群落构建的中性理论和生态位理论

物种共存和生物多样性维持一直是生态学研究的中心论题。基于物种生态位分化的群落构建理论已经发展了近一个世纪, 但我们对群落构建和生物多样性维持的机理仍然不清楚。近年来, 群落中性理论以其简约性和预测能力成为群落生态学研究的焦点, 但由于其“物种在生态功能上等价”的假设与大量研究结果相悖, 同时对自然群落结构的准确预测也只限于少数的生态系统, 因而饱受质疑。如今, 越来越多的生态学家认为群落构建的生态位理论与中性理论之争的最终归宿应该是二者的整合。 在本文中, 我们在简要回顾生态位理论和群落中性理论发展的基础上, 分析二者之间的主要分歧和互补性, 试图梳理二者整合的途径。我们认为, 尽管中性理论的发展极大地丰富了群落构建理论, 但二者的整合尚处于初级阶段; 群落构建零模型假说、中性—生态位连续体假说、随机生态位假说等都不失为有价值的尝试, 今后需要在其他类型的生态系统中进行实验验证, 以更好地理解确定性过程和随机过程在决定群落构建和生物多样性维持中的作用。     

Aquatic Oligochaeta of the Dnieper-Bug Estuary system

This paper describes the influence of different ecological factors on the distribution of Oligochaeta in parts of the Dnieper-Bug Estuary. The important environmental factors in the Dnieper-Bug Estuary were salinity, discharge, water quality, trophic condition and sediment characteristics. In the Lower Dnieper-Bug a correlation was found between abundance and number of oligochaete species and the concentration of ammonium nitrogen and mineral phosphorus in the water.     

南亚热带森林群落种-多度的对数正态分布模型研究

通过对地处南亚热带的广东省黑石顶自然保护区森林群落的定点研究结果的分析表明：当用１,２,３,…分组每种个体数ｒ时,５个不同类型的群落样地的种一多度分布的直方图都呈明显的倒Ｊ－形;经Ｐｒｅｓｔｏｎ“倍程（ｏｃｔａｖｅｓ）”法分组ｒ后,其种－多度都服从对数正态分布。由种－多度模型可以推出另一新的模型一个体一多度分布模型,即Ｉ（Ｒ）＝２R0ＳＯＥＸＰ［［１ｎ２）２／４ａ２〕ＥＸＰ｛－ａ２（Ｒ－（ＲＯ＋１ｎ２／２ａ２）］２｝,它也符合对数正态分布。另外,还运用积分方法推导出估计总体（整个群落）中总种数Ｓ*和总个体数Ｉ*理论值的公式,用此公式估计的结果较为合理。     

Passive restoration in Araucaria Forest: useful ecological indicators in monitoring successional advancement in exotic tree plantation landscapes

Monitoring successional advancement is a complex field involving a constant search for applied ecological indicators which facilitate monitoring of secondary forests for both active and passive restoration. In this study, the authors investigate the successional advancement of floristics and tree structure within Araucaria Forest (AF) fragments under passive restoration in a context where exotic tree plantations (mainly Pinus L. genus) dominate the landscape. The ecological indicators used were floristic dissimilarity (β‐diversity inferences), indicator species, ecological groups of species, basal area, and species abundance distribution (SAD) models (α‐diversity inferences). A total of 182 tree species belonging to 91 genera and 43 botanical families were identified. A high β diversity was verified for which each site has indicator species (for the locations CD—Dicksonia sellowiana; CO—Cryptocarya aschersoniana; and PG—Pinus taeda), where pioneer species contributed to much of the abundance. Different SAD models are useful for describing passive restoration sites in exotic tree plantation landscapes, namely Lognormal, Mandelbrot, and Zipf. SAD models together with basal area, taxonomic group (e.g. Myrtaceae assemblage), and tree abundance in ecological groups are strategic ecological indicators for monitoring successional advancement in AF.     

