by different traps. In total, 65% of the 45 families contained species trapped by one method but not by the other. Scolytidae had the greatest abundance in both IM and UV traps. Mordellidae had the highest species diversity in IM traps, while Coccinellidae had the highest species diversity in UV traps based on the richness, diversity, and evenness indices. The value (1.67) of the ShannonWiener index for the order Coleoptera is within the normal range, but lower than the neighboring area where beetle specimens were collected by sweep nets.IM captures overwhelmingly outnumbered UV captures. This could be the result of more IM traps and longer operating periods than UV traps. However, the values of the ShannonWiener diversity and Pielou evenness indices are about 85% and 120% higher for UV than IM traps, respectively. This indicates that it is important to use different trapping meth

Based on outdoor surveys and suction devicebased collections in a rice field as well as adjacent weed habitat from June to September 2001 and laboratory identifications of specimens obtained from the field investigations, 67 species of parasitoids were collected and identified in the rice field, and 96 in the weed habitat. The species number of parasitoids accounted for 45.9% of the total species number of natural enemies in the rice field, and 46.6% in the weed habitat. For a comparative study of community diversity, species richness (S), ShannonWiener′s diversity index (H′), Simpson′s index of dominant centralization (C) and Pielou′s evenness (E) were calculated. The results showed that the numerical values of S, H′ and C of the parasitoids in the weed habitat were higher than those in the rice field, and the value of E was lower in the weed habitat. Temporal variation of dominant species was also different between the two habitats. In both habitats, Telenomus dignus and Anagrus sp. were dominant, but each habitat also had its unique dominant species, e.g., Monelata sp.1 and Acropiesta sp.2 were common in the rice field but not in weed habitat, while Telenomus gifuensis was only common in the weed habitat. The dominant species of the parasitoids tended to colonize the weed habitat in the seedling-transplanted stage of rice, immigrate into the field in the growing stage of rice, and emigrate from the fields to live in the weed habitat again in the mature stage of rice. This clearly indicates that the weed habitat can serve as a “species pool” of natural enemies, which provides the enemies with opportunities for natural dispersal, host alternation and refuge-seeking when there is lack of suitable food or disturbances caused by cultivation in the rice field. This is favorable for ecologicallybased integrated pest management in rice ecosystems.

. Brown eared pheasant, Crossoptilon mantchuricum, is a globally threatened species of pheasant that is native to China. Following research in 1997, effects of iron mine exploitation on this species were studied again in Wulushan Nature Reserve of Shanxi Province in the spring of 2000, aiming at further understanding the current status of habitats and population dynamics. Before exploitation, brown eared pheasants were observed in all three buffer zones, i.e. <50m, 50-100m, >100　m. Early after exploitation began, the species was not found in the <50m buffers, and there was a small decrease on number in the 50-100m buffers, and an increase in the >100　m buffers. The results indicate that iron mine exploitation caused brown eared pheasants in the <50　m and 50-100　m buffers to move to the >100m buffers. After 3 years, brown eared pheasants did not occur in either the <50　m or the 50-100m buffers. Compared with early after exploitation began, there was also a decrease in >100m buffers. At the beginning of exploitation, because there were few iron mines, the effects on activities of brown eared pheasants were not great and population density did not change markedly. However, with increase in the number of iron mines and longterm exploitation many feeding sites were damaged, and this, combined with the effect of noise and explosives from mining, restricted normal feeding activities directly. Consequently population density and ranging pattern changed greatly. The results indicate that iron mines are an important factor determining habitat use by brown eared pheasants. The species has not accommodated to habitat change caused by iron mine exploitation.

