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1.
随着人类对环境影响的加剧(如空间破碎化),生态系统的空间结构发生了剧烈变化,极大地改变了生态系统的结构和功能.空间结构对生态系统的影响与捕食关系的改变密切相关,探讨两者之间的联系对于了解破碎生境生态变化的机制至关重要.基于此,本文就典型空间结构对捕食关系的影响进行了论述,包括空间大小、形状、方向、布局和连通性等.资料表明,空间变小、连通性降低、空间及集合群落过度破碎化、空间方向和形状变化等导致捕食成功率过度增长,都不利于猎物-捕食者系统的稳定和持续.关于简单空间构型耦合形成的复杂空间结构对捕食关系,尤其是对多物种共存的复杂捕食关系的影响有待在今后的研究中进一步加强.  相似文献   

2.
The homing ability of an intertidal fish, the shanny Lipophrys pholis , was investigated using two experiments that were based on the shanny's natural propensity to home to a refuge. A displacement experiment demonstrated that the fish were able to accurately locate the previous position of a refuge once the shelter itself had been removed so that it could not be used as a cue to directly signal the goal location. This shows that the shanny can encode information about its familiar surroundings into a spatial map and use this information to home. A second experiment in which the cues internal and external to the experimental tank were put in conflict with one another suggested that the shanny can encode cues that are both intra- and external-tank cues in its representation of space, but that there is individual variation in the type of cues that are used, or memorized.  相似文献   

3.
空间分析方法在微生物生态学研究中的应用   总被引:2,自引:0,他引:2  
微生物生态正在受到越来越多的关注,对其研究也渐趋深入。然而由于微生物个体微小的特点及研究手段的限制,多数研究还停留在探索阶段,研究方法也在不断完善当中。近年来,较多的研究开始探讨空间因素在微生物多样性和分布中的影响,对空间分布的探讨有助于更好地认识生态过程,是一种有力的研究手段。微生物空间分析方法已经成为微生物生态学领域中重要的研究方向之一,我国空间方法在微生物生态研究中的应用还没有得到普遍的重视。从不同研究角度出发,结合空间统计的作用,对空间统计方法在微生物生态研究中的应用的必要性及现状做了评述。介绍了空间自相关性的检验,方差图,Mantel检验,Kriging插值等方法在微生物生态研究中的应用,并论述了微生物研究中的尺度问题。这一梳理,对丰富微生物生态学研究中的新方法、新手段具有一定价值。  相似文献   

4.
基于相邻木排列关系的混交度研究   总被引:4,自引:0,他引:4       下载免费PDF全文
娄明华  汤孟平  仇建习  赵明水 《生态学报》2012,32(24):7774-7780
混交度是反映森林群落中树种相互隔离状况的一个重要指标,目前已提出多种混交度指数.Mg考虑了对象木与最近相邻木的树种异同,Mv和Ms进一步考虑了最近相邻木(空间结构单元)树种数,但仍不能准确描述树种隔离程度.基于相邻木排列关系的混交度Mp,利用“1+4”结构的17个不同空间结构单元和天目山常绿阔叶林数据对Mg、Mv、Ms和Mp4个混交度进行了比较分析.结果表明:Mp的区分能力最强,Mv和Ms次之,Mg最差.Mp最适用于分析混交结构复杂的林分.在天目山常绿阔叶林分析中,混交度水平为中度,4个最近邻体中有2个相同种顺序排列的空间结构单元个数明显多于交错排列的个数.基于相邻木排列关系的混交度Mp能准确区分树种隔离程度,提高了混交度的区分度,可反映森林实际混交状况.  相似文献   

5.
中国陆域地表人类活动与自然环境的空间关系研究   总被引:1,自引:0,他引:1  
胡书玲  余斌  卓蓉蓉  张向敏  王明杰 《生态学报》2020,40(12):3935-3943
在人类活动主导人地矛盾的当代背景下,从空间关联角度测度人类活动与自然环境相互作用是推动区域可持续发展的基本前提。以2015年数据为基础,通过选取特征变量构建综合测度指标体系,利用小波多尺度分析、双变量局域空间自相关、人地系统耦合协调度模型等方法多层次刻画中国陆域地表人类活动与自然环境的空间相关关系、空间匹配关系、空间耦合关系。研究结果表明:①人类活动与自然地理基础的空间相关关系随着地域尺度增大而趋于增强,说明自然环境条件对人类活动格局的基础性作用;②人类活动与自然资源支撑的空间匹配关系呈现非均衡性特征,华北地区人类活动规模与自然资源支撑空间错位显著、区域可持续发展面临严峻挑战;③人类活动与自然环境承载的空间耦合协调度从东南向西北递减,调整人类活动的结构与方式是化解区域人地矛盾的理性选择。  相似文献   