弃管杉木林杉木数量与群落物种多样性间的关系

森林群落物种多样性格局和动态一直是生态学的研究热点,人工林弃管后演替进程中物种多样性变化也很值得研究。杉木(Cunninghamia lanceolata)作为我国南方林区人工栽培最广、经济价值最高的用材树种之一,其人工林分布面积很大,通常群落结构简单、物种多样性低,然而群落中杉木数量如何影响植物物种多样性,迄今缺乏研究。在浙江省自然保护区内,选择不同疏伐强度和弃管时间的杉木人工林,建立了6个1 hm~2长期动态监测样地,在10 m×10 m、20 m×20 m、50 m×50 m和100 m×100 m尺度下,探究群落物种多样性(物种丰富度、Simpson指数、Shannon-Wiener指数和Pielou均匀度指数)的变化规律,分析杉木数量(多度和相对多度)对物种多样性的影响。结果显示：弃管前对杉木林的疏伐强度越高,演替恢复后的群落物种多样性越高。相同疏伐程度下,物种多样性随演替时间的延长有先升高后降低的趋势。取样尺度小于100 m×100 m时,杉木数量与物种多样性呈极显著负相关;100 m×100 m尺度下仅杉木相对多度与3种多样性指数呈显著负相关,杉木多度与各物种多样性均无显...     

北京东灵山地区植物群落多样性的研究 Ⅲ.几种类型森林群落的种-多度关系研究

选用描述种－多度关系的二类共８个模型（对数级数分布ＬＳ、对数正态分布ＬＮ、负二项分布ＮＢ和几何分布ＧＯＭ以及“分割线段”模型ＢＳＭ、生态位优先占领模型ＮＰＭ、Ｚｉｐｆ模型ＺＭ和Ｚｉｐｆ－Ｍａｎｄｅｌｂｒｏｔ模型ＺＭＭ）对东灵山地区９个类型的森林群落进行了研究。结果表明,ＬＳ和ＮＢ对大多数群落可以很好地拟合,ＬＮ和ＧＯＭ对每一个群落都不能很好地拟合;ＺＭＭ可以很好地、ＮＰＭ也可以较好地拟合每一个群落,ＺＭ可以很好地拟合大多数群落,而ＢＳＭ则反之。ＬＳ中的参数α与４个丰富度指数呈极强的线性关系,与３个多样性指数也有较强的线性关系。因此,α可以作为群落的一个多样性指数使用,并且它更多地反映了群落的丰富度。本研究也表明,将包含多个参数的非线性方程组逐渐化为只含一个参数的非线性方程,再将ＭｏｎｔｅＣａｒｌｏ方法、区间二分法和迭代法相结合以求解该方程,从而实现参数估计,这种算法是可行的;在拟合三参数模型ＺＭＭ时,先固定参数β,再通过线性化求出另外２个参数,经过多次计算,求出一组参数值作为下一步非线性方程拟合的初值,这种算法也是成功的。在进行种重要性顺序－多度表模型的评价时,不能只考虑剩余标准差或相关指数,它们是基于误差平方和的两个指标,对真实的误差有某种夸张作用;应该尽可能地考虑平均绝对误差这个指标。     

甘南亚高寒草甸稀有种对物种多样性和物种多度分布格局的贡献

稀有种不仅影响群落的物种多度分布格局, 同时也是α多样性的重要贡献者。本研究主要通过加性分配和Fortran软件的RAD程序包拟合的方法, 研究了甘南亚高寒草甸不同坡向物种多样性及多度分布格局的变化, 分析了物种多度分布格局及其α多样性的变化特征, 确定了稀有种在物种多度分布格局中的相对贡献。结果表明: (1)在南坡到北坡的变化中, 环境因子差异比较明显, 其中, 土壤全磷、有机碳、速效磷、碳氮比及含水量呈递增趋势; 土壤氮磷比和pH值呈递减趋势; 土壤全氮在西坡显著低于其他坡向, 而速效氮在所有坡向上差异不显著。(2)稀有种对群落物种多样性的影响在南-北坡向梯度上依次增大, 去除稀有种的影响在各坡向均高于去除非稀有种, 可见, 稀有种在甘南亚高寒草甸物种多样性中的相对贡献高于非稀有种。(3)各坡向的稀有种资源获取模式以随机分配占领模式(random fraction模型)为主, 而非稀有种则以生态位优先占领模式(geometric series模型)为主。由于稀有种有较大的扩散率, 在物种多样性较高的生态系统中, 物种之间的生态位重叠会更加明显, 从而抑制物种多样性的增加, 因此能达到维持原有物种多样性的目的。     

