Distribution Patterns Of Species Diversity Research Articles

Altitudinal variation in soil nematode communities in an alpine mountain region of the eastern Tibetan plateau

Distribution patterns of species diversity in high mountains have received considerable attention in scientific research and conservation efforts. However, our understanding of the corresponding altitudinal patterns of soil fauna across spatial scales, particularly on high-altitude plateaus, remains limited. To address this gap, we conducted a case study on Balang Mountain, located at the eastern margin of the Tibetan Plateau. Our focus was on soil nematodes within an altitudinal range of approximately 3000 to 4000 m. We collected climate, soil, and vegetation data to test multiple hypotheses, including the effects of energy, water availability, productivity, soil resource availability, and pH constraints on nematode communities. Dominance analysis and commonality analysis were employed to determine the relative support of these hypotheses in explaining nematode abundance, diversity, and composition. Beta-diversity, which links local alpha-diversity and regional gamma-diversity, was decomposed into distinct components to elucidate ecological processes along altitude and across diversity facets. Our findings revealed distinct yet significant altitudinal patterns in nematode abundance (concave-down), richness (monotonous decrease), and evenness (concave-up). Water and soil resource availability emerged as dominant factors influencing nematode abundance, while energy and pH played pivotal roles in determining nematode richness. Additionally, water and productivity were identified as the most significant drivers shaping nematode community composition. Furthermore, a significant influence of pH on gamma- and beta-diversities was observed, surpassing the impact of other predictors at a coarse level. Upon decomposing beta-diversities into different components, we discovered that taxa substitution (turnover) and individual substitution (balance-variation) were the primary contributors to community dissimilarity among altitudes, indicating strong effects of environmental sorting or spatial and historical constraints on soil nematode communities. These findings contribute to our understanding of the distribution patterns and processes of soil nematode communities along altitude in alpine ecosystems. Moreover, they offer valuable insights into soil biodiversity distribution and conservation in high-mountain environments.

Diversity of lithophytic moss species in karst regions in response to elevation gradients.

The distribution pattern of species diversity along various elevation gradients reflects the biological and ecological characteristics of species, distribution status and adaptability to the environment. Altitude, a comprehensive ecological factor, affects the spatial distribution of species diversity in plant communities by causing integrated changes in light, temperature, water and soil factors. In Guiyang City, we studied the species diversity of lithophytic mosses and the relationships between species and environmental factors. The results showed that: (1) There were 52 species of bryophytes in 26 genera and 13 families within the study area. The dominant families were Brachytheciaceae, Hypnaceae and Thuidiaceae. The dominant genera were Brachythecium, Hypnum, Eurhynchium, Thuidium, Anomodon and Plagiomnium; The dominant species were Eurohypnum leptothallum, Brachythecium salebrosum, Brachythecium pendulum etc. The number of family species and dominant family genera increased first and then decreased with the increase of altitude, and their distribution in elevation gradient III (1334-1515m) was the largest, with 8 families, 13 genera and 21 species. The elevation gradient I (970-1151m) was the least species distributed, with 5 families, 10 genera and 14 species. The dominant species with the largest number in each elevational gradient were Eurohypnum leptothallum, Brachythecium pendulum, Brachythecium salebrosum and Entodon prorepens; (2) There were five kinds of life forms in different elevation gradients, including Wefts, Turfs, Mat, Pendants and Tail. Among them, wefts and turfs appeared in all elevations, while a small amount of Pendants appeared in the area of elevational gradient I (970-1151m), and the most abundant life form was found in the range of elevational gradient III (1334-1515m); (3) Patrick richness index and Shannon-Wiener diversity index were highly significantly (p<0.01) positively correlated, both of which increased and then decreased with elevation, reaching a maximum at elevation gradient III (1334-1515m); The Simpson dominance index had a highly significant (p<0.01) negative correlation with the Patrick richness index and the Shannon-Wiener diversity index, which showed a decreasing and then increasing trend with increasing altitude; Pielou evenness index showed no discernible trend; (4) β diversity study revealed that while the similarity coefficient tended to decrease with increasing altitude, the species composition of bryophytes increased. The elevation gradient II (1151-1332m) and elevation gradient I (970-1151m) shared the most similarities, whereas elevation gradient III (1515-1694m) and elevation gradient I shared the least similarities (970-1151m). The findings can enrich the theory of the distribution pattern of lithophytic moss species diversity at distinct elevation gradients in karst regions, and serve a scientific and reasonable reference for restoring rocky desertification and protecting biodiversity there.

