The core of the GLOBIO model is a set of empirical cause-effect relationships, describing the impact of the environmental drivers on biodiversity.
The drivers in GLOBIO-Aquatic are:
For each driver the cause-effect relationship is based on a quantitative synthesis of peer-reviewed literature. These so-called meta-analyses aim to distill the ‘overall’ trend from the available studies, acknowledging the often large variability between individual cases.
Nearly 100 empirical studies were used on species composition in disturbed and undisturbed situations. Major species groups covered by these studies are plants, fish, macro-invertebrates and algae. In a few cases the studies focus on birds, mammals or amphibians. For each study, values for the biodiversity indicator MSA were calculated in four steps:
Note that individual species responses are not modelled in GLOBIO. MSA represents the average response of the total set of species belonging to an ecosystem.
The approach taken is the same for GLOBIO-Aquatic and GLOBIO-Terrestrial.