With global decreases in species diversity, the effects of species diversity on aboveground biomass of forest communities, especially tropical forests which store nearly half of terrestrial carbon, have received much attention. It is commonly assumed that species diversity can promote the accumulation of aboveground biomass in forest communities. However, increasing evidence suggests that this positive effect of species diversity can be influenced or neutralized by structural diversity and various abiotic environmental variables. It is still far from clear whether scale dependent effects of various drivers of aboveground biomass exist. Using structural equation modeling, we examined direct and indirect drivers of aboveground biomass in a 50 ha tropical forest dynamics plot on Barro Colorado Island (BCI), Panama. Our results showed that the effect of species diversity on aboveground biomass was non-significant at the smallest scale and became significantly negative at larger scales. The strength of this negative effect increased with spatial scales. Conversely, structural diversity had a significant positive effect on aboveground biomass and the strength of this effect decreased with scale. Abiotic variables had some relationships with both types of diversity and can indirectly affect aboveground biomass. These results suggest that positive relationships between species diversity and aboveground biomass in conventional studies may be caused by structural diversity. The relationship between species diversity and aboveground biomass is more likely to be negative, due to under the gap dynamics and strong asymmetric competition in forest communities.

Medicinal root plants often produce a continuous crop obstacle due to allelopathy during cultivation. Apocynaceae plants are important medicinal plants belonging to tropical flora. Allelopathy is one of the major causes of density dependence. To explore whether density dependence likely exists in root type medicinal plants under natural conditions, we analyzed the species distribution and spatial intraspecific and interspecific correlations of two root medicinal plants of Apocynaceae (Alstonia rostrata and Tabernaemontana bufalina), using a point pattern analysis of pair correlation function Ripley’s g(r) method with complete spatial randomness (CSR) and heterogeneous Poisson (HP). The impacts of topographic factors on the distributions of the two species were analyzed using a Berman-test. Results showed that the spatial patterns of the A. rostrata and T. bufalina were mainly aggregated at 0-100 m scales, while the former’s spatial pattern was still aggregated and the latter became a random pattern within this scale. The spatial patterns of A. rostrata and T. bufalina changed similarly with increases in age stage, as young and middle-aged trees showed aggregated distributions within a larger scale, while adult trees became randomly or uniformly distributed. The spatial association between different age classes individuals of A. rostrata showed that the relationship between young and middle-aged trees was positively associated at the small scale, while it was negatively associated between young and adult trees, and there was no association between middle-aged and adult trees. Positive associations were found between different age classes individuals of T. bufalina within the larger scale (0-65 m), which indicated that different DBH class individuals were consistent with environmental selection. Interspecific associations between A. rostrata and T. bufalina showed positive associations at 0-49 m scale. The spatial association between middle-aged, adult trees of A. rostrata and similarly aged trees of T. bufalina showed no significant correlation, while obvious positive spatial correlation was found between young trees of these two species. Significant positive correlation was found between young trees of these two species and elevation and convexity. We also found significant positive correlations between convex and middle-aged trees of these two species, while only adult trees of A. rostrata showed positive correlation with the degree of slope. We inferred that environmental heterogeneity and diffusional limitation played important roles in the formation of current spatial patterns of woody Apocynaceae in the tropical montane rainforest of Jianfengling, while compared to T. bufalina, density dependence plays a more significant impact on the spatial patterns of A. rostrata.

The Ma’anling volcanic area in Hainan Province, located in the southwest portion of Haikou, is the only tropical island volcano group of China, and contains China’s typical tropical and subtropical biological communities. We carried out a field investigation of the vascular plants in the area. In this paper, we examined the origination and evolution of flora, listing all plants in the region and analyzing the taxonomy and phylogenetic diversity. Results showed that there were 284 species of vascular plants in the Ma’anling area of Haikou belonging to 88 families and 241 genera, which included 194 native species, 23 exotic invasive species, 31 naturalized species, 40 cultivars and 4 rare and endangered plant species. In general, plant species were abundant in the crater area of the saddle ridge and species diversity of the trees under different land use regimes (plantation, secondary forest, and wasteland) was significant, whereas species diversity of shrubs and grasses in different land types was not significant. There were significant diversity differences between the plantations and the wastelands, while the diversity differences between the secondary forests and the plantations were insignificant. In addition, flora was mainly composed of tropical taxa that are most closely related to the flora of Guangdong; likewise, the flora of Vietnam and Guangxi are also closely linked. This study provided a basis for further exploration of flora as well as plant protection and utilization in the area.

