Aim The relationship between biodiversity and ecosystem function contribute to productivity, both directly and indirectly. Therefore, it is a critical issue of ecology. The aim of this study is to quantitatively explore the relationship between tree diversity and biomass or productivity of subtropical natural forest ecosystems in late successional stages.
Methods Based on long-term community surveys of topographies and soil nutrients from permanent forest ecosystems in the subtropical evergreen broad-leaved forest, we analyzed the relationship between tree diversity and productivity/biomass and their influencing factors. In this analysis, the correlations between tree diversity and each factor were evaluated using a Pearson correlation analysis. The single and shared effects of each factor were quantified by variance partitioning analysis (VPA). In addition, the relationships between soil nutrients and topographies and their effects on productivity and biomass were further evaluated, either directly or indirectly, through species and structural diversity by using a structural equation model (SEM).
Result Species diversity displayed a negative correlation with biomass and a positive correlation with productivity. Contrarily, structural diversity was positively correlated with biomass and negatively correlated with productivity. The effects of environment factors on tree diversity and biomass/productivity were varied. Specifically, soil moisture had a significant effect on productivity, species diversity was correlated with soil nutrients and topographies, and structural diversity was strongly related to soil nutrients. The variance partitioning analysis results indicated that the single effect of structural diversity explained the largest portion of variance in biomass (35.39%) and productivity (5.21%), followed by the shared effect of structural and species diversity on biomass (13.66%) and productivity (3.53%). Soil nutrients and topographies explained less variation in productivity and biomass. The structural equation results analysis indicated that structural diversity had a direct positive effect on biomass, and biomass had a strong direct negative effect on productivity. Structural diversity indirectly reduced productivity by increasing biomass. Soil nutrients and topographies were mainly affected by biomass, while productivity indirectly affected tree species and structural diversity.
Conclusions These results indicate that (1) species diversity had the greatest direct effect on productivity, and structural diversity had the greatest direct effect on biomass in southern subtropical evergreen broad-leaved forests; (2) species diversity explained productivity better than structural diversity, while structural diversity explained biomass accumulation better than species diversity; and (3) both species diversity and structural diversity can be affected by soil nutrients and topographies.

Aims There is a growing concern regarding biodiversity loss and its effects on ecosystem functioning. Previous studies have primarily focused on the impact of biodiversity loss on plant productivity in forest ecosystems, but research regarding its effects on enzyme-mediated litter decomposition remains elusive. It has been well documented that the rate of litter decomposition is directly controlled by the activities of extracellular enzymes secreted by microbial decomposers, which is an important indicator of nutrient cycling in forest ecosystems. To explore the effect of biodiversity loss on extracellular enzyme activities in litter, and the underpinning mechanism that regulates litter decomposition, a field experiment was conducted in a subtropical forest.
Methods The experiment was conducted in a subtropical forest biodiversity-ecosystem functioning experimental area established in Xingangshan, Jiangxi Province. In this study area, 31 intensively studied plots which form a gradient of tree species diversity (i.e., 16 monocultures, eight 2-species mixtures, four 4-species mixtures, two 8-species mixtures and one 16-species mixture) were chosen. We collected fresh-fallen leaf litter in the plots of varying tree diversity levels and measured the extracellular enzyme activity, chemicals, and fungi in litter. We hypothesized that extracellular enzyme activities in litter, particularly those relevant to carbon (C), nitrogen (N), and phosphorus (P) cycling would significantly change with tree species diversity loss. We also expected to find that fungal decomposers could modulate the responses of enzyme activities to tree species diversity loss.
Result Our results showed that tree species diversity loss significantly affected the activities of extracellular enzymes, and extracellular enzyme activity showed a positive correlation with increasing tree species richness, except for single species. The activities of α-glucosidase (AG), β-glucosidase (BG), and cellubiosidase (CB), which are involved in C turnover, were the highest in the litter from the plot with the highest tree species diversity. Xylosidase (XS), N-acetyl-β-glucosaminidase (NAG), acid phosphatase (AP), and polyphenol oxidase (PPO), which are respectively involved in the turnover of N and P and the degradation of polyphenol, had higher rates of activity when the tree species diversity was lower. Moreover, we found that the extracellular enzyme activities showed a ‘single peak’ trend that correlated to changes of neighboring tree species diversity. This trend indicates that most of the extracellular enzyme activities relevant to the turnover of C, N and P were highest when the species richness of the six neighboring tree species was high as well. These findings indicate that both plot-level tree diversity and neighboring tree species can significantly alter extracellular enzyme activities in litter of target tree species. Fungal decomposers may play an important role in affecting the response of extracellular enzyme activities to tree species diversity loss.
Conclusions Our findings demonstrate that the loss of tree species diversity may indirectly affect extracellular enzyme activity by influencing the community structure and abundance of fungal decomposers. This study promotes our understanding of how tree diversity loss influences litter degradation and nutrient release through the modulation of extracellular enzyme activities in subtropical forests.

