A new set of metrics to quantify the colonization potential of riverscapes by wind-dispersed plant species

Abstract

Quantifying the potential of a braided riverscape to be colonized by a plant species is important for assessing the ecological state of the river and provides an important basis for nature conservation planning and the implementation of restoration measures. Common landscape and river connectivity indices are largely unsuitable for describing the situation for the mostly wind-dispersed plant species. We aim to provide a set of comparable metrics that allows the quantification of the colonization potential of riverscapes at the patch and riverscape level. We define and describe a set of cell-based, spatially explicit measures that can easily be implemented. We demonstrate their application using two typical plant species and three riverscapes with different habitat configurations as examples. Our metrics consider shape, size and the spatial configuration of habitat patches, along with the dispersal characteristics of the respective species. The metrics provide a linear, balanced, and realistic representation of the colonization potential at the cell, patch, and riverscape levels. The results are comparable between different riverscapes and species and can easily be extended and used for further modeling. The metrics provide a valuable tool for the planning and evaluation of conservation, restoration, and reintroduction measures and close the gap between simple habitat availability analyses and large-scale terrestrial connectivity indices.