Plant diversity patterns along an elevation gradient: the relative impact of environmental and spatial variation on plant diversity and assembly in arid and semi-arid regions

The spatial distribution pattern of species diversity and its driving variables are essential to understanding how biodiversity will respond to the threat of future climatic instability. This study examines how the alpha and beta diversity indices vary along the elevation gradient and which factors are more responsible for arid and semi-arid plant diversity and community assembly. There were 121 species from 90 genera and 42 families found at elevations ranging from 1,200 to 2,600 m within the Ningxia Helan Mountain National Nature Reserve in China. These were primarily shrubs and herbs with characteristics adapted to extreme temperatures. The diversity of both the shrub layer and the herb layer was highest at mid-elevation, underscoring the importance of protecting mid-elevation ecosystems. Climatic distance and topographic distance were more influential than spatial distance in driving the species composition change of shrubs and herbs. In the herb layer, climatic, topographic, and spatial factors contributed more to community assembly than shrub communities. In this case, improving the environment in the community or introducing herbs could help the restoration of these places. These findings provide insight into biogeographic patterns, biodiversity growth mechanisms, and community formation processes. Moreover, it can improve projections of climate change within and across ecosystems and provide the scientific basis for the use and management of plant resources in arid and semi-arid regions.

Predicting spatial variability of species diversity with the minimum data set of soil properties in an arid desert riparian forest

Species diversity has spatial heterogeneity in ecological systems. Although a large number of studies have demonstrated the influence of soil properties on species diversity, most of them have not considered their spatial variabilities. To remedy the knowledge gap, a 1ha (100m × 100m) plots of arid desert riparian forest was set up in the Ebinur Wetland Nature Reserve (ELWNR) in the NW China. Then, the minimum data set of soil properties (soil MDS) was established using the Principal Component Analysis (PCA) and the Norm Value Determination to represent the total soil property data set (soil TDS). The Geo-statistics and two models (i.e., Random Forest/RF and Multiple Linear Regression/MLR) were used to measure the spatial variability of species diversity, and predict its spatial distribution by the soil MDS, respectively. The results showed that the soil MDS was composed of soil salt content (SSC), soil total phosphorus (STP), soil available phosphorus (SAP), soil organic carbon (SOC) and soil nitrate nitrogen (SNN); which represented the soil TDS perfectly (R2 = 0.62). Three species diversity indices (i.e., Shannon-Wiener, Simpson and Pielou indices) had a high spatial dependence (C0/(C0+C)< 25%; 0.72m ≤ range≤ 0.77m). Ordinary kriging distribution maps showed that the spatial distribution pattern of species diversity predicted by RF model was closer to its actual distribution compared with MLR model. RF model results suggested that the soil MDS had significant effect on spatial distribution of Shannon-Wiener, Simpson and Pielou indices (Varex = 56%, 49% and 36%, respectively). Among all constituents, SSC had the largest contribution on the spatial variability of species diversity (nearly 10%), while STP had least effect (< 5.3%). We concluded that the soil MDS affected spatial variability of species diversity in arid desert riparian forests. Using RF model can predict spatial variability of species diversity through soil properties. Our work provided a new case and insight for studying the spatial relationship between soil properties and plant species diversity.

The patterns of co-occurrence variation are explained by the low dependence of bark beetles (Coleoptera: Scolytinae and Platypodinae) on hosts along altitude gradients

BackgroundSeparation of biotic and abiotic impacts on species diversity distribution patterns across a significant climatic gradient is a challenge in the study of diversity maintenance mechanisms. The basic task is to reconcile scale-dependent effects of abiotic and biotic processes on species distribution models. Here, we used a hierarchical modeling method to detect the host specificities of bark beetles (Scolytinae and Platypodinae) with their dependent tree communities across a steep climatic gradient, which was embedded within a relatively homogenous spatial niche.ResultsSpecies turnover of both trees and bark beetles have an opposite pattern along the climatic proxy (represented by the elevation gradients) at the regional scale, but not at local spatial scales. This pattern confirmed the hypothesis wherein emphasis was on influences of macro-climate on local biotic interactions between trees and hosted bark beetle communities, whereas local biotic relations, represented by host specificity dependence, were regionally conserved.ConclusionsAt a confined spatial scale, cross-taxa comparisons of β-diversity highlighted the importance of simultaneous impacts from both extrinsic factors related to geography and environment, and intrinsic factors related to organism characteristics. The effects of tree abundance and phylogeny diversity on bark beetle diversity were, to a large extent, indirect, operating via changes in bark beetle abundance through spatial and temporal dynamics of resources distribution. Tree host dependence, which was considered and represented by host specificities, plays a minor role on the hosted beetle community in this concealed wood decomposing interacting system.

