A landscape scale spatial model for semi-natural broadleaf woodland expansion in Wales, UK

Conservation assessment based on complex species distribution models suffers from a number of conceptual drawbacks when applied to setting conservation priorities. The rule-based model described in this paper uses a set of simple and easily understood ecological rules developed in consultation with local ecologists that are directly applicable to the local landscape. The model determines the suitability for the expansion of target semi-natural habitats, modified by landscape differences, for a selected study site in Wales, UK. The results in a pilot study area for semi-natural broadleaf woodland (SNBW) indicated that the model successfully identifies potential sites for expansion at the scale of the land parcel that represents the dominant management unit. The model generated high suitability scores for broadleaf woodland expansion along river valleys which contain proportionately more remnant broadleaf woodland and other semi-natural vegetation than other, more intensively farmed parts of the contemporary landscape. The results demonstrate that within this landscape type there is the potential to increase woodland area by c. 6.5%. By contrast a landscape type characterised by gentle relief and deep fertile soils currently under intensive agricultural use, shows the potential for lower levels of broadleaf woodland expansion equivalent to c. 3.3% of the area of the landscape unit. The model is flexible and can be re-run to reflect changed circumstances, in particular changes in policy relating to agri-environment targets for habitats and species. Future work is required to refine the model to reflect differences in the cultural as well as the physical characteristics of the underlying landscape. (C) 2010 Elsevier GmbH. All rights reserved.