Spatial and temporal evolution of landscape pattern of urban natural remnant mountains in karst region of central Guizhou: a case study of Anshun City

Urban natural remnant mountains are precious and fragile ecological resources in mountainous city, which play an irreplaceable role in maintaining the stability of urban ecosystem. However, in recent years, the high-intensity of urban construction had caused serious interference and stress on them.In this study, we selected the built-up area of Anshun City as the research area, with the support of spatial information technology, landscape pattern index and buffer zone analysis method were comprehensive applied. The spatial and temporal evolution of landscape pattern of urban natural remnant mountains of Anshun City was quantitatively studied from three aspects of the urban landscape pattern dynamics, urban natural remnant mountains landscape dynamics, and the interaction between urban construction and urban natural remnant mountains, in order to reveal its response law to urban expansion under the background of rapid urbanization in recent 10 years. The results showed that 1) the fragmentation index of urban landscape increased, the patch richness density decreased, and the shannon′s density index, shannon′s evenness index and dominance index showed change of upper and lower volatility. 2) The number of patches, classl area, and landscape dominance index of the urban natural remnant mountains patches increased. The patch shape tended to be regular, connectivity index decreased, and the aggregation index decreased first and then increased. 3) In the process of rapid urbanization, the interaction between urban construction and urban natural remnant mountains was obvious, which mainly performed as the continuous damage and reduction of urban natural remnant mountains due to urban construction and its attraction to urban construction. 4)Within the 500 m buffer zone of urban natural remnant mountains, Average proportion of urban construction land and average proportion of urban artificial garden green space in buffer zone were significantly negatively correlated with the buffer distance of urban natural remnant mountains. The correlation degree between urban natural remnant mountains with the urban construction land in buffer zone showed as small patch > medium patch > relatively large patch > large patch. The correlation degree with the urban artificial greening in buffer zone showed as the highest for medium patch and the lowest for relatively large patch. The urban natural remnant mountains were obviously attractive to the urban construction and its artifici