摘要
随着气候变化黄土高原植被与坡面侵蚀关系面临更多复杂和极端降雨情景的挑战。以黄土丘陵区草地坡面为对象,选择3场当地典型降雨事件,研究植物冠层、枯落物和根系与土壤侵蚀的关系及其对不同降雨情景的响应规律。事件-Ⅰ为短历时、高强度和大雨量,事件-Ⅱ为中等历时、强度和雨量,事件-Ⅲ为长历时、低强度和小雨量,3场事件分别代表2015—2017年侵蚀性降雨事件聚类分析后的3种情景。从多年次降雨事件尺度来看,冠层主要作用于降低泥沙浓度,减少了48.20%的径流含沙量,占总贡献率的53.03%,并贡献了约1/3的减流和减沙效应;枯落物的减流效应最高,减少了28.43%的径流量,占总贡献率的50.75%,其减沙的相对贡献率仅为26.41%;根系的减沙效应最高,减少了36.33%的土壤流失量,占总贡献的37.95%,远高于其减流相对贡献率(15.58%)。说明草地植物对土壤侵蚀的作用机制受到冠层、枯落物和根系的影响,各组分越完整,减流减沙能力越高。单次事件分析表明,由事件-Ⅰ、事件-Ⅱ到事件-Ⅲ,冠层的减流率和减沙率均为负值(-77.97%至-0.91%),相对贡献呈逐渐减小趋势;而枯落物和根系的减流率和减沙率却分别高达12.05%—57.70%和86.90%—95.51%,相对贡献则逐渐增大。说明草地不同组分控制土壤侵蚀的主要途径受到降雨情景的影响,长时间尺度的统计性结论不一定适用于特定降雨情景。研究对比分析了草地植物在单次和多年尺度降雨事件中的保水保土功能,可为黄土高原植被恢复和气候变化加剧背景下,降雨-植物-侵蚀关系研究提供科学依据。
The relationship between vegetation and slope erosion in the Loess Plateau will face challenges of more complex and extreme rainfall scenarios with the climate change. This study selected the grassland slope in the loess hilly area as the experimental subject. Three typical rainfall events in the local area were used to research the relationship between plant canopy, litter and roots and soil erosion, and their response regularity to different rainfall scenarios. Event-Ⅰ had short duration, high intensity and large rainfall amount;event-Ⅱ had moderate duration, intensity, and rainfall amount;and event-Ⅲ had long duration, low intensity and small rainfall amount. The three events represented the three scenarios which classified by the k-means clustering analysis of erosive rainfall events during 2015—2017. At the scale of multi-year rainfall events, the canopy mainly affected the reduction of sediment concentration, which reduced 48.20% of sediment concentration and accounted for 53.03% of the total contribution, and the canopy also contributed about 1/3 of the total reduction of runoff and soil loss;the litter showed the highest effects on runoff reduction, which reduced 28.43% of runoff and accounted for 50.75% of the total contribution, but the relative contribution rate of the litter on soil loss reduction was only 26.41%;and the roots had the highest effects on soil loss reduction, reducing soil loss by 36.33% and contributing 37.95% of the total contribution, which was much higher than its relative contribution rate of runoff reduction(15.58%). It indicated that the influencing mechanism of grassland plant on soil erosion was controlled by the canopy, litter and roots, where the more complete of components, the higher capacity of reducing runoff and soil loss. The single event analysis showed that with the change of event-Ⅰ, event-Ⅱ to event-Ⅲ, the contribution of canopy to reducing runoff and soil loss were both negative values(from-77.97% to-0.91%), and the relative contribution gradually dec
作者
刘见波
高光耀
傅伯杰
LIU Jianbo;GAO Guangyao;FU Bojie(Tianjin Key Laboratory of Water Resources and Environment,Tianjin Normal University,Tianjin 300387,China;State Key Laboratory of Urban and Regional Ecology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;National Observation and Research Station of Earth Critical Zone on the Loess Plateau in Shaanxi,Xi'an 710061,China)
出处
《生态学报》
CAS
CSCD
北大核心
2023年第4期1496-1505,共10页
Acta Ecologica Sinica
基金
国家自然科学基金项目(41991233,42041004)
城市与区域生态国家重点实验室开放基金(SKLURE2020-2-3)
天津市教委科研计划项目(2019KJ091)。
关键词
黄土高原
水土流失
降雨型
植物垂直结构
减流减沙
the Loess Plateau
soil and water loss
rainfall regime
vegetation vertical structure
runoff and soil loss reduction
