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Nature, landscapes and biodiversity

What is the Mean Species Abundance (MSA)?

Question and Answer | 18-06-2015

A crucial question is whether the current trends of species biodiversity loss are likely to continue in the future. The lack of a quantitative overview of global species trends makes it difficult to project development trends into the future. To by-pass species biodiversity data problems, a pressure-based version of the Natural Capital Index (NCI) has been developed at the European and global levels, using a number of proximate drivers (or pressures) as a crude measure for ecosystem quality. These relationships between pressures and species abundance are based on extencive literature reviews.

Initially called NCI-pressure based, this indicator has been renamed Mean Species Abundance (MSA). The main difference between NCI and MSA is thus that NCI is mainly based on actual observations in a studied area, while the MSA uses relations between pressures and impacts on species abundance. The MSA can be caluculated with the GLOBIO model.

The NCI-pressure based and MSA have been used in various assessments reports amongst which UNEP's Global Environment Outlooks, CBD’s Global Biodiversity Outlook 2 and the OECD Environmental Outlook. The MSA has been accepted by the CBD as a possible indicator for the 2010 target.

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