Environmental Science Chapter 12
• Landscape ecologists measure variables such as:
Habitat size Shape Relative amount of core and edge Kinds of land cover surrounding habitat
ENESCO (1986)
"Man and Biosphere" program (MAB) calling for the establishment of biosphere reserves, protected areas divided into zones with different purposes.
12%
% of Earth's land area is protected in a park, preserve, or wildlife management area
90%
% of coral reefs are threatened by rising temperatures, destructive fishing, coral mining and sediment runoff --- If conditions persist all will be gone if 50 years
Causes for Deforestation
- Conversion of forest to agriculture - Large Scale Commercial Logging - Fires - Biofuel production
Forests
- Cover 30% of land surface - Most forests are in tropical and boreal regions - Defined as an area where trees cover more than 10% of the land, (this ranges from the Open Savannas to closed canopy forests)
Overuse of National Parks in U.S.
- Entertainment trumped nature protection -Fire suppression resulted in large fires - Traffic congestion - Surrounding areas clear cut or mined - Air pollution and smog - Parks are profitable, but do not get to keep the money they generate
Preserves not save from Exploitation
- Excessive stock grazing - Dam building -Oil drilling - Mining - Logging - Coral reefs damage by dynamite fishing - Hunting; Eggs from endangered sea turtles are taken by hunters - Overuse by the public
Tropical Forest
- Largest tropical forests are in South America (22% of worlds forest found here and has the worlds largest undisturbed rain forest) - Occupy less than 10% of land surface but contain half of all plant, animal and microbial species on earth
6 Ecosystem Management practices
- Managing across whole landscapes, watersheds, or regions over ecological time scales - Considering human needs and promoting sustainable economic development and communities - Maintaining biological diversity and ecosystem processes - Utilizing cooperative institutional arrangements - Generating meaningful stakeholder and public involvement and facilitation collective decision making - Adapting management over time, based on conscious experimentation and routine monitoring.
Forests provide Valuable products
- Wood plays bigger role than any other commodity - International trade > $100 billion per year - Paper -- Paper Pulp
Primary and Old Growth Forests
- composed primarily of native species in which there is little indication of human activity and ecological processes are not significantly disturbed - Home to much of the worlds biodiversity, ecological services and indigenous human cultures
Size and Design of Nature Preserves
-- Core habitat-- areas deep in interior -- Edge effects -- Habitat edges -- Corridors of natural habitat essential to connect smaller habitat areas to one another.
Primary Forests
-Account for 1/3 of the worlds forest - 6 million hectares of these are cleared or heavily damaged each year - 9 of 10 of the countries where 80% of these forests exist are experiencing unsustainable logging rates
Temperate Forest Threatened
-Climate Change - Insect Threats - Wildfires - Droughts - Urbanization - Logging in nearby areas - Road Building
China
-Cut all forests 1000 years ago and suffered massive soil erosion and floods -Outlawed timber cutting - Planted 50 billion trees since 1990
Reforestation
-Successful programs exist in China, Korea, and Japan
Categories of protection (With Human impact)
1. Ecological reserve and wilderness areas (Little or non) 2. National Parks (Low) 3. Natural monuments and archaeological sites (low to medium) 4. Habitat and wildlife management areas (Medium) 5. Cultural or scenic landscapes, recreation areas (Medium to high)
Three objectives of World Conservation Strategy
1. Maintain essential ecological processes and life support system (Soil regeneration and protection, nutrient cycling, and water purification) 2. Preserve genetic diversity essential to improving cultivated plants and domestic animals 3. Ensure that utilization of wild species and ecosystems is sustainable
Wood production
1/4 of the worlds forests are managed for this.
Paper Pulp
1/5 of all wood consumption - used in wealthier countries such as North Am. Europe, and Asia
Total annual wood consumption
4 billion (more than plastic and steel combined)
12%
About what percentage of the world's forests are now protected?