Geographic patterns of Lucanus (Coleoptera: Lucanidae) species diversity and environmental determinants in China.

Clarifying the geographic patterns of species diversity and the determinant factors can provide essential information for species conservation and management. Stag beetles (Coleoptera: Lucanidae) of Lucanus are important saproxylic insects and can be used for biomonitoring forests. Most of Lucanus species are facing conservation concerns due to their limited distribution and fragmented habitats, particularly in China, which has the richest species diversity of this genus. The distribution patterns of species diversity of Lucanus at large spatial scales remain portly understood. We studied the distribution patterns of Lucanus and its environmental and geographic determinants in China. Distribution data for 72 species and subspecies were examined. All these species are distributed in southern China except for Lucanus maculifemoratus dybowskyi, which is mainly distributed in north China. The hotspot for Lucanus in China is southeastern Tibet. Our study indicated that the species richness of Lucanus in China was shaped by the precipitation of the wettest and driest month, net primary productivity, digital elevation model, and latitude at a large scale. These variables collectively explained 56.2% of the variation in species richness; precipitation contributed the most (44.1%). Our results provide valuable insights to improve the conservation of Lucanus and can contribute to furthering our understanding of the biogeography of stag beetles in China.

Multiscale spatial patterns of species diversity and biomass together with their correlations along geographical gradients in subalpine meadows

Researchers frequently discuss spatial distribution patterns of species diversity and biomass together with their correlations along geographical gradients. Typical subalpine meadows occur widely on the east of the Loess Plateau, China; here, we selected nine mountains belonging to four mountain systems from north to south on the east of the plateau. We analyzed five latitudinal and longitudinal gradients together with six elevational gradients to study the spatial distribution patterns of species diversity (including α, β, and γ diversity) and biomass plus with their relationships at various scales. Results showed that (1) for diversity, α-Diversity manifested unimodal variation patterns in horizontal spaces, peaking at high latitude and low longitude. However, α-diversity was not sensitive to elevation in vertical spaces and tended to decrease with increasing elevation. With increased latitude, longitude, and elevation, β-Diversity diminished; meanwhile, the rate of species turnover decreased and the similarity of community composition enlarged. γ-Diversity demonstrated quadratic function changes that were initially incremental and then decreased with increasing longitude, elevation, and latitude from 37.5° to 40°. In general, β-diversity had positive correlation with γ-diversity and negative correlation with α-diversity, which conformed to the function of β = γ/α. (2) For biomass, changes of aboveground biomass (AB) were more obvious along latitudinal gradients, whereas variations of belowground biomass (BB) had smaller differences along longitudinal and latitudinal gradients. More biomass was allocated to BB toward the north and east, whereas root-to-shoot ratio (R/S) was more evident at greater latitude than greater longitude. With increased elevation, more biomass was also allocated to BB, and the relationship of biomass to elevation was closer in AB. In short, the relation of biomass allocation tended to belowground plant parts with different geographical scales. (3) Species diversity had the strongest positive influence on AB. The Patrick and Shannon indices had correlations of power functions with AB and R/S, respectively, indicating that an allometric model could be used to model relationships between species diversity and biomass. In conclusion, the unique geomorphological structures with a series of basins between mountain systems on the east of the Loess Plateau, meant that subalpine meadows were mostly distributed along latitudinal directions, so the spatial distribution of species diversity and biomass was more evident along latitudinal gradients, and thus the response of aboveground biomass was more sensitive to variations of spatial gradients and species diversity.