Aim Cycas hainanensis, an ancient species of Cycas, is a top priority plant species in China and is also classified as endangered by the International Union for Conservation of Nature (IUCN) Red List. We aim to study the relationship between population structure and forest canopy density of C. hainanensis in the Baomeiling Provincial Nature Reserve of Changjiang County, Hainan Province.
Methods After an investigation of the C. hainanensis population and its community by utilizing the sample survey, we analyzed community characteristics including structure and species diversity, and population characteristics such as age structure, survival curve, spatial patterns, and population density. We also studied the relationship between C. hainanensis and forest canopy density.
Results The vertical structure of the community of C. hainanensis was divided into two tree layers, shrub layer and herb layer. The species diversity index of the community was high and the community species composition was rich. The distribution of C. hainanensiswas uneven in all quadrats and formed clusters in the undergrowth as well as the forest edge at an elevation of 500 m. The population dynamics belonged to growth type, and the population renewal ability is strong. The population survival curve of C. hainanensistended to the Deevey-II type. The population mortality increased with age, which indicated that the population of C. hainanensis was in a state of stable growth. The population viability decreased with the growth and development of individual specimens. The spatial distribution pattern of C. hainanensis population conformed to clumped distribution, and the degree of aggregation was positively correlated with an increase of forest canopy density. A curve estimation demonstrates that the density of C. hainanensisseedlings and saplings increased significantly in the study area where forest canopy density was 36.11%-58.33%.
Conclusions In conclusion, the C. hainanensispopulation in the Baomeiling Provincal Nature Preserve of Changjiang County is in a stable growth state and preferred to grow in a forest environment with an elevation of approximately 500 m and forest canopy density of 35%-60%.

Aims: Polyploidization is an important mechanism for plants to adapt to extreme environments. The Qinghai-Tibet Plateau (QTP) alpine and Pan-Arctic regions have a similar low-temperature environment, and there were closely biotic exchanges between the two regions. However, it is unclear whether the QTP alpine and Pan-Arctic floras have similar polyploid buildup or not. Here, we compared polyploid proportions between these two floras and explored the potential causes for the difference.
Methods: By comprehensive searches in the databases and various literatures, we obtained species lists with chromosome numbers and ploidy of seed plants for the QTP alpine and Pan-Arctic regions, and then calculated polyploid proportion in totality as well as polyploid proportion for different life forms in the two regions.
Results: A total of 1,770 species of seed plants with chromosome numbers were collected, of which 774 occur in the QTP alpine region and 996 occur in the Pan-Arctic. According to the statistical analyses, the proportions of polyploid plants are 20.9% in the QTP alpine region and 61.5% in the Pan-Arctic. The proportions of polyploids of annual herbs, perennial herbs and woody plants in the QTP alpine region are 20.7%, 21.6%, and 12.8%, respectively. The proportions of polyploids of annual herbs, perennial herbs and woody plants in the Pan-Arctic are 60.2%, 65.5%, and 38.3%, respectively.
Conclusions: The polyploid proportions in totality and for different life forms in the Pan-Arctic are higher than those in the QTP alpine region obviously, which is associated with the different evolutionary history of the two floras, as well as their different geological and climatic events. The modernization of the QTP alpine flora took place around the Oligocene-Miocene boundary, and since then the QTP has had a relatively constant low-temperate environment, whereas the Pan-Arctic flora did not develop until 3-4 Ma, and since then the Pan-Arctic flora experienced repeated glacial and interglacial periods and repeated sea-level fluctuations, which might have resulted in the polyploidization of plants. This study contributes to our knowledge on how polyploids adapt to low-temperate environments.

