林草交错带县域景观格局粒度效应研究

林草交错带作为生态系统过渡带，具有景观格局演替敏感、类型复杂多样等特点，呼伦贝尔林草交错带是我国北方重要的生态屏障，对其景观格局粒度效应的研究、识别景观格局研究的适宜粒度是建立合理生态安全格局的基础. 本研究基于呼伦贝尔林草交错带-鄂温克自治旗2000—2015年土地利用数据，分析不同类型景观指数随粒度变化特征以及不同粒度下各景观指数的时间演替特征，并综合信息损失法识别区域的适宜研究粒度，分析不同景观指数的粒度敏感性，为进一步明晰不同景观指数适用范围提供基础. 研究结果表明，呼伦贝尔林草交错带景观指数粒度变化特征可以分为Ⅰ型（随着粒度的粗化逐渐下降）、Ⅱ型（随着粒度的粗化逐渐升高）和Ⅲ型（先增加后下降的波动变化）指数，景观指数粒度效应敏感性差异显著，结合景观指数时空粒度效应分析和信息损失法确定区域景观格局研究适宜粒度为200 m，粒度效应的影响远远高于时间尺度对于景观指数变化趋势的影响，由此可见粒度效应对于景观指数应用的影响不容忽视，而根据景观指数粒度效应敏感性选取低敏感指数不失为一种高效便捷的手段. 本研究推荐粒度敏感性较差的景观指标TA、PAFRAC、AWMPFP、SHDI、SHEI、COHESION作为评价研究中的优选指标，而粒度敏感性高的MPI、MNN、MPS和IJI 4个指标在评价应用时要谨慎选取. 

Grain effects of landscape in forest-grassland ecotone by county extent

Forest-grassland ecotone is sensitive, complex and diverse. Hulun Buir forest-grassland ecotone is an important ecological barrier in northern China. Study of landscape grain effect and identification of appropriate grain size are essential to establish ecological security. Analysis of grain effect, grain sensitivity, and appropriate grain in Evenk Autonomous Banner, a county in Hulun Buir forest-grassland ecotone, was performed. Variation curve of landscape index was classified into three types. Type Ⅰ declined with coursing of grain. Type Ⅱ increased with coursing of grain. Type Ⅲ waved with coursing of grain. The most appropriate grain size in was found to be 200 m. Sensitivity of landscape index was significantly different. Low sensitivity landscape index contained TA, PAFRAC, AWMPFP, SHDI, SHEI and COHESION, high sensitivity index contained MPI, MNN, MPS and IJI. The former had priority in landscape analysis, the latter index considered grain effect. The time curve of landscape index in different grain indicated that grain effect influence was more important than time change. The importance of grain effect is proved in this study. Choice of index is also given.