杨属物种多样性在中国的地理分布格局

PDF HTML阅读 XML下载 导出引用 引用提醒 杨属物种多样性在中国的地理分布格局 DOI: 10.5846/stxb201612222638 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（91425304，91525101） Geographical distribution pattern of species diversity of the genus Populus L. in China Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:利用地理信息系统技术与空间统计相结合的方法，研究了杨属物种多样性在中国区域尺度上的空间分布格局，并且采用线性回归分析方法研究了杨属物种多样性与经纬度的关系。结果表明：（1）杨属物种在中国呈带状分布，东西分布幅度大于南北分布幅度；（2）纬度梯度上杨属物种集中分布区位于30-40°N，经度梯度上位于110-120°E，说明杨属物种多样性格局在经、纬度梯度上并非单调递增或递减，而是在某一最适区域具有最高的物种多样性；（3）中国杨属物种多样性的分布中心集中于东北-西南方向的黑河-腾冲线两侧，从黑腾线向西北和东南方向延伸过程中，物种多样性逐渐降低；沿黑腾线从东北向西南方向物种多样性呈增加趋势；（4）从分组、分种检索上看，白杨组和青杨组物种在中国分布范围最广，山杨、小叶杨、响叶杨和青杨4种物种分布范围最广，可见同一类群中不同分类等级的植物多样性地理分布格局存在差异。 Abstract:The geographical distribution of the species diversity of the genus Populus in China was studied using the geographical information system and spatial statistics. The relationship between the Populus species diversity and longitudinal and latitudinal bands was analyzed using linear regression analysis. The results showed that:(1) In China, the genus Populus exhibited a zonal distribution that was in an east-west direction, which was wider than that in the north-south direction; (2) The greatest species diversity of the Populus distribution on the latitudinal and longitude gradient was located in the latitudinal and longitudinal bands of 30-40°N and 110-120°E, respectively, indicating that species richness was the greatest where the longitude and latitude were optimized and decreased as the longitude and latitude moved above or below the optimal range; (3) The distribution center of the Populus species biodiversity in China was located on both sides of the Heihe-Tengchong line in the northeast-southwest direction, and species diversity increased from the northeast to southwest of China along the line, but decreased from this line to the northwest and the southeast; (4) In terms of the level of taxonomy, the sections of Populus with the most extensive distribution range were sect. Populus and sect. Tacamahaca Spach in China and the four species with the most extensive distribution ranges were Populus davidiana Dode, Populus simonii Carr, Populus adenopoda Maxim, and Populus cathayana Rehd, which revealed that the differing levels of taxonomy within the same taxa resulted in a varied species diversity pattern on the same scale. 参考文献 相似文献 引证文献

桂西北喀斯特常绿落叶阔叶混交林物种多样性分布格局的尺度效应

PDF HTML阅读 XML下载 导出引用 引用提醒 桂西北喀斯特常绿落叶阔叶混交林物种多样性分布格局的尺度效应 DOI: 10.5846/stxb201709231713 作者: 作者单位: 中国科学院亚热带农业生态研究所,中国科学院亚热带农业生态研究所,中国科学院亚热带农业生态研究所,中国科学院亚热带农业生态研究所,中国科学院亚热带农业生态研究所,广西壮族自治区木论国家级自然保护区管理局,中国科学院亚热带农业生态研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点研发计划项目（2016YFC0502405）；广西重点研发计划项目（桂科AB16380255，桂科AB17129009）；国家自然科学基金项目（31770495）；广西特聘专家项目 Scale-dependent spatial patterns for species diversity in a karst evergreen and deciduous broad-leaved mixed forest of northwest Guangxi Author: Affiliation: Institute of Subtropical Agriculture Chinese Academy of Sciences,Institute of Subtropical Agriculture Chinese Academy of Sciences,Institute of Subtropical Agriculture Chinese Academy of Sciences,Institute of Subtropical Agriculture Chinese Academy of Sciences,Institute of Subtropical Agriculture Chinese Academy of Sciences,,Institute of Subtropical Agriculture Chinese Academy of Sciences Fund Project: Dthe National Key Research and Development Program ( 2016YFC0502405), the Guangxi Key Research and Development Program (AB17129009, AB16380255), the National Natural Science Foundation of China (31370485, 31370623, 31400412), and the Guangxi Program of Distinguished Expert 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:物种多样性的空间分布格局及其与尺度的关系研究对于了解群落物种多样性形成机制具有重要意义。为了探讨喀斯特地区物种多样性空间分布格局的尺度效应，以喀斯特常绿落叶阔叶混交林25 hm2样地的（胸径DBH≥1）木本植物为研究对象，分析了6个空间尺度（5 m×5 m，10 m×10 m，20 m×20 m，50 m×50 m，100 m×100 m，250 m×250 m）上的多度、物种丰富度、Shannon-Wiener指数、Simpson指数以及Pielou均匀度指数的变化规律。结果表明：物种多样性指数的空间分布均表现出较高的空间异质性；物种多样性指数的方差随取样尺度增加呈现单峰分布特征，并且在100 m×100 m尺度上达到最大值；物种多样性指数的变异系数随尺度的增加呈线性下降趋势，其中，Shannon-Wiener指数、Simpson指数以及Pielou均匀度指数均在5 m×5 m至20 m×20 m尺度上明显减小；在大于50 m×50 m的尺度上，物种丰富度与多度的正相关性不显著（P > 0.05）。喀斯特常绿落叶阔叶混交林物种多样性的空间分布格局与不同空间尺度密切相关，深入解析物种多样性随空间尺度的变化模式，需要在类似的森林生态系统做更多的研究。 Abstract:Spatial distribution patterns of species diversity and their relationships with scale are of great significance to understand the mechanism of community species diversity formation. Here, a field survey was conducted to assess the variation in species diversity along spatial scales in a karst evergreen and deciduous broad-leaved mixed forest, Southwest China. Based on the dataset of woody plants (DBH ≥ 1) from a 25 hm2 plot, the spatial distribution patterns of species abundance, species richness, and Shannon-Wiener, Simpson, and Pielou's evenness indices were analyzed at six spatial scales-5 m×5 m, 10 m×10 m, 20 m×20 m, 50 m×50 m, 100 m×100 m, and 250 m×250 m. The results showed that spatial distributions of species diversity indices were highly heterogeneous. The variance of species diversity indices changed with spatial scale following a unimodal pattern, i.e., with a maximum value at the 100 m×100 m scale. Variation coefficients of species diversity decreased linearly with increasing scale. The Shannon-Wiener, Simpson, and Pielou's evenness indices decreased sharply at the 5 m×5 m and 20 m×20 m scales. No significant positive relationship was found between species richness and abundance at scales over 50 m×50 m (P > 0.05). Our results suggest that the spatial pattern of species diversity in this evergreen and deciduous broad-leaved mixed karst forest is closely related to spatial scale. To better understand spatial variation of species diversity across spatial scales, more such studies in other similar forest ecosystems are needed. 参考文献 相似文献 引证文献

