伊洛河流域草本植物群落物种多样性

生物多样性沿环境梯度的变化是生物多样性研究的重要内容,环境梯度包含了多种环境因子(海拔高度、水热条件、人类扰动等)的综合。以伊洛河流域草本植物群落为对象,沿河从入黄河口到河源地选取典型样地调查研究伊洛河流域草本植物群落物种多样性及其分布格局。结果表明:物种丰富度和Shannon-Wiener多样性指数沿河均稍呈\"S\"型曲线变化,不同群落类型中分布格局差别不大,各群落类型中的物种丰富度和多样性均呈现出中游丘陵山地交界区最高,上游河源区次之,下游平原地区最低的趋势;β多样性指数的变化趋势与α多样性较一致,总体上呈现出中游丘陵山地区物种更替速率较快,平原区更替较慢;在流域内上游河源地属于自然植被区,人为干扰较轻,具有较高的物种多样性,物种替代主要受物种的竞争扩散能力和生境条件的制约;在下游平原农业区,人类活动强烈,区域内以人工生态系统为主,物种组成简单,物种替代具有跳跃性的特征,主要受人类活动的制约;在中游从自然生态系统向农业生态系统的过渡区域,人类活动的扰动有一定的强度,导致该区域内自然分布种和伴人种混合生长,具有较高的物种多样性和较快的物种替代速率。总体上伊洛河流域草本植物群落物种多样性分布格局强烈的受到人类活动的影响,物种替代速率较高。     

西双版纳热带山地常绿阔叶林蕨类植物多样性研究

基于4个50m×50m(包含400个5m×5m)样方调查,统计了蕨类植物的α多样性指数、优势度指数、相似性指数及β多样性指数。结果表明:在调查的1hm2西双版纳热带山地常绿阔叶林里,蕨类植物的物种丰富度为32种;不同样地蕨类植物丰富度指数、多样性指数、优势度指数及均匀度指数的变化趋势一致;该森林群落蕨类植物的物种多样性虽然不高,但优势种群显著;通过3个无人为干扰与1个受人为干扰样地的对比分析研究看出,该类森林遭受一定程度的人为干扰后,蕨类植物物种丰富度、多样性、优势度及相似性等均显著下降,其中物种多样性的降低尤为显著,既使群落的外貌、结构等恢复至接近原始林状态,蕨类植物丰富度及多样性也难以恢复,故此,保护原始的森林植被是保护该森林蕨类植物多样性的有效措施之一。     

河南省自然林草本层植物群落β多样性及其影响因素

对反映不同群落间物种组成的时空差异或变化的β多样性及其组分开展研究,有助于提高对群落结构及其维持机制的理解和认识.森林草本层是森林群落和森林生态系统的重要组成部分,尽管对林下草本层植物群落β多样性已有一些相关研究,但关于β多样性的组分(如物种周转和嵌套组分)的相对比例、影响因素及其影响程度等方面仍缺乏统一认识.该研究基于河南省168个自然林样地草本层植物群落调查数据资料,通过Jaccard相异性指数、方差分解等方法分析河南省自然林草本层植物群落β多样性格局,并量化空间距离、环境因素和物种丰富度等影响因素对其β多样性的相对贡献.结果表明:(1)自然林草本层植物群落总β多样性的Jaccard相异性指数为0.94,主要来源于物种周转组分(占总β多样性的96.8％).(2)自然林草本层植物群落总β多样性及物种周转组分随空间距离增加呈显著增加趋势,而嵌套组分随空间距离增加呈显著减少趋势.(3)Mantel检验显示空间距离、环境因素和物种丰富度对自然林草本层植物群落总β多样性均具有显著影响,其中环境因素影响最大,空间距离影响次之,物种丰富度影响最小;方差分解结果进一步显示空间距离、环境因素和物种丰富度共分别解释了总β多样性及其周转组分27.14％、20.35％的变异,其中环境因素可以单独解释的变异最多(分别占总β多样性的10.62％和周转组分的9.35％).该研究有助于增强对自然林草本层植物组成变化规律及其影响因素的认识,进而为森林植被保护管理和生态修复提供坚实的科学基础.     

