福建将石自然保护区鸟类物种相对多度模型的拟合研究

应用对数级数分布模型、对数正态分布模型、几何级数分布模型和分割线段模型对福建将石自然保护区鸟类物种相对多度分布格局对比研究结果表明 ,对数级数分布模型、对数正态分布模型能较好地描述将石自然保护区鸟类多样性 ,而几何级数分布模型和分割线段模型则不适于描述该自然保护区鸟类多样性 ;“多度 /频度”图解可较好地反映对数级数分布模型拟合效果 ,丘陵山地鸟类群落物种相对多度不遵从对数级数分布 ,各生境群落百分率相似性指数说明各生境群落百分率相似性较低。     

黄土沟壑区不同坡位白羊草群落物种多度分布研究

物种多度分析是研究群落结构和分析群落生态学机制的重要方法,以黄土沟壑区地带性白羊草群落为对象,研究了坡位对白羊草群落物种多度分布格局的影响。结果表明:(1)坡位对白羊草群落物种多样性有显著性影响,坡中的Shannon指数、Simpson指数、Patrick指数显著低于坡上和坡下(p<0.05),坡上和坡下上述指数无显著差异(p>0.05)。坡上、坡中和坡下的群落Pielou均匀度指数和Alatalo均匀度指数无显著差异(p>0.05);(2)采用Zipf、Zipf-Mandelbrot、几何序列、分割线段、优势优先5种生态位模型对不同坡位上白羊草群落的物种多度分布格局进行模拟,发现仅前两个模型能很好地拟合白羊草群落在坡上、坡中和坡下的多度分布格局。说明尽管在不同坡位上白羊群落的物种多样性不同,但不同坡位上群落的形成过程和机理基本一致。本研究支持了Zipf模型和Zipf-Mandel-brot模型能较好的描述演替后期群落分布格局的观点。     

海拔对表居土壤动物不同取食功能群多度分布的影响

物种多度分布格局是群落生态学研究的前沿领域之一。海拔梯度下开展土壤动物多度分布研究有利于认识分解者群落的构建过程如何响应环境变化。选用5种常见的生态位分配模型(断棍模型、生态位优先占领模型、生态位重叠模型、随机分配模型和优势优先模型),分别采用个体数量与生物量作为多度表征指标,对分布于北京东灵山辽东栎林下不同海拔范围的表居土壤动物群落整体与不同取食功能群(杂食者、植食者、捕食者、腐食者)的相对多度分布进行研究。结果表明,拟合表居土壤动物群落整体的最优生态位分配模型不受海拔影响,均为断棍模型。但表居土壤动物各功能群多度分布受海拔影响,杂食者随海拔升高,最优模型由断棍模型转变为生态位优先占领模型,而植食者与之相反。多度表征指标选择影响拟合表居土壤动物不同功能群(捕食者和腐食者)多度分布的最优模型。总体而言,海拔和多度指标选择并未影响表居土壤动物整体的多度分布,但对表居土壤动物中不同取食功能群的多度分布有影响。     

闽北檫树群落乔木层物种多样性特征研究

采用对数级数模型对檫树群落物种多度分布格局进行预测与检验结果表明 ,该檫树群落物种多度分布遵从对数级数分布 ,即群落的均匀度相对较小 ,群落稳定且具有较高的生物多样性。     

左家自然保护区大型土壤动物与土壤因子关系研究

从生态序列的角度研究了左家自然保护区微地貌中大型土壤动物群落的分布格局,同时考虑到土壤因子对大型土壤动物的综合作用,从小尺度上探讨大型土壤动物群落与土壤因子的关系。研究结果表明,凋落物的种类和数量差异对大型土壤动物的分布影响明显,阴坡和阳坡的四个生境坡谷、坡麓、坡中、坡顶植被差异较小,土壤因子是研究区大型土壤动物序列分布的一个重要影响因子。微地貌条件下,土壤有机质、土壤含水率、pH、全氮、全磷变化趋势接近,土壤温度与土壤含水率、pH、土壤有机质、全氮和全磷这5个指标变化趋势相反,土壤有机质、土壤含水率、pH、全氮、全磷和土壤温度这6个指标对研究区主要的大型土壤动物类群的分布有重要的影响。     

