The influences of habitat proportion and patch-level structural factors in the spatial habitat importance ranking for connectivity and implications for habitat conservation

Urbanization has resulted in significant habitat loss and fragmentation worldwide, which threats the provision of ecosystem services for human health and life. Maintaining and improving the connectivity of the remnant habitats in and around cities is essential for landscape planning. Landscape metrics have been widely used for modeling and evaluating how landscape structures affect habitat connectivity for different species in many previous studies. However, the results of some previous studies were not consistent and even contradictory. This might limit the applications in practical habitat conservation. In the present study, four actual landscapes with a series of forest cover ratios in Fuzhou City, China, were selected. By using graph-based connectivity indices, the importance of habitat patches for landscape connectivity was explored. The effects of habitat proportion and three patch-level structural factors (i.e., patch size, shape, and position) on habitat patch importance indices were examined. Our results suggest that habitat proportion governed the overall landscape connectivity. The three structural factors explained approximately 80 % of the variation in the patch importance of connectivity indices. Patch size was the primary factor determining patch importance, while patch location was related to the partition of the three fractions of patch importance. Considering the different roles of the three structural factors played in landscapes with different habitat proportion, the spatial advice for local habitat conservation was proposed. Moreover, general conservation strategies regarding different habitat proportions were provided at the landscape scale and patch scale. Our findings would provide scientific evidence for local decision makers, and could be combined with other conservation planning tools.