近七十年(1954-2021)长江中下游湖泊沉水植物群落多样性演变特征

沉水植物在维持浅水湖泊生态系统健康和稳定等方面起着重要作用, 掌握其长期动态及驱动因子对湖泊生态系统恢复和富营养化治理具有重要的理论和现实意义。本研究以长江中下游17个湖泊为研究对象, 分析了近70年(1954-2021)来沉水植物的α和β多样性格局及其变化情况, 并基于Sørensen相异性指数将β多样性分解为周转(turnover)和嵌套(nestedness)两个组分, 探讨了湖泊环境异质性变化与沉水植物群落多样性格局的联系。结果表明: (1)在湖泊尺度上, 11个湖泊沉水植物的α多样性呈减小趋势; 而大多数湖泊β_temporal多样性(同一湖泊不同年份之间的群落结构相异性)无显著变化, 且其变异主要由不同物种间的嵌套成分驱动。(2)在流域尺度上, 长江中下游湖泊沉水植物的α多样性在演化过程中呈先增大后减小的趋势, β_spatial多样性(同一时期不同湖泊之间的群落结构相异性)在演化过程中呈逐渐减小的趋势, 而湖泊环境异质性呈逐渐增大的趋势。(3)环境异质性越高的湖泊, 其α多样性越小, β多样性越大。这些变化可能是多种因素综合作用的结果, 包括人类活动、水质污染、水文变化和气候变化等。本研究对于长江中下游湖泊生态系统管理和保护具有一定理论价值, 为制定有效的保护策略和措施提供了科学依据。     

基于中国科学院西北高原生物研究所馆藏标本分析青藏高原雀形目鸟类物种和功能多样性

物种多样性和功能多样性是生物多样性的两个主要研究内容, 研究不同区域物种多样性和功能多样性可以为生物多样性保护提供重要的理论支撑。本研究以中国科学院西北高原生物研究所馆藏的青藏高原11个生态地理分区雀形目鸟类为研究对象, 结合其性状数据, 计算3种物种α多样性指数(物种丰富度、Shannon熵和Pielou均匀度)、3种功能α多样性指数(功能丰富度、功能均匀度和功能离散度)、物种和功能β多样性及其对应的周转和嵌套成分, 并分析了物种多样性与功能多样性之间的关系。研究结果表明: (1)青藏高原鸟类物种α多样性呈东南高、西北低的趋势。功能丰富度和功能均匀度显示出明显的空间差异, 全区物种丰富度和功能丰富度平均值较低, 功能离散度在全区均较高; (2)物种β多样性高于功能β多样性, 但二者整体均具有较高的数值。物种β多样性主要由周转成分构成, 而嵌套和周转成分在功能β多样性中占比接近; (3)功能丰富度与物种丰富度及Shannon熵呈显著正相关关系。物种和功能β多样性呈显著相关关系, 物种和功能周转成分贡献率呈显著相关关系。以上结果表明功能丰富度较高的分区中鸟类占据较大的功能性状空间, 而分区中功能均匀度和功能离散度较高则体现出鸟类可以更均匀、更有效地利用食物资源。结合物种和功能α、β多样性可以很好地表征鸟类多样性与生态系统的关系。     

Can dispersions be used for discriminating water quality status in coastal ecosystems? A case study on biofilm-dwelling microbial eukaryotes

Multivariate dispersions are an effective ecological indicator to evaluate the environmental heterogeneity and human disturbance in global ecological research. To explore the feasibility of the dispersions for assessing water quality status, a dataset of the biofilm-dwelling microbial eukaryote communities was studied in coastal waters of the Yellow Sea, northern China at two numerical resolutions. The community dispersion patterns represented a significant variability in both community structure and species composition in response to environmental heterogeneity. Multivariate approaches revealed that the species composition was the primary contributor to the community dispersion. Mantel analysis showed that the spatial variations in both community structure and species composition were significantly correlated with the changes of the nutrients, pH, dissolved oxygen (DO) and chemical oxygen demand (COD). The dispersion measures at both numerical resolutions were found to be remarkably related to the nutrient ammonium nitrogen and DO. Thus, we suggest that multivariate dispersions of the microbial eukaryote communities may be used as a potential bioindicator of water quality status in marine ecosystems.     

