Predicting species occurrences with habitat network models

1. Biodiversity conservation requires modelling tools capable of predicting the presence or absence (i.e. occurrence-state) of species in habitat patches. Local habitat characteristics of a patch (lh), the cost of traversing the landscape matrix between patches (weighted connectivity; (wc), and the position of the patch in the habitat network topology (nt) all influence occurrence-state. Existing models are data demanding or consider only local habitat characteristics. We address these shortcomings and present a network-based modelling approach, which aims to predict species occurrence-state in habitat patches using readily available presence-only records. 2. For the tree frog Hyla arborea on the Swiss Plateau, we delineated habitat network nodes from an ensemble habitat suitability model, and used different cost surfaces to generate the edges of three networks: one limited only by dispersal distance (Uniform), another incorporating traffic, and a third based on inverse habitat suitabil...1. 生物多样性保护亟需能够预测栖息地斑块内物种存在与否（即出现状态（occurrence-state））的建模工具。斑块的本地生境特征（local habitat characteristics，lh）、斑块间景观基质的穿越成本（加权连通性（weighted connectivity），wc），以及该斑块在生境网络拓扑（habitat network topology，nt）中的位置，均会对物种出现状态产生影响。现有模型要么数据需求极高，要么仅考虑本地生境特征。针对上述局限，本研究提出一种基于网络的建模方法，旨在利用极易获取的仅存在记录，预测栖息地斑块内的物种出现状态。 2. 针对瑞士高原上的欧洲树蛙（Hyla arborea），我们基于集成生境适宜性模型划定生境网络节点，并通过不同的成本表面生成三类网络的边：一类仅由扩散距离限制（Uniform），另一类纳入了交通因素，第三类则基于生境适宜性的反值……