Data from: Predictive mapping to identify refuges for plant communities threatened by earthworm invasion

1. Biological invasions by cryptic ecosystem engineers can alter the ecological and socio-economic values of ecosystems in ways that may take decades to detect. The invasion of North American glacial refuges by non-native earthworms offers a prominent but understudied example of a cryptic invasion. Non-native earthworms are known to alter carbon sequestration, disrupt mycorrhizal networks, and homogenize plant communities, but natural resource managers still lack robust protocols to identify and safeguard high conservation value communities (HCVCs) from such invasions. In the absence of such protocols, or reliable methods to eradicate non-native earthworm populations once established, there is an urgent need for methods to identify HCVCs at risk of or potentially shielded from earthworm invasion by the existence of abiotic barriers to their dispersal or persistence in such sites. 2. We developed species distribution models (SDMs) using in-situ field surveys and remotely sensed data to (1) identify factors limiting the occurrence of non-native Lumbricus earthworms in imperiled coastal Douglas-fir (Pseudotsuga menziesii) forest and Garry oak (Quercus garryana) and maritime meadow ecosystems endemic to glacial refugia of the Pacific Northwest of North America to (2) evaluate their influence on plant species diversity and identify abiotic factors capable of preventing their dispersal or persistence at a site. 3. As predicted, shallow, drier soils, and steeper terrain limited earthworm occurrence and abundance in our highly heterogeneous study area, and earthworm presence appeared to reduce plant species richness. Our results indicated that HCVCs endemic to shallow-soil (