Vital GEO Graphics

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Defining and measuring biodiversity

Biodiversity as defined by the Convention on Biological Diversity encompasses the diversity of genes, species and ecosystems. One terrestrial measure of species-level diversity is the average remaining abundance of each individual species belonging to an ecosystem, or “mean original species abundance” (MSA). MSA represents the remaining abundance of native species, relative to

a natural state. For example, if a forest is cleared, then the MSA is based on the surviving forest species. MSA is modelled on a relative scale from 0 per cent (ecosystem destroyed) to 100 per cent (ecosystem intact).

Mean species abundance in 2000

< 50% 50–60% 60–70% 70–80% 80–90% 90–100% Mean species abundance index (2000)

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Harmful effects of ecosystem changes on human health

Environmental changes, loss of biodiversity, and ecosystem impairment

Examples of health impacts

1 Direct health impacts

FLOODS, HEATWAVES, WATER SHORTAGE, LANDSLIDES, EXPOSURE TO POLLUTANTS

LOSS OF SPECIES AND GENETIC RESOURCES

LAND DEGRADATION AND DESERTIFICATION

Note: This figure describes the causal pathway from escalating

2 “Ecosystem-mediated” health impacts

FOREST CLEARANCE AND LAND COVER CHANGE

ALTERED INFECTIOUS DISEASE RISK, REDUCED FOOD FIELDS (MALNUTRITION, STUNTING), DEPLETION OF NATURAL MEDICINES, MENTAL HEALTH (PERSONAL, COMMUNITY), IMPACTS OF AESTHETIC/CULTURAL IMPOVERISHMENT

Escalating human pressure on global environment

human pressures on the environment through to

WETLANDS LOSS AND DAMAGE

ecosystem changes resulting in diverse health consequences. Not all ecosystem changes are included. Some changes can have positive effects (such as food production).

FRESHWATER DEPLETION AND CONTAMINATION

3 Indirect, deferred, and displaced health impacts

URBANIZATION AND ITS IMPACTS

DIVERSE HEALTH CONSEQUENCES OF LIVELIHOOD LOSS, POPULATION DISPLACEMENT (INCLUDING SLUM DWELLING), CONFLICT, INAPPROPRIATE ADAPTATION AND MITIGATION

DAMAGE TO COASTAL REEFS AND ECOSYSTEMS

Source: Adapted from WHO 2005

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