4.2 Water and soil resources loss a

4.2 Water and soil resources loss and flooding
Deforestation also disrupts the global water cycle (Bruijnzeel, 2004). With removal of part of the forest, the area cannot hold as much water creating a drier climate. Water resources affected by deforestation include drinking water, fisheries and aquatic habitats, flood/drought control, waterways and dams affected by siltation, less appealing waterrelated recreation, and damage to crops and irrigation systems from erosion and turbidity (Anon., 1994a ; Bruijnzeel et al., 2005). Urban water protection is potentially one of the most important services that forest provides (Chomitz et al., 2007). Filtering and treating water is expensive. Forests can reduce the costs of doing so either actively by filtering runoff or passively by substituting for housing or farms that generate runoff (Dudley and Stolton, 2003). Deforestation can also result into watersheds that are no longer able to sustain and regulate water flows from rivers and streams. Once they are gone, too much water can result into downstream flooding, many of which have caused disasters in many parts of the world. This downstream flow causes soil erosion thus also silting of water courses, lakes and dams. Deforestation increases flooding mainly for two reasons. First, with a smaller ‘tree fountain’ effect, soils are more likely to be fully saturated with water. The ‘sponge’ fills up earlier in wet season, causing additional precipitation to run off and increasing flood risk. Second, deforestation often results in soil compaction unable to absorb rain. Locally, this causes a faster response of stream flows to rainfall and thus potential flash flooding (Chomitz et al., 2007). Moreover deforestation also decrease dry season flows.
The long term effect of deforestation on the soil resource can be severe. Clearing the vegetative cover for slash and burn farming exposes the soil to the intensity of the tropical sun and torrential rains. Forest floors with their leaf litter and porous soils easily accommodate intense rainfall. The effects of deforestation on water availability, flash floods and dry season flows depend on what happens to these countervailing influences of infiltration and evapotranspiration- the sponge versus the fountain (Bruijnzeel, 2004).
Deforestation and other land use changes have increased the proportion of the basin subject to erosion and so over the long run have contributed to siltation. Heavy siltation has raised the river bed increasing the risk of flooding especially in Yangtze river basin in China, the major river basins of humid tropics in East Asia and the Amazonian basin (Yin and Li, 2001; Bruijnzeel, 2004; Aylward, 2005, Bruijnzeel et al., 2005; van Noordwijk et al., 2006).
4.3 Decreased biodiversity, habitat loss and conflicts
Forests especially those in the tropics serve as storehouses of biodiversity and consequently deforestation, fragmentation and degradation destroys the biodiversity as a whole and
habitat for migratory species including the endangered ones, some of which have still to be
catalogued. Tropical forests support about two thirds of all known species and contain 65
per cent of the world’s 10, 000 endangered species (Myers and Mittermeier, 2000). Retaining
the biodiversity of the forested areas is like retaining a form of capital, until more research
can establish the relative importance of various plants and animal species (Anon., 1994a ). According to the World Health Organization, about 80 per cent of the world’s population relies for primary health care at least partially on traditional medicine. The biodiversity loss and associated large changes in forest cover could trigger abrupt, irreversible and harmful changes. These include regional climate change including feedback effects that could theoretically shift rainforests to savannas and the emergence of new pathogens as the growing trade in bushmeat increases contact between humans and animals (Anon., 2005).

Hasil (Melayu) 1:

4.2 air dan kehilangan sumber tanah dan banjirDeforestation also disrupts the global water cycle (Bruijnzeel, 2004). With removal of part of the forest, the area cannot hold as much water creating a drier climate. Water resources affected by deforestation include drinking water, fisheries and aquatic habitats, flood/drought control, waterways and dams affected by siltation, less appealing waterrelated recreation, and damage to crops and irrigation systems from erosion and turbidity (Anon., 1994a ; Bruijnzeel et al., 2005). Urban water protection is potentially one of the most important services that forest provides (Chomitz et al., 2007). Filtering and treating water is expensive. Forests can reduce the costs of doing so either actively by filtering runoff or passively by substituting for housing or farms that generate runoff (Dudley and Stolton, 2003). Deforestation can also result into watersheds that are no longer able to sustain and regulate water flows from rivers and streams. Once they are gone, too much water can result into downstream flooding, many of which have caused disasters in many parts of the world. This downstream flow causes soil erosion thus also silting of water courses, lakes and dams. Deforestation increases flooding mainly for two reasons. First, with a smaller ‘tree fountain’ effect, soils are more likely to be fully saturated with water. The ‘sponge’ fills up earlier in wet season, causing additional precipitation to run off and increasing flood risk. Second, deforestation often results in soil compaction unable to absorb rain. Locally, this causes a faster response of stream flows to rainfall and thus potential flash flooding (Chomitz et al., 2007). Moreover deforestation also decrease dry season flows. The long term effect of deforestation on the soil resource can be severe. Clearing the vegetative cover for slash and burn farming exposes the soil to the intensity of the tropical sun and torrential rains. Forest floors with their leaf litter and porous soils easily accommodate intense rainfall. The effects of deforestation on water availability, flash floods and dry season flows depend on what happens to these countervailing influences of infiltration and evapotranspiration- the sponge versus the fountain (Bruijnzeel, 2004).Deforestation and other land use changes have increased the proportion of the basin subject to erosion and so over the long run have contributed to siltation. Heavy siltation has raised the river bed increasing the risk of flooding especially in Yangtze river basin in China, the major river basins of humid tropics in East Asia and the Amazonian basin (Yin and Li, 2001; Bruijnzeel, 2004; Aylward, 2005, Bruijnzeel et al., 2005; van Noordwijk et al., 2006).4.3 Decreased biodiversity, habitat loss and conflictsForests especially those in the tropics serve as storehouses of biodiversity and consequently deforestation, fragmentation and degradation destroys the biodiversity as a whole andhabitat for migratory species including the endangered ones, some of which have still to becatalogued. Tropical forests support about two thirds of all known species and contain 65per cent of the world’s 10, 000 endangered species (Myers and Mittermeier, 2000). Retainingthe biodiversity of the forested areas is like retaining a form of capital, until more researchcan establish the relative importance of various plants and animal species (Anon., 1994a ). According to the World Health Organization, about 80 per cent of the world’s population relies for primary health care at least partially on traditional medicine. The biodiversity loss and associated large changes in forest cover could trigger abrupt, irreversible and harmful changes. These include regional climate change including feedback effects that could theoretically shift rainforests to savannas and the emergence of new pathogens as the growing trade in bushmeat increases contact between humans and animals (Anon., 2005).