restoration ecology
Post on 31-Dec-2015
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Key terms
• Intervention• Mitigation• Reallocation• Reclamation• Re-creation• Rehabilitation• Remediation• Restoration
The 6th Mass Extinction
• Estimate: 50,000 species per year• Global declines in genetic diversity of wildlife
seen; leads to inbreeding depression• Global declines in genetic diversity of
crops/livestock• Global declines in species diversity• Global declines in ecosystem function
Causes of Declining Biodiversity
• Loss of Habitat• Alien species (non-native/exotic) if they
spread rapidly, → Invasive• Population• Pollution• Climate change• Overharvesting
Helping Nature Heal
• Humans have disturbed and degraded nature for as long as we have existed
• We are able to repair some of the damage (ecological restoration)
• Recovery: linked to the idea “natural climax community will return if we leave it alone”
• Modern Ecology: this may not be the case (random process)
Helping Nature Heal
• Aims of restoration driven by human values (beauty, recreation, utility) rather than science
• General principles of restoration are drawn from ecology, hydrology, soil science, etc.
• Most influential American forester: Gifford Pinchot*
• Another pioneer: Aldo Leopold
Gifford Pinchot
• Introduced selective harvest and replanting of choice tree species
• This increased the value of the forest• Also produced a sustainable harvest • First head of U.S. Forest Service
Habitat Destruction
• Deforestation is the greatest eliminator of species,) followed by coral reefs & wetlands
• Fragmentation (roads, logging, agriculture)• Increase vulnerability• Changes migratory patterns (buildings, etc.)• Case Study: Birds as indicators (p 195 – 197)
Invasive Species
Characteristics of Successful Invasive Sp. Characteristics of Vulnerable Ecosystems
r-selected species Climate similar to habitat of invader
Pioneer species Absence of natural predators
Long lived Early successional systems
High dispersal rate Low diversity of native species
Generalists Absence of fire
High genetic variability Disturbed by human activities
Invasive Species
Controlling Invasive SpeciesDo not capture or buy wild plants and animals
Do not remove plants and animals from natural areas
Do not dump aquarium contents into waterways, wetlands, storm drains
Use wood found near your camp site
Do not dump unused bait into waterways
Brush your dog’s fur after being in woods or water
Clean recreational vehicles/gear before going home
Laws and Treaties
• Lacey Act, 1900; many amendments; forbids interstate trade of illegally harvested plants and animals
• Convention on International Trade in endangered Species (CITES), 1975; 175 countries
• Marine Mammal Protection Act, 1972
Laws and Treaties
• Endangered Species Act, 1973; amended in ‘82, ‘85, ‘88
• ESA implements CITES agreement• US Fish and Wildlife Service is main overseer• Controversial at times; spotted owl v. logging
in NW US during 1990s
Laws and Treaties
Convention on Biological Diversity (1992)• Conserve biodiversity• Sustainably use biodiversity• Share the benefits that emerge (ex – pharma-
ceuticals)
Other Methods
• Wildlife refuges• Gene/seed banks• Botanical gardens• Wildlife farms• Zoos and aquariums
Nature Can Be Resilient
• First step in restoration: stop whatever is causing the damage
• Ex. – prohibiting logging, mining, etc., may be enough to allow nature to heal by itself
• Sometimes rebuilding populations of native plants and animals is a simple process of restocking breeding individuals to an area
Video Focus Questions: Forest Fires
• Climate impact on frequency, intensity of fires• Human impact on frequency, intensity of fires• Natural recovery from fires• Restoration efforts• Importance of forests
Forest Restoration
• Lumber companies routinely replant forests that they have harvested
• Mechanical restoration results in a monoculture of uniformly placed trees
• Japan was almost completely deforested at the end of WWII, now more than 60% is forested
• Today: Largest reforestation in China; 50 billion trees have been planted over the past 50 years
Forest Restoration
• Urban planting important• 2007: UN announced “billion tree campaign”• Historically, fire has been important in
controlling vegetation in savannas• Settlers eliminated fire and grazing by native
animals → shrub and tree growth• Accumulated veg. is cleared before fires are
started; herbicides prevent re-growth
Forest Restoration
• Sequoia National Park: 70 years of fire suppression → dense undergrowth → more fuel for destructive fires
Prairie Restoration
• Before European settlement, prairies covered most of the middle U.S.
• Tall-grass: eastern edge of the Great Plains. Less than 2% remains
• Fire is also crucial for prairie restoration; kills many weedy species and removes nutrients (esp. N)
• The Nature Conservancy has established many preserves to protect tallgrass prairies
Prairie Restoration
• Huge areas of short-grass prairie are being preserved
• Bison help maintain prairies; with fire, an important tool in restoration
Wetland and Stream Restoration
• Wetlands occupy < 5% of US land; 1/3 of all endangered species spend at least part of their lives in wetlands
• Until recently governments encouraged drainage for development
• 1972 Clean Water Act began protecting streams and wetlands by requiring discharge permits for dumping waste into sfc waters
Wetland and Stream Restoration
• For wetlands, sometimes all that’s needed is to stop destructive forces
• The Everglades is a fresh water river that comes from springs that has been diverted, causing 90% of wading birds to be lost
• It is hoped that by restoring the former flow will allow the biological community to recover
Wetland and Stream Restoration
• The Chesapeake Bay is a drowned river valley with fresh and salty water mixing
• Overfishing, sewerage discharge, silt, heavy metals, toxic chemicals from industry and agriculture, oil spills and habitat destruction are causing a loss of productive fisheries
• Restoration = minimal success
Wetland and Stream Restoration
• Cities: artificial wetlands provide a low-cost way to filter sewerage
• Stabilizing stream banks, stopping pollution, controlling invasive species, preventing erosion are restoring streams
• Remediation means finding remedies from problems involving noninvasive techniques
• Reclamation implies using intense physical or chemical methods to repair ecosystems
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