Data from: Infrastructure features outperform environmental variables explaining rabbit abundance around motorways

Human disturbance is widespread across landscapes in the form of roads that alter wildlife populations. Knowing which road features are responsible for the species response and their relevance in comparison with environmental variables will provide useful information for effective conservation measures. We sampled relative abundance of European rabbits, a very widespread species, in motorway verges at regional scale, in an area with large variability in environmental and infrastructure conditions. Environmental variables included vegetation structure, plant productivity, distance to water sources, and altitude. Infrastructure characteristics were the type of vegetation in verges, verge width, traffic volume, and the presence of embankments. We performed a variance partitioning analysis to determine the relative importance of two sets of variables on rabbit abundance. Additionally, we identified the most important variables and their effects model averaging after model selection by AICc on hypothesis-based models. As a group, infrastructure features explained four times more variability in rabbit abundance than environmental variables, being the effects of the former critical in motorway stretches located in altered landscapes with no available habitat for rabbits, such as agricultural fields. Model selection and Akaike weights showed that verge width and traffic volume are the most important variables explaining rabbit abundance index, with positive and negative effects, respectively. In the light of these results, the response of species to the infrastructure can be modulated through the modification of motorway features, being some of them manageable in the design phase. The identification of such features leads to suggestions for improvement through low-cost corrective measures and conservation plans. As a general indication, keeping motorway verges less than 10 m wide will prevent high densities of rabbits and avoid the unwanted effects that rabbit populations can generate in some areas.

以道路为代表的人类干扰广泛遍布各类景观，会对野生动物种群造成显著影响。明确哪些道路特征会引发物种的响应，以及这些特征与环境变量的相对重要性，可为制定有效的保护措施提供科学依据。本研究在环境与基础设施条件变异度较高的区域尺度下，针对高速公路路肩（motorway verges）生境中的欧洲兔（European rabbits）——一种分布极为广泛的物种——的相对丰度开展了采样调查。本研究纳入的环境变量包括植被结构、植物生产力、距水源距离以及海拔高度；基础设施特征则包括路肩植被类型、路肩宽度、车流量以及路堤（embankments）的存在情况。本研究通过方差分解分析（variance partitioning analysis），明确了两类变量对欧洲兔丰度的相对重要性。此外，本研究基于假说驱动的模型，通过校正赤池信息准则（AICc）进行模型选择后，采用模型平均法识别出了对兔类丰度影响最为显著的变量及其效应方向。整体而言，基础设施特征对欧洲兔丰度变异的解释度是环境变量的四倍，且在农田等已被改造且缺乏适宜生境的景观区域内的高速公路路段中，基础设施特征的效应尤为关键。模型选择结果与赤池权重（Akaike weights）表明，路肩宽度与车流量是解释欧洲兔丰度指数的最关键变量，二者分别对兔类丰度产生正向与负向影响。基于上述研究结果，可通过调整高速公路的相关特征来调控物种对基础设施的响应，其中部分特征可在道路设计阶段进行优化。明确这些关键特征，可为通过低成本整改措施与保护规划优化道路设计提供参考方向。作为一般性指导原则，将高速公路路肩宽度控制在10米以内，可避免欧洲兔种群达到过高密度，从而规避其在部分区域可能引发的不良生态影响。