喀斯特流域水源涵养功能时空分异及其对景观格局的响应

针对喀斯特地区景观格局驱动水源涵养功能演变机制的相关研究较少，而水源涵养功能是岩溶石漠化治理等生态修复工程生态效益的关键指标之一，具有重要的研究意义。以地处西南喀斯特中心的野纪河流域为研究对象，基于InVEST模型、偏最小二乘模型(PLSR)、景观生态学理论等，探究野纪河流域2005—2020年水源涵养功能的时空分异特征及其与景观格局的耦合关系。结果表明：(1)野纪河流域景观类型以旱地、草地和灌木林等为主，各类型之间相互转化较为频繁，总体特征表现为旱地、灌木林和草地之间的转化以及建设用地对其余地类的挤占。(2)研究期间，旱地景观趋于破碎化，建设用地呈集聚性的扩张趋势，其他景观类型相对稳定。总体上，景观格局呈破碎化发展趋势，景观连通性呈小幅上升趋势。(3)研究区水源涵养量年际变化呈现持续增长趋势，在空间分布上呈现中部低、南北两侧高的态势。水源涵养深度由高到低排序为灌木林>有林地>疏林地>草地>旱地>建设用地>水田>湖泊>水库坑塘。(4)景观破碎化的增加及斑块质量的提高，可提升喀斯特流域水源涵养功能，但过高的景观破碎化程度可能导致水源涵养功能...

Spatial and Temporal Differentiation of Water Conservation Function in Karst Basin and Its Response to Landscape Pattern

There are few related studies on the evolution mechanism of water conservation function driven by landscape pattern in karst areas,and water conservation function is one of the key indicators of ecological benefits of ecological restoration projects such as the central of karst rocky desertification,which has important research significance.Taking the Yeji River Basin located in the center of the Southwest Karst as the research object,based on the InVEST model,partial least squares model (PLSR),landscape ecology theory,etc.,this paper explored the spatial and temporal variation of water conservation function and its coupling relationship with landscape pattern in the Yeji River Basin from 2005 to 2020.The results showed that:(1) The landscape types of the Yeji River Basin were mainly dryland,grassland and shrubbery,and the mutual transformation between each type is relatively frequent.The general characteristics were the conversion among dryland,shrubbery and grassland and the squeezing of construction land on other land types.(2) During the study period,dryland landscape tended to be fragmented,the construction land showed an agglomerative expansion trend,and other landscape types were relatively stable.In general,the landscape pattern showed a fragmented development trend,and the landscape connectivity showed a slight upward trend.(3) The interannual variation of water conservation in the study area showed a continuous growth trend,and the spatial distribution showed a trend of low in the middle and high in the north and south.The order of water conservation depth from high to low was shrub forest > forest land > sparse forest land > grassland > dryland > construction land > paddy fields > lakes > reservoirs and ponds.(4) The increase of landscape fragmentation and the improvement of patch quality could improve the water conservation function of karst basins,but the excessive degree of landscape fragmentation may lead to the decline of water conservation function.In general,during the study period,the landscape pattern of the Yeji River Basin showed a trend of fragmented development,and the water conservation function showed a continuous increasing trend.The impact of landscape pattern on the water conservation function was complex.The research results can provide important scientific basis for landscape planning and water resources protection in karst watershed.