Mangroves (and Roseate Spoonbill Ajaia ajaja)Image © Laura Erickson
As a species, we rely heavily on what are termed ecosystem services
to survive. These services are in effect the resources and processes provided by natural ecosystems, classic examples that are frequently cited are those of water purification and pollination.
As a rule, these services can be grouped into a number of different types:
- Provisioning services - for instance, foods, energy sources
- Regulating services - for instance, carbon-fixing, waste decomposition
- Supporting services - for instance, pollination, filtration of water
- Cultural services - for instance, recreational importance, spiritual needs
- 'Preserving services' - for instance, maintaining a wide gene pool
Ecosystem services have rarely been seen as having a major economic benefit traditionally, yet the importance of pollination, waste decomposition or water purification, for example, is hard to ignore. The value of some services is sometimes only appreciated after they have been disrupted: the value of mangroves (pictured here) and offshore 'barrier islands' in dissipating the force of hurricanes has been highlighted through the impacts of the recent tsunami in south Asia and hurricane Katrina[1]. The problem has been valuing these services in terms that economists and decision-makers can understand.
The importance of biodiversity in maintaining a healthy, functioning ecosystem is generally considered to be high. A biologically diverse ecosystem is likely to be more stable than a less diverse system, the idea being that different species respond in a different manner and to a different degree to an environmental perturbation; hence diversity confers the ability to absorb 'shocks' more effectively.