Env. Science Chpt 6: Env Conservation, Forests, grasslands, parks, and nature preserves

Forest

area where trees cover > 10% of land

Coniferous Forest (europe asia)

Largest overall tract

Amazon (South America)

Largest tropical Tract

old-growth forests

forest that has been relatively undisturbed by humans, has old trees; 25% still retain these charcteristics

Wood

plays a part in more activities of the modern economy than any other commodity

Developed Countries

produce less than half of all industrial wood, but account for about 80% of consumption

Managed Forests

where much of industrial logging in North America and Europe occur

Forestry

growth and harvest of trees as a commercial product

Heating and cooking fuel

firewood and charcoal serve as the main source

Deforestation

removal of trees w/o replacement

Sustainable harvest

key to regeneration; involves monoculture forestry

monoculture forestry

large plantations of single-species, single-use, intensive cropping

Tropical Forests

less than 10% of earths land surface; contain more than 2/3rds of higher plant biomass;at least 1/2 of plant, animal, and microbial species in world

Causes of Deforestation

Logging (for timber), CONVERSION TO AGRICULTURE, nutrient-poor tropical soils getting worn out, shifting cultivation, etc

Protection of Tropical Forests

12% of forests protected, involve local citizens, promote sustainable benefits to forest, dont buy products grased in rainforest

Northern Countries

they have a long history of liquidating forest resources

Old-Growth Temerpate forests

less than 10% remain; 80% of what is left is scheduled to be cut down in the near future

Clearcutting

harvest of all trees

clearcut w/reserves

patches of trees left standing

shelterwood harvesting

single "seed trees" left standing for several years then harvested later

strip cutting

trees cut in successive strips at different times

selective harvesting

scattered trees or small groups are harvested

overgrazing

causes erosion, loss of native forage species, and even desertification in arid areas

Rangelands

Grasslands and open woodlands suitable for livestock grazing