Upload
ivy
View
20
Download
0
Tags:
Embed Size (px)
DESCRIPTION
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 - PowerPoint PPT Presentation
Citation preview
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 Service1912 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?TropicalTemperatePolar
Types of growth forests
Old Growth Forests:
uncut forests that have not been seriously disturbed for several hundred or thousands of years
Second Growth Forests:
stands of trees resulting from secondary ecological succession after cutting
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 high-quality 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.