Designing recreational trails in a forest dune habitat using least-cost path analysis at the resolution of visitor sight distance

Abstract

Dune plantation forests are typically used for recreation. However, the soil and vegetation of these forests are sensitive to trampling. Therefore, recreational trails should have clearly defined boundaries. The aim of this study was to test a cell-based survey for the alignment of interpretative trails in sand dune plantation forests, where each cell of a sampling grid is surveyed in the field at a grain size of 10-m, which is an appropriate scale for both visitors and to accurately assess vegetation and stand structure. The alignment of the trail was then performed using a combined least-cost path algorithm with GIS-based land suitability analysis. Using this approach, sets of key factors for land suitability and visibility which are generally applicable to dune plantation forests were identified. Specific criteria were adopted to score and weigh each factor in this case study, where each of the 284 cells of a 10-m grid were surveyed for two weeks in a coastal urban reserve located in one of the major tourist beach resorts of the Mediterranean basin (Bibione, Northern Italy). The factors surveyed in the field were used to calculate the potential trail index, and the least-cost path method was used to optimally align the trail in order to achieve the lowest cumulative resistance value possible. The novel cell-based survey did not require the conversion of any land suitability layers to their raster counterpart grids, as the grain and resulting alignment of the trail were scaled to the neighbourhood of the users. In addition, we did not focus on the concept of the patch, as we were not interested in reclassifying the surveyed attributes, as features were originally collected at the scale of the walking paths. We conclude that the proposed method is a feasible approach, and amenable to situation where a fine-grained alignment of recreational trails is required, and/or when a careful assessment of a trails’ environmental impact is needed.