短期围封对河北塞罕坝草甸草原植物功能多样性的影响

本研究以河北塞罕坝的草甸草原为对象,研究3年期的短期围封对植物群落物种和功能多样性的影响。结果表明: 相比于放牧,围封显著改变了土壤化学性质和植物群落组成,优势种由车前变为地榆。围封没有改变植物群落的物种多样性。围封样地中叶片和根系的功能丰富度分别是放牧样地的16.9(1.18 vs. 0.07)和1460.2(3.57 vs. <0.01)倍,叶片性状的功能分离度和根系性状的功能均匀度相比于放牧分别降低了7.7%(0.72 vs. 0.78)和12.3% (0.57 vs. 0.65)。围封和放牧样地中,物种β-多样性主要由周转成分贡献(74.9%和62.4%),而功能β-多样性主要由嵌套成分贡献(叶片:82.6%和70.6%;根系:73.9%和79.5%)。围封样地总体的物种和功能β-多样性由土壤性质和空间因子共同驱动(物种:R²=0.53;叶片:R²=0.47;根系:R²=0.29);放牧样地总体的物种和功能β-多样性主要由空间因子驱动(物种:R²=0.31;叶片:R²=0.36;根系:R²=0.40)。综上所述,围封对物种多样性与功能多样性的影响存在差异,物种的更替并不一定导致性状的更替。因此,在评估草地修复效果时,应综合考虑物种多样性和功能多样性。探讨不同维度的群落β-多样性及其组成部分,有助于我们更深入理解群落的构建机制。     

环境筛选和扩散限制对长江流域湖北段湿地植物群落构建的共同影响

湿地植物群落构建机制的研究可为湿地生态系统管理和受损湿地生态恢复与重建提供重要理论依据。地处长江流域的湖北省是我国湿地资源最为丰富的地区之一,通过野外调查研究了长江流域湖北段内不同类型湿地中的主要湿地植物群落类型,分析了研究区内湿地植物群落物种β多样性格局;利用相关性检验(Mantel test)方法和基于相似或相异度矩阵的多元回归模型(MRM)分析了环境差异和地理距离与湿地植物群落的物种相异性的相关性,及其对该区域湿地植物群落构建的相对贡献率。结果表明长江流域湖北段8个不同类型湿地内的湿地植物群落物种相异性指数差异显著,群落间物种相异性指数与地理距离和环境距离均呈显著正相关关系;MRM分析表明环境筛选和扩散限制共同解释了研究区内群落物种变异指数的54.72%;其中,环境距离独立解释率为22.03%,地理距离独立解释率为9.98%,二者联合解释率为22.71%。结果表明环境筛选和扩散限制共同影响了长江流域湖北段湿地植物群落构建过程,且环境筛选贡献更大。建议除了考虑空间尺度、环境因子、植被类型外,未来需进一步研究时间尺度及人类干扰等因子对该区域湿地植物群落构建的影响。     

Response of reed community to the environment gradient water depth in the Yellow River Delta, China

