Permeability of commercial landscapes: integrating plantation forest trackways into ecological networks

Abstract

AbstractContextReconnecting fragmented habitat is a major challenge in biodiversity conservation. It is especially important in landscapes that have undergone significant change through agriculture and forestry conversion. This is particularly prevalent within heathland regions across Western Europe where remaining fragments are significantly isolated in intensely managed landscapes.ObjectivesThis study examines to what extent forest trackways can facilitate connectivity between open patches, and how invertebrate dispersal ability (terrestrial or aerial) influences functional landscape connectivity. We also investigate a range of management scenarios to examine the efficacy of landscape management plans to facilitate connectivity for vulnerable invertebrate communities.MethodsWe develop thePath-Cost Index(PCI) that combines multiple environmental factors to quantify species-specific habitat suitability within forestry trackways. ThePCIgenerates dispersal cost values for resistance-based connectivity models that represent specific forest environments and species/guild responses. We demonstrate the use of this index through the modelling of least-cost pathways for heathland invertebrates and test management scenarios (clustered and contiguous habitat improvements) developed to support heathland biodiversity.ResultsThe plantation landscape provided significant barriers for vulnerable heathland invertebrate guilds. Landscape metrics indicate that management plans incorporating contiguous corridors would provide significantly greater improvements over clustered corridors for target invertebrate guilds in our study landscape.ConclusionThePCIpresented in this study delivered easily definable resistance costs allowing comparative assessment of landscape enhancements plans. ThePCIcan be easily adapted to other linear features and landscapes, affording a low-cost tool to assist the evaluation of management plans and biological networks.