浅谈生态位理论在风景园林中的应用     

陈连波  张国军 《山东林业科技》2008,38(2):76-78

生态位理论（niche）是生态学中的重要的理论之一，被广泛的应用在各个领域当中。而以生态学理论框架为依托，吸收现代地理学和系统科学之所长的景观生态学作为风景园林学科最重要的理论基础和实践准则，越来越多地受到关注。作者在简单介绍生态位理论的概念及发展历史的同时，尝试着从景观生态学的角度出发，研究生态位理论与风景园林学的关系及其在风景园林设计中的应用。  相似文献   

胡萝卜抗冻蛋白的快速大量突变及原核表达     

张党权  谭晓风  仲健  王金发 《中南林业科技大学学报(自然科学版)》2006,26(5):15-19

胡萝卜抗冻(DcAFP)具有典型的LRR特征,由约24个氨基酸残基组成重复单元,其中的保守基序是:P×××××L××L××L×LS×N×L×G×I,其中的保守天冬酰胺在与冰晶表面结合中起着关键的作用．为了探明该关键氨基酸对DcAFP重要性,需要对其进行一系列突变,以检测这些突变体的热滞可能发生的变化,而这需要构建大量的突变体．基于此,采用定点突变技术对该基序中保守的天冬酰胺进行了一系列的疏水性缬氨酸突变和亲水性的谷氨酰胺突变,并将这一系列突变体克隆至原核表达载体pET-11a中,在大肠杆菌BL21(DE3)中进行了高效表达与初步纯化,为后续测定其热滞活性的变化和验证天冬酰胺的重要性打下了基础．  相似文献   

攀枝花块菌资源及适宜生境初探   总被引：1，自引：1，他引：1  

唐平  兰海  雷彻虹  张奎  杨荣喜 《四川林业科技》2005,26(2):72-75

对攀枝花的块菌资源进行了较为系统的调查，查清了攀枝花的块菌种类、分布范围以及其生态环境．并与欧洲块菌主产国的气候环境进行比较，认为攀枝花是块菌生长的理想气候区之一，且得出块菌生长环境的pH值由弱碱性扩展到微酸性结论，同时采用Vanderloeg和Scavia选择系数Wi和选择指数Ei作为衡量块菌对生境适宜程度指标，提出了块菌适宜生境的标准。  相似文献   

Assessing components of a competition index to predict growth in an even-aged Pinus nigra stand     

De Luis  M.  Raventós  J.  Cortina  J.  Moro  M.J.  Bellot  J. 《New Forests》1998,15(3):223-242

The relationship between tree growth and competition may depend on some subjective choices that are commonly left to the researcher. Among these are the neighborhood radius, the number of years of growth that are integrated, and tree age. We have evaluated the importance of these factors when relating growth and competition in a forest stand with contrasted densities of the dominant tree species (Pinus nigra) and understory shrub species (Adenocarpus decorticans). Previous to this evaluation we performed a randomization test to assess the relationship between tree growth and neighbors. By using Daniels index of competition we found that the use of a fixed neighborhood radius underestimated the importance of tree competition. The coefficient of determination (r²) of the relationship between tree growth and Daniels index increased asymptotically with the number of years considered. Five years of growth gave high r² independently of the density of trees and shrubs. The intensity of competition was weakly affected by the characteristics of the plot (tree and shrub densities), and did not change with time. In contrast, the potential growth at equal competition – as represented by constant a in the allometric model – changed with time suggesting a gradual decrease in potential tree growth in the plots with higher tree density, and a gradual increase in those plots with high density of shrubs. These results may reflect tree canopy closure and the senescence of Adenocarpus decorticans. A method is suggested to select optimum neighborhood radius and growing period for the calculation of competition indices. By applying this method we were able to explain as much as 79–84% of the variability in tree growth of this stand.  相似文献   

浙江六十田常绿阔叶林主要乔木种生态位研究   总被引：1，自引：0，他引：1  

陈子林  张志祥  刘鹏  康华靖  陈煜 《中南林业科技大学学报(自然科学版)》2007,27(6):77-82

应用Shannon-Wiener生态位宽度指数、生态位相似性比例系数及生态位重叠指数,对浙江省六十田省级自然保护小区常绿阔叶林群落中主要乔木树种的生态位特征进行了研究.结果表明:红楠Machilus thunbergii、华东楠Machilus leptophylla、青冈Cyclobalanopsis glauca、紫楠Phoebe sheareri、木荷Schima superba、东南石栎Lithocarpus harlandii具有较大的生态位宽度,分别为0.969、0.951、0.898、0.867、0.819和0.773,而香槐Cladrastis wilsonii、树参Dendropanax dentiger、枫香Liquidambar formosana的生态位较小,仅为0.345、0.245和0.245;生态位宽度大的树种间一般有较高的生态位相似性比例;香槐、树参和枫香的生态位宽度较小,但与其它树种的相似性却很高,表明这些树种对资源有较明显的共享趋势;从生态位重叠值来看,整体上表现为生态位宽度较大的树种间都有较高的生态位重叠,生态位宽度较小的树种与其它树种的生态位重叠较小.  相似文献   

