Supervisor(s): Chinese Academy of Sciences Sponsor(s): Biodiversity Committee of the Chinese Academy of Sciences, CAS;Botanical Society of China; Institute of Botany, CAS;Institute of Zoology, CAS;Institute of Microbiology, CAS CN：11-3247/Q
Biodiversity Science（formerly Chinese Biodiversity）published its first issue in October 1993. It is sponsored by the Biodiversity Committee of the Chinese Academy of Sciences (CAS), Botanical Society of China and jointly managed by Institute of Botany, Institute of Zoology and Institute of Microbiology, CAS. It is the first nationwide academic journal that specifically addresses the issues of biodiversity, aiming to enhance information exchange between Chinese and international scholars.
Editor-in-Chief Ma Keping
Deputy Editor-in-Chief Fu Shenglei;Guo Liangdong Jiang Zhigang;Kong Hongzhi Li Bo;Xue Dayuan
Camellia oleifera is the dominant woody oil crop in China, and wild C. oleifera is a valuable genetic resource for C. oleifera breeding. Using the distribution data of wild C. oleifera from the Chinese Virtual Herbarium (CVH, http://www.cvh.org.cn/), together with climate and soil data, ecological niche models were constructed with MaxEnt and genetic algorithm for rule-set prediction (GARP) models to predict the potential distribution of wild C. oleifera, and the major environmental factors influencing the distribution of wild C. oleifera were analyzed. Based on the presence probability of wild C. oleifera predicted by the models, the distribution regions of wild C. oleifera were divided into different suitable growing categories, which were then compared with actual distribution data of major C. oleifera production fields to evaluate reliability. Results indicated that the predictions of both MaxEnt and GARP models represented the distributions of C. oleifera well. The potential distribution range predicted by the GARP model was wider, while that predicted by the MaxEnt model was more accurate. The predictions of both the MaxEnt and GARP models showed that the potential distribution regions of wild C. oleifera were located mainly in China and partly in the Indo-China Peninsula. According to the predictions of the MaxEnt model, the potential distribution regions of wild C. oleifera in China matched with the distribution regions of subtropical evergreen broad-leaved forests, and the high suitable growing regions could be divided into three large regions: (1) northeastern-southwestern trending Wuyi Mountain and adjacent mountainous regions; (2) easternwestern trending Nanling Mountain and adjacent mountainous regions; (3) northeastern-southwestern trending Wuling Mountain and adjacent mountainous regions. The analysis of the MaxEnt model showed that the major environmental factors influencing the distribution of wild C. oleifera were mean monthly diurnal temperature range, precipitation during the driest quarter, and precipitation during the warmest quarter. The vast majority of the regions with large growing areas of C. oleifera were located in the medium to high suitable growing regions predicted by the MaxEnt model, suggesting that the division of suitable growing regions was reliable. The field investigations showed that the model predictions had high reference values for finding wild C. oleifera resources. Additionally, the study showed that using the plant distribution data from CVH and related environmental data to construct an ecological niche model can help to understand the geographic distribution of crop wild relatives.
Island biogeography theory is an important part of community ecology, and its core process is species turnover, which is determined by species colonization and extinction. A large number of studies have shown that community dynamics of many biotic taxa can be influenced by their dispersal abilities. Our study explored the effects of dispersal abilities on the community dynamics of breeding birds. Between April 2007 and June 2013, we surveyed bird communities using line-transects on 36 land-bridge islands during breeding seasons in the Thousand Island Lake, China. We divided breeding birds into two types according to their dispersal abilities. We then used multivariate logistic regression and the maximum likelihood method to estimate the biogeographical parameters and to analyze community dynamics of these breeding birds. Results showed that birds with strong dispersal ability were less influenced by island parameters than others, with a higher turnover rate. Therefore, the difference of dispersal abilities of breeding birds has significant effects on their community dynamics on the land-bridge islands in the Thousand Island Lake, China.
