流动沙丘与丘间低地过渡带的时空格局对植被恢复的影响  

Effects of Spatial and Temporal Pattern of Transition Zones between Active Dunes and Interdune Lowlands on Vegetation Restorations

作　　者：闫守刚[1] 沈自彬 李晓东[1] 许清涛[1] 

机构地区：[1]白城师范学院地理科学学院,白城137000 [2]山东省泗水县环境保护局,泗水273200

出　　处：《林业科学》2015年第4期103-109,共7页Scientia Silvae Sinicae

基　　金：吉林省科技发展计划资助项目(20140101211JC);吉林省教育厅"十二五"科技研究项目(2013-392);吉林省重点科技攻关项目(20130206027NY)

摘　　要：【目的】研究流动沙丘与丘间低地过渡带的生态过程，探讨过渡带的时空格局及其对流动沙丘－植被面积的关系的调控作用。【方法】在科尔沁沙地西部乌兰敖都地区，利用样带法在所选择的流动沙丘背风坡迎风坡与丘间低地的连接处，测量沙埋高度、宽度以及风蚀深度，并在生长季末调查样方内植物的丰富度和多度。【结果】1）流动沙丘背风坡在风力作用下，沙子埋压丘间低地植被，导致部分沼泽－草甸植物退出丘间低地；沙丘迎风坡底部的裸沙带，每年生长季初有沙丘先锋植物侵入，在生长季末形成建植种群，最终形成迎风坡过渡带。迎风坡过渡带的宽度为3～5 m，背风坡过渡带的宽度为4～6 m，因此，流动沙丘与丘间低地过渡带属于小尺度过渡带。2）流动沙丘背风坡－丘间低地过渡带的宽度与丘间低地面积及其垂直风向宽度都呈显著负相关（P ＜0.05），而迎风坡过渡带的相关性不显著（P＞0.05），但与丘间低地植被扩展宽度呈显著正相关（P ＜0.05）。3）流动沙丘区的植被覆盖面积呈增加趋势。4）面积大于5 hm2的丘间低地，垂直风向宽度大，且植被密度大、植株高，容易形成风障，降低风速，致使背风坡沙埋速度慢，而且迎风坡植物入侵速度快，导致丘间低地植被宽度和面积增加。【结论】在自然条件下，流动沙丘区的植被恢复开始于迎风坡过渡带；迎风坡过渡带和背风坡过渡带的权衡直接调控丘间低地植被的覆盖面积和格局。另外，大面积的丘间低地对于流动沙丘区的植被恢复具有重要作用。[Objective]In active dune fields,the transition zones between active dunes and interdune lowlands,which have high temporal and spatial heterogeneity and complex ecological processes,can indicate or coordinate the relative relationship between vegetation and sand dune and regulate the area and structure of vegetation in the whole active sand dunes. In the last few decades,much attention has been paid to the vegetation processes in active sand dunes or interdune lowlands,while researches on how vegetation establishes and develops in transition zones between active dunes and dune slacks are still scarce. Most of all,study on temporal and spatial patterns,vegetation composition,plant adaptation mechanism and the restrictive factors in transition zones between active dune and interdune lowland is not still reported.[Method]In this paper,by means of the belt transect method in the field investigation,we measured the height and width of sand burial on leeward slopes of active sand dunes as well as the depth of wind erosion on windward slopes of active sand dunes at Wulanaodu region,the western Horqin Sandy Land,and examined the plant richness and abundance in the quadrats by the end of growing seasons. We especially investigated the effects of transition zone dynamics on vegetation areas and patterns in interdune lowlands. Through this study,we aim at answering two questions that how aeolian erosion and sand burial influence the temporal and spatial patterns of the transition zones between active dunes and interdune lowlands and that how the transition zone dynamics affect vegetation areas and patterns in whole active dune fields.[Result]The result showed that （1） part of Limnocryptophyte-meadow and Steppe species in interdune lowlands retreated from the transition zones in leeward slopes and part of pioneer vegetative propagation was dominant in frequency and density in the transition zones of windward slopes due to the dynamic changes of the transition zone between active dune and interdune lowland. The width of t

关 键 词：风蚀 沙埋 过渡带 丘间低地 植被恢复 

分 类 号：Q14[生物学—生态学]