Litter fall provides organic matter and nutrients to forest ecosystems and is central to the exchange of substances between soil and plants. It plays a vital role in the maintenance of soil organic matter and nutrient cycling in forest ecosystems and it is one of the main sources of soil fertility. We used litter fall data for six common tree species collected between March 2014 and February 2015 from 90 litter fall traps, and fifty soil samples collected in July 2014 along an altitudinal gradient from 185 to 368 m in a tropical karst forest in Guangxi, China. We studied the C, N and P stoichiometric characteristics of soil and litter fall, and their trends along an altitudinal gradient. Soil C and N contents were all positively associated with altitude, while P content was negatively associated with altitude. Soil C : N was negatively associated with altitude, while C : P and N : P were positively associated with altitude. Due to the narrow altitudinal range of the soil samples, we speculate that the association of soil nutrients with altitude is due to the effect of micro-topography and not a climatic effect. Apart from the higher slope and summit, the soil C, N, P contents reached the first classification level of the national criterion of soil nutrients. Compared with other forest ecosystems, we found greater C and N contents and lower P content than the average value of C, N, P contents for litter fall of six common species. There were no trends for C, N and P stoichiometric characteristics of the mixed sample of leaf litter for the six common tree species along an altitudinal gradient. The six common tree species have higher C content in spring and higher contents of N and P in summer. The per unit total basal area of trees in this forest was much lower than other forest ecosystems, indicating its low biomass stock. This study provides useful information for ecological restoration of a typical vulnerable karst ecosystem in China.

Halo-tolerant plants compose a huge group of plants with unique ecological and economical value. Little is known about their DNA barcoding speciality. In this study, 562 samples of coastal halo-tolerant plants (including 53 families, 97 genera and 116 species) were collected from 10 coastal provinces, ranging from Liaoning to Hainan. Three chloroplast DNA markers (matK, rbcL and trnH-psbA) and one nuclear DNA marker (ITS) were amplified and sequenced. Primer universality and sequence availability of each locus were examined and species resolution rates were tested. When considering sequence availability, matK and trnH- psbA were among the best. But the primer universality of ITS was marginally worse than expected. The all-to-all BLASTn searches indicated that the species resolution rate of ITS was the highest (73.36%), followed by those of matK (64.03%), trnH-psbA (61.21%) and rbcL (46.41%). Phylogenetic trees (NJ trees) indicated that the species resolution rate of matK was the highest (82.3%), but no reliable NJ tree based on trnH-psbA could be acquired because of unequal sequence length. NMDS and PCoA results demonstrated that both chloroplast DNA markers and nuclear DNA markers should be considered when conducting coastal plant DNA barcoding studies. Based on the above results, we suggest that the combination of ITS + matK should be regarded as the barcode for halo-tolerant plants in Chinese coastal regions. In total, the 1939 newly acquired sequences in this study lay the foundation for a DNA barcode database of costal halo-tolerant plants.

It has been shown that the established nature reserves will affect the surrounding ecological environment, that is, the space neighborhood effect on nature reserves. At present, the ecological environment of the surrounding areas of some nature reserves has changed greatly, especially in the temporal and spatial changes of artificial objects. To study the space neighborhood effect on nature reserves based on temporal and spatial changes of artificial objects will do significant help to maintain the survival and safety of nature reserve and its protected objects. To analyze the variation intervals of the space neighborhood effect and the distance scale, and to identify the driving factors, we chose Ningxia Shapotou National Nature Reserve as a case study. We divided the study area within a range of 20 km around the nature reserve, extracted the artificial objects from the remote image analysis between 1990 and 2015, and used Mann-Kendall trend analysis and driving factor correlation test analysis, to assess the space neighborhood effect of nature reserves based on temporal and spatial changes in artificial objects. Results showed that the areas and patterns of artificial objects were expanding, which meant the impacts of human activities were increasing over time. In addition, the space neighborhood effect was most evident with increases in time and decreases in the distance scale. Trends in the space neighborhood effect were divided into three descending intervals, and the driving factors differed. In the first interval (1-5 km), the trend was occasionally significant, and shelter forest was the main driving factor. In the second interval (6-10 km), significance of the descending trend could be observed, and building became the driving factor. Lastly, the driving factor was farming, and a very significant descending trend was found in the third interval (11-20 km). Since the establishment of the Ningxia Shapotou National Nature Reserve, its surrounding land-use changes are significantly influenced by human activities, which needs attention.

During the past two decades, camera-trapping has been widely used in biodiversity monitoring and wildlife research across China. Most of the existing camera-trapping projects focus on mammals, and birds are frequently considered in by-catch records. We analyzed 230 wildlife camera-trapping research projects in China since 1992, on the basis of an exhaustive review of Chinese and English literature, including published articles, conference reports, public news, and additional unpublished datasets. Results showed that at least 393 wild bird species, belonging to 17 orders and 56 families and accounting for 28.67% of the total number of bird species in China, have been documented using camera-trapping since 1992. The order with the most recorded species was Passeriformes (268). On the family level, Turdidae had the highest number of recorded species (58), followed by Timaliidae (50) and Phasianidae (42). There were 23 families that each only had one recorded species. Ground- and understory-dwelling forest birds accounted for the majority of all birds recorded, in terms of either species richness or camera detections. Published bird records were characterized by regional imbalances. Sichuan and Yunnan provinces were the most surveyed provinces, with 16 and 14 sites, respectively. The highest species richness was recorded in Sichuan (160), followed by Yunnan (91) and Zhejiang (66). A total of 104 new regionally recorded species were reported. Given the fact that there is still an abundance of camera-trapping data that has not been published, we speculated that the actual recorded bird species should be higher. These results indicated that camera-trapping can produce considerable bird distribution data of high accuracy, high quality and large amounts, which may provide a significant contribution to biodiversity monitoring and regional inventories of birds in China. Terrestrial birds, including Galliformes, Turdidae and Timaliidae, should be included as one of the target groups in current and future monitoring networks using standardized camera-trapping techniques, and such networks could also complement data and support the inventory and diversity monitoring of other taxa.