Ecological niche modeling (ENM) is widely used in the study of biological invasions and conservation biology. Maxent is the most popular algorithm and is being increasingly used to estimate species’ realized and potential distributions. Most modelers use the default Maxent setting to fit niche models, which originated from an earlier study containing 266 species, with the purpose of seeking their realized distributions. However, recent studies have shown that Maxent uses a complex machine learning method. It is sensitive to sampling bias and tends to overfit training data, and is only transferrable at low thresholds. Default settings based on Maxent outputs are sometimes not reliable, making it difficult to interpret. Using Halyomorpha halys and classical modeling approaches (i.e., niche models that were calibrated in native East Asia and transferred to North America), we tested the complexity and performance of the Maxent model under different settings of regulation multipliers and feature combinations, and chose a fine-tuned setting with the lowest complexity. We then compared the response curves and model interpolative and extrapolative validations between models calibrated using default and fine-tuned settings. Our purpose was to explore the effects of the model’s complexity on niche model performance in order to improve the development and application of Maxent in China. We argue that selection of environmental variables is crucial for model calibration, which should include ecological relevance and spatial correlation. Reducing sampling bias and delimitating a proper geographic background, together with the comparison of response curves and complexity of Maxent models built under different settings, is very important for fitting a good niche model. In the case of H. halys, the default and fine-tuned settings are different, however the response curve is much smoother in the fine-tuned model, and the omission error is lower in introduced areas when compared to default model, suggesting that the fine-tuned model reflects the response of H. halys to environmental factors more reasonably and precisely predicts the potential distribution.
The Himalayas are a biodiversity hotspot. In this study, the taxonomic diversity of climbing plants in the Himalayan region and its connection with neighbouring regions were analyzed, the distribution patterns of climbers in the Himalayas and the Indo-Gangetic Plain were compared, and mechanisms were discussed. Results showed that: (1) The Himalayan region harbored a total of 1,083 climbing species in 309 genera and 72 families. Approximately 66.9% (725 species) of these species were woody or semi-woody climbers (lianas) and the remaining 33.1% (358 species) were herbaceous (vines). Twining climbers accounted for 51.3% of the climbing plants in this region. (2) The climbing plant flora in the Himalayas was significantly affected by neighboring floras. About 74.1% (802 species) of the climbers in the Himalayas were also found in Southeast Asia, 548 species (50.6%) were found in South Asia, and 530 species (48.9%) were found in Southwest China. Only 125 climbers (11.5%) were endemic to this region and no endemic genus was recorded. (3) Species diversity of climbing plants and their proportion in the flora gradually decreased from east to west in the Himalayas. Twining climbers and lianas became more dominant in the western regions. At the genus level, species diversity of most climber-rich genera decreased westward across the Himalayas and species diversity of only a few genera (e.g. Vicia and Cuscuta) showed an increase from east to west. (4) The distribution patterns of climbing plants in the Himalayas and the Indo-Gangetic Plain were consistent. However, species diversity was higher in the Himalayas and its decreasing trend westward was more significant. At the genus level, the average decreasing rate of CCGs from east to west is 8.4 genera per 100 km in the Himalayas and 6.3 genera per 100 km in the Indo-Gangetic Plain. A total of 272 CCGs in the Himalayas were shared with the Indo-Gangetic Plain, and 196 genera were not found in the west regions (Central Asia and Iranian plateau). In the 196 genera, 61 genera (31.1%) were distributed more to the west in the Himalayas than in the Indo-Gangetic Plain, while only 8 genera (4.1%) were distributed more to the west in the Indo-Gangetic Plain than in the Himalayas. In conclusion, species diversity and distributional characteristics of climbers in the Himalayas were attributed in part to the geographical location of this region, the altitudinal and longitudinal gradients of climate and habitats, and the diversification of adjacent floras. The similarities of the distribution patterns of climbing plants in the Himalayas and the Indo-Gangetic Plain may be primarily due to similar east-west water gradients.
