Trade-offs between timber production, carbon stocking and habitat quality when managing woodlots for multiple ecosystem services

Abstract

Managing for multiple ecosystem services is a growing issue for forest managers. As trade-offs arise between conflicting management objectives, stakeholders must be informed of the possible outcomes of alternative choices in order to facilitate decision-making. We modelled stand dynamics under single-management and functional zoning multiple-management (TRIAD; i.e. three-zone) scenarios in different forest types typical of eastern North America with the Forest Vegetation Simulator (FVS). Timber production, carbon stocking and habitat quality ecosystem services were calculated with simulation outputs. Habitat quality was measured using a habitat suitability index that integrated stand structural indicators. A multi-criteria decision analysis (MCDA) was performed in order to rank scenarios. We show that the most intensive management yielded greater timber volumes but resulted in the weakest carbon and habitat quality scores. The TRIAD scenarios in sugar maple-beech stands offered the best compromise in services compared to single management. In shade-intolerant deciduous stands, there was a loss of timber production with TRIAD scenarios, but greater carbon stock and habitat quality were observed. Our study contrasts alternative management scenarios for ecosystem services in woodlots of different forest types. It confirms that multiple harvest systems better achieve multiple services. The coupling of simulation modelling with MCDA offers a simple and flexible method to help stakeholders and managers make sound decisions.