拟南芥中与植物生长和耐寒相关的miRNA表达载体的构建     

蔡杰  杨成龙  段瑞军  郭建春 《广西农业生物科学》2010,(4):804-808

本研究通过PCR方法从拟南芥基因组序列中分离了3个理论推断与耐寒相关的miRNA片段（miRNA402,miRNA319和miRNA393）和1个与植物生长相关的片段miRNA172。利用重叠延伸PCR技术将miRNA172小分子,以及3个与耐寒相关的miRNA402,miRNA319和miRNA393小分子串连在一起分别导入植物表达载体pVKH-35S-GUS-pA,取代表达载体中的GUS基因,构建了pVKH-35S-mir172-pA和pVKH-35S-mir31＋402＋393-pA融合表达载体。经PCR和双酶切及测序鉴定,pVKH-35S-mir172-pA和pVKH-35S-mir319＋402＋393-pA构建成功,为后续利用基因工程手段,miRNA转化木薯,提高木薯生长和木薯耐寒相关研究奠定基础。  相似文献   

宁夏盐池人工封育荒漠化草原植物生态位研究   总被引：1，自引：1，他引：0  

刘建  张克斌  程中秋  孟力猛 《干旱区资源与环境》2012,(1):184-188

运用Levins生态位宽度指数及Pianka生态位重叠指数,对宁夏盐池人工封育荒漠化草原2008和2009年植物生态位宽度及生态位重叠进行计量,以了解干旱半干旱区草原植物生态位格局。结果表明:黑沙蒿生态位宽度在2008、2009两年中均最大,分别为0.543、0.497,是人工封育区的优势种。此外,两年间封育区其他优势种也相同,分别为:苦豆子、丝叶山苦荬、刺沙蓬、阿尔泰狗娃花。2008和2009年的生态位重叠计测结果均表明,生态位宽度大的物种不一定和其他物种有大的重叠指数,即使是生态位宽度较大的物种之间的重叠指数也不高,可见较高的生态位宽度和较高的生态位重叠度之间并不存在直接的线性关系;2008、2009年较高的Pianka生态位重叠指数都出现在生态位宽度较小的物种之间,这一现象从另外一个角度说明植被恢复过程中环境资源存在着高度的空间异质性。  相似文献   

Diet overlap of non‐native alewife with native yellow perch and spottail shiner in nearshore waters of southwestern Lake Michigan, 2000–2007     

Sara M. Creque  Sergiusz J. Czesny 《Ecology of Freshwater Fish》2012,21(2):207-221

Abstract – Lake Michigan has experienced many ecological changes as a result of introductions of non‐native species. Arguably the most significant was that of alewife (Alosa pseudoharengus), yet studies on diet overlap with native species are lacking. We analysed diet trends of alewife, spottail shiner (Notropis hudsonius) and yellow perch (Perca flavescens) collected in summer and fall 2000–2007 near Waukegan, IL, in 3–10 m depths. Mean percentage composition by dry weight for 23 prey taxa was used in multivariate analysis to test whether diet differed across species and size classes. We also tested whether zooplankton and benthic invertebrate community composition changed over time. Fish diets were similar over all years but differed seasonally. In summer, diets of large alewife were similar to both small alewife and small yellow perch, with Bosminidae, chironomid larvae and copepods as primary common prey. During fall, alewife and yellow perch size classes exhibited strong intraspecific diet overlap, while there was low diet overlap between species. Primary distinctions between species’ diets in fall were higher consumption of amphipods by yellow perch and dreissenids by spottail shiners compared to alewife, which consumed higher proportions of zooplankton. Overall, high yellow perch diet overlap with alewife during summer and with their larger conspecifics during fall could lead to negative implications for yellow perch growth before the critical overwintering period. Detailed insights into diet overlap and prey availability are critical first steps in understanding competitive interactions between native and non‐native fish that dominate the nearshore community in southwestern Lake Michigan.  相似文献   

南岭国家级自然保护区广东松群落优势种群生态位研究   总被引：7，自引：0，他引：7  

张中峰  张璐  陈北光  谢正生 《华南农业大学学报》2006,27(2):74-77,103

在广东南岭国家级自然保护区广东松Pinus kwangtungensis群落内,通过典型样地调查（调查面积共7200m^2）,以不同林层作为一维资源位,以个体多度作为计测指标,计测了广东松群落中10个优势种群的生态位宽度和生态位重叠值．结果显示,在考虑资源利用率和不考虑资源利用率2种情况下,所得出的生态位宽度值不同,2种情况下优势种群排列顺序有很大差异．结合重要值分析结果,认为在考虑资源利用率情况下所计测的生态位宽度值更具有合理性．群落优势种生态位宽度值大部分较高,各优势种之间能相互适应与互补,整个群落处于稳定状态．广东松与其他优势种之间的生态位重叠值较小,一方面与其生物学和生态学特性有关,另一方面与在不考虑资源利用率情况下其生态位宽度值较小有关．  相似文献   

亚高山草甸弃耕地植物群落演替的数量研究——Ⅳ.组分种生态位分析     

王刚  张大勇  杜国祯 《草地学报》1991,1(1):93-99

用甘南亚高山草甸弃耕地演替群落的样方数据及计测生态位置迭的改进公式,计算了十五个主要组分种间的重迭值和相异系数。用极点排序和等级聚合分类的方法和种的相异系数数据,对此十五个种进行了排序和分类,从而使定量比较种的生态学特性的生态应分析在整个群落水平上得以实现。  相似文献