AimsThe Philippine Sea is a habitat that produces many important biological resources. The purpose of this paper is to summarize baseline data on the distribution of marine Chordata biodiversity with threatened status, and provide suggestions for conservation planning for marine biodiversity in the Philippine Sea.
Methods In this paper, the Ocean Biogeographic Information System (OBIS) and the IUCN Red List of Threatened Species (IUCN Redlist) were used to collect and assess current biodiversity data of Chordata in the Philippine Sea. A list of Chordata species with threatened status in the Philippine Sea was compiled and sorted. A visualization of the spatial distribution of biodiversity at different taxonomic and threatened levels in this area was also produced. The relationships between the richness at varying taxonomic levels and environmental factors, such as net primary productivity, surface sea temperature, and water depth in the Philippine Sea were also explored by correlation analysis.
Result The results showed that the 2,876 species in the phylum of Chordata in this region belong to 11 classes, 56 orders, 320 families, 1,171 genera. The richness at varying taxonomic levels was high in the waters near the Philippine Islands, Taiwan Island, Japanese Island, the Kyushu Palau ridge, and Mariana Islands, while the richness in the central basin of the Philippine Sea was low. The taxonomic richness and species abundance were positively correlated with primary productivity, but negatively correlated with water depth significantly. Among them, 4 classes, 45 orders, 292 families, 1,105 genera and 2,768 species of fish were recorded in this area, accounting for 96% of the total Chordata species based on the OBIS. Moreover, 54 species of Chordata were included in the IUCN Redlist in this area; these included 3 critically endangered species, 5 endangered species, 22 vulnerable species and 24 near threatened species, accounting for 0.10%, 0.17%, 0.76%, and 0.83% of the total Chordata species, respectively. Like the distribution of biodiversity in this area, the threatened species were mainly localized near the edge and the central ridge of the Philippine Sea, and less so in the central deep-water basin.
Conclusion Based on the results, biodiversity protection measures for Chordata fauna in the Philippine Sea, especially for threatened species, should place the priority on the marginal areas. Due to the insufficient data on deep-sea biodiversity in the Philippine Sea, more surveying efforts should be invested in this area, particularly in the central ridge and deep-water basin.

Aims Biodiversity monitoring is the foundation of conservation work in national parks. Systematic conservation planning and effective management actions within these parks highly rely on an in-depth evaluation of biodiversity metrics. In China, the Giant Panda National Park (GPNP) is one of the first five national parks. To establish baseline metrics of mammal and bird diversity in GPNP, we conducted a meta-analysis based on published camera-trapping data.
Methods We systematically searched academic publications, project reports, and news articles that reported on wildlife camera-trapping studies between 2005 and 2020 in GPNP. We also conducted a questionnaire survey on the history and results of camera-trap monitoring projects within the protected areas of the region. These data were compiled for statistical analysis.
Result Between 2005 and 2020, 71 wild mammal species belonging to 6 orders, 22 families and 55 genera, and 232 wild bird species belonging to 13 orders, 45 families and 132 genera were recorded via camera-trap monitoring in 51 protected areas within GPNP. Among the four mountain ranges within GPNP (i.e., Mts. Qinling, Mts. Minshan, Mts. Qionglai and Mts. Xiangling), the species richness of large- and medium-sized terrestrial mammals and birds was the highest in Mts. Qionglai and Mts. Minshan (40 mammal and 12 pheasant species for each) and the lowest in Mts. Xiangling (25 mammal and 7 pheasant species). The recorded number of target species in individual protected areas was positively correlated with the area of protected area, sampling effort (measured as number of camera-days), and the camera station elevation range. The numbers of species recorded in national protected areas (28 ± 8.3, mean ± SD) were significantly higher than those in provincial protected areas (19 ± 8.9). Four large carnivores of Felidae and Canidae (leopard Panthera pardus, snow leopard P. uncia, wolf Canis lupus and dhole Cuon alpinus) were recorded in GPNP, primarily from Mts. Qinling and Mts. Qionglai, while no large carnivores were recorded within the park in Mts. Minshan and only one wolf was recorded in Mts. Xiangling.
Conclusion The previous protected area network and camera-trapping monitoring network prior to the establishment of GPNP have already accumulated a high quantity of data on wild mammals and birds in this region. These data provide a reliable baseline biodiversity inventory for the pilot and construction phases of GPNP. In light of these results, GPNP should design and implement a standardized wildlife monitoring system to further provide additional data for future evaluations of park management, decision-making, and conservation effectiveness.