During April-August 1998, 200 questionnaires were distributed and collected in each of 200 towns and villages in the National Chinese Alligator Nature Reserve in Anhui Province. Based on the results of the questionnaires, quantitative nocturnal spotlight surveys were carried out from July to October of 1999, 2000, 2001, 2002 and 2003 in areas most likely to have wild alligator populations. The survey area included 36 sites in five counties or municipalities (Xuancheng, Jingxian, Guangde, Langxi, Nanling) in Anhui Province, seven sites in Changxing County and Anji County of Zhejiang Province, and two sites (Fuxijian and Dahanjie) near Yixing City in Jiangsu Province. Based on these surveys we estimate that the current size of the wild Chinese alligator population in Anhui and Zhejiang Provinces is 120 individuals. The population is fragmented into 23 isolated small local populations with 1-10 individuals each. No alligators were found in Jiangsu Province. Analysis of our data revealed that the wild Chinese alligator population and its distribution have declined sharply since the 1950s. The current population size of wild Chinese alligators has declined an estimated 76.5% from its levels in the 1980s. However, the population appears to have been stable from 1998 to 2003 with an estimated 120 individuals. The factors most responsible for the population decline have varied over the last fifty years but overall have been habitat fragmentation and degradation, hunting, natural disasters (floods and drought), low productivity and pollution. From the 1950s to 1990s, habitat loss and the killing of alligators were the most significant factors. Presently, killing of alligators is less of an issue but the loss of habitat has been virtually complete. Therefore, the highest priority for conservation of Chinese alligators must be habitat restoration as the first step towards reintroducing alligators by releasing captivebred individuals. In addition, the potential consequences of environmental pollution and reduced genetic diversity of wild Chinese alligator population must also be addressed.

A preliminary study on the diversity of soil invertebrate communities was conducted at Yushan Hill, Changshu, Jiangsu Province. Twenty-six taxa of invertebrates were identified, belonging to 10 classes and five phyla, of which Acarina，Collembola and Nematoda were dominant, accounting for 88.2% of the total individuals. Vegetations at Yushan Hill were grouped into three categories: pine-broad-leaf mixed forest, tea garden and bamboo forest. Pine-broad-leaf mixed forest ranked the highest in taxon and individual numbers of invertebrates, H′ index, DG index and DIC index. The lowest was in the bamboo forest. Evenness (J) of invertebrates in the three categories showed a complex pattern of variation: the highest value was observed in tea garden and the lowest in bamboo forest. The invertebrate community in bamboo forest had the highest Simpson index　(C) compared with the other two forests. The results also showed that the similarity (q) of soil invertebrates among these three forests was moderate (q>0.5) in all communities. The numbers of groups in soil decrease rapidly with increase in depth of soil layer.

Ferns were the first terricolous vascular plants, and still comprise an important part of primary productivity of ecosystems. On the one hand, they make a great contribution to the processes of dynamics and development of the forest community; on the other hand, because of their sensitivity to change in ecological factors, the composition of the fern community and its adaptations change with the development of forest community. In order to understand the changes of composition and the adaptability of ferns in the process of vegetation succession, a survey on a successional series of vegetation was carried out in Gudoushan Nature Reserve, 112°52′30″－113°03′25″E and 22°5′00″－22°21′15″N, which is located in the southcentral area of Guangdong Province, China. Four quadrats of 100 m2 each (4×5 m×5 m) were located in grassland, shrub, secondary forest dominated by heliophytic trees, and typical southern subtropical monsoon evergreen broadleaf forest (hereafter abbreviated as “primary forest”) dominated by shadeadapted trees. The importance value (IV) of each fern species and the index of α and β-diversity of communities in the process of vegetational succession were calculated. Changes in leaf characteristics, shade tolerance and reproductive strategy of ferns in the course of vegetation succession were analyzed. The results showed that, with the development of communities from grassland to shrub, to secondary forest and to primary forest, (1) the index of β-diversity among different fern communities increased, but the index of similarity among different communities decreased; (2) species richness increased, but the ShannonWeiner index, Simpson index and index of evenness did not increase with the change in richness; (3) proportion of ferns with leathery leaves decreased gradually, but the proportion of ferns with herbaceous leaves increased, and ferns with membranous leaves appeared in the last stages; (4) the proportion of shadetolerant ferns increased gradually, and suntolerant ferns decreased; (5) the proportion of ferns with sexual reproduction increased gradually, while the ferns with asexual reproduction decreased. The results also indicate that the ferns and their adaptation to the environment are useful indexes that reflect the change of the environment in different vegetational stages. More attention should be paid to the interaction between ferns and trees in the practice of restoration and conservation of biodiversity.