Vertical patterns in plant diversity and their relations with environmental factors on the southern slope of the Tianshan Mountains (middle section) in Xinjiang (China)

The investigation of distribution patterns of species diversity is significant for successful biodiversity conservation. The spatial patterns of vegetation and different life-forms species diversity along an elevation gradient in the middle section of the southern slope of the Tianshan Mountains in Xinjiang, China were explored, using the detrended canonical correspondence analysis (DCCA) and the generalized additive model (GAM) methods based on a field survey of 53 sampling plots. In this work 158 species of seed plants were recorded, including 141 herbaceous, 14 shrub, and 2 tree species, in which the woody plants are very limited. 53 sampling plots were classified into 9 major plant communities. The results indicate that the herb communities were the most sensitive to changes in elevation gradient. The diversity indices of the community as a whole presented bimodal patterns. The peak values for the species diversities were found in the transition region between mountain steppe desert and mountain desert steppe (2,200–2,300m), and in the alpine grassland region (2,900–3,100m), while maximum species diversities were in the areas of intermediate environmental gradient. The main environmental factors on the distribution patterns in plant diversity were the elevation, soil water, total nitrogen, available nitrogen, organic matter, and total salt. The response tendency of the four diversity indices for the whole community to the soil environment was the same as that of the herb layers.

