Incorporating landscape connectivity into household pond configuration in a hilly agricultural landscape

Abstract

Manmade ponds are common landscape features in rural areas and also important habitats for maintaining biodiversity. However, they are vulnerable to anthropogenic activities, land-use changes, and habitat degradation; many ponds being filled or (re)created arbitrarily. Little attention has been paid to quantifying the spatial structure of these manmade ponds at a landscape scale, nor to their potential functional benefits in promoting ecological flows and interactions between habitats for whole-ecosystem integrity. In this study, we investigated the patch-based landscape connectivity of household ponds, a particular type of domestic pond prevalent in hilly rural areas of China, by using least-cost path modelling and graph theory based network analysis. A hierarchical network was modelled consisting of 4606 individual ponds, 373 pond patches and 772 potential links within a 1.5-km threshold distance. Network importance analysis revealed that the largest pond patch contributes 24.5 % to network building and that patches with larger areas are generally more important. In contrast, the importance of the simulated links is only 2.3 % at most, indicating that the network has spatial redundancy which can strengthen resilience to uncertain disturbances. Our study moves beyond network simulation and importance assessment by directly relating the connectivity analysis to a real construction context through the incorporation of a spatially explicit land suitability analysis. This approach systematises the analysis of pond landscapes and guides integration with the wider landscape matrix. It provides operational spatial suggestions for holistic landscape planning across local to regional scales.