Random Amplified Polymorphic DNA (RAPD) markers were used to measure genetic diversity of 48 individuals from four natural populations of Isoetes sinensis，　a rare and endangered plant in China. A total of 124 DNA fragments were scored from 14 RAPD primers, of which 58.06% were polymorphic. A low level of genetic diversity within populations was detected, with PPB (percentage of polymorphic bands) values ranging from 0.81% to 12.90%. An Analysis of Molecular Variance (AMOVA) was used to apportion the variation within and among populations. Results indicated that most of the variation (58.9%) resided among populations and a small amount of variation (41.1%) represented differences within populations. Inbreeding is likely the factor that results in the low level of genetic diversity within the populations. Genetic drift and limited gene flow might also have enhanced genetic differentiation among the populations. In view of the ecological and genetic information available for I. sinensis,we suggest establishing as many in situ conservation spots as possible and cross transplanting plants or seedlings mutually among populations in order to enhance gene flow. By this means, the genetic diversity resources of I. sinensis can be preserved to the greatest extent.

The complexity of a forest community is defined as having the average amount of its information by eliminating the uncertainties of species and layers of a tree individual randomly selected from all trees in the forest community. The joint entropy H(X,Y) is proposed to measure the complexity of a forest community H(X,Y)=H(X)+H(Y|X), in which H(X)=-∑[DD(]S[]i=1[DD)][SX(]ni[]N[SX)]log2([SX(]ni[]N[SX)]) and H(Y|X)=-∑[DD(]S[]i=1[DD)][SX(]ni[]N[SX)]∑[DD(]4[]j=1[DD)][SX(]nij[]ni[SX)]log2([SX(]nij[]ni[SX)]), where S stands for the number of tree species (X), N for the total number of individuals in the forest community, ni for the number of the ith tree species, and nij ?for the number of the ith tree species in the jth layer. H(X) is defined as the compositional complexity of tree species and H(Y|X) as the structural complexity of tree species. The higher the H(X,Y) value, the greater the complexity in the forest community. A case study is presented based on the survey data from three types of forest communities in Heishiding Nature Reserve, Guangdong Province. Three sampling plots were established, each with a size of 60 m×60 m, representing coniferous forest, mixed coniferous broadleaved forest and evergreen broadleaved forest. Each plot was divided into 36 quadrats with a size of 10 m×10 m. The data for all trees with DBH1 cm were gathered, including their coordinates in the sampling plots. Tree sizes were divided into four categories based on their DBH: DBH1, 5, 10, and 30 cm. Using computer simulation, 13 types of quadrat sizes (12 m×12 m, 16 m×16 m, …, 60 m×60 m) within a plot were objectively selected based on the method of nested quadrat sampling. The results show that the order of H(X,Y) of three typical forest types is as follows: evergreen broadleaved forest > mixed coniferous broadleaved forest > coniferous forest. At the same time, the fractal relationships between H(X,Y) and sampling size among the three forest types reveal that H(X,Y) has a statistical selfsimilarity feature.