地形对喀斯特山地植物物种多样性及分布格局的影响

[目的]研究地形对喀斯特地区植物物种多样性与分布格局的影响,为喀斯特区生态保护与维持提供科学依据。[方法]利用方差分析、典范对应分析(CCA)研究贵州省施秉县喀斯特山地不同地形下乔木、灌木和草本植物物种多样性差异及地形因子对其分布格局的影响。[结果]乔木在山顶的均匀度显著低于其他坡位;优势度显著高于其他坡位。灌木在山顶的多样性显著高于下坡和河谷;丰富度为山顶显著高于中、下坡和河谷,上坡显著高于下坡和河谷;河谷的优势度显著高于山顶。草本的多样性为山顶显著低于中、下坡和河谷;丰富度为山脊和山顶显著低于中、下坡和河谷;优势度与多样性表现相反。半阴坡的草本丰富度显著大于半阳坡。坡度对乔木丰富度与多样性的影响一致,均为平坡显著大于缓坡和斜坡,陡坡显著大于斜坡;均匀度为斜坡显著低于平坡和陡坡,优势度与均匀度表现相反。CCA排序表明,海拔和坡度对3种生长型植物分布格局的影响均显著,坡位对乔木分布格局的影响显著,坡向对3种生长型植物分布格局的影响均不显著。[结论]喀斯特区植物物种多样性及其分布格局受以海拔、坡度为主,坡位和坡向为辅的多个因子共同的影响。     

长白山地丘陵区不同土地利用方式土壤动物群落生态分布特征

在长白山地丘陵区选择次生落叶阔叶林、灌木林、采伐迹地以及耕地四种土地利用方式,对其土壤动物群落的组成、多样性和分布特征进行研究。结果表明:不同土地利用方式土壤动物群落的水平分布呈现明显的差异。采伐迹地中型土壤动物个体密度和耕地中型土壤动物类群数季节变化明显。次生落叶阔叶林和灌木林土壤动物分布随土层加深急剧减少,采伐迹地和耕地垂直分布递减和缓。同一季节土壤动物的丰富度指数和多样性指数在不同土地利用方式差异显著。土壤动物的多样性表现为灌木林最高,耕地最低。不同土地利用方式影响土壤动物群落的生态分布,其中pH、土壤有机质、有效磷和速效氮是影响长白山地丘陵区不同土地利用方式土壤动物群落分布的主导因子。     

新疆西天山雪岭云杉林不同海拔高度大型土壤动物群落结构特征

【目的】明确新疆西天山不同海拔高度雪岭云杉林下大型土壤动物群落的组成、分布特征和多样性，为当地森林资源生态系统健康评价、土地利用管理及资源可持续利用提供土壤动物学依据。【方法】选取新疆西天山不同海拔高度雪岭云杉林样地(Ⅰ,海拔1414 m；Ⅱ，海拔1595 m；Ⅲ,海拔1724 m；Ⅳ，海拔1868 m)，使用手捡法收集云杉林下大型土壤动物，采用单因素方差分析（One-way ANOVA）和最小显著差异法（LSD）比较大型土壤动物群落不同数据组间的差异，采用冗余分析（Redundancy analysis, RDA）排序方法分析土壤动物群落物种重要值与环境变量的关系。【结果】四个样地共捕获大型土壤动物427只，隶属于3门7纲16目23科。四个样地垂直分布特征表现为样地Ⅱ大型土壤动物平均密度在7月的表聚性特征较为明显，随着土层深入呈现递减趋势，其它样地无明显的分布规律。大型土壤动物多样性指数、均匀度指数、优势度指数和丰富度指数在不同海拔高度均有所不同，样地Ⅰ大型土壤动物的多样性指数、均匀度指数和丰富度指数为四个海拔中最高。各个样地杂食性大型土壤动物的个体密度所占4个功能群个体密度总量的比...     

