干旱内陆沙区丘间地植被生态过程及其驱动机制

Interdune lowland is the main habitat of vegetation in arid inland sandy areas, and is also the main place of interactions between biotic and abiotic components in sand dunes ecosystem. Vegetation in interdune lowland plays an important role to maintain biodiversity and control desertification expansion in sandy area. The project will select typical inland arid sandy area as the study area , vegetation formation and succession as research , on the basis of investigate the morphology and environmental factors of intedune lowland such as hydrology, soil, wind-sand activities, through analyzing the relationships of vegetation pattern with environmental factors, obtain the dominant factor affecting the ecological processes of interdune lowland vegetation. Grasp the formation and succession process of interdune lowland ecosystem vegetation patterns through comparing and analyzing different developmental stages vegetation community characteristics. Based on vegetation community's variation of interdune lowland which is affected by different human disturbances, explore the different succession way of interdune lowland ecosystems respond to human disturbance. Determine the key area of wind-sand activities hazards and its criterion and methods by the analysis of characteristics of sand activities. By the coupling relationship between vegetation ecological processes and the various factors, it will analyze and reveal the ecological processes characteristics of vegetation and its' changes driving mechanism. Furthermore, the effect and influence on biodiversity conservation and habitat protection in the arid sandy area should be study, in order to provide theoretical support for ecological recovery and prevention of desertification of inland sandy areas.

丘间地是干旱内陆沙区植被的主要生境，是沙丘生态系统中生物和非生物成份相互作用的主要场所，丘间地植被在维持沙区生物多样性、控制沙漠化扩展方面扮演着重要角色。本项目选择典型内陆干旱沙区为研究区域，以丘间地植被形成、演替为研究内容，在掌握丘间地形态及水文、土壤、风沙活动等环境因素的基础上，通过植被格局与环境因子关系分析，得到影响丘间地植被生态过程的主导因子；通过不同发育阶段植物群落特征比较分析，掌握丘间地植被格局的形成与演替过程；通过不同人为干扰方式影响下植被群落及环境要素变化特征，分析探讨丘间地生态系统应对干扰的不同演替发展方向；通过风沙活动特征分析，确定丘间地风沙危害的重点区域及其判定标准和方法。综合各因子与植被生态过程的耦合关系，分析揭示丘间地植被生态过程特征及其变化驱动机制，进而探讨丘间地在干旱沙区生物多样性保育和生境保护中的作用及影响，以期为内陆沙区生态恢复以及沙漠化防治提供理论依据。

本研究通过系统调查分析掌握了干旱内陆沙区丘间地基本属性特征、生态要素及植被特征，分析了丘间地生态要素与植被的变化及其对相互关系与影响，探讨了丘间地生态意义及受人为活动的干扰。研究表明：（1）研究区丘间地是沙漠-绿洲过渡带区域一种主要景观类型且生境类型多样，丘间地与砾质平沙地共同组成了区域本底景观，丘间地也是沙漠-绿洲过渡区域农业耕地的重要来源。（2）不同区域、不同类型沙丘-丘间地植物种空间分布具有较高的生活型相似度，差别只体现在植物种分布的地带性差异和不同生活型植物物种优势度大小的差异上。（3）研究区整体物种多样性较小，不同类型区丘间地植物群落物种多样性整体差异不明显，但各类型区内不同地段多样性差异较大。（4）沙丘-丘间地水、土等生态要分布具有较明显的规律性且与丘间地风沙活动密切相关，各生态要素在不同类型区对植被的影响不同。（5）丘间地是干旱沙区主要的风沙源，丘间地风速及风沙流与构成丘间地的沙丘高度（H）密切相关，丘间地中后部（沿风向6H~11H）是风蚀发生的主要地段，可作为丘间地沙化危害防治地段的判断依据。（6）人类农业生产及相关干扰活动对丘间地自身形态特征及其生态要素、丘间地植被都产生着重要的影响。（7）丘间地在干旱沙区物质和能量运移中发挥着重要“汇”与“源”作用，同时它也是区域重要的农业生产资料，因此应该受到足够的重视和保护。