Predicting community rank‐abundance distributions under current and future climates

Understanding influences of environmental change on biodiversity requires consideration of more than just species richness. Here we present a novel framework for understanding possible changes in species' abundance structures within communities under climate change. We demonstrate this using comprehensive survey and environmental data from 1748 woody plant communities across southeast Queensland, Australia, to model rank‐abundance distributions (RADs) under current and future climates. Under current conditions, the models predicted RADs consistent with the region's dominant vegetation types. We demonstrate that under a business as usual climate scenario, total abundance and richness may decline in subtropical rainforest and shrubby heath, and increase in dry sclerophyll forests. Despite these opposing trends, we predicted evenness in the distribution of abundances between species to increase in all vegetation types. By assessing the information rich, multidimensional RAD, we show that climate‐driven changes to community abundance structures will likely vary depending on the current composition and environmental context.     

吉林蛟河阔叶红松林物种多度分布模型研究

以吉林蛟河阔叶红松林的木本植物为研究对象,将30hm²的样地面积划分为5m×5m,10m×10m,20m×20m,25m×25m的连续取样单元,在4个不同尺度下分别统计各物种在每个取样单元中的有无,得到每个物种在不同尺度下的取样单元数。利用随机分布模型和负二项分布模型分析物种的多度分布,对比预测多度与观测多度讨论两个模型的科学性与实用性。结果表明：对于阔叶红松林而言,负二项分布模型在所有研究尺度上的预测精度都要优于随机分布模型。随机分布和负二项分布的模型预测误差随着研究尺度的增大而增大,因此选取较小的取样单元可以切实提高物种多度的预测精度。利用随机分布和负二项分布模型对多度较小的物种进行预测的效果要优于多度较大的物种。负二项分布模型适合用来模拟阔叶红松林的物种多度分布格局,并且模型的拟合效果受取样单元大小影响。     

北部湾海域浮游介形类物种组成、丰度分布及多样性

根据1998年1月～1999年5月北部湾海域4个航次生态环境综合调查资料,对北部湾海域浮游介形类进行分析研究。结果表明,北部湾渔场浮游介形类物种组成较为简单,记录有小型海萤（Cypridina nana）、齿形海萤（Cypridina dentata）、尖尾海萤（Cypridina acuminata）、纳米海萤（Cypridina nami）、针刺真浮萤（Euconchoecia aculeata）、细长真浮萤（Euconchoecia elongata）、后圆真浮萤（Euconchoecia maimai）等18种;隶属于2亚目、2科、4亚科、12属,其中有4种周年出现,9种只在特定的单一季节出现,其余5种季节性出现;夏季和冬季出现的物种数最多,达到11种;春季次之,为9种;秋季最少,只有6种。北部湾浮游介形类可以划分为3个生态类群,即低盐暖水类群、广温广盐类群和高温高盐类群,优势种群主要是近岸低盐暖水类群的针刺真浮萤和尖尾海萤。全海域栖息密度变化范围为0．02～51．58ind．／m^3,年平均1．22ind．／m^3,春季最高,达2．73ind．／m^3,在湾西北部密集有大量的针刺真浮萤;夏季此密集区逐渐向湾中部移动,纳米海萤为其密集种,栖息密度也有所降低;秋、冬季量少,但在湾南、北部各出现一个丰度相对较高的密集区,并由南北向湾中部递减。总生物量具有明显的季节性变化,平面分布趋势与栖息密度相似。生物多样性指数低,以湾口较高、湾顶较低,呈湾口向湾内西北方向递减趋势;全海域年平均多样性阈值为0．329,四季多样性水平皆为Ⅰ级,多样性程度低;多样性程度较高的区域,多出现于受外海水影响较大、水文状况变化较为复杂的海域。对浮游介形类的物种组成、丰度分布及多样性与北部湾的水系、水团、水温及盐度等环境因子的关系进行了探讨。     

