The dark side of the “redundancy hypothesis” and ecosystem assessment

Integrating Ecology into Land Planning and Development: Between Disillusionment and Hope, Questioning the Relevance and Implementation of the Mitigation Hierarchy

Scientific research on the mitigation hierarchy has steadily increased over the past few years at the international level. While some seek to improve the application of this public action instrument, others point out its shortcomings and risks. This opinion paper—which focuses on the French context—does not provide an exhaustive overview of existing research but instead targets specific issues considered to be a “priority”. We mainly investigate the relevance and implementation of the mitigation hierarchy, especially from an ecological point of view. Part of this paper thus questions the very principle of biodiversity offsetting (BO)—the last resort of the mitigation hierarchy that brings together numerous controversies—and the adequacy of the mitigation hierarchy with the objective of no net loss (NNL) of biodiversity. The general idea underlying this paper is to show how the mitigation hierarchy has been built and based on what values (mainly economic and legal, which leads us to conclude about the lack of ecology in the policy itself). In doing so, we provide a few perspectives as to what should be done to (better) integrate ecology into land use planning and development.

Ecosystem services show variable responses to future climate conditions in the Colombian páramos

Background

The páramos, the high-elevation ecosystems of the northern Andes, are well-known for their high species richness and provide a variety of ecosystem services to local subsistence-based communities and regional urbanizations. Climate change is expected to negatively affect the provision of these services, but the level of this impact is still unclear. Here we assess future climate change impact on the ecosystem services provided by the critically important páramos of the department of Boyacá in Colombia, of which over 25% of its territory is páramo.

Methods

We first performed an extensive literature review to identify useful species of Boyacá, and selected 103 key plant species that, based on their uses, support the provision of ecosystem services in the páramos. We collated occurrence information for each key species and using a Mahalanobis distance approach we applied climate niche modelling for current and future conditions.

Results

We show an overall tendency of reduction in area for all ecosystem services under future climate conditions (mostly a loss of 10% but reaching up to a loss of 40%), but we observe also increases, and responses differ in intensity loss. Services such as Food for animals, Material and Medicinal, show a high range of changes that includes both positive and negative outcomes, while for Food for humans the responses are mostly substantially negative. Responses are less extreme than those projected for individual species but are often complex because a given ecosystem service is provided by several species. As the level of functional or ecological redundancy between species is not yet known, there is an urgency to expand our knowledge on páramos ecosystem services for more species. Our results are crucial for decision-makers, social and conservation organizations to support sustainable strategies to monitor and mitigate the potential consequences of climate change for human livelihoods in mountainous settings.