| In this study, we analyzed trends in land use dynamics in the upper Erhai Lake basin and its relationship with ecosystem service values (ESV) in the basin. The study was based on Landsat TM/OLI remote sensing images from five years of land use data (2000, 2005, 2010, 2015 and 2019). The transfer matrix, land use dynamics, and equivalent factors for improved ecosystem service values were used to analyze land use change patterns, dynamic trends of ecosystem service values, and their interactions in the basin. The aim was to provide a reference for protecting the ecological environment and treating non-point pollution in the Erhai Lake basin. Results show that: (1) Forestland, grassland, and cultivated land were the primary land-use types and land transition types in the study area. The dynamic degree of “other land-use” type was the highest (13.76%), while the dynamic degree of grassland (-2.17%) was the lowest. Over the 20 year period, the total area of cultivated land and grassland decreased, while forestland increased. Grassland area decreased the most (102.734 km2, 8.83%), while forestland increased the most (122.519 km2, 10.34%). (2) The ESV of different land-use types was calculated according to improved ecosystem service value equivalent factors in the study area, and the ESV of the primary service functions followed the order, regulation service > supporting service > supply service > cultural service, and the secondary service functions with the highest ESV was for hydrological regulation and the lowest was for maintaining nutrient cycles. (3) The ESV of forestland and grassland in the upper Erhai Lake watershed was highest over the 20 year period, with an overall upward tendency. The primary contribution and sensitive factors were forestland, grassland, and water, which had the highest ecological contribution rates of 62.62%, 64.12% and 53.66%, respectively, over the periods of 2000?2005, 2005?2010, 2010?2015, and 2015?2019. (4) There was a linear relationship between the change of ESV and the transfer areas, in and out, of each land-use type. The transfer in and out areas of woodland, grassland, and water were the primary contributors to the changes in ESV in the upper Erhai Lake basin. The overall land use development demand in the upper Erhai Lake watershed was relatively low, so the ecological environment continues to improve and the ESV trended upward.. |
