Invasive nonnative plants spread rapidly. Many have invaded into national nature reserves and are a threat to biodiversity. Based on a survey of 134 plots of herbaceous species in Jiuwan Mountain National Nature Reserve, we compared spatial distribution patterns of invasive and native herbaceous species diversity and examined the impact of climate factors on these patterns. A total of 143 native herbs were recorded, belonging to 54 families and 115 genera. Another 16 were invasive nonnative herbs, belonging to 7 families and 13 genera. With increasing altitude, species richness and the Shannon-Wiener index of native herbs increased significantly (P < 0.05), whereas that of invasive herbs decreased (P > 0.05). Evenness of neither native herbs nor invasive herbs changed significantly with altitude (P > 0.05). At different altitude gradients, the Shannon-Wiener index of native herbs was significantly higher than that of invasive herbs, but evenness was significantly lower. Regression analysis revealed that 41.6% of variance in native herb richness could be explained by temperature and precipitation (temperature = 21.4% of variance and precipitation = 10.7%), and native herb richness was significantly related to temperature (P < 0.05). Neither temperature nor precipitation was significantly related to invasive herb richness (P > 0.05), and variance explained by these two factors was low (temperature = 0.9% and precipitation = 0.4%). Our results suggest that in Jiuwan Mountain National Nature Reserve, invasive and native species diversity display opposite spatial distribution patterns with altitude, and that climate factors had differential effects on these patterns. Invasive herbs had a relatively diverse community composition and stable community structure at altitudes of 800-1,000 m, which may threaten native herb diversity. We propose that the management of reserves should pay more attention to invasive and nonnative herbs at this altitude range.

Understanding plant composition, community structure and community distribution of karst climax communities can provide a reference for biodiversity conservation and forest management. Based on topographic factors, soil factors and species composition data of a 25 ha forest dynamic plot in Mulun, Guangxi, we numerically classified the association of karst evergreen deciduous broad-leaved mixed forests multivariate regression trees and a modified Godron stability analysis ( Godron, 1971; Zheng, 2000) method to measure the stabilities of associations. The results showed that the forest community was divided into six associations. They were as follows: (I) Ass. Cryptocarya microcarpa + Itoa orientalis + Lindera communis, (II) Ass. Cryptocarya microcarpa + Cleidion bracteosum + Brassaiopsis glomerulata, (III) Ass. Platycarya longipes + Rapanea neriifolia + Clausena dunniana, (IV) Ass. Platycarya longipes + Luculia intermedia + Clausena dunniana, (V) Ass. Cryptocarya microcarpa + Brassaiopsis glomerulata + Eurycorymbus cavaleriei, (VI) Ass. Boniodendron minus + Rubovietnamia aristate + Platycarya Longipes. Except for Ass. I, diversity indices of each association were higher. Shannon-Wiener index, Simpson index and Pielou evenness index showed similar trends: Ass. VI > Ass. V > Ass. IV > Ass. III > Ass. II > Ass. I. Species richness did not follow this trend and decreased in the following order: Ass. VI > Ass. IV > Ass. V > Ass. I > Ass. III > Ass. II. Species diversities of these associations were highest at middle altitudes. The stabilities of associations were highest at medium-high slope positions, while associations were lowest in depressions. Elevation is critical for community structure and composition and may be an important factor affecting community distribution.

Evergreen broad-leaved forests (EBLFs), which are the primary zonal vegetation of subtropical East Asia, shelter high biodiversity and contribute significantly to human welfare. Today, most EBLFs are secondary growth due to long-term human activity. The few remaining old-growth EBLFs are small, scattered patches. Understanding how secondary and old-growth EBLFs differ in their community characteristics would provide guidance for their conservation and restoration. Here, we compare the dominant species composition, species and functional diversity, and aboveground biomass between old-growth (fifteen 20 m × 20 m plots) and secondary (fourteen 20 m × 20 m plots) EBLFs in Gutianshan National Nature Reserve (GNNR). We found that: (1) Both old-growth and secondary EBLFs were dominated by the same set of evergreen broad-leaved species, such as Castanopsis eyrei and Schima superba, but the species dominance order was inconsistent in the two forest types. (2) Secondary EBLFs had a higher Shannon-Wiener index value and greater functional dispersion than old-growth EBLFs, but neither the Bray-Curtis dissimilarity index values nor the functional Sørensen index values differed greatly between secondary and old-growth EBLFs. (3) When considering three vertical forest layers separately, the differences in the Shannon-Wiener and Bray-Curtis indices between secondary and old-growth EBLFs were mainly reflected in the tree and shrub layers. (4) Looking at the community structure overall, the stem density was greater in secondary EBLFs than old-growth EBLFs. Additionally, the community level and the individual level biomass were both lower in secondary EBLFs than old-growth EBLFs. These findings suggest that human disturbance has changed multiple characteristics of the EBLFs in GNNR, and their recovery process has been asymmetrical. Accordingly, any conservation plans to restore the biodiversity and ecosystem functioning in EBLFs should adopt a multi-faceted strategy.

