Studying community phylogenetic diversity within forest stands of different diameter classes (i.e. size classes) is helpful for understanding relationships among species at different ages while at the same time community phylogenetic structure. However, little research has been focused on the influence of species abundance on phylogenetic structure of community. This study was conducted in the Jianfengling tropical montane rainforest on Hainan Island. First, we assessed the impact of species abundance on four widely used phylogenetic diversity indices at different size classes. Next, two of the indices (i.e. net relatedness index, NRI and nearest taxon index, NTI) were standardized and used to quantify phylogenetic relatedness of woody plants at different size classes across a series of local habitat types. The results showed that: (1) The unweighted MPD (mean pairwise distance) index significantly overestimated phylogenetic diversity relative to MPD weighted according to species abundance. This overestimation when using unweighted MPD was greatest for small trees and shrubs (1 cm≤DBH<5 cm). Therefore species abundance information should be taken into consideration in the study of phylogenetic structure of community when most of the trees and shrubs are young and small. (2) The community phylogenetic structure was most likely overdispersed among almost all size classes and habitats of the Jianfengling tropical montane rainforest (NRI<0). This phylogenetic overdispersion increased as size class increased. (3) The partial community phylogenetic structure tended to be clustered at middle and small size classes (NTI>0). However, this pattern continued to show overdispersion within communities made up of large trees (DBH≥15 cm) (NTI<0). In summary, studies assessing the influences of species abundance and size classes on community phylogenetic structure are required.

Species abundance distribution (SAD) delineates abundance of all species sampled within a community. As one major stepping stone in understanding the community, the generation mechanisms of SAD have attracted much attention. Evergreen and deciduous plants are two types of species with distinct phenological traits and growth strategies. They widely coexist in evergreen broad-leaved forests (EBLFs). Compared to deciduous plants, evergreen species have slightly lower species richness but substantially higher abundance and basal area in the 20 ha EBLF plot at Tiantong. This study independently analyzing their SAD characteristics provided a new perspective on the understanding of species diversity maintenance in EBLFs. Therefore, in order to compare SADs and determine reasons for differences, an empirical cumulative distribution function (ECDF) was utilized to describe the SADs of evergreen and deciduous trees in Tiantong plot. A Kolmogorov-Smirnov test (K-S test) was employed to detect the significance of these differences. Additionally, three types of models, including statistic model (log-normal model and log-series model), niche model (broken-stick model and niche preemption model) and neutral theory model (metacommunity zero-sum multinomial distribution model and Volkov model), were used to fit the SAD of each lifeform. The K-S test and AIC values were applied to test the goodness of fit for each model. We found that the differences in SAD between the two life forms were not significant based on the results of the K-S test. Among the three types of models, the neutral theory model was the best fitting model, and the niche model was the poorest fit. Thus we conclude that evergreen and deciduous trees had similar SAD patterns, although they differed in species richness and abundance. However, the model fitting results were found to be a necessary but insufficient condition in understanding the maintenance mechanism of biodiversity. Hence we may only preliminarily conclude that neutral processes had a major effect on the generation of biodiversity patterns of both evergreen and deciduous trees, whereas the possible contributions made by other processes, such as niche differentiations, could not be excluded and measured by this method.

It has been found that density dependence plays a crucial role in determination of species distribution and coexistence, and the effect of negative density dependence also plays an important part among phylogenetically related species. Based on two census datasets in 2009 and 2014 of the 1-ha deciduous broad- leaved forest plot in Baotianman National Nature Reserve, generalized linear mixed models (GLMMs) were used to examine the density dependence on individual survival of the top 11 species (with high important value) at different neighborhood scales and different DBH sizes (1 cm ≤ DBH< 5 cm, 5 cm ≤ DBH < 10 cm, DBH ≥ 10 cm). The results showed that (1) mean annual mortality and recruitment rate of individuals (DBH ≥ 1 cm) were 5.85% and 0.27%, respectively; (2) survival rate of 5 tree species was negatively correlated with abundance or neighbor conspecific basal area; (3) density dependence and phylogenetic diversity exerted significant effects on survival of small individuals (at 5 m neighborhood scale), whereas no significant influence on medium trees. With increasing tree size, phylogenetic diversity exerted important effect on large individuals at 7.5 m and 10 m neighborhood scales. In conclusion, density dependence and phylogenetic diversity play different roles on tree survival at different life stages and neighborhood scales in the deciduous broad-leaved forest in Baotianman National Nature Reserve.