Based on the classical morphological and molecular taxonomy, 55 scleractinian coral species, belonging to 17 genera and 10 families, were recorded in five different coastal areas (Yunlong Bay, Wenchang; Dazhou Island, Wanning; Linqiangshi Island, Danzhou; Shayutang Village, Changjiang; Luhuitou, Sanya) of Hainan between 2014 and 2015. The dominant families included Acroporidae, Poritadae and Faviidae. The community structures of coral reefs in the five coastal areas were different. In Sanya, located in the south of Hainan, branching Acropora corals dominated the coral communities. In Wenchang and Wanning, on the eastern coast of Hainan, the laminar and branching Montipora corals were the dominant groups. In contrast, the mass corals Poritadae and Faviidae dominated the western coast in Danzhou and Changjiang. Analyses of community structure indicated that different geographic environments regulated successional differences. Coverage rates and diversity index values had a positive correlation and were as follows: Sanya > Wenchang > Changjiang > Wanning > Danzhou. Compared with the data obtained between 2005 and 2010, the coverage rates and diversity index values increased in Wenchang and Wanning and were relatively stable in Sanya and Changjiang, but showed an obvious decrease in Danzhou. However, the death rate of scleractinian corals was the highest in Changjiang, and most of the corals died within the last six months of 2015. In our opinion, human activities (including both protective and destructive activities) greatly affected coverage rates, death rates and diversity of the coral reefs.

Wolong National Nature Reserve is the core nature reserve in the reserve network found in the Qionglai Mountains. Between 2014 and 2016, we conducted a baseline survey in Wolong on large fauna using camera-trapping. After an extensive survey effort comprised of 10,961 camera-days from 83 camera stations in 58 survey blocks (1 km × 1 km each), we recorded 32 wild and 4 domestic mammal species (belonging to 6 orders and 15 families) with 2,095 detections. Five and eleven mammals were listed as Class I and Class II Nationally Protected Wildlife, respectively, and 4, 6, and 4 species were listed as EN, VU, and NT species, respectively, according to the IUCN Red List. Among the recorded wild mammals, Carnivora was the order with the greatest species richness (16 from 6 families), followed by Artiodactyla (8 from 4 families) and Rodentia (5 from 2 families), whereas Artiodactyla was the order with greatest detection (accounting for 63.33% of all mammal detections), followed by Carnivora (20.01%) and Rodentia (5.73%). The most detected species in Carnivora was the hog badger (Arctonyx collaris, RAI = 12.23), and tufted deer (Elaphodus cephalophus, RAI = 32.21) in Artiodactyla. Three large apex carnivores were detected in Wolong, including snow leopard (Panthera uncia), wolf (Canis lupus) and dhole (Cuon alpinus). We recorded 59 bird species (belonging to 5 orders and 18 families) with a total detection of 655, including 4 newly recorded species in the reserve. Pheasants (Galliformes) had the highest detection of bird groups and accounted for 56.76% of all bird detections. Our results provide basic information on the community structure, spatial distribution and relative abundance of terrestrial wild mammals and birds in Wolong, which provide support and guidelines for reserve management and long-term monitoring of Wolong.

This research surveyed the current situation on the trade of alien species in pet markets in Beijing, Shanghai, Nanjing, Guangzhou, and Harbin, in order to systematically understand the trade scale, to prevent the ecological disasters with alien species, and to develop effective management policies. The investigation was undertaken in 20 pet markets in five cities using the key survey and on-the-spot investigation methods. Results are as follows: (1) 96 alien wildlife species were recorded, among which 29 were threatened species, accounting for 30%, and 35 were CITES Appendix species, accounting for 36%. (2) The highest number of alien species and IUCN red listed species were found in Beijing. However, the greatest number of species found in the local survey and the number of species included in CITES Appendix I / II were found in Guangzhou. (3) The trade volume of 41% of species and 61% of CITES Appendix species were less than 10. (4) The trade prices of 45% of species were between 100 and 1,000 RMB, which was the acceptable price range for most consumers. According to this study, important measures must be undertaken to strengthen trade supervision, combat illegal trade, regulate behavior of animal releasing, and raise public awareness on controlling the trade of alien wildlife in Chinese pet markets.