Aim: Culter recurviceps (Cypriniformes: Cyprinidae) is an economic fish species in South China. Nevertheless, the resources of this species declined rapidly during recent years due to water conservancy, overfishing, and environmental pollution. Therefore, more attention and conservation measure are needed for this species. Population genetic analyses can both reveal genetic diversity and population structure of particular species and provide implications for management and conservation of these species. The aim of this study is to investigate the population genetic structure and genetic diversity of C. recurviceps and further provide implications for the preservation and reasonable development of its resources.
Methods: We collected 207 individuals from 23 populations in the drainages in Southern China. With respect to the 207 individuals, two mitochondrial genes (Cytb and ND2) were sequenced and the corresponding mitochondrial COI gene was obtained from the Barcode of Life Data System (BOLD) database. We then combined the three genes to study the genetic structure and genetic diversity of C. recurviceps populations. Multiple analyses including phylogenetic analysis, divergence time estimates, haplotype network, population genetic analyses, and Mantel tests were employed.
Results: Phylogenetic analysis and haplotype network revealed that C. recurviceps populations contained three lineages (I, II and III). The members of lineages I and III contained populations from the Pearl River and the representatives of lineage II comprised of populations from the Hainan Island. Divergence time estimates indicated the three lineages were split between 0.028 and 0.251 million years ago (Ma), suggesting that Pleistocene climate change may have triggered the divergence of the three lineages. Population genetic analyses showed significant genetic differentiation (F_ST = 0.511, P < 0.001) and isolation by distance pattern (R = 0.348, P = 0.0010) was observed among C. recurviceps populations. Demographic analyses revealed that C. recurviceps populations might experience population expansion during 0.010-0.025 Ma, implying that Pleistocene climatic fluctuations have influenced the population size and distribution of C.recurviceps populations.
Conclusion: We observed that C. recurviceps populations in South China consisted of three mitochondrial lineages. Pleistocene climate changes have not only triggered the divergences of the three lineages, but also influenced the demographic history of C. recurviceps populations. Furthermore, spatial distance acted as a key factor that improved the population differentiation among C. recurviceps populations.

Aims Nematodes are considered as an important part of the soil food web, and their community characteristics are an effective indicator of soil health and ecosystem restoration. The accurate measurement of soil nematode communities is necessary to better understand their ecological function. Historically, comparisons in nematode morphology has been used to understand nematode community characteristics. In recent years, the use of high-throughput sequencing (HTS) methods has become more popular. However, relatively little is known about how these two methods compare when analyzing soil nematode communities.
Methods Here, we used morphological identification and HTS methods to simultaneously analyze soil nematode abundance, community composition and structure, and ecological indexes, under different vegetation restoration approaches (cropland, naturally restored grassland, Caragana korshinskiiplantation and Medicago sativaartificial grassland) in the mountain area of southern Ningxia in the Loess Plateau region.
Result We found that morphological identification is a more accurate method to determine the absolute abundance of soil nematodes, while HTS can only obtain relative abundance data. In our study, the morphological method showed higher abundance of soil nematodes in the sites under vegetation restoration, especially in the naturally restored grassland and C. korshinskiiplantation. The HTS method, on the other hand, detected more nematode genera (42 genera belonging to 3 classes, 4 orders, and 26 families) than morphological method (27 genera belonging to 2 classes, 3 orders, and 18 families). However, only 15 genera were simultaneously identified with both methods, because the HTS method detected more plant-parasitic nematode genera (22) but fewer genera of bacterial-feeding nematodes and omnivores-predators than the morphological method. One major result indicated by both methods showed that the relative abundance of microbial-feeding nematodes greatly decreased, while those of plant parasites and omnivores-predators substantially increased, in all the sites under vegetation restoration when compared with nematodes in the farmland. This was especially the case in the naturally restored grassland and C. korshinskiiplantation, accompanied with the increases of maturity index (MI) and plant-parasitic index (PPI) and a decrease in the Wasilewska index (WI). When compared with the morphological method, the HTS method could detect more abundant and diverse plant parasites. Therefore, more significant differences were found in the composition, structure and ecological indexes of soil nematode communities when the HTS method was applied.
Conclusion Overall, the characteristics of soil nematode communities and their response patterns to vegetation restoration highly depended on the applied methodology, which greatly influences the understanding and evaluation of how vegetation restoration impacts the soil ecosystem.