The expansion of Phyllostachys edulis into the adjacent secondary evergreen broad-leaved forest (EBF) is obvious and greatly affects its ecological function. Little research has examined its effects on community structure and biodiversity. We comparatively analyzed the characteristics of species composition, community structure and diversity before and after the expansion of P. edulis forest (PEF), P. edulis-broad-leaved mixed forest (PBMF) and EBF along a gradient of P. edulis expansion in the Jinggangshan National Nature Reserve in Jiangxi Province using a space for time substitution method. Results indicated that: (1) The Bray-Curtis similarity index values of the tree layer, shrub layer and herb layer between PEF and EBF were 0.003, 0.046 and 0.030, respectively. (2) The PEF vertical structure showed a “>” type and the abundance percentage was 33.3% in 12-14 m interval, its diameter at breast height (DBH) class structure concentrated distribution in 5-10 cm interval, whose percentage was as high as 90.0%; while the EBF vertical structure showed a “L” type and the abundance percentages was 54.3% in 2-4 m interval, its DBH class distribution range was relatively wide, the average percentage of four larger diameter grades was 10.3%. (3) The Shannon-Wiener index value in the tree layer declined from 2.56 in EBF to 0.06 in PEF, with a reduction of 98%. In the shrub layer, the index value dropped from 2.58 to 2.03, declining 21%. We suggest that the expansion of P. edulis simplified the community composition and structure of the secondary evergreen broad-leaved forest and reduced species diversity, which can cause adverse impacts on forest ecosystem functioning.

Understanding how overall patterns of spatial variation in species richness are affected by species distributional is one of the key questions in species diversity research. In the present study, we investigated the relative contributions of common and rare species to overall plant species richness in the Liaodong oak (Quercus wutaishanica) forest, which is located in the Ziwu Mountains of Loess Plateau, northwestern China. Based on species frequency distribution, we developed rank sequences of the most common to the most rare and the most rare to the most common species. We then correlated the rank sequences with cumulative species distributions. Our results showed that common species had a higher correlation with the cumulative species distribution in comparison with rare species. Moreover, common species had stronger effects on species α diversity and species β diversity as compared with rare species. Although the number of rare species was greater than that of common species, the overall species richness pattern was better predicted by common species than rare species. Therefore, common species were confirmed to be good indicators of species richness pattern and need to be protected priority.

The flowering time plays an important role in the mating opportunities of male and female functions and final reproductive success in plants. The mating environment hypothesis predicts that the differences of flowering time in protandrous species can change individual’s phenotypic gender and the mating environment within a population, finally affect the optimal allocation of resources to sexual functions. To determine the effect of flowering time on sexual durations and phenotypic gender in protandrous plants, we recorded the male and female phase durations of all flowers in protandrous Aconitum gymnandrum (Ranunculaceae), and examined the relationships of flowering phenology and floral sexual durations and phenotypic gender. The results showed that the late flowers (top) had longer male duration versus female duration compared to early those (basal) within a inflorescence, showing temporally male-biased allocation. The relatively temporal allocations to both sexual durations also presented a similar trend among plants with different flowering time. Relatively longer male duration vs. female duration in the later flowers or late-flowering individuals, showed temporally male-biased allocation. Furthermore, individual’s variation in flowering time affected floral sex ratio within population and the dynamics of phenotypic gender of individuals. It showed a shift from male-biased to female-biased gender during flowering season in A. gymnandrum population, because most of the individuals had only male-phase flowers at the beginning of flowering stage and only female-phase flowers at the end. Therefore, mean phenotypic gender of individuals shifted from femaleness to maleness with flowering time. Our results support the mating environment hypothesis, i.e. male-biased floral sexual ratio (mating environment) early in protandrous A. gymnandrum population leads to female-biased phenotypic gender of individuals flowered early and thus female-biased temporal sex allocation in early-flowering individuals and early flowers within inflorescences in comparison with the late-flowering individuals and late flowers.

