基于分层投影盖度的荒漠植被相对生态功能测定  

Determination of relative ecological function of desert vegetation based on layered projection cover

作　　者：常兆丰[1] 张大彪[1] 段小峰[1] 韩福贵[1] 仲生年[1] 王强强[1] 张剑挥[1] 

机构地区：[1]甘肃省治沙研究所,甘肃兰州730070

出　　处：《干旱区地理》2016年第4期777-784,共8页Arid Land Geography

基　　金：国家973前期-"绿洲边缘高大新月形沙丘稳定性研究"(2014CB460611)

摘　　要：以往有关荒漠植被的生态功能的研究基本上是以盖度为主要指标的,而荒漠植物枝条极不规则,盖度不能反映植物覆盖地表的真实状况,且盖度与投影盖度一般不存在对应关系,加之荒漠植被稀疏,用盖度不仅不能表征植物的生态功能和地位,而且往往忽视了植物高度的生态功能。以2002-2013年民勤荒漠区定位样方观测资料为例,运用分层投影盖度分析了5种主要植物群落的生态功能,结论表明:2002-2013年这5种植物群落的盖度大小的排序是:白刺>梭梭+白刺>沙蒿>麻黄>梭梭,投影盖度大小的排序是:梭梭+白刺>白刺>麻黄>沙蒿>梭梭,生态功能排序是:白刺>麻黄>梭梭+白刺>梭梭>沙蒿,即植被盖度、投影盖度和生态功能并不对应。研究结论认为:今后在做荒漠植物功能分析亦即用到植物的盖度时,应以投影盖度为主,而冠幅盖度只应作为一个对照参考指标;在研究荒漠植物的生态功能时,植株高度是一个不可忽视的重要指标。Though coverage has been regarded as the key indicator of ecological functions and status of desert vegetation for a long time,it cannot reflect the real situation of plant cover surface because of its very irregular branches;besides,generally there is no corresponding relationship between cover and the projector cover,then the vegetation cover cannot characterize the ecological functions and status of the plant,and it also often resulted in overlook of the ecological function of plant height. As an example,the ecological functions of 5 kinds of main plant communities were analyzed by using the layered projection cover degrees with locating plots observation data from 2002 to 2013 years in Minqin desert area,Gansu Province,China. The results show that cover and projection cover of desert vegetation was quite different,e.g. the average projected coverage of Nitraria tangutorum communities was only 28.6% of crown cover. From large to small,the vegetation cover of the 5 kinds of plant communities in 2002- 2013 were ranked as：Nitraria tangutoru,Haloxylon ammodendron＋Nitraria tangutorum,Artemisia arenaria,Ephedra przewalskii and Haloxylon ammodendron;for projection cover,they were ranked as：Haloxylon ammodendron ＋ Nitraria tangutorum,Nitraria tangutorum,Ephedra przewalskii,Artemisia arenaria and Haloxylon ammodendron;and for ecological functions,they were ranked as：Nitraria tangutorum,Ephedra przewalskii,Haloxylon ammodendron＋Nitraria tangutorum,Haloxylon ammodendron and Artemisia arenaria,indicating that the vegetation cover,projector cover and ecological functions did not correspond with each other.When taking the standard deviation of interannual variation of vegetation cover and projected cover as the representatives for the community stability,the communities with lower coverage showed higher stability,while those with higher coverage showed relatively lower stability,e.g. vegetation cover of Ephedra przewalskii community was relatively low,but the community was most stable;vegetation cover of Haloxyl

关 键 词：植物群落 分层投影盖度 测定 生态功能 民勤荒漠区 

分 类 号：Q948.1[生物学—植物学]