As the seedling stage is the bottleneck in forest tree regeneration, knowledge of the composition and structure of seedlings is crucial to understanding the mechanisms of community assemblage and diversity maintenance. However, based on the limited sampling intensity which is common in previous studies, seedling census datasets are representative of common species, but are ineffective for monitoring rare species. In this study, we established a new seedling monitoring network in the 24 ha GTS (GTS) forest dynamics plot (FDP) consisting of 285 seedling quadrats (5 m × 5 m) in 2012. In the seedling quadrats, all woody plants (DBH < 1 cm and height ≥ 10 cm) were tagged, mapped and measured every two years. We used the first census data to investigate seedling composition, species diversity patterns, seedling, and non-seedling species habitat association. Our results are as follows. (1) There were 138 species, consisting of a total of 20,581 individuals in 285 seedling quadrats of 5 m × 5 m. The Shannon-Wiener diversity index and Rarefied species abundance were higher than those of the 1 m × 1 m seedling quadrats and 24 ha FDP census (DBH ≥ 1 cm). Similar results were found when using rarefaction approach. Compared with 1 m × 1 m seedling quadrats, the number of species showed a significant increase and the species-area curve became more asymptotic. (2) The relationship between seedling abundance and tree species exhibited negative allometry, suggesting that the mortality of plants at the seedling stage was relatively high compared with the rate found at the non-seedling stage due to the negative density dependence. (3) Sampling intensity and selection of DBH cutoffs influence the definition of rare species. Some rare species defined by trees with DBH ≥ 1 cm were not actually rare when individuals with DBH < 1 cm were considered (i.e., Ardisia crenata, Litsea cubeba, Lespedeza thunbergii subsp. formosa). (4) The indicator species of the 5 m × 5 m seedling quadrats were different from those found in the 24 ha FDP and the 1 m × 1 m seedling census. A total of 13 species were significantly correlated with single habitat type in these 5 m × 5 m seedling quadrats, which shared only three species that identified as indicator species for 1 m × 1 m seedling quadrats and two species for non-seedling quadrats. In conclusion, sampling intensity influenced patterns of tree seedling composition and community diversity, and increasing sampling intensity can provide deeper insights into the processes of diversity maintenance.
By combining the classical faunal analysis method and the value of faunal presence method, we analyzed fish diversities and their representatives in three first level tributaries including Nangunhe, Nantinghe and Mengboluohe in Yunnan to the midstream of Salween River system, to compare the difference in values of fish faunal presence and to analyze the characteristics of the faunal composition and the importance of families and genera in fauna formation. The purpose of the study was to explore the guiding role of the fish faunal presence value index in planning and establishing fish nature reserves. Results showed that a total of 74 endemic species were recorded in midstream of Salween River system in the Yunnan section, belonging to 5 orders, 12 families, and 45 genera. 53 species were recorded in these three first level tributaries, belonging to 5 orders, 12 families, and 38 genera, among which there are 32 species, 23 genera, 9 families in Nangun River; 47 species, 33 genera, 11 families in Nanting River; and 33 species, 26 genera, 10 families in Meng Bo Luo River. Sorted by species absolute number, Cyprinidae, Cobitidae and Sisoridae ranked the top 3 families in the three first level tributaries. Sorted by the fauna presence value, Anguillidae, Channidae, Mastacembelidae, Cobitidae, Synbranchidae and Sisoridae ranked the top 5 families in the three first level tributaries. The results from the two methods were consistent with one another. The faunal presence value in the same genus changed greatly in the different tributaries, and the regional distribution features of the genus and species became obviously. The fish composition in the three first-level tributaries was composed of a primitive group from the Palaeogene, a group that originated from the south, and a small number of taxa that originated from Qinghai-Tibet Plateau. The results of the fish fauna presence values indicated that one or more of the first level tributaries should be selected as reserves in the upstream, midstream and downstream of the main stream when setting up freshwater fish natural reserves. The greater the taxa of orders and families with a high fauna presence value covered when planning fish natural reserves, the greater the protection, which was not an element must be considered. However, the fauna presence value of the genera should be a special concern when planning reserves.
