边缘效应的空间尺度与测度

综述了边缘效应的空间尺度类型以及在不同尺度上的测度方法.基于大量的研究整合,认为边缘效应空间尺度的划分,可以根据空间尺度的不同以及边缘效应形成和维持因素,分为大中小3个尺度类型,即大尺度的生物群区交错带、中尺度的景观类型之间的生态交错带和小尺度的斑块(生态系统)之间的群落交错区.大尺度主要是以植被气候带为标志的生物群区间的边缘效应,这种地带性的交错区主要受大气环境条件的影响.中尺度类型主要包括城乡交错带、林草交错带、农牧交错带等类型,是不同生态系统要素的空间交接地带,在物质能量等相互流动的作用下变得更为复杂.小尺度水平上是指斑块之间的交错所形成的边缘效应,受小地形等微环境条件及生物非生物等因子的制约,研究主要集中在群落边缘、林窗边缘和林线交错带等方面.对边缘效应测度的定量化研究有助于更加深入理解边缘效应.在大尺度水平上,边缘效应测度的研究主要是应用数量生态学等方法,研究不同气候带之间界线的划分及其物种分布的梯度规律性.中尺度水平上应用景观生态学的3S技术等方法,侧重于研究交错带的动态变化趋势及位置宽度的判定.小尺度水平上通过对距离边缘的长度,各群落中种群的数量、结构、多样性等定量指标的测定来构建测度公式,从而对边缘效应的强度进行量化,并反映边缘对群落的正负效应.总体上看,主要集中于中小尺度上,未来应该强化大尺度边缘效应测度的研究.

Spatial scale and measurement of edge effect in ecology

Classification of spatial scales and measurement of edge effects in ecology were reviewed. The spatial scales can be classified into large scale (biome ecotone), meso-scale (ecological ecotone) and small scale (community ecotone) through the formation and maintenance of edge effects in ecology based on the synthetic analysis of published literatures. The biome ecotone is influenced by climate, regional dominant vegetation and terrain environment. The ecological ecotone is usually distributed in the transitional region with remarkable habitat heterogeneity. It connects adjacent ecosystems and affects the flow of energy and nutrient. Nowadays, study on edge effects in ecology mainly focuses on boundary sensitivity which associates with urban-rural ecotone, forest-grassland ecotone, agro-pastoral ecotone, forest-farmland ecotone, water-land ecotone and forest-swamp ecotone. As to the community ecotone which links with different patches to the interior of the community, previous studies focused on community edge, gap edge and treelines. The borderlines of different biome ecotones and the gradients of species distribution in the biome ecotones have been investigated through the method of quantitative ecology. The dynamic change, location and width of the ecological ecotone have been studied using the Geographic Information System (GIS), Remote Sensing (RS) and Global Positioning System (GPS) technologies and the landscape ecology theory. As important indicators, distance from edge, population, structure and diversity determined for establishing models can be applied to measure the intensity of edge effects and decide the positive or negative impact on communities. Although study on the edge effects in ecology was mostly reported at the meso-scale and small scale, study at large scale should be paid more attention as it is the potential value in ecology and global change fields.