Aims Because of the connotation and extension of biosafety, the fuzziness of basic elements, the diversity of evaluation indexes and evaluation methods, China has not yet formed a comprehensive and effective biosafety evaluation index system. The purpose of this paper is to construct the biological safety evaluation system and to study the current situation of biological safety.
Methods Firstly, we analyze the characteristics and shortcomings of the concept of “biosafety” in Biosafety Act by using normative analysis method. From the point of view of national security, biosafety refers to the ability and state of the country to effectively prevent and deal with the threat of dangerous biological factors and related factors, and to maintain and safeguard its own security and interests. Clearly the extension of biosafety, that is, only the interests of national security, public health, ecological and environmental protection threats to biological risk, is the object of biosafety regulation. Secondly, the basic elements of biosafety include natural biosafety and socio-economic biosafety. Natural biological safety mainly refers to people’s health and ecological environment protection, including individual biological safety and biodiversity safety. Socio-economic biosafety focuses on national security interests, that is, social stability and national economic interests, including biotechnology safety, biological laboratory safety. Thirdly, taking the basic elements of biosafety as the Yardstick of management, taking national security interests, public health and ecological environment protection as the evaluation subject, taking the concept of biological rule of law as the idea, using the model construction method, based on the DPSEEA (driving force-pressure-state-exposure-effect-action) model, a biosafety evaluation index system with the characteristics of biological rule of law is constructed by combining qualitative index and quantitative index.
Result A set of biological safety evaluation index system with the characteristics of biological rule by law is constructed, including the level of biosafety laws and regulations system, the degree of cracking down on biosafety related crimes, the establishment and perfection of the coordination mechanism among biosafety departments, the number and percentage of biosafety laboratories meeting the prescribed standards, the number and density of biosafety talents, the total amount of official assistance to the biological industry and the basic health sector and other investments, the proportion of target population covered by vaccines, the popularization rate of biosafety publicity and education, and a total of 32 biosafety evaluation indicators.
Conclusion Based on the field investigation and data statistical analysis, the evaluation system was validated by the biological safety work in Shenzhen in 2019 and 2020. The results show that the biological safety work in Shenzhen has achieved remarkable achievements in agricultural biological safety, animal and plant epidemic prevention, and prevention of alien species invasion. However, there are still some deficiencies in laws and regulations system, cultivation of biosafety personnel, investment of funds and biosafety popularization rate. In view of the above problems, this paper puts forward some suggestions, such as perfecting the legal system of biosafety and paying attention to the coordination of laws, realizing the multi-coordinated biocontrol of “One health”, strengthening the talent training and capital investment, and strengthening the propaganda and education of biosafety.

Background & Aim: Nesting behavior is important for birds because this stage is critical for breeding success. Since urbanization is expanding worldwide, birds living in cities face huge challenges but the urban environment can also provide living opportunities. This review summarizes bird nesting behaviors in cities, analyzing the influence of factors such as climate, food resources, nest site availability, predation pressure, pollution, and anthropogenic disturbance on bird nesting based on publications in Biblioshiny programme.
Summary: This study demonstrates that urbanization influences bird nesting period, nest site and nest material selection significantly, and that spatio-temporal nesting ranges and nesting materials differ between urban and rural birds. We highlight the need to evaluate whether city birds are well adapted or negatively affected by urbanization, which would require specific analysis of target populations and habitat conditions.
Perspectives: We should propose effective and specific suggestions to protect city birds during urbanization based on our research results, instead of simply providing general guidelines. Developing citizen science to solve practical issues in urban animal ecology is a promising direction for the future.

