Multi-criteria decision analysis for ecological restoration site-selection in an anthropogenic watershed

The Anthropocene has seen people become one of the largest drivers of change on our planet. Unfortunately, large-scale degradation of habitat caused by human-driven land use choices has led to a reduction in biodiversity persistence globally, where many native species lose out in competition for space against land uses such as monocrop agriculture. However, if we can carry out ecological restoration to bring back suitable habitat for imperiled species in even the most altered areas, we may hope to aid their survival. Though the question remains, where do we restore in these places, when there are few patches of habitat left to start from? In this work I try to answer this question in a strongly human-altered system, using publicly available data, and an approach which can combine both ecological and socioeconomic influences when deciding as to where do we restore? I used a method called Multi-Criteria Decision Analysis to combine data surrounding what current conditions are (e.g., distance to existing habitat patch), with those that describe what the barriers may be to restoring (e.g., value of land for agriculture), and also asked the same question of where to restore, but focused on where to conserve land in its current condition to compare outcomes. The resulting areas I identified were then modelled for how suitable they would be for a native species – the Northern Harrier. I showed that areas which appeared most suitable for both restoration and conservation clustered around watercourses and existing protected areas. If restored, then several thousand square kilometers of grassland and wetland might come to exist again in the study area. A theoretically restored landscape also held greater suitability for our chosen native species too. However, my research also showed that great care needed to be taken to choose appropriate decision criteria and justify their weight in the decision. Though challenging, questions of where to restore, in human-dominated landscapes are valuable, advocating for species which have lost much of their space to live.