We investigated and monitored a reed community in the fields.Data on the bio-ecologieal characteristics and β-diversity of reed communities in different environmental gradients (mainly based on water depth) of the Yellow River Delta were collected through multianalysis,extremum analysis and β-diversity index analysis.In accordance with the square sum of deviations (Ward)cluster analysis,10 sampling plots were divided into six types with the dominant plants in different plots varying according to the change in environmental gradients.The dominant plants in these plots varied from aquatic plants to xerophytes and salt tolerant plants as water depth decreased.The average height and diameter of the reeds at breast level were significantly correlated with the average water depth.The fitness curves of average density and coverage with average water depth were nonlinear.When the average water depth was 0.3 m,the average density and coverage of reeds reached the apex value,while the height and diameter of the reeds at breast level increased with the water depth.There were obvious changes to the environmental gradient in the Yellow River Delta.The transitional communities were also found to exist in the Yellow River Delta by β-diversity analysis.Vicarious species appeared with the change in water depth.The occurrence of substitute species is determined by the function of common species between adjacent belts.The different functions of common species led to differences in community structure and function and differences in dominant plants.The result reflects the variations of species present in different habitats and directly reflects environmental heterogeneity.The values of//-diversity indices of adjacent plots were higher than those of nonadjacent plots.There are transition zones between the xerophytes and aquatic plants in the Yellow River Delta.In an aquatic environment,the similarity of reed community is higher than that of xeromorphic plants.The β-diversity index can reflect plant succession trends caused by the change in environmental gradients in the Yellow River Delta.The β-diversity index reveals plant responses to changes in environmental gradient and is helpful in observing changes in patterns of species diversity in relation to environmental gradient change and evolving trends in the future,which in turn plays a prominent role when environmental water requirements of wetland are discussed.     

Enhancing the structural diversity between forest patches—A concept and real-world experiment to study biodiversity,multifunctionality and forest resilience across spatial scales

Intensification of land use by humans has led to a homogenization of landscapes and decreasing resilience of ecosystems globally due to a loss of biodiversity, including the majority of forests. Biodiversity–ecosystem functioning (BEF) research has provided compelling evidence for a positive effect of biodiversity on ecosystem functions and services at the local (α-diversity) scale, but we largely lack empirical evidence on how the loss of between-patch β-diversity affects biodiversity and multifunctionality at the landscape scale (γ-diversity). Here, we present a novel concept and experimental framework for elucidating BEF patterns at α-, β-, and γ-scales in real landscapes at a forest management-relevant scale. We examine this framework using 22 temperate broadleaf production forests, dominated by Fagus sylvatica. In 11 of these forests, we manipulated the structure between forest patches by increasing variation in canopy cover and deadwood. We hypothesized that an increase in landscape heterogeneity would enhance the β-diversity of different trophic levels, as well as the β-functionality of various ecosystem functions. We will develop a new statistical framework for BEF studies extending across scales and incorporating biodiversity measures from taxonomic to functional to phylogenetic diversity using Hill numbers. We will further expand the Hill number concept to multifunctionality allowing the decomposition of γ-multifunctionality into α- and β-components. Combining this analytic framework with our experimental data will allow us to test how an increase in between patch heterogeneity affects biodiversity and multifunctionality across spatial scales and trophic levels to help inform and improve forest resilience under climate change. Such an integrative concept for biodiversity and functionality, including spatial scales and multiple aspects of diversity and multifunctionality as well as physical and environmental structure in forests, will go far beyond the current widely applied approach in forestry to increase resilience of future forests through the manipulation of tree species composition.     

The relationship between soil water storage capacity and plant species diversity in high alpine vegetation

Background: In those alpine regions where growing season precipitation is decreasing due to climate change, the capacity of soils to retain water may become an important factor for the persistence of plant species. However, the importance of soil water storage capacity (WSC) for plant species diversity has not been studied so far.

Aims: We aim to evaluate the relevance of WSC for species diversity of alpine plant communities in relation to temperature and length of growing season.

Methods: Species diversity was determined in 150 plots from a broad range of alpine vegetation types in the calcareous western part of the central Swiss Alps. WSC of soil cores sampled in every plot was determined, as well as rooting zone temperature and snowmelt date. Linear mixed models were used to assess the relationship between environmental data and species diversity.

Results: Species diversity was most strongly and positively related to WSC, followed by mean daily minimum temperature (T_min) of the growing season. Species diversity was significantly related to date of snowmelt only in sites with high WSC and/or T_min.

Conclusions: WSC represents an integrative measure for habitat quality and accounts for differences in species diversity within the study region. In order to understand and predict responses of plant species to climate change in high mountain regions, it may be crucial to also take changes in plant water supply into account.