Background & Aim The green peafowl (Pavo muticus) is listed as Class-I National Key Protected Wildlife in China and has irreplaceable value in China’s traditional culture. Historically, green peafowl were widely distributed across Southern China, but now its range is restricted to a few locations in Yunnan Province. There have been several studies that described the status and ecological traits of green peafowl in China, however, key information relating to population size and its adaptations to anthropogenic disturbance is still poorly understood. Furthermore, the green peafowl in Southeast Asia has also experienced drastic decline in both population size and distribution in the past 50 years. The studies on green peafowls’ biology, ecology, and conservation planning in Southeast Asia could inform related research and conservation strategies in China. In this paper, we reviewed previous studies related to green peafowls’ ecology and conservation research, and summarized green peafowls’ population dynamics, habitat use and interspecific interactions with sympatric species in China and Southeast Asia. Based on these results, we proposed suggestions for future research and conservation planning.
Review Results The wild population of green peafowl has less than 500 individuals in China, only distributed in Yunnan Province. In Southeast Asia, green peafowl is distributed in four strong-holds in Indo-China Peninsula and Java Island, in which the Eastern Plains landscape on the border of Cambodia and Vietnam holds the largest habitat and population. Studies conducted in Southeast Asia revealed that green peafowls had strong dependence on water resources and were associated with tropical dry forest, but were absent in tropical rain forest. They often herd with large ungulates such as banteng (Bos javanicus). Studies on habitat use demonstrated a significant variation in habitat use between dry and rainy season. Tiger (Panthera tigris), leopard (P. pardus), Asiatic golden cat (Catopuma temminckii) and civets (Viverridae spp.) were recognized as the green peafowl’s main predators. Poaching and habitat loss resulting from agriculture expansion and infrastructure construction are the main anthropogenic threats to green peafowls.
Perspectives We suggest that a long-term monitoring network combining camera trap and sign transect surveys are important for the conservation of green peafowl. Molecular biology can also help understand the conservation genetics of green peafowl. Most importantly, we strongly recommend that new protected areas along the river valleys of upper Red River where large habitat patches of tropical dry forest remain should be established. Patrols in green peafowl habitat should be enforced to protect against poaching. Furthermore, restoration of degenerated green peafowls’ habitats should be initiated. Finally, Indian peafowl (Pavo cristatus) farms should be prohibited in and around green peafowl habitat in order to prevent genetic contamination.

Aim: Bamboo is one of the main collecting targets in China and has been widely introduced to the United States. Among the numerous collectors of bamboo, Floyd Alonzo McClure has made the biggest impact. During his research at Lingnan University from 1919 to 1940, he collected bamboo specimens and introduced bamboo to the United States many times. In order to understand the history of collection and introduction of plants from China to the United States, it is necessary to investigate the history of McClure’s collection and introduction of bamboo in China.
Method: We conducted an extensive review of the literature and collection archives to sort out the route, collection locations, and scientific names of bamboo collected by McClure. We analyzed the history of McClure’s research, collection and introduction of bamboo in China.
Results: During McClure’s research in China, there were a total of 12 provinces (39 prefecture-level cities), where bamboo was collected. Guangdong, Hainan, and Hong Kong were the locality where the most bamboo was collected. There were a total of 9 provinces and 25 prefecture-level cities where bamboo was introduced. Of these introduced bamboos, a total of 1,840 sheets and 727 numbers bamboo specimens were collected, belonging to 93 species from 20 genera (including subspecies units, the same below). This accounts for 58.8% of bamboo genera and 17.4% of bamboo species in China. A total of 255 bamboos were introduced, belonging to 77 species of 17 genera, accounting for 14.4% of the species and 50.0% of the genera in China, respectively.
Conclusions: McClure’s collection and introduction of bamboo in China was important for the development of bamboo taxonomy. The bamboo specimens collected by McClure were invaluable for subsequent bamboo research. The bamboo introduced by McClure greatly enriched bamboo species in the United States and also helped promote the application of bamboo in the United States.