子午岭天然柴松林土壤种子库

采取子午岭天然柴松林地3个坡位与1个对照区共4个大样地54个小样方的土壤样品,通过室内种子萌发和地上植被调查相结合的方法对其种子库进行研究,以揭示其土壤种子库特征及与地上植被的关系。结果显示：1）土壤种子密度平均为1 496.7粒/m^2,最小为1 240.0粒/m^2,最大为1 785.0粒/m^2,荒山对照区为510.0粒/m^2;2）种子库的垂直分布格局显示,近90%的种子储存于枯枝落叶层和0-7.5 cm土层中;3）研究中共统计到植物种32种,分属于20科,其中多年生草本和常绿灌木种子比例最高,分别占种子库种子总数的48.3%和41.9%;4）不同坡位的物种丰富度指数介于2.523-3.082之间,而物种多样性指数介于1.458-1.781之间,其中中坡物种丰富度指数最大而多样性指数最小,上坡多样性指数和均匀度指数都最大;5）各坡位地上植被主要建群植物种中,除白颖苔草、大披针苔草、胡枝子、唐松草在对应坡位的土壤种子库中出现且分别占该坡位种子库的19.7%、2.1%和0.8%、1.7%和3.1%0、.4%外,其他建群种如榛子、子、地榆等在种子库中均未出现,种子库不能很好地反映地上植被组成,部分未出现物种与其自身萌发性质有关;6）土壤种子库中柴松种子所占比例约为0.6%（地上植被调查发现）,柴松林下有更新幼苗,约5-7粒/m^2,说明种子库具有潜在萌发能力,森林具备一定的自我更新能力。     

残塬沟壑区果园复合种植对土壤动物群落特征的影响

为了解苹果复合种植即果-蔬[MB]、果-草[MH]、果-荒[MW]、果-粮[MZ]模式下土壤动物群落结构特征,采用手拣法和改良干、湿生漏斗法,对黄土残塬沟壑区苹果园4种复合种植模式下的土壤动物群落组成及特征进行调查研究。4种模式下共分离得到土壤动物57.33百只/m~2,隶属4门11纲23目42个类群。4种复合种植模式下土壤动物个体密度和类群数的垂直分布特征表现出明显的表聚特征,水平分布特征表现为果-草[MH]果-蔬[MB]果-荒[MW]≥果-粮[MZ]。果-草[MH]复合种植模式下土壤动物的多样性指数、均匀度指数及丰富度指数最高,优势度指数最低,表明4种复合种植模式对果园土壤动物类群多样性的影响呈现不同的特征。研究结果可为黄土残塬沟壑区苹果果园生物多样性保护提供土壤动物生态学依据。     

Soil faunal assemblage composition modifies root in-growth to plant litter patches

Local-scale heterogeneity in the spatial distribution of soil nutrients promotes a suite of physiological and morphological responses in plants. These responses influence the competitive ability of plants within communities and potentially plant primary productivity. There is a growing appreciation then for the need to study factors that may modulate these plant responses to soil nutrient heterogeneity. Soil fauna are potentially one such modulating factor. For example, through impacts on organic matter decomposition and distribution they may directly modify nutrient patches and therefore the stimulus plants are responding to. In addition they may modify plant root mass and architecture through processes such as herbivory, potentially altering the outcome of a plant's response to a nutrient patch. Using grassland microcosms, consisting of a multi-species plant assemblage, multiple soil horizons and a speciose soil biota, we tested whether soil faunal assemblage composition might modulate plant responses to nutrient patches represented by litterbags. We show that root proliferation into a nutrient patch, a variable which is positively related to a plant's success under conditions of interspecific competition in a nutrient-limited environment, is reduced by the presence of mesofauna, and even more so by the presence of mesofauna together with macrofauna. Reductions in this proliferation response when mesofauna were present without macrofauna appeared to be a function of reduced root density. When macrofauna were included, reduced root density, and higher rates of litter patch disappearance, together contributed to the reduction in proliferation but additional mechanisms must also have played a role. Our results suggest that the effects and interactions generated by soil fauna need to be explicitly considered in analyses of how plants forage for nutrients in a patchy environment.     

