Geodiversity is an inseparable but underutilized aspect of ecological connectivity assessments under climate change

Abstract

Conservation has shifted towards a climate change adaptation approach in which expected species range shifts are increasingly considered to mitigate effects of climate change and habitat fragmentation on biodiversity. As part of this, ecological connectivity needs to be ensured to support gene flow and viable populations in the face of changing environmental conditions. This makes it critical to understand which landscape elements facilitate and impede species movement. Geodiversity, i.e. the diversity of abiotic nature, is strongly connected to species' distributions through underpinning geophysical settings and gradients, and by affecting the distribution of resources like water, nutrients, and light. These, in turn, contribute to landscape permeability and, ultimately, affect species movement potential. However, it is unclear to what extent geodiversity has been incorporated into connectivity assessments. We present a systematic literature review examining how measures of geodiversity and its' components, i.e. geology, soils, hydrology, and geomorphology, are used and understood in the context of connectivity. We reviewed the current understanding of geodiversity's role in facilitating species adaptation and connectivity, as well as how this information has been incorporated into connectivity modeling. Our findings highlight that a geodiverse landscape is often assumed to foster connectivity and climate resilience of biodiversity mainly through resource and niche provisioning. We also find that the quantitative measures of geodiversity used in connectivity modeling often represent simplistic metrics that may overlook important abiotic components that contribute to species persistence and movement under changing conditions. The key challenges hindering a wider use of geodiversity information in connectivity include the limited adoption of the term outside geosciences and the lack of established quantitative metrics of the geodiversity-biodiversity relationship. Addressing these gaps could greatly enhance ecological connectivity assessments through a wider adoption of geodiversity information, especially in cases where detailed data on multiple species' local environmental requirements are poorly understood.