Modelling the effect of intersections in linear habitat on spatial distribution and local population density

This article may be used for research, teaching and private study purposes. Any substantial or systematic reproduction, redistribution , reselling , loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material. Many species in human-dominated landscapes find their habitat in linear elements, such as road verges, hedgerows and ditches. Local concentrations of species have been observed in the intersections of linear elements, but their spatial distribution and local population density in this linear habitat are not well captured by existing theory. Using a simple, spatially explicit individual-based GIS-model simulating hedgerow bird species with different movement abilities, local high population density of our model species in intersections and their reduced density or absence in linear habitat could be explained by limited movement. We hypothesise that, for species with low movement ability, intersections of linearly shaped habitat could contain several local populations. We argue that these predictions are valid for organisms occurring in linear habitat with limited movement relative to the dimensions of their habitat, and whose movement is directed by their habitat. Our findings support the importance of intersections for biodiversity in human-dominated landscapes, as they may serve as refuges from which individuals can (re-)colonise unoccupied habitat. 1. Introduction A large body of theory has been developed over the last few decades for the spatial dynamics of plant and animal populations in human-dominated landscapes example, the presence of many species within agricultural landscapes is restricted to such non-cropped, linear elements (Grashof-Bokdam and Van Langevelde 2005, Kleijn and Van Langevelde 2006), especially when agricultural land use is intensive (Kleijn et al. 2001, Weibull et al. 2000). These linear elements may act as corridors as well as habitat for many species, including plants, small mammals and birds