Ecological network design based on optimizing ecosystem services:case study in the Huang-Huai-Hai region, China

In modern agricultural landscapes, constructing 'ecological networks' is regarded as an efficient way to conserve biodiversity and maintain ecosystem services. Here we aimed to develop an approach to design ecological corridor by employing the ecological source -resistance surface -ecological corridor framework in combination with semi-natural habitat planning and ecosystem service trade-off assessment. 'Ecological source patches' were identified based on a 'Remote Sensing Ecological Index' (RSEI) to objectively classify ecological and environ-mental conditions. Our resulting spatial resistance surface was further modified used based on the 'Cultivated Land Use Intensity' index, to derive a high accuracy and rationality of ecological corridor extraction in agri-culture landscape. While planning the ecological network, key nodes and resulting semi-natural habitat (SNH) distribution were identified using Linkage Mapper tools and circuit theory. We constructed ecological network scenarios with different amounts of semi-natural habitats and calculated resulting regional ecosystem service values (ESV) using an equivalence factor method to explore optimal spatial layouts. The results showed, while regional ecosystem service values generally increased in line with semi-natural habitat area contained within the ecological network, ecological networks with forests covering 10% of the total area were predicted as an optimal scenario balancing ecosystem services with agricultural yield in the study region. Networks with mixed forest and grassland cover totaling 20% of the area represented an alternative choice that strongly enhanced regional ecosystem services while may still allowing for high agricultural productivity. In constructing corridors, iden-tifying, restoring and protecting key ecological nodes using targeted management and habitat restoration, while protecting existing wetlands and other water bodies that support regional water cycle and supply services, should be prioritized. Regional policy measures furthermore need to promote targeted ecological network planning to help improve the overall sustainability of agricultural production.