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Habitat Fragmentation II. I. Components of fragmentation A. Reduction in total amount of habitat type B. Apportionment of remaining habitat into smaller and more isolated patches II. What constitutes a barrier? III. Biological responses to habitat fragmentation
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Habitat Fragmentation II I. Components of fragmentation A. Reduction in total amount of habitat type B. Apportionment of remaining habitat into smaller and more isolated patches II. What constitutes a barrier? III. Biological responses to habitat fragmentation A. initial exclusion B. isolation C. island-area effects D. edge effects IV. The case of migratory songbirds V. Protecting wildlife/biotic integrity in a fragmented landscape: Challenges facing remnant natural areas
Major challenges facing managers: 1. Natural resource area management will increasingly consist of managing a mosaic of remnant patches. -using fragments as stepping stones -road overpasses -Tall grass prairie case study 2. Increasing necessity of balancing tradeoffs between enhancing connectivity and maintaining barriers -the case for NOT removing dams on rivers draining into the Laurentian Great Lakes 3. The issue of fragment size B. Management solutions C. Video: reducing river fragmentation by removing dams (~20 min) V. Protecting wildlife/biotic integrity in a fragmented landscape
US Tallgrass Prairie Example
161 nature reserves containing • tallgrass prairie in 14 US states • 1/2 are less than 100 acres • only 0.5% of the original prairie • remains in the state of Missouri
Example of increasing necessity of balancing tradeoffs between enhancing connectivity and maintaining barriers: The case for maintaining dams to stop the upstream migration of toxic- laden exotic fishes thereby protecting bald eagle populations upstream
Fragment Size: Ninety eight percent of the world’s parks are less than 10,000 km2
Most of worlds national parks and reserves are too small in area to maintain populations of many species and to protect ecosystems and biodiversity in the long-term
V. Protecting wildlife in a fragmented landscape(CONT) • Management solutions: 1. Buffer zones and pulling together in-holdings 2. Optimization of internal patch structure 3. Consider ecological and socioeconomic pros and cons of linking fragments 4. Avoid internal fragmentation 5. Manage matrix outside of fragments
I. Establishing buffer zones around fragments and acquiring inholdings within the matrix
Consider ways to optimize internal patch structure to promote specific species
3. Careful consideration of the pros and cons of connecting fragments together via corridors; good for some species bad for others
What are the Pros and Cons of linking ‘protected areas’ in urban environ- ments via land corridors?
4. Avoid internal fragmentation within reserves by roads, fences, etc and remove or mitigate effects of these ‘barriers’ when possible
Manage areas of the landscape matrix that are outside of fragments to protect the fragment and to minimize regional environmental degradation A. US Public Lands and water issues -National Forests -National Parks -Wildlife Refuges B. Success and failure stories relating to managing specific public lands and the necessity of considering watershed, aquifer and airshed connectivity
Manage areas of the landscape matrix that are outside of fragments to protect the fragment and to minimize regional environmental degradation B. Specific Examples 1. Watershed (a) Zion National Park (b) Danube Delta Biological Reserve 2. Aquifer (a) Yellowstone National Park (b) Death Valley National Park 3. Air-shed . (a) Great Smoky Mountains National Park
ZNP = Zion National Park (593 km2) GSMNP = Great Smoky Mountains National Park (2107 km2) DDBR = Danube Delta Biosphere Reserve (6,792 km2) YNP = Yosemite National Park (8,998 km2) DVNP = Death Valley National Park (13,365 km2) GSMNP ZNP DDBR YNP DVNP
Watershed: Controlling Water Consumption and Use outside of Zion National Park
Aquifer: Controlling groundwater pumping and drilling for natural gas
The importance of managing: groundwater pumping; and (2) Disposal of nuclear waste Outside of the boundaries of Death Valley National Park
Air-shed: Controlling acid deposition to protect Great Smokey Mountains National Park
ZNP = Zion National Park (593 km2) GSMNP = Great Smoky Mountains National Park (2107 km2) DDBR = Danube Delta Biosphere Reserve (6,792 km2) YNP = Yosemite National Park (8,998 km2) DVNP = Death Valley National Park (13,365 km2) GSMNP ZNP DDBR YNP DVNP
What are the consequences of not addressing and managing environmental problemsoutside of fragments or remnant protected areas?