what are the protective functions of a forest
Answers
Answered by
1
Protective function - the forest has a stabilising effect onthe natural environment (water circulation, precipitation, aircirculation, temperature, global and micro-climate, soil erosion prevention)
Answered by
0
The world’s forests have many protective functions, some local and some global.
Influence on climate. Forests affect climate globally by reflecting less heat back into the atmosphere than other types of land use that have more bare soil and less green cover. They also play a very significant role in the global carbon cycle that affects global climate change. Locally, in both cities and rural areas, trees provide shade and absorb heat energy, producing a cooling effect. During the cold season, they obstruct, filter and deflect wind, reducing wind chill. Windbreaks of trees can reduce evaporative losses from small water bodies. These functions of reducing wind velocity, moderating soil temperature and increasing relative humidity are also beneficial in agroforestry systems (Vergara and Briones, 1987).
Protection from wind erosion. Wind-rows and shelterbelts reduce the loss of nutrient-rich topsoil and protect young plants from wind within their zone of influence. They also help stabilize dunes.
Coastal protection. Coastal forests, particularly mangroves, reduce shoreline erosion and siltation and the impacts of storm surges and tsunamis. Mangroves also filter and remove some of the nutrients and heavy metals coming from upstream land uses and industry, immobilizing them in the mud – as long as they prove non-toxic to the mangroves themselves (Wharton et al., 1976). Salt-spray barriers of salt-tolerant trees have been planted along windward coasts to protect crops.
Protection from avalanches. The Alpine countries in Europe have had much experience with protection from snow avalanches by forests and have many forests designated for this purpose. As more tourism and infrastructure enter the mountain areas of other countries, this function of forests should be increasingly recognized.
Air-pollution filters. Trees perform a valuable role in intercepting and trapping windborne particulate matter – again, as long as the pollution does not damage or kill them. This is one of the benefits of urban forests and greenbelts. Dust, ash, pollen and smoke that adversely affect human health and visibility can be ‘raked’ from the atmosphere, then washed to the ground by rainfall or snow.
Protecting water resources. Forests protect water by reducing surface erosion and sedimentation, filtering water pollutants, regulating water yield and flow, moderating floods, enhancing precipitation (e.g. ‘cloud forests’) and mitigating salinity. Additional information on forests and water is presented in a separate thematic study.
Many countries have identified forest areas that serve a protective function and have given them special status, e.g. avalanche protection, watershed reserve, natural catchment area or multiple-use management area. Maintenance of these environmental services, including protective functions, looms large among the management objectives of the IUCN Category System for Protected Areas (1994). This is the system of nomenclature most widely accepted and adopted throughout the world (Table 6.1), and efforts are underway to determine how it can be appropriately applied to the protective functions of the forest estate.
Forests in all categories, whether they be in national parks or marine/coastal reserves, perform some of the protective functions discussed above. For example, a watershed reserve might fall within Category I (Strict Protection) or Category VI (Managed Resource Protection Area). Yet not all protected areas have protection of soil and water as their main objective. Many are primarily established for the conservation of biological diversity or natural/cultural features. Conversely, some forests that have protection as their primary management objective may not form part of a protected area network, e.g. plantations established to combat desertification. The area of forest in protected areas is thus not necessarily a good measure of the protective functions of forests.
Influence on climate. Forests affect climate globally by reflecting less heat back into the atmosphere than other types of land use that have more bare soil and less green cover. They also play a very significant role in the global carbon cycle that affects global climate change. Locally, in both cities and rural areas, trees provide shade and absorb heat energy, producing a cooling effect. During the cold season, they obstruct, filter and deflect wind, reducing wind chill. Windbreaks of trees can reduce evaporative losses from small water bodies. These functions of reducing wind velocity, moderating soil temperature and increasing relative humidity are also beneficial in agroforestry systems (Vergara and Briones, 1987).
Protection from wind erosion. Wind-rows and shelterbelts reduce the loss of nutrient-rich topsoil and protect young plants from wind within their zone of influence. They also help stabilize dunes.
Coastal protection. Coastal forests, particularly mangroves, reduce shoreline erosion and siltation and the impacts of storm surges and tsunamis. Mangroves also filter and remove some of the nutrients and heavy metals coming from upstream land uses and industry, immobilizing them in the mud – as long as they prove non-toxic to the mangroves themselves (Wharton et al., 1976). Salt-spray barriers of salt-tolerant trees have been planted along windward coasts to protect crops.
Protection from avalanches. The Alpine countries in Europe have had much experience with protection from snow avalanches by forests and have many forests designated for this purpose. As more tourism and infrastructure enter the mountain areas of other countries, this function of forests should be increasingly recognized.
Air-pollution filters. Trees perform a valuable role in intercepting and trapping windborne particulate matter – again, as long as the pollution does not damage or kill them. This is one of the benefits of urban forests and greenbelts. Dust, ash, pollen and smoke that adversely affect human health and visibility can be ‘raked’ from the atmosphere, then washed to the ground by rainfall or snow.
Protecting water resources. Forests protect water by reducing surface erosion and sedimentation, filtering water pollutants, regulating water yield and flow, moderating floods, enhancing precipitation (e.g. ‘cloud forests’) and mitigating salinity. Additional information on forests and water is presented in a separate thematic study.
Many countries have identified forest areas that serve a protective function and have given them special status, e.g. avalanche protection, watershed reserve, natural catchment area or multiple-use management area. Maintenance of these environmental services, including protective functions, looms large among the management objectives of the IUCN Category System for Protected Areas (1994). This is the system of nomenclature most widely accepted and adopted throughout the world (Table 6.1), and efforts are underway to determine how it can be appropriately applied to the protective functions of the forest estate.
Forests in all categories, whether they be in national parks or marine/coastal reserves, perform some of the protective functions discussed above. For example, a watershed reserve might fall within Category I (Strict Protection) or Category VI (Managed Resource Protection Area). Yet not all protected areas have protection of soil and water as their main objective. Many are primarily established for the conservation of biological diversity or natural/cultural features. Conversely, some forests that have protection as their primary management objective may not form part of a protected area network, e.g. plantations established to combat desertification. The area of forest in protected areas is thus not necessarily a good measure of the protective functions of forests.
Similar questions