The Taibai larch, Larix potaninii var. chinensis, is an endangered plant only found in the Qinling Mountains in China. It is densely distributed on Mount Taibai and plays an important role in environmental protection in the high altitude zone. In order to characterize the age structure and dynamics of the L. potaninii var. chinensis population so as to better conserve its resources, 29 plots (10 m ×10 m) were investigated on Mount Taibai. The analysis of the age structure of five populations of L. potaninii var.chinensis showed that most individuals (68.6%) were concentrated in the 60-140 year age classes. Younger and older individuals were dramatically few. Because of different environmental conditions, different populations developed their own characteristic age structure. The population in L. potaninii var. chinensis-Abies fargesii-Lonicera hylocomium-moss association showed a stable development tendency. However, another four populations in L. potaninii var. chinensis-A. fargesii-Betula utilis var. sinensis-Rhododendron clementinae association, L. potaninii var. chinensis-Rhododendron clementinae-Lonicera hylocomium-moss association, L. potaninii var. chinensis-Rhododendron capitatum-Juniperus pingii var. wilsonii-Carex sp. association and L. potaninii var. chinensis-Rhododendron purdomii-R. capitatum association all showed obvious declining tendencies. The analysis of life tables and survival curves showed that even under different environmental conditions, survival curves of L. potaninii var. chinensis populations belonged to Deevey type III, and death peaks of different populations were the in period of 100-180 years old. Time sequence prediction models for different populations after 20, 60, 100, 200 years indicated that the numbers of old individuals would increase in the beginning and finally decrease, giving rise to difficulties for maintenance of these populations. The age structure and dynamic trends of L. potaninii var. chinensis populations were similar to those of other endangered species in China, such as Cathaya argyrophylla. The key cause for population decline was that shade in the forest obstructed germination and seedling growth. In situ conservation should be strengthened in future, especially for middle and old individuals with reproductive ability. The heliophytic and xerophytic characteristics of L. potaninii var. chinensis should be considered and special countermeasures for fostering the species should be made according to these biological characteristics and habitats. In the lower altitudes, nontarget species in the tree layer and some shrub species should be thinned. In higher altitude areas, actions for fostering forest, such as cutting shrubs, clearing herbs, etc. should be taken, so as to create the environmental condition for development of young seedlings of L． potaninii var. chinensis.

Fourtyone dsRNA viruses of Cryphonectria parasitica isolates from eastern China were divided into five types on the basis of gel electrophoresis patterns. Type I contained only one segment of 12.7 kb, accounting for majority of the dsRNA viruses. Type II had another segment about 5.2 kb besides the segment of 12.7 kb, and was only found in the pathogen isolate 354. Type III possessed the 12.7 kb segment and other three small ones shorter than 2 kb, which was detected from the two isolates 238 and 250. Type IV was separated from pathogen isolates 269 and 344, which contained only two small dsRNA segments about 1.8-3.1 kb. Type V, including four small dsRNA segments about 2.6-3.3 kb and the 12.7 kb one, was only extracted from the isolate 280. The cultural characters of all these tested isolates, whether or not including dsRNA viruses, were diverse and could be also divided into five cultural types. The cultural type of C. parasitica isolate is not consistent with the type of dsRNA virus and virulence test results showed that most of the tested isolates containing dsRNA viruses were hypovirulent.

The history of conservation of dawn redwood (Metasequoia glyptostroboides), in a sense, is a miniature of the history of conservation of Chinese rare and endangered plants since New China was founded more than 50 years ago. The establishment of Hubei Province Xingdoushan National Nature Reserve mainly to protect dawn redwood is an important milestone in the development and history of protection of dawn redwood. Understanding this history is beneficial for effectively formulating plans and adopting measures for the future in situ protection and ex situ conservation of dawn redwood. The history of conservation of dawn redwood is reviewed in this paper. Based on an analysis of the current situation and current problems for dawn redwood, four detailed conservation measures are suggested: (1) to continuously improve the conditions of nature reserves for the natural seedsource trees of dawn redwood, and to design a longterm programs to protect them. The organization and personnel as well as the funds should meet the needs for protection of the original natural seedsource trees of dawn redwood and their habitat； （2）to effectively implement relevant laws for protection of dawn redwood；（3） to establish a geneconservation forest in order to fully preserve all the original natural founder trees′ genes of dawn redwood； and (4) to actively coordinate the relationships among environmental protection agencies, forestry agencies, units of the Academy of Sciences, and other education and research units. We should cooperate and help each other in the fields of protecting dawn redwood and other natural resources by means of scientific research and exchange of research experiences.