Soil fauna abundance and diversity in a secondary semi-evergreen forest in Guadeloupe (Lesser Antilles): influence of soil type and dominant tree species

The importance of secondary tropical forests regarding the maintenance of soil fauna abundance and diversity is poorly known. The aims of this study were (1) to describe soil fauna abundance and diversity and (2) to assess the determinants of soil fauna abundance and diversity in two stands of a tropical semi-evergreen secondary forest. Soil macrofauna and microarthropod abundance and soil macrofauna diversity were described at two sites developed on different soils and with different site histories: (1) a natural secondary stand (natural forest) under two dominant tree species, Pisonia subcordata and Bursera simaruba, and (2) a planted secondary forest (planted forest) under three tree species, B. simaruba, Swietenia macrophylla, and Tabebuia heterophylla. The effects of both soil and main tree species’ litter quality were assessed to explain soil fauna abundance and diversity. The abundance of soil macrofauna was significantly higher in the soil under the planted forest, and soil fauna communities were contrasted between the two sites. In the planted forest, a soil-dwelling macrofauna community developed (mainly consisting of the anecic earthworm Polypheretima elongata). In the natural forest, soil macrofauna and microarthropod communities were located at the soil surface. The effect of plant litter quality varied according to each dominant tree species and was superimposed to soil effect. The lowest macrofauna abundance was associated with B. simaruba in the natural forest. T. heterophylla supported a much greater macrofauna community than the two other tree species studied at the same soil, and it appears likely that this is due to the palatability of its leaves compared with the other trees (low lignin, tannins, soluble phenols).     

Species abundance distribution of collembolan communities in forest soils polluted with heavy metals

The species frequency of collembolan communities along a gradient of heavy metal pollution in soil of pine forest soils was studied. Sampling plots were established in forests 1, 3, 5, 8, 11, 68 and 148 km from the Miasteczko Śląskie zinc smelter. At each plot the plant associations, physicochemical characteristics of soil, and collembolan species composition and abundance were examined. The structure of collembolan communities was analyzed with regard to species distribution, testing geometric series, broken-stick, logarithmic series, log-normal and negative binomial distribution models. Most of the collembolan communities occurring both in contaminated and in uncontaminated soils had structure similar to a negative binomial distribution. In the samples from the oldest forest, the species frequencies could also be fitted to a log-normal distribution. The species frequency model was independent of the degree of soil pollution. Under the assumption of a negative binomial distribution of Collembola from soil samples, it is possible to estimate the theoretical number of collembolan species in the habitats studied. The difference between estimated and empirical numbers of species (the number of species not revealed in samples) was linearly correlated with metal concentrations in soil, indicating the elimination of a number of rare species from severely polluted forests.     

Impact of faunal complexity on microbial biomass and N turnover in field mesocosms from a spruce forest soil