Biological invasion is now considered one of the three major environmental issues worldwide. Freshwater fish invasion becomes more serious with globalization of the world economy. We reviewed the current status of global freshwater fish invasions and discussed the definitions, distributions, introduction pathways, mechanisms, ecological and economic impacts, and risk assessments of freshwater fish invasions. Non-native fish are mainly introduced through food aquaculture (51%), as ornamental fish (21%), or for sport fishing (12%) and fisheries (7%). The number of introduced fish has reached 624 species, doubled the number found thirty years ago. Successful invasions may bring many negative ecological consequences, such as predation, hybridization, structure and function alteration of local freshwater ecosystems, as well as diseases transmission. However, it also brings positive biological and economic values. The number of fish invasion studies has increased eight times over the last 20 years, with studies mainly focusing on biology and the biological impact of invasive fish species. Risk assessments of freshwater fish invasions were studied over the last 10 years, and fish invasiveness screening models have been applied in countries of five continents. The number of non-native freshwater fish in China totaled 439. However, research papers on freshwater fish invasions in China was only 3.7% of the global total, and these researches were mainly on the distribution and biology of invasive fish species, and very few studies included risk assessments. Therefore, we suggest investigating the history, distribution, and mechanisms of invasive species at the national level, evaluating both the positive and negative effects of freshwater fish invasions, and also reinforcing studies of risk assessments in China.

The Economics of Ecosystems and Biodiversity (TEEB), which provides new insight and approaches for biodiversity conservation and sustainable use, is an integrated approach to assess, demonstrate, and apply policy for biodiversity and ecosystem value. TEEB was firstly proposed in 2007, and has been supported by United Nations Environment Programme (UNEP) since 2008. Ecosystem services include supply services, regulating services, cultural services, and habitat services based on the TEEB framework. The value evaluation methods generally include the direct market value method, revealed preference method and stated preference method. We also summarized the measures to mainstream biodiversity at the global, regional, national and local levels. Presently, more than 30 countries have undertaken studies on TEEB and have produced positive impacts on policy-making and further application of TEEB. For example, at the country level, it can be used to green economy, sustainable development and corporate green management. At the international level, it can support the implementation of the Convention of Biological Diversity and other relevant international action. For the future, this paper suggested TEEB’s focuses: (1) At the international level, it is needed to enhance cross-sector and inter-regional cooperation in biodiversity and promote findings at the science-policy interface; (2) In China, it is needed to build TEEB methodology from the sub-levels (ecosystem, species and gene) and sub-scales (national, provincial and local), and explore the application of TEEB concepts in local development assessment, cadre performance appraisal, paying utilization of natural resources, ecological compensation and other policies in order to promote regional equity and sustainable use of natural resources.

To investigate the phylogenetic status of badgers (Meles sp.) in the Qinghai Lake area and to estimate the divergence time within Eurasian badgers, the cytochrome b gene and the partial control region (CR) of mitochondrial DNA were examined as genetic markers. Our results indicated that Meles is divided into four species. Twenty one haplotypes were identified in 23 combined sequences (1,652 bp) of Cyt b and CR sequences. Results showed that Eurasian badgers were clearly divided into two major lineages: one of Western lineage, composed of badgers from Europe and Southwest Asia, and the other of Eastern lineage, composed of badgers from North and East Asia (including Japan). Furthermore, the Bayesian tree and the haplotype network indicated that the badgers in the Qinghai Lake area are Asian badgers (M. leucurus). The estimated divergence time was consistent with palaeontological evidence. The first split between the Western lineage and Eastern lineage occurred approximately 2.24 Ma. After the separation, the Southwest Asia clade split from Europe approximately 1.27 Ma and the Japan clade split from continental Asia approximately 0.99 Ma.

Field surveys are basic methods for biodiversity research and conservation. During field surveys, geographic conditions are usually complex, knowledge about local geographical information, design of routes for surveying, and the precision of field navigation directly influence the efficiency of fieldwork, and even personal security. Using Google Earth, we can convert and edit various geographic data and overlay these onto a 3 dimensional model of the Earth, to create a comprehensive geo-database. Then, we can choose the location of plots and design the routes of field surveys. By using OruxMaps, which can be installed on an Android mobile device, we can download and compile online maps into offline maps, find current locations, auto-record track logs, display designed routes onto the maps and precisely navigate to target locations. By using these tools interactively, we can easily manage the geographic data, design the routes in field survey and precisely navigate in the field. Thus, we not only enhance the efficiency of fieldwork but also improve personal safety during field surveys.