A comparison between diversity, similarity and biotic indices applied to the macroinvertebrate community of a small stream: the Ravella river (Como Province, Northern Italy)

This study aimed at comparing the results obtained by processing a series of data according to several diversity indices (Simpson, Berger-Parker, Margalef, Menhinick, McIntosh, Shannon) and one similarity index (Jaccard) with those obtained from two biotic indices (Trent River Biotic Index, Extended Biotic Index). In addition, Cody's index was adopted to measure the species turnover along the stream gradient. The source of the data was a study of the seasonal variations of macroinvertebrates from the Ravella stream (Como Province, Northern Italy). The conclusions are the following. There is clearly a certain connection between the organic debris in the habitat, the abundance of individuals and the decrease in the diversity value of the macroinvertebrate association. The species turnover along the stream gradient is rapid which is due, in addition to birth and death rates, to the fact that most of the insects emerge as terrestrial adults. The species abundance distribution is a very simple and powerful tool for describing and comparing the species diversity from different sampling stations. Any type of monitoring (e.g., biotic indices, diversity indices) is useful in comparing non-polluted and heavily polluted environments. Conversely, small differences between species associations are better highlighted if diversity indices with high discriminant ability (e.g., Simpson's index) or species abundance distribution are used rather than biotic indices.     

Species composition, abundance distribution and diversity of planktonic Ostracoda in the Beibu Gulf, China

Four cruises of survey were carried out in the Beibu Gulf between Feb 1998 and May 1999. A total of 18 species of planktonic Ostracoda were identified, including Cypridina nana, Cypridina dentata, Cypridina acuminata, Cypridina nami, Euconchoecia aculeata, Euconchoecia elongata, Euconchoecia maima, and other taxa. Planktonic Ostracoda in the gulf were divided into three ecological types: (1) a hyposaline and warm-water group, (2) a eurythermal and eurysaline group, and (3) a hyperthermal and hysaline group. The warm water species such as Euconchoecia aculeate and Cypridina acuminate were the dominant Ostracoda species in the gulf, where the overall Ostracoda density ranged from 0.02 ind./m³ to 51.58 ind./m³ and averaged 1.22 ind./m³. The highest average value (2.73 ind./m³) was found in spring. Fuzzy evaluation measures indicated that the diversity in the gulf remained low (level of class I) during all seasons. Diversity appeared to be relatively higher in some regions in which the water mass was strongly influenced by the open sea and had complex structures. This article also discusses how the species composition, abundance and diversity of planktonic Ostracoda are influenced by environmental factors (e.g., aquatic system, water mass, water temperature and salinity) in the Beibu Gulf.     

放牧强度和地形对内蒙古典型草原物种多度分布的影响

为了更好地理解放牧对草原生态系统物种多度分布格局的影响, 以及常见种和稀有种对维持群落多样性的作用, 以内蒙古典型草原为研究对象, 基于长期放牧控制实验平台(包括7个载畜率水平(0、1.5、3.0、4.5、6.0、7.5、9.0 sheep·hm^-2)和两种地形系统(平地和坡地)), 研究了群落内全部物种、常见种和稀有种的丰富度和多度对放牧强度的响应规律, 并选取对数正态模型、对数级数模型和幂分割模型, 对物种多度数据进行拟合。结果表明: 1)平地系统中, 物种丰富度和多度在低放牧强度下(1.5、3.0 sheep·hm^-2)增加, 而在中、高度放牧强度下(4.5-9.0 sheep·hm^-2)降低, 全部物种的多度分布在大多数放牧强度下符合幂分割模型, 在高放牧强度下也符合对数正态模型; 坡地系统中, 物种丰富度和多度随着放牧强度增加而显著降低, 全部物种的多度分布在各个放牧强度下, 均符合幂分割模型和对数正态模型。2)随着放牧强度增加, 常见种的多度响应趋势与全部物种的响应趋势一致, 其多度分布均符合幂分割模型和对数正态模型; 稀有种的丰富度响应趋势与全部物种的响应趋势一致, 其多度分布符合幂分割模型, 同时也部分符合对数正态和对数级数模型。总之, 适宜的载畜率有利于生物多样性和初级生产力的提高, 平地系统中物种多度的响应在一定程度上支持放牧优化假说; 而坡地系统中不同物种多度的响应差异说明: 确定最佳载畜率时, 还需要考虑地形因素的影响。此外, 模型的拟合结果表明: 生态位分化机制对内蒙古典型草原物种多度分布起着主要作用, 常见种和稀有种通过不同的响应方式共同维持着草原生态系统的物种多样性。     

