不同时间尺度下基于绿量的草地水土保持效应研究  

Time scale influence on the study of water and soil conservation effects of grass based on live vegetation volume

作　　者：吴晓霞[1] 顾祝军[1] 

机构地区：[1]南京晓庄学院环境科学学院,南京211171

出　　处：《生态科学》2016年第1期85-91,共7页Ecological Science

基　　金：国家自然科学基金项目(41571415;41071281);江苏省自然科学基金项目(BK20131078);江苏省教育厅"青蓝工程"中青年学术带头人培养计划

摘　　要：基于福建省长汀县河田镇土壤侵蚀试验小区连续四年的自然降雨、植被、产流和产沙观测数据,分析了次降雨、月、季和年这四种时间尺度下草地植被绿量、降雨指标和保水、保土效应的变化特征及其相互关系。结果表明,随着时间尺度的增大,降雨和植被参数呈现或增或减的变化特征,保水效应值(RE)变幅较小,而保土效应值(SE)的变幅则缓慢降低。各时间尺度RE的均值呈约10%—20%幅度的变化,RE表征的草地保水效应以季尺度最好,年尺度最差,而SE表征的草地保土效应以月尺度最好,季和次降雨尺度最差且接近。草地植被的保水效应多受制于降雨因素,次降雨尺度下,RE与降雨历时和降雨量关系密切,较长时间尺度下最大30分钟雨强是主要的控制因子。而保土效应则多受制于植被因素,在次降雨尺度下,贴近地表的枯叶层对保土效应的贡献值得重视,在中等的月和季尺度保土效应同时受降雨和植被的影响,而在较大的年时间尺度下,草本植被绿量参数可有效表征植被的保土效应。可见,在不同的时间尺度,影响水土保持的诸要素呈现不同的变化和耦合特征,水土保持效应亦存在差异,因而在水土保持的研究和管理工作中应关注时间尺度的影响。Based on the continuous 4-year observation data of rainfall, vegetation, runoff and sediment yield in the experimental plots located in Hetian Town, Changting County of Fujian Province, the change characteristics and the interrelation were analyzed at four time scales of rainfall event, month, season, and year with the live vegetation volume of grass, rainfall parameters and water（soil） conservation effect RE（SE）. Results show that with the coarsened time scale, the rainfall and vegetation indices increase or decrease more or less, the variation range of RE is small, while SE slowly decreases. The mean RE has 10%-20% variations at different time scales and the observed water conservation effect of grass is the best at season scale while the worst at year scale. The soil conservation effect of grass is the best at month scale, while the worst and close to each other at season and rainfall event scales. The water conservation effect of grass is mainly controlled by rainfall characteristics, including rainfall duration and precipitation at rainfall event scale, and maximum 30-min rainfall intensity at longer time scales. However, the soil conservation effect of grass is mainly controlled by vegetation properties, including the contribution of the litter on soil surface at rainfall event scale, the interaction of rainfall and vegetation at month and season scales, and the live vegetation volume of grass at the year scale. Consequently, at different time scales, the factors influencing water and soil conservation change and interact, and the observed water and soil conservation effects are also different, indicating that the time scale influence deserves attention in both research and management practices.

关 键 词：绿量 时间尺度 保水效应 保土效应 

分 类 号：S157.1[农业科学—土壤学]