小秦岭自然保护区苔藓植物群落数量分类、排序及多样性垂直格局

PDF HTML阅读 XML下载 导出引用 引用提醒 小秦岭自然保护区苔藓植物群落数量分类、排序及多样性垂直格局 DOI: 10.5846/stxb201512242568 作者: 作者单位: 河南农业大学,河南农业大学,河南农业大学,河南农业大学,河南小秦岭国家级自然保护区管理局,河南农业大学,河南农业大学 作者简介: 通讯作者: 中图分类号: 基金项目: 河南省科技攻关（132102110133）；河南省教育厅科学技术研究重点项目（14A180013） Numerical classification, ordination, and species diversity of bryophytes along elevation gradients in Xiaoqinling Author: Affiliation: Henan Agricultural University,Henan Agricultural University,Henan Agricultural University,Henan Agricultural University,Administration Bureau of Xiaoqinling National Nature Reserve of Henan,Henan Agricultural University,Henan Agricultural University Fund Project: 河南省科技攻关（１３２１０２１１０１３３）；河南省教育厅科学技术研究重点项目（１４Ａ１８００１３） 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:苔藓物种多样性沿海拔梯度呈什么样的分布格局?基于53个20 m×20 m样地，采集并鉴定了样地内所有生境中的苔藓物种；采用多元回归树（multivariate regression trees， MRT）对苔藓植物进行分类；采用典范对应分析（canonical correspondence analysis， CCA）进行排序分析；用广义线性模型（Generalized Linear Model， GLM）研究苔藓物种多样性沿海拔的分布格局。结果如下：（1）采集的1378份苔藓植物标本经过鉴定，共有33科89属240种，其中藓类226种，苔类14种；（2）经交叉验证认为本区苔藓植物可分为4类，Ⅰ长肋青藓（Brachythecium populeum）+大叶匐灯藓（Plagiomnium succulentum）+圆叶匐灯藓（Plagiomnium vesicatum）群落，Ⅱ灰白青藓（Brachythecium albicans）+宽叶青藓（Brachythecium curtum）+短肋羽藓（Thuidium kanedae）+平肋提灯藓（Mnium laevinerve）群落，Ⅲ短肋羽藓（Thuidium kanedae）+光萼叶苔（Jungermannia leiantha）+薄罗藓（Leskea polycarpa）+叉肋藓（Trachyphyllum inflexum）群落，Ⅳ宽叶青藓（Brachythecium curtum）+垂蒴棉藓（Plagiothecium nemorale）+全缘匐灯藓（Plagiomnium integrum）群落；（3）海拔、坡度和坡向对苔藓物种分布的解释量为7.29%；（4）苔藓物种多样性随海拔的变化成明显的上升格局。通过研究了解了小秦岭国家级自然保护区苔藓物种组成、群丛划分以及每种苔藓植物的海拔分布范围；苔藓物种多样性随海拔的上升呈显著的上升格局，与乔木、灌木和草本的分布格局不同。希望此研究能为苔藓植物生态学研究和物种多样性保护提供参考。 Abstract:Bryophytes are widely distributed and constitute an important part in vegetation diversity. More than 20,000 species of bryophytes are found worldwide. Bryophytes play important roles in the ecosystem, particularly in water balance and nutrient accumulation. However, bryophytes are smaller than vascular plants and are often ignored in ecological studies. Spatial patterns of species diversity along the elevation gradient are of great significance in illuminating community ecology. What is the distribution pattern of bryophyte species diversity along an elevation gradient? We do not find the related research in China. The Xiaoqinling National Nature Reserve is located in Lingbao (34°23'-34°31'N, 110°23'-110°44'E, Henan Province, China). This nature reserve covers 31 km from east to west and 12 km from north to south, and spreads over a total area of 15,160 km2. The reserve harbors the highest peak in Henan, with an elevation of 2413.8 m. The area has rich biological resources with a diverse and complex vegetation composition. We constructed 53 plots in a 400m2 area (20 m×20 m) along the altitudinal gradient in Xiaoqinling, collected all bryophyte species encountered in these 53 plots, and recorded habitat types such as ground, tree trunks, roots, and rotten wood. Investigators carefully checked every corner of each plot to collect all bryophyte species growing on the plot. A total of 1378 specimens were collected. All specimens were transported back to the laboratory and identified. The bryophyte community was classified using multiple regression trees. Ordination analysis was conducted by canonical correspondence analysis, and the generalized linear model was used to study the distribution pattern of species diversity along elevation gradients. Results were as follows. (1) The collected 1378 bryophyte specimens belonged to 33 families, 89 genera, and 240 species, including 226 species of mosses and 14 species of liverworts. (2) The bryophyte community was divided into four categories by cross validation: I: Brachythecium populeum + Plagiomnium succulentum + Plagiomnium vesicatum; Ⅱ: Brachythecium albicans + Brachythecium curtum + Thuidium kanedae + Mnium laevinerve; Ⅲ: Thuidium kanedae + Jungermannia leiantha + Leskea polycarpa + Trachyphyllum inflexum; IV: Brachythecium curtum + Plagiothecium nemorale + Plagiomnium integrum. (3) The interpretation of the elevation, slope, and aspect to the distribution of the bryophyte species was 7.29%. (4) The bryophyte species diversity increased with the increase in altitude. In this study, we examined the species composition, classification, and distribution range along elevation gradients of the bryophyte species in Xiaoqinling. The diversity of the bryophyte species along the altitude showed an increasing tendency and differed from the distribution patterns of trees, shrubs, and herbs. Thus, this study provides a reference for research on bryophyte species coexistence and protection of species diversity. Vascular plants and bryophytes coexist in an ecosystem and the relationship between vascular plants and the bryophyte community is complex. However, we did not consider the effect of vascular plants on the bryophyte community and these factors need further analysis. Environmental factors, such as climatic conditions, physical and chemical properties of bark, and light intensity, must also be considered in future studies. 参考文献 相似文献 引证文献

Combining endangered plants and animals as surrogates to identify priority conservation areas in Yunnan, China.