Nanguang River is a tributary of upper Yangtze River that provides important resources and food to various communities. To understand the current status of fish diversity within Nanguang River, we sampled the river and its primary tributaries six times from November 2017 to September 2018. A total of 64 fish species were collected, two of which (Percocypris pingi and Procypris rabaudi) are protected fish in Sichuan Province, 17 species were endemic to the upper Yangtze River, and 9 were listed as endangered or vulnerable species in Red List of China’s Vertebrates. The most dominant fish were small in size, of which Zacco platypus and Cyprinus carpio were most dominant. Additionally, the Nanguang River fish community possess considerable diversity based on Margalef species richness index, Shannon-Wiener diversity index, Simpson dominance index, and Pielou evenness index values. While there are obvious differences in fish composition across different reaches of the Nanguang River, dam construction and overfishing may have considerably impacted fish distribution and fish resources, the results of which our investigation presents.

The Lancang-Mekong River is the longest river in Southeast Asia, and is one of the richest areas of freshwater biodiversity in the world. Because it is an international river through six countries and holds extremely high fish biodiversity, there is a lack of systematic understanding of freshwater fish diversity. Over the past two decades, this team systematically compiled a list of freshwater fish species in 32 sub-basins or tributaries in the upper and middle reaches of the Lancang-Mekong River. Now in this paper, the species composition and distribution of fish have been analyzed, and the species diversity of the upper and middle reaches of the Lancang-Mekong River has been evaluated using the taxonomic diversity index. The results showed that 745 species of freshwater fish were recorded in the middle and upper reaches of the Lancang-Mekong River. These fish belong to 229 genera, 63 families, 17 orders and 2 classes. Of these, 451 species of Cypriniformes fish accounted for 60.5% of the species. The taxonomic diversity index showed that, from the source to the middle reaches of the river, the taxonomic distribution of freshwater fish became increasingly more even, the relationships were increasingly further apart, and the fish diversity gradually increased. Cluster analysis (CA) and multi-dimensional scaling analysis (MDS) results showed that the 32 sub-basins could be divided into three groups (Jaccard similarity coefficient=8.69), and the analysis of similarity (ANOSIM) indicated that the composition of freshwater fish differed significantly between the groups (R = 0.877, P = 0.001). Similarity percentage analysis (SIMPER) results indicated that Cypriniformes and Siluriformes were the main fish that differed among the three groups, and the species composition of groups presented distinctive changes at the family and species levels with the altitude rising. With the rapid population growth and economic development of the countries in the river basin in recent decades, the fish diversity and fishery resources of the Lancang-Mekong River face serious threats. Thus, it is urgent that countries in the river basin cooperate and formulate a scientific protection plan at the basin scale.

To explore spatial patterns and environmental factors affecting ground ant species diversity in the Thousand Island Lake, China, we surveyed ground ants using pitfall traps, leaf litter extraction and hand collecting on 33 islands from May to August in 2017 and 2018. We divided all ground ants into predator or omnivore ants and then used the regression models to analyze relationships between ant species diversity and island attributes. Island area had positive effects on species richness of total ants, predator ants and omnivore ants; but isolation had no significant effects. The β diversity of ants was dominated by spatial turnover component. Difference in island area had positive effects on the nestedness-resultant component of total ants, predator ants and omnivore ants communities. Difference in isolation had significant positive effects on the total β diversity of omnivore ants. Island area was the main factor affecting spatial patterns of ant species richness. In addition, island area affected the β diversity of ants via changing nestedness-resultant component, which indicates a selective extinction process in ant community assembly. Different responses of predator ants and omnivore ants to island attributes may be due to variation of dispersal ability.

