沙漠型景区游步道沿线生态环境对踩踏干扰的响应

植被是沙漠景区水土保持和防风固沙的重要屏障。选取宁夏沙坡头和黄沙古渡景区,采用既成事实法就景区游步道沿线生态环境对踩踏干扰的响应进行调查研究。结果表明:①自然状态下,踩踏干扰主要集中在道路边缘4 m范围内,但不同性质道路差异较大;②采用地表覆盖物响应指数来衡量道路沿线生态环境响应程度,在道路边缘1 m范围内各调查样区受冲击均达到非常严重的程度,只有沙坡头北区沙漠栈道调查路段地表覆盖物响应指数值全部在44.9%以下,属于中等-轻微程度干扰,这是由于栈道两侧木栏作用明显;③游客对游步道沿线沙漠植被盖度可接受改变限度为16.4%,沙漠植被覆盖率应在此水平以下,其中沙坡头北区沙漠栈道两侧植被盖度达到了难以接受程度,说明游客在沙漠中的空旷、苍凉的体验需求与沙漠生态治理之间是天然的难以调和的对立体;④游步道沿线生态环境响应强弱与道路坡度、边坡坡度、游步道两侧生态系统以及游步道宽度具有一定相关性。研究结果也表明,目前游客踩踏干扰已对沙漠景区道路沿线生态环境以及游客游憩体验产生了一定的负面影响。研究对沙漠景区景观和游步道设计、规范游客行为、建立沙漠景区环境容量预警机制、实现宁夏沙漠旅游可持续发展具有指导价值。

Response of Ecological Environment along Desert Scenic Spot Trails to Trampling Disturbance

Vegetation is important barrier in desert area at soil and water conservation windbreak and sand-fixation. Selecting Shapotou and Huangshagudu scenic spots in Ningxia as study area, the response of desert scenic spot trails to tourist trampling disturbance was studied. In addition to vegetation and soil change represented by vegetation cover reduction (CR), vegetation floristic dissimilarity (FD), vegetation height reduction (HR), soil crust fragmentation (SCF) and index of land cover impact (ILCI), the limits of acceptable change (LAC) was also selected as and indicator. The results showed that: (1) The tourist trampling disturbance mainly were limited 0-4 meters distance from the tourist trails, but there was difference for different tourist trails. (2) The index of land cover impact (ILCI) of the investigating sections indicated the 1 meter distance from tourist trail is seriously disturbed; Because of the palisade on both sides of the plank road, the average value of ILCI in north of Shapotou (investigating section 4) is less than 44.9%. (3) Based on limits of acceptable change (LAC) visitor questionnaires, the limit of acceptable change in ground coverage was 16.4%. The vegetation coverage should be below this level at desert scenic spots. It shows that there is natural incompatible relationship between tourist demand to the empty and desolate desert and desert ecological management. (4) The impact variables were correlated to the gradient border area gradient and the tourist trail width. The results also indicated that the current tourism disturbance had some negative effect on the tourist experience and ecosystem.