In a field study using soil mesocosms in an acid spruce forest soil we investigated the effects of mesofauna and macrofauna on microbial biomass, dissolved organic matter, and N cycling. Intact soil monoliths were taken from the ground, defaunated by deep-freezing, and wrapped in nets of various mesh-sizes to control re-immigration of different faunal size-classes. The monoliths were then replanted in the field. Three treatments of mesocosms were prepared: (1) with only microbiota, (2) microbiota and mesofauna, and (3) microbiota, mesofauna, and macrofauna (= complex fauna). After 8 months of exposure the mesocosms and the unmanipulated control plots (treatment 4) were destructively sampled. We estimated microbial biomass by substrate-induced respiration and the chloroform fumigation-extraction method. N cycling was measured by monitoring microbial N mineralization, the NH _inf4 ^sup+ content, and selected amino acids and the activities of protease, urease, and deaminase. The results from the L/F layer showed that the pool of the microbial biomass was not changed by the activity of the mesofauna. However, the mesofauna and macrofauna together enhanced SIR. An increase in microbial N mineralization was only observed in treatment 3 (microbiota + complex fauna). Protease activity and NH _inf4 ^sup+ content increased in treatments 2 (microbiota + mesofauna) and 3 (microbiota + complex fauna). The complex fauna induced a soil pH increase in treatment 3 as opposed to treatment 1 and the control. This increase was presumably due to excretory NH _inf4 ^sup+ . Principal component analysis revealed that the complex fauna in treatment 3 caused a significantly higher N turnover per unit of microbial biomass.     

四川紫色土丘陵区不同土地利用方式下大型土壤动物群落结构

为了解不同利用方式土地大型土壤动物群落结构,于2006年冬季和2007年春季对四川紫色土丘陵区农田边界、农田、果园和退耕林地进行了大型土壤动物调查,采用野外手捡法共采集大型土壤动物2 838只,隶属于3门9纲24类.研究结果表明:不同土地利用方式大型土壤动物群落的个体密度、类群数和DG多样性指数存在差异.冬季,农田边界的个体密度显著高于其他土地利用方式,类群数和DG多样性指数显著高于退耕林地和农田;农田的个体密度、类群数和DG多样性指数明显处于最低水平.大型土壤动物群落的个体密度和类群数在垂直分布上具有明显的表聚性.Jaccard相似性系数和Grower系数表明农田边界、果园与退耕林地三者间相似程度较高,农田与农田边界、退耕林地、果园之间相似程度较低.研究认为土地利用方式对大型土壤动物的群落结构有明显影响,农田边界的存在对大型土壤动物生物多样性的保护具有重要意义.     

Effects of plant diversity on plant biomass production and soil macrofauna in Amazonian pastures

We examined the effect of plant diversity on plant production and soil macrofauna density and diversity. Four plants species (Arachis pintoi, an herbaceous legume; Brachiaria brizantha, a perennial grass; Leucaena leucocephala, a legume shrub; Solanum rugosum, a non-legume shrub) were used in a field experiment and communities of all combinations of one, two, three or four species were established. Plant diversity neither significantly affected density and diversity of soil macrofauna nor total plant biomass, however, the biomass of specific plants was negatively affected by plant diversity. Earthworm and ant densities were significantly higher in the presence of A. pintoi although this plant influenced neither the density of the other group nor fauna diversity. Earthworm and diplopod densities increased significantly with shoot biomass of A. pintoi. Fauna diversity increased significantly with shoot biomass (specific and total). Root biomass did not affect fauna density and diversity. Our results suggest that fauna density is affected by litter quality and that it is more affected by resource quantity than quality. Our results also confirm the importance of nitrogen fixers to ecosystem function.     

米亚罗林区冬季大型土壤动物的空间分布特征

土壤动物是陆地生态系统的组成部分,对多种地下生态过程具有重要的作用[1-2]。近些年,对土壤动物多样性及其功能的研究已成为生态学领域的一个新兴前沿[3-4]。土壤动物群落组成对植被变化有明显的依赖性,不同植被类型有着与其相适应的土壤动物群落[5-7]。但植被类型的变化常与海拔     

