Exam 2 Review: ch 8-10, 12, 13, 15

• cover 31% of land • occur mostly as boreal and tropical rainforests • ecologically complex

upper level (treetops)

middle portion, beneath the crowns

shaded region; houses shrubs, small trees, groundcover

• soil stability prevents erosion & slows runoff • produces O2 & stores CO2 • purifies water & supports biodiversity

today, most deforestation occurs in ___, ___, and ____.

forest cleared for cattle ranching & soybean farming to supply US demand

oil palm plantations have displaced more than 22 million acres of rainforest

occurs when land is cleared due to logging, agriculture, or urban development - edge affects are amplified and percentage of forest interior is reduced

conservation concession & debt-for-nature swap are both_____

conservation group leases land but keeps in forested

conservation group agrees to pay off some of a developing nation’s debt, or a wealthy nation agrees to forgive a certain amount of debt, in exchange for a promise to keep forests intact

maximizes the amount of resource harvested while sustaining it in perpetuity

the clearing and loss of forests due to the removal of trees quicker than they can regrow

occurs more rapidly in developing nations because of the need to expand quickly, powerful industrial tech, and growing populations

changes in population or community structures that occur at the boundary of two habitats - conditions along the edges differ from those in the interior

species composition predation and parasitism species loss –> loss in biodiversity

microclimate changes soil and vegetation alter ecological processes

• clear cutting • seed-tree/ shelterwood • selection

most cost-effective timber harvesting method

cost efficient, but with severe ecological consequences

timber harvesting method with smallest ecological impact

small number of seed-producing trees are left to reseed the area; provide shelter for growing seedlings

widely spaced trees cut singly or in small patches - most expensive method with more safety risks