Forest to agriculture
Accounts for 2/3 of destruction in Africa Conversion to cattle ranching and soy farming is most common in Latin America
Firewood
Accounts for 50% of forest harvests
Ecosystem Management
Attempts to integrate sustainable ecological, economic, and social goals in a undivided systems approach.
Large Scale Commercial Logging
Building roads to remove trees also allows entry to forest by farmers, miners, and hunters
Causes fires to be larger and More severe
By eliminating fires and accumulation of woody debris has caused fires to be?
Grazing on grasslands
Can be used for sustainably, as pastoralists herd their animals to adjust to variations in rainfall and seasonal conditions
Rational Grazing
Confines animals to small area for a day or two before shifting to a new location. -- allows vegetation to be eaten evenly -- Can be used to raise wild bison which forage more efficiently and fend off predators, disease and pests. Also have different feeding preferences
Debt for Nature Swaps
Conservation organizations buy debt obligations, then offer to cancel the debt if the debtor country protects biologically important areas
Deforestation
Current rate will leave no primary forests outside of parks or preservations by the end of this century
Forest Fires
Destroy 350 million hectares of forest annually - Many are intentional to clear land for other uses
World Conservation Strategy
Developed by the IUCN- International Union for Conservation of Nature
Boreal Forests
Found in North America and Eurasia
Grasslands
Frequently converted to cropland, urban areas, or other human use - 3x higher disturbance rate than that of tropical rainforest - More threatened plants than any other american biome
Marine Ecosystems need protection
Global fish stocks are becoming depleted and biologists are calling for protected areas where species can be sheltered - 20% of nearshore territory should be marine refuge area -- Refuge can replenish nearby areas
70 Years
How long has the U.S. had a policy of aggressive fire control?
40 Million
How many Americans are moving to remote areas and now live in areas of high wildfire risk?
30,000 Hectares
How many hectares of forest are deforested every day?
1/4
How much land surface do grasslands cover?
Australia
Largest marine reserve: The Great Barrier Reef Marine Park
Overgrazing
Leads to desertification - Grazing fees for public land use below market value - 55% of U.S. public range lands are in poor or very poor condition
10%
Marine reserves only make up 10% of the worlds protected areas even though oceans cover 70% of the earth's surface
Topics
Produce 1/2 of all industrial wood but consume only 20%
Developed countries
Produce < 1/2 of all industrial wood but consume 80%
Monoculture Forestry
Produces rapid growth and easier harvesting Supports little diversity and few ecological services (soil erosion control, clean water production.)
New Grazing Methods
Rational Grazing
Fire Management
Recent Studies show that many biological communities are fire-adapted and require periodic burning for regeneration
Conservation and Economic Development
Struggle to save ecosystems cannot be divorced from struggle to meet human needs
40%
Today what % of federal lands are at risk of severe fires?
Korea and Japan
Total denuded after World War II but now about 70% forested
Ecotourism
Tourism that is ecologically and socially sustainable; more beneficial in many places than extractive industries such as mini or logging
Largest producers of Paper pulp and industrial wood products
U.S, russia, and Canada
7.3 Million Hectares per year
What is the net loss due to replanting or succession for revegetation?
10 A.M.
What time must the fires be extinguished?
Africa
Which country has the largest % of protected forest?
U.S
Who declared 3 new National Marine Monuments in territorial waters in the pacific in 2007
Landscape Ecology
science that examines the relationship between spatial patterns and ecological processes such as species movement or survival
Habitat Size
• Brazilian scientists are tracking wildlife in plots of various sizes, either connected to existing forests or surrounded by clear-cuts • Some species disappear quickly, especially from small areas • Sun-loving species flourish in forest edges • Study revealed importance of maintaining core habitat 41
SLOSS debate- is it better to have single large or several small reserves
• One of the reasons that large preserves are considered better than small reserves is that they have more core habitat, area deep within the interior of the habitat that has better conditions for specialized species. ---As human disturbance fragments the ecosystem, habitat is broken into increasingly isolated islands with less core and more edge, supporting fewer rare species.