A Framework for Identifying Reference Wetland Conditions in Highly Altered Landscapes

This paper arose from collaboration and discussions over the past years between the authors about what wetlands should be restored to in landscapes that have been intensively altered due to human activities over many centuries and where reference conditions are lacking. It is not intended as an in-depth review of the thinking about reference conditions, but as an opinion paper, with the goal of stimulating discussions about wetland restoration approaches, particularly in regions around the world with highly altered landscapes where restoration of wetlands has been gaining traction only relatively recently. We first explain why the thinking on reference wetlands is biased towards North America, where large areas exist with wetlands that are relatively unimpacted by anthropogenic activities. We then argue that in regions with few unimpaired wetlands those of fair condition may still be good enough to be used as reference wetlands, and that restored and created wetlands should be considered as well.