高寒草地植被与土壤水源涵养功能的时空耦合关系

Spatial and Temporal Coupling Relationship Between Alpine Grassland Vegetation and Soil Water Conservation Function

探究草地植被格局与土壤水源涵养功能的关系,对于评价和有效利用土壤及草地植被资源起着重要的作用。以黄河源区的高寒草地生态系统为研究对象,运用MODIS数据构建土壤水源涵养功能模型并探究其时空变化特征,明确草地植被的时空变化规律,以耦合协调度理论为基础探讨二者耦合关系的季节性变化和空间分布特征。结果表明:(1)2000—2021年土壤水源涵养功能指数和综合植被指数在各个季节上均呈增加趋势,22年的季平均值表现为夏季和秋季高于春季和冬季;(2)2000—2021年各个季节土壤水源涵养功能—植被(SWCF—VEG)的耦合协调度基本上均呈增加趋势,同时各土层深度耦合协调度值的空间分布差异明显,且在季节上表现为夏季>秋季>春季>冬季;(3)2000—2021年季节上各草地类型的SWCF—VEG耦合协调度均为增加趋势;各季节温性草原不同土层深度耦合协调度的平均值均最大,且夏季、秋季和冬季各草地类型的值均表现为10—20 cm>0—10 cm;各草地类型不同季节的耦合协调发展类型各异。研究结果为黄河源区草地植被与土壤水源涵养功能的耦合关系提供高效定量的时空分析方法,可为草地植被—土壤的可持续发展奠定基础。

Exploring the relationship between grassland vegetation patterns and soil water conservation function plays an important role in evaluating and effectively utilizing soil and grassland vegetation resources.The study was conducted on the alpine grassland ecosystem in the Yellow River source area,a model of soil water conservation function was constructed using MODIS data and its spatial and temporal variation characteristics were explored.The spatial and temporal variation patterns of grassland vegetation were clarified,and the seasonal variation and spatial distribution characteristics of their coupling relationship were explored based on the theory of coupling coordination.The results showed that:(1)Soil water conservation function index and comprehensive vegetation index showed an increasing trend in all seasons from 2000 to 2021,and the seasonal average values were higher in summer and autumn than those in spring and winter.(2)The coupling coordination of soil water conservation function-vegetation(SWCF-VEG)basically showed an increasing trend in all seasons from 2000 to 2021,and the spatial distribution of the coupling coordination values were significantly varied among different soil layer depths,and the seasonal performance followed the order of summer>autumn>spring>winter.(3)The coupling coordination of SWCF-VEG showed an increasing trend for each grassland type in all seasons from 2000 to 2021.The mean values of coupling coordination for various soil depths in temperate grasslands were the maximum in all seasons,and the values of 10—20 cm were greater than those of 0—10 cm for each grassland type in summer,autumn and winter.The coupling coordination development types varied among grassland types in different seasons.The study could provide an efficient and quantitative spatiotemporal analysis method for the coupling relationship between grassland vegetation and soil water conservation function in the Yellow River source area,and the results could be the basis for the sustainable development of vegetation-soil in grassland.