Urbanization and agricultural intensification are the main drivers of biodiversity losses through multiple stressors, especially habitat fragmentation, isolation and loss. Designing Blue and Green Infrastructure Networks (BGIN) has been recommended as a potential tool for land-use planning to increase ecosystem services while preserving biodiversity. All municipalities in France are required to perform BGIN planning. This article focuses on the Couesnon watershed (Brittany, France) and the participatory process used to define and analyze five possible pathways of future land-use and land-cover changes that included implementation of BGINs. Impacts on biodiversity were estimated by quantifying the change in landscape connectivity of woodlands, grasslands and wetlands. The effectiveness of BGIN policies was assessed by comparing current landscape connectivity (2018) to those in possible futures. Landscape connectivity referred to functional connectivity for three indicator species (Abax parallelepipedus, Maniola jurtina and Arvicola sapidus) across three landscape features: woodlands, grasslands and wetlands, respectively. Results allowed impacts of urban and agricultural land-use changes to be identified in terms of extent and quality. If BGIN policies were applied effectively to control the expansion of gray infrastructure, they would help increase the area and the quality of grassland and woodland connectivity by no more than 2%. Agricultural land-use and land-cover changes could have more impact on the extent of grassland (−82% to +38%) and wetland (−49% to +47%) connectivity. Current and future trends for hedgerows implied a decrease in woodland connectivity of 9.8–33.8%. Impacts on the quality of landscape connectivity is not proportional with the extent, as a decrease of the latter can have relatively more negative impacts on the former, and inversely. The study highlights that the BGIN strategy can preserve landscape connectivity effectively in urban ecosystems, where human density is higher, but can be threatened by agricultural intensification.

城市化和农业集约化是通过多重压力导致生物多样性丧失的主要驱动因素，特别是栖息地的破碎化、隔离和丧失。设计蓝色和绿色基础设施网络 (BGIN) 已被推荐为土地利用规划的潜在工具，以在保护生物多样性的同时增加生态系统服务。法国的所有城市都必须执行 BGIN 规划。本文重点介绍 Couesnon 流域（法国布列塔尼）以及用于定义和分析未来土地利用和土地覆盖变化的五种可能途径（包括 BGIN 的实施）的参与过程。通过量化林地、草地和湿地景观连通性的变化来估计对生物多样性的影响。BGIN 政策的有效性通过将当前的景观连通性（2018 年）与可能的未来进行比较来评估。景观连通性是指三个指标物种的功能连通性（Abax Parallelepipedus , Maniola jurtina和Arvicola sapidus) 分别跨越三个景观特征：林地、草原和湿地。结果允许在范围和质量方面确定城市和农业土地利用变化的影响。如果有效运用北广域网政策，控制灰色基础设施的扩张，将有助于提高草地和林地连通性的面积和质量不超过2%。农业用地和土地覆盖变化可能对草地（-82% 至 +38%）和湿地（-49% 至 +47%）连通性的范围产生更大影响。树篱的当前和未来趋势表明林地连通性下降了 9.8-33.8%。对景观连通性质量的影响与程度不成正比，后者的减少会对前者产生相对更大的负面影响，反之亦然。