The macrobenthic communities of estuaries are often indicative of important community traits, such as the environmental pollution a community may experience. To better understand the structure of Pearl River Estuary’s macrobenthic community, macrobenthic species were identified based on investigations carried out from November 2014 to August 2015, and biodiversity analyses were performed. More specifically, biodiversity index calculations, cluster analysis, and nMDS (non-metric MDS) analysis were performed used PRIMER 6.0 software. While 52 macrobenthic species were identified in the Pearl River estuary, the dominant species in this study area were Potamocorbula laevis, Glaucomya chinensis, Potamocorbula ustulata and Dendroneris pinnaticirrus. The annual mean density of macrobenthos in the Pearl River Estuary was 269.3 ind./m ² and the annual mean biomass was 129.61 g/m ². The mean values of richness index (D), evenness index (J') and Shannon-Wiener diversity index (H') of 12 samplings were 1.81 ± 1.38、0.50 ± 0.27 and 1.60 ± 1.13, respectively. The results showed a range of environmental quality from clean to severe pollution, in which only P01 section indicated clean environmental quality in autumn and winter. Cluster and nMDS results revealed that low community similarity were observed among P01 section and P02 together with P03 sections, potentially due to the geographical distribution factors. Additionally, the P02 section and P03 section gathered crosswise with higher community similarity. Our results suggested the combination of environmental factors with physical and chemical sediment factors were significantly correlated with the distribution characteristics of communities. Also to note, water salinity and pH can help explain the biodiversity distribution pattern of the microbenthic community in the Pearl River Estuary.

Cytospora chrysosperma is a very important pathogenic fungus that can be infects many different trees. Currently, the diversity, phylogenetic and genetic relationships of C. chrysosperma remain unclear as host differences could cause substantial genetic and diverse differences among C. chrysosperma strains. To analyze the genetic, phylogenetic, and current diversity of C. chrysosperma, physiological and biochemical characteristics and genetic tests were performed from different hosts in Xinjiang. Using molecular markings Biolog-FF and ISSR, 47 strains of C. chrysosperma have been divided into 15 types. Strains were cultured and displayed varying culture characteristics and carbon source utilization and metabolic capacity traits. Each strain tended to utilize more carbon over time, however, strains varied in their carbon source preferences and metabolic capacities. Using cluster analysis, 47 strains of C. chrysosperma divided into two clusters based on genetic similarity (0.58), suggesting genetic structure is essential to understanding C. chrysosperma diversity, as host species and geographical origins were not significant.

Understanding key species and their roles and impacts within communities plays a vital role in protecting key species within communities. Species relationship indicators, i.e., betweenness centrality (BC), closeness centrality (CC), and degree centrality (DC) measured food web connectivity among a community of 49 species. Once indicators were calculated, a clustering analysis analyzed species influences on connectivity robustness among different species classes. In addition to clustering analysis, node removal was tested to measure connectivity robustness under removal modes. Based off of clustering results, species were divided into three food web classes: (1) Class I species have relatively higher BC, CC, and DC values. (2) Class II species have relatively lower BC, CC, and DC values while (3) Class III species are intermediate between Class I and Class II species. In our analyses, it appeared that Class I species are more important for food web processes and are therefore considered key species, contributing to our understanding of how to quantify key food web species. Besides, the connectivity robustness decreased along with the increase in removed nodes under the ascending order removal mode. In the descending order and random removal modes, the connectivity robustness slightly increased after a continuous decrease along with the increase in removed nodes. It indicates that removal modes significantly affect the connectivity robustness. Moreover, under the three removal methods, the significant change in the connectivity robustness corresponds to almost the same number of removed nodes. It suggests key species play an essential role in maintaining the connectivity robustness of the food web.

