Spatio-Temporal Evolution Patterns of Hydrological Connectivity of Wetland Biodiversity Hotspots in Sanjiang Plain between 1995 and 2015

Hydrological connectivity is the main non-biological driving factor of wetland ecological processes and is key to maintaining the stability and biodiversity of the whole ecosystem. Socio-economic activities have had a significant impact on the hydrological connectivity of wetlands, resulting in the loss of biodiversity and the degradation of the ecological functions of wetlands. Wetland biodiversity hotspots in Sanjiang Plain that were identified in the previous literature using the Systematic Conservation Planning (SCP) method were chosen as the research objects. The SCP method was combined with the structural hydrological connectivity index (Integral Index of Connectivity (IIC) and Probability of Connectivity (PC)) and the functional hydrological connectivity index (Morphological Spatial Pattern Analysis) to analyze the spatio-temporal changes in the hydrological connectivity of the wetland biodiversity hotspots in Sanjiang Plain. The results showed that the hydrological connectivity within the eight identified wetland biodiversity hotspots in Sanjiang Plain experienced varying degrees of decline in the period between 1995 and 2015. Structurally, the IIC values of wetlands in all of the biodiversity hotspots were more than 0.5, and the PC values were more than 0.9, but most of the hotspots showed declining trends of varying degrees from 2010 to 2015. Functionally, the average proportion of core wetlands in the hotspots has decreased by 4.82%, and the average proportion of edge wetlands has increased by 2.71% over the last 20 years. The findings on the hydrological connectivity evolution patterns can aid in the conservation and restoration of wetlands and biodiversity hotspots.