Abstract: We used five Landsat remote sensing images from 1977 to 2015, acquired land cover data based on an object-oriented classification method, and explored wetland area changes in four Ramsar sites in the Yunnan-Guizhou Plateau. With landscape metrics, dynamic index and human disturbance index, we analyzed the effects of human stress on wetlands and the protective efficiency in the four Ramsar sites over the plateau. Results showed that total area of wetlands decreased by 7.6% (i.e. 299 hm²) in the past 38 years, with direct human occupation as the most important driver. Human disturbance index increased from 7.4% in 1977 to 13.5% in 2015. During the 38 years, landscape fragmentation index and patch number increased, whereas aggregation degree and contagion decreased. Changes in these landscape metrics indicated obvious fragmentation of wetland landscapes. There were differences in changes of wetland landscapes among the four Ramsar sites. Wetland landscape in Lashihai and Dashanbao changed dramatically with human stresses. Wetland landscape in Bitahai and Napahai changed slightly with better protection effects. Our results can provide scientific basis for wetland protection and sustainable management in the Yunnan-Guizhou Plateau.

Key words: Ramsar site, human stress, landscape metrics, remote sensing, Yunnan-Guizhou Plateau.