Using point process intensity to establish the spatio-temporal grain of continuous landscape tessellations and graphs

Abstract

The choice of grain (or resolution) for a landscape study will affect the findings of ecological investigations, so the grain adopted must be explicitly stated. However, stating the grain of the spatial data structure representing a landscape can be difficult as a variety of continuous tessellations or graphs of different regular and irregular geometries can be used. We demonstrate how spatial point process intensity (or density) can be used to define the grain of landscape tessellations and graphs with a variety of geometries. To illustrate this novel approach, we used analyses of radio-telemetry data for the brushtail possum (Trichosurus vulpecula) on the North Island of New Zealand to produce point patterns of differing intensities to create a continuous landscape tessellation and graph at different spatio-temporal scales. In doing so we highlight how point process intensity can provide a general way of reporting the grain of landscape tessellations and graphs. Therefore, this approach may facilitate communication of grain and so aid interpretation of ecological investigations and facilitate comparisons between studies.