Context

The current biodiversity crisis has intensified the need to predict species responses to landscape modification and has renewed attention on the fundamental question of what influences the dynamics of species distributions. Landscape composition can affect two main components that dictate distributions: habitat suitability and habitat connectivity. Elucidating the relative importance of these factors and associated landscape features can help prioritize management action for species conservation.

Objectives

Our objective was to use species distribution models and network-based landscape connectivity models to understand which landscape factors were most predictive of the distribution of an anuran, Blanchard’s cricket frog (Acris blanchardi), in an agriculturally-dominated landscape.

Methods

We conducted our study in Ohio, USA, near the edge of the cricket frog’s contracting range. To obtain a current assessment of cricket frog distribution, we surveyed 367 pond and stream locations across three North–South transects. We then tested seven regression models, combining habitat suitability and landscape connectivity metrics, to determine which factors best predicted cricket frog presence.

Results

We detected cricket frogs in 24% of surveyed locations and they were more likely to occupy pond sites than stream sites. Cricket frog presence was best predicted by models with habitat suitability and the number of interconnected habitat patches. We found that, while there was high variation in habitat suitability across the study area, landscape connectivity was relatively uniform where we surveyed.

Conclusions

Agricultural landscapes around the world are often mosaics of land cover types, which may functionally provide connectivity for some species. In such areas, conservation management should focus on preserving and restoring regions of highly suitable habitat. This focus may be particularly relevant for species that do not appear to be dispersal limited and, therefore, able to maintain metapopulation dynamics.

中文翻译：

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建立联系：结合栖息地适宜性和景观连通性，了解农业景观中的物种分布

语境

当前的生物多样性危机加剧了预测物种对景观改变的反应的需求，并重新关注影响物种分布动态的基本问题。景观构成可以影响决定分布的两个主要组成部分：栖息地适宜性和栖息地连通性。阐明这些因素和相关景观特征的相对重要性有助于优先考虑物种保护的管理行动。

目标

我们的目标是使用物种分布模型和基于网络的景观连通性模型来了解哪些景观因素最能预测在以农业为主的景观中无尾蚴、布兰查德蟋蟀 ( Acris blanchardi )的分布。

方法

我们在美国俄亥俄州靠近蟋蟀收缩范围的边缘进行了研究。为了获得对蟋蟀分布的当前评估，我们调查了三个南北横断面的 367 个池塘和溪流位置。然后，我们测试了七个回归模型，结合栖息地适宜性和景观连通性指标，以确定哪些因素最能预测蟋蟀的存在。

结果

我们在 24% 的调查地点检测到蟋蟀蛙，它们更可能占据池塘地点而不是河流地点。具有栖息地适宜性和相互连接的栖息地斑块数量的模型可以最好地预测蟋蟀蛙的存在。我们发现，虽然整个研究区域的栖息地适宜性差异很大，但我们调查的地方的景观连通性相对统一。

结论

世界各地的农业景观通常是土地覆盖类型的马赛克，这可能在功能上为某些物种提供连接。在这些地区，保护管理应侧重于保护和恢复非常适宜栖息地的地区。这一重点可能与似乎不受扩散限制的物种特别相关，因此能够维持复合种群动态。