ABSTRACT

Sediment and nutrient retention have significant impacts on agricultural productivity and water quality. As a fragile region, obvious changes of climate and land-use in Guizhou Province have deeply affected freshwater ecosystem services in the last several decades. Nevertheless, it is unclear what the differences are in the impact of climate and land-use changes on freshwater ecosystem services. Therefore, the impacts of climate and land-use change on sediment and nutrient retention (two essential freshwater ecosystem services) in Guizhou Province were evaluated with the help of the Integrated Valuation of Environmental Services and Tradeoffs (InVEST) model. The results from the study area suggest a decreasing trend in sediment and nutrient retention from 1995 to 2015 when climate and land-use were changed simultaneously. A decreasing trend in sediment retention and an increasing trend in nutrient retention were presented under scenario A (climate change from 1995 to 2015 with land-use unchanged), while the sediment exported and nutrient retention exhibited a decreasing trend except sediment retained under scenario B (land-use change from 1995 to 2015 with unchanged climate). Rainfall erosivity and soil erodibility were more sensitive to the output of sediment retention, while retention efficiency produced more of an effect on nutrient retention. The results of this study provide explicit information for land-use managers to reduce the negative effects associated with sediment and nutrient retention.

摘要

沉积物和养分的保留对农业生产力和水质有重大影响。在过去的几十年中，贵州省作为一个脆弱的地区，气候和土地利用的明显变化深刻影响了淡水生态系统服务。但是，目前尚不清楚气候和土地利用变化对淡水生态系统服务的影响有什么区别。因此，在环境服务与权衡综合评估（InVEST）模型的帮助下，评估了气候和土地利用变化对贵州省沉积物和养分保留（两种基本的淡水生态系统服务）的影响。研究区域的结果表明，从1995年到2015年，当气候和土地利用同时变化时，沉积物和养分的保留量呈下降趋势。在方案A下（1995年至2015年的气候变化，土地利用未发生变化）呈现出沉积物滞留量下降的趋势，而在养分保持率上呈上升趋势，而在方案B下的沉积物保留量除外，而沉积物的出口量和养分保持率则呈下降趋势（从1995年到2015年的土地利用变化（气候不变）。降雨侵蚀力和土壤易蚀性对沉积物的保留更为敏感，而保留效率对养分的保留产生更大的影响。这项研究的结果为土地利用管理者提供了明确的信息，以减少与沉积物和养分保留相关的负面影响。除情景B（1995年至2015年的土地利用变化，气候不变）外，沉积物的出口和养分保留率呈下降趋势。降雨侵蚀力和土壤易蚀性对沉积物的保留更为敏感，而保留效率对养分的保留产生更大的影响。这项研究的结果为土地利用管理者提供了明确的信息，以减少与沉积物和养分保留相关的负面影响。除情景B（1995年至2015年的土地利用变化，气候不变）外，沉积物的出口和养分保留率呈下降趋势。降雨侵蚀力和土壤易蚀性对沉积物的保留更为敏感，而保留效率对养分的保留产生更大的影响。这项研究的结果为土地利用管理者提供了明确的信息，以减少与沉积物和养分保留相关的负面影响。