Ecosystem services

ECOSYSTEM SERVICES

The products of ecosystem processes e.g. healthy forest ecosystems purify air and water, mitigate droughts and floods, cycle nutrients, generate fertile soils, provide wildlife habitat, maintain biodiversity, pollinate crops, provide storage site for carbon and also provide aesthetic, cultural and spiritual values.

– Researchers like Robert Constanza et. al., have put an average price tag of US $ 33 trillion a year on these fundamental ecological services (i.e. nearly twice the value of a global GNP -US $ 18 trillion).

– Out of total cost, soil formation accounts for about 50%, recreation and nutrient cycling less than 10% each, climate regulation and habitat for wildlife are about 6% each.

Some Important Definitions

1. Ecosystem: Sum total of interactions between living and non-living components which is capable of independent existence.

2. Stratification: Vertical distribution of different species occupying different levels in the community.

3. Gross primary productivity: Rate of organic matter synthesized by producers per unit area per unit time.

4. Net primary productivity: Rate of organic matter built up or stored by producers in their bodies per unit time and area.

5. Secondary productivity: Rate of increase in energy containing organic matter or biomass by heterotrophs or consumers per unit time and area.

6. Community productivity: Rate of net synthesis of built up of organic matter by a community per unit time and area.

7. Ecological efficiency: Percentage of energy converted into biomass by a higher trophic level over the energy of food resources available at the lower trophic level.

8. Decomposition: Breakdown of complex organic matter into inorganic substances with the help of decomposers.

9. Humification: Process of formation of humus from detritus.

10. Mineralisation: Release of inorganic substances from organic matter during the process of decomposition.

11. Food chain: Sequence of living organisms due to interdependence in which one organism consumes another.

12. Standing state: Amount of all the inorganic substances present in an ecosystem per unit area at a given time.

13. Standing crop: Amount of living material present in different trophic levels at a given time.

14. Ecological pyramid: Graphic representation of trophic levels of a food chain.

15. Nutrient cycling: Movement of nutrient elements through the various components of an ecosystem.

16. Ecological succession: Gradual and fairly predictable changes in the species composition of a given area.