6.
7.
Visualizing the pattern of variation using microsatellites within a Eucalyptus globulus forest on the island of Tasmania provided surprising insights into the complex nature of the fine-scale spatial genetic structure that resides in these forests. We used spatial autocorrelation and principal coordinate analysis to compare fine-scale genetic structure between juvenile and mature cohorts in a study area, 140 m in diameter, located within a typical, continuous E. globulus forest. In total, 115 juvenile and 168 mature individuals were genotyped with eight highly polymorphic microsatellite loci. There was no significant difference in the level of genetic diversity between cohorts. However, there were differences in the spatial distribution of the genetic variation. Autocorrelation analysis provided clear evidence for significant spatial genetic structure in the mature cohort and significant, but weaker, structure in the juvenile cohort. The spatial interpolation of principal coordinate axes, derived from ordination of the genetic distance matrix between individuals, revealed a spatially coherent family group which was evident in both cohorts. Direct comparison of the genetic structure within each cohort allowed visualization of a shift in the spatial distribution of genetic variation within the population of approximately 10 m. As the shift coincided with the direction of prevailing winds, it is hypothesized that this phenomenon is due to downwind dispersal of seeds and is indicative of the important role of prevailing winds in forcing eastward gene flow in these high-latitude forests.  相似文献   

8.
Spatial analyses are indispensable analytical tools in biogeography and macroecology. In a recent Guest Editorial, Hawkins (Journal of Biogeography, 2012, 39 , 1–9) raised several issues related to spatial analyses. While we concur with some points, we here clarify those confounding (1) spatial trends and spatial autocorrelation, and (2) spatial autocorrelation in the response variable and in the residuals. We argue that recognizing spatial autocorrelation in statistical modelling is not only a crucial step in model diagnostics, but that disregarding it is essentially wrong.  相似文献   

9.
Abstract In the presence of permanent spatial heterogeneity, local dispersal, especially short‐range dispersal, can facilitate coexistence by concentrating low‐density species in the areas where their rates of increase are higher. We present a framework for predicting the effects of local dispersal on coexistence for arbitrary forms of dispersal and arbitrary spatial patterns of environmental variation. Using the lottery model as an example, we find that local dispersal contributes to coexistence by enhancing the effects of environmental variation on scales longer than typical dispersal distances, which can be characterized solely by the variance of the dispersal kernel. Higher moments of the dispersal kernel are not important.  相似文献   

10.
山西植被空间格局及演替   总被引:1,自引:0,他引:1  
在ArcGIS软件中采集1984年和2005年山西植被类型的图形,得到山西群系、森林、灌丛、草本植被及栽培植被的图形及面积,用叠置分析和景观格局分析方法研究植被的空间分布及其演替、空间格局及其变化。森林在西南部相对集中分布,在西北角增加明显,它在山西植被中所占面积及比重都最小,最为破碎。油松林在山西森林中占优势,恢复森林主要是油松林、小叶杨林、辽东栎林。1984年灌丛的面积在植被中最大,所占比例也最高,超过50%,集中连片分布面积较大,但灌丛缩减迅速,主要在中南部,在山西植被中遭破坏最为严重。沙棘、虎榛子灌丛和黄栌、连翘灌丛对灌丛的影响最大。草本植被主要在北部减少,在中南部分散增加,更加破碎。白羊草草丛在山西草本植被中占优势,蒿、禾草草原和百里香、禾草草原变化最大。栽培植被明显增加,在植被中所占比重急剧增加,成为山西优势植被。森林、栽培植被分别增加24.3%、71.5%,而灌丛、草本植被却分别减少70.3%,15.6%,演替主要是人为因素造成的。  相似文献   

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