Vital Forest Graphics

of ecological services

Flood protection Forests can also protect against flooding. While forest cover will not appreciably reduce the total amount of water moving into water courses from a large storm event, they can influence the degree of flooding and flood dam- age (FAO 2008c). Mangrove forests occur naturally in intertidal zones along sheltered shore- lines and in deltas in tropical regions. They are vital breeding grounds for fish and shrimp and also provide a buffer against coastal hazards such as storms, cyclones, wind and salt spray by reduc- ing wind and wave action (Braatz et al. 2007). Evidence collected in Thailand and Sri Lanka following the 2004 Indian Ocean tsunami showed that the loss of life was lower where mangrove and other coastal forests remained intact (Forbes and Broadhead 2008). A con- tributing factor in the loss of life and property resulting from cyclone Nargis in Myanmar in May 2008 is believed to have been the destruction of mangrove forests, in particular in the Irrawaddy Delta where the area of mangrove for- est had been reduced to less than half its level in 1975 (Kinver 2008). Micro climate The micro-climate associated with forest areas is often a critical factor in growing cash crops. In East Africa, tea is grown in areas adjacent to mon- tane forests where conditions for tea production are optimal due to con- stant moisture levels, air temperatures between 10° and 30° C and soil tem- peratures between 16° and 25° C. The high moisture levels in these montane

Tea production area and forest distribution in Kenya

Forests regulate groundwater level

forests combined with the high heat capacity of water reduces the day/night temperature range and lowers the chances of frost. In Indonesia, areas close to the for- ests in the Kerinci-Seblat National Park in Sumatra are among the best places in the world to grow cinnamon due both to the relatively cold climate and rich local volcanic soils (World Bank 2007). These examples help to illustrate how humans and production cycles depend on regulatory services pro-

vided by forests. They also highlight the importance of securing these serv- ices – for too long taken for granted. Methods of economic valuation are progressively enabling the incorporat- ing of these services into cost-benefits analysis and helping to make forest conservation not only economically feasible but also desirable.

See also pages 56 & 60

VITAL FOREST GRAPHICS 33