Suitable surrogates are critical for identifying optimal priority conservation areas (PCAs) to protect regional biodiversity. This study explored the efficiency of using endangered plants and animals as surrogates for identifying PCAs at the county level in Yunnan, southwest China. We ran the Dobson algorithm under three surrogate scenarios at 75% and 100% conservation levels and identified four types of PCAs. Assessment of the protection efficiencies of the four types of PCAs showed that endangered plants had higher surrogacy values than endangered animals but that the two were not substitutable; coupled endangered plants and animals as surrogates yielded a higher surrogacy value than endangered plants or animals as surrogates; the plant-animal priority areas (PAPAs) was the optimal among the four types of PCAs for conserving both endangered plants and animals in Yunnan. PAPAs could well represent overall species diversity distribution patterns and overlap with critical biogeographical regions in Yunnan. Fourteen priority units in PAPAs should be urgently considered as optimizing Yunnan’s protected area system. The spatial pattern of PAPAs at the 100% conservation level could be conceptualized into three connected conservation belts, providing a valuable reference for optimizing the layout of the in situ protected area system in Yunnan.

北京松山自然保护区森林群落物种多样性及其神经网络预测

物种多样性是群落结构和功能复杂性的一种度量,物种多样性的空间分布格局受许多环境因子的影响。运用多样性指数,多层感知器网络,分析了松山保护区森林群落物种多样性与群落类型、结构和生境之间的关系。结果表明:(1)大果榆+山杨混交林、油松+青杨混交林物种丰富度、多样性和均匀度均较高,而大果榆林、华北落叶松林的各项指数值均较低。Patrick指数和Shannon-Weiner指数在森林群落中均表现为草本层>灌木层>乔木层;Pielou指数在榆林中表现为草本层>乔木层>灌木层,而在其他森林群落中表现为灌木层>草本层>乔木层。(2)功能层物种多样性在海拔梯度上的变化趋势不同,在乔木层,丰富度、多样性和均匀度随海拔的升高逐渐降低;在灌木层,丰富度、多样性和均匀度均呈比较明显的单峰曲线变化趋势;在草本层,丰富度和多样性随海拔的升高都呈下降趋势,而在草本层,均匀度变化不大。(3)用多层感知器网络预测功能层多样性效果很好,结果发现坡向对乔木层和灌木层物种多样性的影响最大,而海拔高度对草本层物种多样性的影响最大。;Species diversity is a measure of the complexity of community structure and function, and the spatial distribution pattern of species diversity is affected by many environmental factors. In this paper, the relationships between species diversity and community type, habitat and community structure of forests in the Songshan National Nature Reserve were analyzed by diversity indices and multi-layer perceptron network. The dataset included 68 quadrats, 291 species, and 6 environmental variables (elevation, slope, aspect, litter layer thickness, soil depth, and soil solidity). The results showed that species richness, species diversity and evenness values of <em>Ulmus macrocarpa </em>+ <em>Populus davidiana</em> mixed forest and <em>Pinus tabulaeformis</em>+<em> Populus cathayana</em> mixed forest were higher, but these values of<em> Ulmus macrocarpa</em> forest and <em>Larix principis-rupprechtii</em> forest were lower. The Patrick and Shannon-Weiner indices varied in order of herb layer > shrub layer > tree layer; the Pielou value of <em>Ulmus pumila</em> forest varied in order of herb layer > tree layer >shrub layer, and other community types varied in order of shrub layer >herb layer > tree layer.<br>Species diversity of functional layers changed differently along elevational gradient. In tree layer, the species richness, diversity and evenness decreased with increasing elevation. In shrub layer, the species richness, diversity and evenness were significantly peaked at the intermediate elevation. In herb layer, the species richness and diversity decreased with increasing elevation, but the evenness value changed little.<br>Applying multi-perceptron network to predict the diversity of functional layers, we found that aspect affected species diversity of tree and shrub layers greatly, but elevation affected species diversity greatly in herb layer.

Distribution pattern and environmental interpretation of plant species diversity in the mountainous region of Ili River Valley, Xinjiang, China.