Species composition, abundance distribution and diversity of planktonic Ostracoda in the Beibu Gulf, China

Four cruises of survey were carried out in the Beibu Gulf between Feb 1998 and May 1999. A total of 18 species of planktonic Ostracoda were identified, including Cypridina nana, Cypridina dentata, Cypridina acuminata, Cypridina nami, Euconchoecia aculeata, Euconchoecia elongata, Euconchoecia maima, and other taxa. Planktonic Ostracoda in the gulf were divided into three ecological types: (1) a hyposaline and warm-water group, (2) a eurythermal and eurysaline group, and (3) a hyperthermal and hysaline group. The warm water species such as Euconchoecia aculeate and Cypridina acuminate were the dominant Ostracoda species in the gulf, where the overall Ostracoda density ranged from 0.02 ind./m³ to 51.58 ind./m³ and averaged 1.22 ind./m³. The highest average value (2.73 ind./m³) was found in spring. Fuzzy evaluation measures indicated that the diversity in the gulf remained low (level of class I) during all seasons. Diversity appeared to be relatively higher in some regions in which the water mass was strongly influenced by the open sea and had complex structures. This article also discusses how the species composition, abundance and diversity of planktonic Ostracoda are influenced by environmental factors (e.g., aquatic system, water mass, water temperature and salinity) in the Beibu Gulf.     

Limits to the estimation of species richness: The use of relative abundance distributions

The present study demonstrates the possibility of estimating species numbers of animal or plant communities from samples using relative abundance distributions. We use log‐abundance–species‐rank order plots and derive two new estimators that are based on log‐series and lognormal distributions. At small to moderate sample sizes these estimators appear to be more precise than previous parametric and nonparametric estimators. We test our estimators using samples from 171 published medium‐sized to large animal and plant communities taken from the literature. By this we show that our new estimators define also limits of precision.     

Elevation and temporal distributions of Chrysomelidae in southeast Brazil with emphasis on the Galerucinae

In this study we present an ecological pattern of elevation and temporal variations found in the Chrysomelidae in one of the highest mountains in southeastern Brazil. Monthly surveys using an entomological sweep-net were conducted between April 2011 and June 2012, at five different elevations (800 m, 1000 m, 1750 m, 2200 m and 2450 m). A total of 2318 individuals were collected, belonging to 91 species. The elevation and temporal patterns of distribution of Chrysomelidae were heavily dominated by the Galerucinae. This subfamily had the highest richness and abundance at intermediate altitudes and during the rainy season. Probably the food availability as well as abiotic factors this time of the year favor the development of Galerucinae. Also, most of the more abundant Galerucinae species showed broad elevation ranges but approximately 20% of these species were only collected on the mountaintop sites. We would expect these species to be ones most prone to extinction in a scenario of climate warming or even after local disturbances.     

Dynamics of core and occasional species in the marine plankton: tintinnid ciliates in the north-west Mediterranean Sea