The Vegetation Map of the People’s Republic of China (1:1,000,000) is the most important dataset for vegetation studies in China. However, some vegetation formations were not included in the Vegetation Map of China due to limitations of data and mapping techniques in the last century. In order to update the dataset, we collected data of vegetation formations and their distributions from the literature (1950-present). Based on the phytocoenology-ecology principle, formations with the same dominant species were classified as the same formation. Compared to formations in the Vegetation Map of the People’s Republic of China (1:1,000,000), we added 1,475 new vegetation formations of forests and scrubs.

Aristolochia (s. l.) is widely distributed in tropical, subtropical and temperate regions of the world, with monochlamydeous and tubular flowers, gynostemia, inferior ovaries, axile placentations, pluriovulate capsules, and others as the main characters. It is the largest genus in Aristolochiaceae, which consists of about 600 species. According to Flora of China, there are 45 species in China, 33 of which are endemic. In recent years, many new species have been discovered in China, especially in Yunnan and Guangxi. Additionally, some taxa were confirmed, reinstated, republished and revised. Isotrema, previously treated as a subgenus of Aristolochia, was recently reinstated as an independent genus based on molecular and morphological evidences. This genus has strongly curved calyxes, 3-lobed gynostemia with paired anthers on the outer surface of each gynostemium segment, and basipetally dehiscent capsules. Through extensive field work, careful examination of many specimens, digital photos and related literatures, an updated checklist and identification key of Aristolochia (s. s.) and Isotrema in China are presented here. Relevant discussions and distribution for the 17 species of Aristolochia, 58 species and one subspecies of Isotrema are also provided. Among them, I. mollis and I. neolongifolia are reinstated and illustrated, the relationship among A. gentilis, A. chuandianensis and A. gracillima, and the relationship between I. kunmingense and A. bonatii are discussed, knotty taxa, such as I. ovatifolium complex, I. cucurbitoides complex, I. griffithii complex, I. versicolor complex, I. dabieshanensis complex and suspected species I. saccata, are also discussed.

Camera-trapping provides an excellent tool for biodiversity and wildlife protection research. In this study, mammals and birds in Chishui Alsophila National Nature Reserve were monitored using 20 gridded camera traps. A total of 1,936 independent images (out of 45,953 recognizable images) were collected with an extensive survey effort of 6,370 camera-days during August 2015 to August 2017. We identified 19 mammal species and 28 bird species, of which 7 species were second-class National Protected Wildlife in China. The relative abundance index (RAI: number of records per trap effort) is widely used to assess the regional species abundance. The five most abundant mammal species with highest RAIs in Chishui Alsophila National Nature Reserve were Elaphodus cephalophus, Melogale moschata, Macaca thibetana, Muntiacus reevesi, Sus scrofa, and the five most abundant bird species with highest RAIs were Myophonus caeruleus, Tragopan temminckii, Bambusicola thoracicus, Garrulax chinensis, Pomatorhinus ruficollis. Rarefaction and species accumulation curves suggest that mammal sampling asymptotes around 300 days, suggesting monitoring efforts were sufficient although bird species continued to grow over time. The results of this extensive survey provide a comprehensive diversity study of mammals and birds in Chishui Alsophila National Nature Reserve and may provide primary baseline data for biodiversity management resources.

With the increasing exploitation of marine biodiversity, conservation is facing several challenges. The Intergovernmental Conference to create an international legally binding instrument (ILBI) under the United Nations Convention on the Law of the Sea (UNCLOS) on the conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction (BBNJ) was convened. They aimed to address the gap between conservation and sustainable use of marine biological diversity in areas beyond national jurisdiction. One of the core talking points of the ILBI, area-based management tools (ABMTs), including marine protected areas (MPAs), were widely recognized as a key mechanism for conserving and restoring biodiversity. Though the process of creating the ILBI is still in its early stages, there has been a lack of common understanding among United Nations (UN) member states regarding the elements of this new protocol. Thus, here we analyze the differences and commonalities of definitions and objectives from the UNCLOS, as well as other instruments and frameworks, relevant global, regional and sectoral bodies, general principles and approaches, current legal and policy frameworks, technological challenges and stakeholder engagement. Our recommendations to increase understanding of ABMTs/MPAs include improving the scientificity of establishing MPAs, establishing effective monitoring and enforcement mechanisms and strengthening international cooperation for the establishment of ABMTs/MPAs in areas beyond national jurisdiction.