Aims Our major objective was to reveal the distribution pattern of plant species diversity in the mountainous region of Ili River Valley, Xinjiang, China and explore how environmental gradients influenced the pattern. Methods Based on a survey of 94 sample plots in the study area, DCCA was performed to analyze the relation- ships between diversity indices and environmental gradients and GAM was employed to model the response curve of diversity indices to elevation. Important findings We recorded 259 plant species, including 235 herbaceous species; the species of woody plants were very limited. Communities with complex vertical structure had higher values of diversity. The distri- bution pattern of species diversity on the northern slope was affected by elevation, slope aspect, slope gradient, total nitrogen, total potassium, soil water content, organic matter, etc., and that on the southern slope was mainly affected by slope gradient, elevation, available phosphorus, soil water content, etc. On the northern slope, Patrick index and Shannon-Wiener index had a bimodal pattern with elevation and Simpson index and Pielou index showed a partially unimodal pattern. On the southern slope all the distribution pattern of species diversity indices showed two peaks, though that of the Patrick index was not obvious. These patterns were formed by the synthetic action of a variety of environmental factors in which elevation played an important role.

Distribution pattern of plant species diversity in the mountainous Region of Ili River Valley, Xinjiang

In this paper, detrended canonical correspondence analysis was performed to analyze the relationships between diversity indices and environmental gradients, generalized additive model was employed to modal the response curves of diversity indices to the elevation, based on data from field investigation in the mountainous region of the Ili River Valley and a survey of 94 sample plots. Two hundred fifty-nine plant species were recorded in the 94 sample plots investigated, up to 235 species all appeared in the herb layer, and the species of woody plants were very limited. The communities with a complicated vertical structure presented higher values of indices. The distribution pattern of plant species diversity on the northern slope was affected by such factors as elevation, slope aspect, slope gradient, total nitrogen, total potassium, soil water content, organic matter, and that on the southern slope was mainly affected by such factors as slope gradient, elevation, available phosphorus, and soil water content. On the northern slope, Patrick index and Shannon-Wiener index of the plant communities presented a bimodality pattern along altitude; Simpson index and Pielou index showed a partially unimodal pattern. On the southern slope all the distribution pattern of species diversity indices showed two peaks, though Patrick index's bimodality pattern was not an obvious one. These altitudinal patterns were formed by the synthetic action of a variety of environmental factors with elevation playing an important role.

Distribution patterns of macrofaunal species diversity in subtidal soft sediments: biodiversity–productivity relationships from the MacroBen database

We analyzed patterns of species diversity in a compiled data set covering the European coast (from Norway to Crete) that was made available in the framework of the MarBEF European Network of Excellence. The focus was on the distribution patterns of species diversity over large areas across Europe. The objectives of our analysis were two-fold. First, we attempted to separate the effects of species-area relationships from that of species accumulation. Second, we explored the rela- tionship between species diversity and productivity, and compared this to the proposed explaining factors (depth, survey area and latitude). The following conclusions are drawn. (1) Within a given habitat (subtidal soft sediment), the distribution of marine macrofaunal species richness in different areas between 3 and 200 m in average depth throughout Europe is shown to follow general rules derived from observations and experiments mostly based on terrestrial communities; (2) soft-bottom macrofauna accumulate in the subtidal environment (up to 200 m) following the Arrhenius plot model at a rate (≈0.5) corresponding to about a 3-fold increase in the number of species when the sampling area increases by 1 order of magnitude; (3) the distribution of the intrinsic species richness (point species richness) between the selected data sets (subtidal soft sediment) is significantly correlated with the levels of organic flux reaching the sea bottom; and (4) the close relationship between depth and the fraction of surface primary production that reaches the sea bottom is proposed as an explanation for the previously described increase of species richness with depth.

Macrobenthic resources of the shallow soft-bottom sediments in the eastern English Channel and southern North Sea

To obtain a baseline for future comparisons and to assist in the conservation of marine biodiversity, the distribution patterns and faunal composition of shallow (0–15 m depth) macrobenthic assemblages were studied along the French coast of the eastern English Channel and southern North Sea from two surveys conducted in 1998 and 2000. A total of 227 sites were sampled from Cap d’Ailly to the Belgian border, from which a total of 167 species were collected. Species richness, abundance and biomass were all increased in the vicinity of outflows from harbours, major bays and estuaries. Three principal macrobenthic assemblages were defined: (i) an Ophelia borealis medium to fine sand assemblage; (ii) a muddy heterogeneous sediment assemblage; and (iii) an Abra alba muddy fine sand assemblage. The Abra alba assemblage covered approximately 80% of the seabed in the survey area. Sediment characteristics and a latitudinal gradient accounted for a significant proportion of the observed variability in assemblage distribution patterns. In the eastern English Channel, the distribution patterns of species diversity, abundance and biomass values were most continuous, whereas in the southern North Sea a more heterogenous distribution was observed. 2003 International Council for the Exploration of the Sea. Published by Elsevier Science Ltd.