Aim To assess short‐term variability in the community composition and community structure of tintinnid ciliates, herbivores of the microzooplankton. Location North‐west Mediterranean Sea. Methods We sampled on 18 dates over a 4‐week period in 2004 at an open‐water site. Species were classified as ‘core species’, found on every date, or ‘occasional species’, absent on one or more dates. Species abundance distributions of the entire community, and separately the core and occasional species, were compared with geometric, log‐series and log‐normal distributions. Core and occasional species were compared in terms of the shell or lorica oral diameter (LOD), analogous to gape size. Results We found 11 core and 49 occasional species. Diversity metrics were stable compared with shifts in abundances. Core species accounted for the majority of individuals in all samples. On each date, 9–22 occasional species, representing 10–15% of the population, were found. Species richness of the occasionals was positively related to population size. The identities of the occasional species found were unrelated to the time between sampling. The species abundance distribution of the occasional population was best fit by a log‐series distribution, while that of the core species was best fit by a log‐normal distribution. The species abundance distribution of the entire community was best fit by a log‐series distribution. Most of the occasional species had LODs distinct from that of a core species and occupied size classes left empty by the core population. However, the most abundant and frequent of the occasional species had a LOD similar to that of a core species. Main conclusions Among tintinnids, which are planktonic protists, occasional species have a species abundance distribution pattern distinct from that of core species. Occasional species appeared to be composed of two groups, one of relatively abundant species and similar to core species, and a second group of ephemeral species with morphologies distinct from core species. The existence of two categories of occasional or rare species may be common: (1) those similar to, and thus perhaps able to replace, dominant species in the absence of a change in the environment; and (2) those distinct from dominant species and requiring different conditions to prosper.     

Species composition,abundance and habitat association of non-volant small mammals in Gibe Sheleko National Park,southwestern Ethiopia

The objective of this study was to assess the species composition, abundance and habitat association of non-volant small mammals from grassland, Acacia woodland, farmland, riverine forest, bushland and wooded grassland habitats in Gibe Sheleko National Park, southwestern Ethiopia. Data were collected using 49 Sherman live traps in 70 × 70 m sized girds and visual observations from December 2018 to August 2020. A total of 937 small mammals belonging to 10 species were captured and directly identified. The identified small mammal species and their relative abundance include Arvicanthis niloticus (7.04%), Crocidura olivieri (1.92%), Grammomys dolichurus (3.84%), Lemniscomys striatus (10.25%), Mastomys awashensis (24.55%), Mastomys natalensis (33.83%), Mus tenellus (0.85%), Myomys fumatus (6.30%), Rattus rattus (4.70%) and Stenocephalemys albipes (6.72%). Hystrix cristata, Xerus rutilus and Tachyoryctes splendens were documented through observation. The highest number of species (6) was registered at farmland and wooded grassland followed by bushland and riverine forest (5) and Acacia woodland and grassland (4). Lemniscomys striatus, M. awashensis and M. natalensis were common in all habitats. More, 216 (23.05%) individuals were recorded in farmland, while the least, 111 (11.85%) were recorded in Acacia woodland. The study area has various topographical land settings additional study is needed using different traps.     

Changes in the composition of British butterfly assemblages over two decades

Changes in the abundance and distribution of individual species have been widely documented in Britain and other countries in recent decades, but little has been done to determine changes in community composition over broad geographic areas. Here, we studied species turnover in 51 butterfly assemblages in Britain since 1976, examining extinction and colonisation events together with variation in the abundances of the species. We showed that the species turnover that occurred over 20 years in Britain was associated with colonisation and extinction events and also with variability in the abundance of the species. These changes in community composition differed according to the habitat requirements of the species and their previous distributions, being more evident for habitat specialists and for southerly distributed species. Colonising species often became abundant components of the communities they joined, although this was more evident for generalist than for specialist species. The abundance of species following their arrival, increased with time since colonisation. Species turnover associated with southerly species expanding northwards is consistent with being a response to climate change. The results suggest that climate- and habitat-driven changes in the identity and abundance of species within communities are widespread, and probably ubiquitous. Similar changes are likely to be occurring in other groups of organisms that are similarly undertaking major range shifts associated with climate change.     

How species richness and total abundance constrain the distribution of abundance

The species abundance distribution (SAD) is one of the most intensively studied distributions in ecology and its hollow‐curve shape is one of ecology's most general patterns. We examine the SAD in the context of all possible forms having the same richness (S) and total abundance (N), i.e. the feasible set. We find that feasible sets are dominated by similarly shaped hollow curves, most of which are highly correlated with empirical SADs (most R² values > 75%), revealing a strong influence of N and S on the form of the SAD and an a priori explanation for the ubiquitous hollow curve. Empirical SADs are often more hollow and less variable than the majority of the feasible set, revealing exceptional unevenness and relatively low natural variability among ecological communities. We discuss the importance of the feasible set in understanding how general constraints determine observable variation and influence the forms of predicted and empirical patterns.