Transcript Chapter 23
Wildlife and Ecosystems Chapter 23 Sustain Ecosystems: Land Use Conservation Management Land Use Frontier World view-They saw a hostile Wilderness to be conquered and exploited for its resources as quickly as possible 1850 80% of the total land area of the territorial U.S. was government owned • 1872 Yellow Stone National Park • Between 1870 and 1900 began concern of environmental degradation Land Use 1903 First Federal Refuge at Pelican Island 1905 Created the U.S. Forest Service 1912 Congress Created the U.S. National Park Land Use Between 1900 and 1927 public health boards were created in most cities Era of Roosevelt new time of national resource conservation Bought land for cheap from cash-poor landowners Taylor Grazing Act of 1934 required permits and fees for the use of grazing lands Environmental Developments Migratory Bird Hunting Stamp Act of 1934 Soil conservation Service 1935 U.S. Fish and Wild Life Service Silent Spring Books about air pollution like DDT 1964 wilderness Act 1973 Ban of oil Shipments to the U.S. Environmental Developments 1980’s Reagan was against conservation He greatly increased private energy and mineral development and timber cutting on public lands Conservation Biodiversiyt and ecological integrity are necessary to all life on earth and should not be reduced by human actions Public Lands Multiple Use lands Principle of sustainable yield Principle of multiple use Moderately Restricted-Use Lands Restricted-Use Lands Managing and Sustaining Rangelands Land that supplies forage or vegetation for grazing and browsing animals and that is not intensively managed Overgrazing occurs when too many animals graze for too long and exceed the carrying capacity of grassland area Riparian zones- thin strips of lush vegetation along streams To manage rangelands to maximize livestock productivity without overgrazing rangeland overgrazing National Parks Cause of increased popularity is one of the biggest problems of national parks They are way under staffed National Park Management Require integrated management plans for parks and other nearby federal lands Increase the budget for adding new parkland near the most threatened parks Increase the budget for buying private lands inside parks Land Management Map Existing natural Vegetation Map Distribution of native vertebrate species Map public land ownership and private conservation lands Show the current network of conservation lands Chapter 24 Sustaining ecosystems: Deforestation, Biodiversity, and Forest Management photo2.si.edu/turtles/ forest.html What are the major types of Forests? Tropical Temperate Polar Types of growth forests Old Growth Second Growth Forests: Forests: uncut forests that stands of trees have not been resulting from seriously secondary disturbed for ecological several hundred succession after or thousands of cutting years Economic Importance of Forests Lumber for housing, biomass for fuelwood, pulp for paper, medicines, mining, grazing livestock, and recreation up to $300 billion a year in supplies Ecological Importance of Forests Regulate the flow of water from mountain highlands to croplands and urban areas influence climate vital to global carbon cycle provides oxygen, air purification, soil fertility, erosion control, water recycling, and humidity control How Rapidly are Old-Growth Forests being Cleared? 85-95% of the temperate-zone old growth forests have been cleared away since the mid-1960’s, a large amount of old growth forests have been cleared away and replaced with tree plantations most of remaining old-growth forests are in fragmented sections on U.S. public lands in Washington, Oregon, and northern CA Old Growth Forests http://www.colorado.edu/communication/meta-discourses/Theory/burke/img005.gif How fast are Tropical Forests being cleared and degraded? Mature tropical forests once covered at least twice as much area as they do today Between 1960 and 1990, 1/5 of all tropical forest cover was lost 40% of current tropical deforestation is taking place in South America rates of deforestation in Southeast Asia and Central America are 2.7 times higher than those in South America Tropical Forests What Causes Tropical Deforestation? Population growth poverty government policies Degradation of Tropical Forests http://www.rcfa-cfan.org/english/issues.12-3.html Reducing Tropical Deforestation and Degradation Conservation biologists suggest quickly protecting areas of tropical forests that have many unique species; called hot spots environmentalists push governments to reduce the amount of poor in forests by slowing population growth and stopping poor from migrating to tropical forests use economic policies to protect and sustain tropical forests Debt-for-nature swaps and conservation easements Fuelwood Crisis in Developing Countries 1998-2.2 billion people in 63 developing countries could not get enough fuelwood to meet their basic needs or were forced to meet their needs by using wood faster than it was replenished fuelwood scarcity places a burden on the rural poor, especially women and children buying fuelwood or charcoal can take 40% of a poor family’s income Solutions for Fuelwood Crisis Planting more fast-growing fuelwood trees or shrubs and burning wood more efficiently placing emphasis on community woodlots encourage villagers to use the sun-dried roots of gourds and squashes as cooking fuel solar ovens Major Types of Forest Management Even-aged management: goal is to grow and harvest trees using monoculture techniques begins with 1 or 2 cuttings and is then replanted with seedlings Uneven-aged management: variety of tree species in given stand are maintained at many ages and sizes to foster natural regeneration goals are biological diversity, long-term production of highquality timber, reasonable economic return, and multiple use Ways Trees are Harvested Selective cutting Shelterwood cutting Seed-Tree cutting clear-cutting strip cutting whole-tree harvesting Forest Fires Surface Fires Crown Fires ground fires moosehorn.fws.gov/ Forest_Management.htm Protecting forest resources Prevention, prescribed burning- setting controlled ground fires for prevention presuppression-early detection and control of fires suppression-fighting fires once they have already started Chapter 25 Sustaining Wild Species The Importance of Wild Species They provide many of the ecological services that make up earth capital. They help sustain the earth’s biodiversity and ecological integrity. Preservation is important because most people believe that each wild species has an inherent right to exist, or to struggle to exist. Passenger Pigeon: Gone Forever It was said that in the 1800s the passenger pigeon flocked in groups up to 2 billion strong, but by 1914 the species was extinct. Who is to blame? Humans Who Is Responsible? Passenger pigeons were: Good to eat Good to make pillows out of Used for fertilizer Easy to kill Is There an Extinction Crisis? It is hard to tell because there is such a wide range of species (Between 5 and 100 million species) It is difficult to observe species extinction, especially if it is a species we know little about A species is considered extinct when it hasn’t been seen for 50 years. Types of Extinction Local Extinction- When a species is no longer found in an area it once inhabited but is still found elsewhere. Ecological Extinction- When there are so few members of a species left that it can no longer play its ecological roles in biological communities. Types of Extinction (Cont.) Biological Extinction- When a species is no longer found anywhere on the earth. Endangered and Threatened An endangered species has so few individual survivors that the species could soon become extinct. A threatened species is still abundant in its natural range but is declining in numbers and is likely to become endangered.