Strengthening the Scientific Basis of Ecosystem Collapse Risk Assessments

Adrian C Newton

doi:10.3390/land10111252

Abstract

Progress is being made in assessing the conservation status of ecosystems, notably through initiatives such as the IUCN Red List of Ecosystems (RLE) and the NatureServe Conservation Status Assessment (NCS). Both of these approaches consider conservation status in terms of the risk of ecosystem collapse. However, the scientific understanding of ecosystem collapse is still at a relatively early stage. Consequently, concerns have been raised regarding the scientific basis of ecosystem conservation assessments focusing on collapse risk. Here I explore how these concerns might potentially be addressed by considering how the concept is defined, and by briefly reviewing the theoretical basis of ecosystem collapse. I then examine the implications of recent research results for the design of ecosystem collapse risk assessments, and the challenges identified in those assessments conducted to date. Recommendations are made regarding how collapse risk assessments might be strengthened based on current scientific understanding, and how this understanding could be improved by further research. In addition, I examine the potential implications for conservation policy and practice if the scientific basis of collapse risk assessments is not strengthened in this way.

Highlights

As a partner of the IUCN Red List, NatureServe has latterly sought to align its ecosystem assessment approach with that of the Red List of Ecosystems (RLE), which accounts for the common reference to ecosystem collapse among their assessment categories [4,11]
This suggested definition differs from that developed by the RLE in a number of additional ways: (i) it does not require replacement by a different ecosystem type; it could just refer to a loss of defining features, without necessarily involving a transformation of identity; (ii) it could be applied to individual occurrences of an ecosystem, such as those located within a particular area, and is more applicable for use at a local scale; (iii) it explicitly requires that collapse is persistent, precluding the possibility of recovery within decadal timescales
To provide a stronger scientific basis for the criteria and thresholds used in collapse risk assessments, Boitani et al [21] suggest that a general theory is needed that links ecosystem reduction to collapse, which is applicable at all scales and to all ecological systems

Summary

Change the Endpoint

Both the RLE and NCS include “Collapsed” as an assessment category, to signify the endpoint of a process of ecosystem degradation and loss. This suggested definition differs from that developed by the RLE in a number of additional ways: (i) it does not require replacement by a different ecosystem type; it could just refer to a loss of defining features, without necessarily involving a transformation of identity; (ii) it could be applied to individual occurrences of an ecosystem, such as those located within a particular area, and is more applicable for use at a local scale; (iii) it explicitly requires that collapse is persistent, precluding the possibility of recovery within decadal timescales. This terminology would be consistent with the definition of the endpoint developed by the RLE (Table 1)

Strengthen Links with Theory

Identify and Address Knowledge Gaps

Share and Communicate Challenges

Conclusions