Optimizing solutions to conservation conflicts in mosaic ecosystems
The introduction of sustainable land-use practices often leads to conflicts between the agriculture sector and conservationists. A successful conflict resolution is one that ensures both the livelihood of human inhabitants and the persistence of healthy and biologically diverse ecosystems. Identifying and implementing resolutions are difficult tasks due to the demand for land heavily outweighing the supply. One promising strategy that has been introduced, and has the potential to compensate for this imbalance, is to identify alternative spatial arrangements of the vegetative states on the landscape that improve both biodiversity and agricultural productivity. Multi-objective, global optimization approaches have been developed to achieve this goal, and although global solution techniques can be effective at identifying the best solution, they are inherently ineffective at identifying alternative solutions and implementation strategies.
Here we introduce a local optimization method that complements global approaches. Species-area relationships constructed from data collected from forest-grassland mosaics in Rio Grande do Sul, Brazil were used to parameterize an objective function that models plant species biodiversity. Landsat images were then used to characterize the land use and land cover of areas in this region, and the optimization algorithm was initiated from landscapes with these attributes.
Via a local search algorithm applied to the objective function, spatially rearranged landscapes were identified that improve biodiversity without having an adverse effect on agricultural activities. The new methodology resulted in several incremental improvements on previous approaches, including: (i) its ability to provide multiple, viable options to decision-makers for resolving conservation conflicts, (ii) its ability to provide an implementation strategy to obtain each of the viable options, and (iii) an evaluation system for comparing and contrasting the list of candidates. The method is presented in the context of a forest-grassland mosaic ecosystem, but is flexible by design in that it can be applied to any ecosystem, and easily adapted to fit the needs of decision-makers.
Local optimization approaches can be an effective planning tool, both on their own and in tandem with other approaches. Identifying the best possible global solution may be ideal, but it is not always possible to implement. Thus, alternative, good solutions that result from local approaches should be considered, especially when those solutions sustain more biodiversity than the initial landscape and provide a flexible implementation strategy.