Summary Of Global Forest And Environment Handout
→IMPORTANCE OF FORESTS •Forests play a role indispensable for life on earth by absorbing carbon dioxide and fixing carbon while releasing oxygen into air through Photosynthesis, particularly, tropical forests absorb almost 2-3 times as much carbon dioxide as temperate forests and have thus been called ‘the lungs of our planet’ •Conservation of water resources •Prevention of disasters •Supplying forest products •Sheltering Rich Ecosystems Wholesome influence of forest on environment:
a.) During the hottest day of the year the temperature in a forest than outside the forest could be 5˚F lower;
b.) In light intensity, a forest canopy intercepts 50% to 70% of the light from reaching the ground;
c.) The relative humidity of the air within a forest is 3%-10% higher than outside;
d.) During rainfall, the crowns of trees in a thick forest may intercept as much as 10%-30% of the precipitation; that part of the rainwater that wets the surface of the leaves and branches is evaporated back to atmosphere;
e.) Of the rainwater that falls directly to the ground, or slides down the branches and trunks, all could be soaked and absorbed by the forest litter and humus if the rainfall is light; if rainfall is heavier, a part of the rainwater sinks to the ground the root network; if the rain is very heavy and the forest litter and soil have reached their saturation point, the excess water becomes the runoff that flows down slope;
f.) The quantity of water that becomes the runoff or stream flow is the total volume of rainfall minus all the water losses due to interception, evaporation, transpiration and seepage;
g.) The humus of forest soil is so porous that it can absorb and hold water double its weight; the surface of the forest floor will retain water from one to five times its dry weight;
h.) More springs are found on forested areas, or starts from forested lands, than in deforested areas; streams and rivers from undisturbed forests are generally clear and
a.) During the hottest day of the year the temperature in a forest than outside the forest could be 5˚F lower;
b.) In light intensity, a forest canopy intercepts 50% to 70% of the light from reaching the ground;
c.) The relative humidity of the air within a forest is 3%-10% higher than outside;
d.) During rainfall, the crowns of trees in a thick forest may intercept as much as 10%-30% of the precipitation; that part of the rainwater that wets the surface of the leaves and branches is evaporated back to atmosphere;
e.) Of the rainwater that falls directly to the ground, or slides down the branches and trunks, all could be soaked and absorbed by the forest litter and humus if the rainfall is light; if rainfall is heavier, a part of the rainwater sinks to the ground the root network; if the rain is very heavy and the forest litter and soil have reached their saturation point, the excess water becomes the runoff that flows down slope;
f.) The quantity of water that becomes the runoff or stream flow is the total volume of rainfall minus all the water losses due to interception, evaporation, transpiration and seepage;
g.) The humus of forest soil is so porous that it can absorb and hold water double its weight; the surface of the forest floor will retain water from one to five times its dry weight;
h.) More springs are found on forested areas, or starts from forested lands, than in deforested areas; streams and rivers from undisturbed forests are generally clear and