大兴安岭不同冻土带土壤动物生态地理研究

2003年6月、8月、10月对大兴安岭不同冻土带选择沼泽、柳丛、耕地、次生林群落进行土壤动物调查，共获土壤动物39225只，隶属于4门8纲24目。由对大型、中小型及湿生三类土壤动物的数量分析可知，三类土壤动物数量的变化在群落间并不总是成正相关的关系。水平分布调查表明，中小型土壤动物的个体数量和类群数量从岛状冻土带到连续多年冻土带逐渐减少，该分布与土壤动物分布的一般规律（土壤动物分布通常符合纬度地带性分布规律，即由低纬向高纬逐渐减少）一致，但大型土壤动物的个体数量、类群数和生物量基本上从岛状冻土带到连续多年冻土带逐渐增加（即由低纬向高纬逐渐增加），湿生动物的数量也如此分布，这与土壤动物分布的一般规律不一致甚至相悖，这一特点表现出生态系统局部-区域相互关系的复杂性；土壤动物的类群数、个体数量与土壤有机质、全氮的含量呈明显的正相关；垂直分布调查表明，中小型土壤动物的个体数量和类群数量分布表现出明显的表聚性，但大型土壤动物的个体数量与生物量最大值出现在第二层；土壤动物多样性分析表明，中小型土壤动物的多样性指数从岛状冻土带到连续多年冻土带逐渐减小，而大型土壤动物的多样性指数在不同冻土带间的变化规律不明显。     

Plant litter quality influences the contribution of soil fauna to litter decomposition in humid tropical forests, southwestern China

The aim of this field experiment was to quantify the contribution of soil fauna to plant litter decomposition in three forest sites differing in C/N ratio under natural conditions in Xishuangbanna, southwestern China. We conducted a survey of soil fauna communities, the forest floor litter and investigated mass loss of mixed tree species leaf litter for two years in a tropical secondary forest, an evergreen broad-leaf forest and a tropical rain forest. Exclusion treatments of different sized soil fauna from the leaf litter by using varying mesh size litter bags (2 mm and 0.15 mm) were also performed. Mass loss and C and N concentrations in litter bag leaf materials were determined at monthly intervals. We found that: (1) the three forests differed in floor litter biomass and nutrient contents but not in soil fauna richness and abundance; (2) litter mass loss and decomposition rate were slower when soil macrofauna and most of mesofauna were excluded; and (3) greatest soil fauna contribution to plant litter decomposition occurred in the rain forest, where leaf litter C/N ratio was also highest (41.5% contribution: 54.8 C/N ratio), in comparison to 8.69% in the broad-leaf forest and 19.52% in the secondary forest, both with low leaf litter C/N ratios (<32). Our results suggested that, soil fauna played a more pronounced role in the decomposition of mixed leaf litter in tropical rain forest, and significantly bigger effects from fauna were ascribed to the enhancement of N concentration and decrease of C concentration of the initially high C/N ratio litter in this forest site.     

The influence of plant litter diversity on decomposer abundance and diversity

Although there has been much recent interest in the effect of litter mixing on decomposition processes, much remains unknown about how litter mixing and diversity affects the abundance and diversity of decomposer organisms. We conducted a litter mixing experiment using litterbags in a New Zealand rainforest, in which treatments consisted of litter monocultures of each of 8 forest canopy and understory plant species, as well as mixtures of 2, 4 and 8 species. We found litter mixing to have little effect on net decomposition rates after either 279 or 658 days, and for each species decomposition rates in mixture treatments were the same as in monoculture. Litter species identity had important effects on litter microfauna, mesofauna and macrofauna, with different litter types promoting different subsets of the fauna. Litter mixing had few effects on densities of mesofauna and macrofauna, but did have some important effects on components of the microfauna, notably microbe-feeding and predatory nematodes. At day 279, litter mixing also consistently reduced the ratio of bacterial-feeding to microbe-feeding (bacterial-feeding+fungal-feeding) nematodes, pointing to mixing causing a significant switch from the bacterial-based to the fungal-based energy channel. Litter mixing sometimes influenced the community composition and diversity of nematodes and macrofauna, but effects of litter mixing on diversity were not necessarily positive, and were much weaker than effects of litter species identity on diversity. We conclude that litter mixing effects on the abundance and diversity of decomposer biota, when they occur, are likely to be of secondary and generally minor significance when compared to the effects of litter species identity and composition.