APES Ch. 10


Terms in this set (...)

What are the major threats to forest ecosystems?
Unsustainable cutting and burning of forests, along with diseases and insects, & climate change
old growth forest/primary forest
an uncut or regenerated forest that has not been seriously disturbed by human activities or natural disasters for several hundred years or more; Reservoirs of biodiversity b/c they provide ecological niches for a multitude of wildlife species
second-growth forest
a stand of trees resulting from secondary ecological succession; develop after trees in an area have been removed by human activities
tree plantation/ tree farm or commercial forest
a managed forest containing only one or two species of trees that are all of the same age; harvested by clear cutting as soon as they become commercially valuable; Can produce wood at a fast rate and thus increase their owners' profits (papermaking) helps old growth and secondary forests
Percentages of the types of forests
60% of the world's forests are second growth forests, 36% are old growth or primary forests, 4% are tree plantations; 6% in US
ecological services provided by forests
Support energy flow and chemical cycling, reduce soil erosion, absorb and release water, purify water and air, habitats
economic services provided by forests
Wood for fuel, lumber, pulp to make paper, livestock grazing, employment
Clear-cutting forests
all trees in an area removed at once (most efficient for loggers and most harmful to ecosystem)
Advantages of clear cutting
higher timber yields, maximum profits in shortest time, can reforest with fast growing trees, good for tree species needing full or moderate sunlight
Disadvantages of clear cutting
reduces biodiversity, destroys and fragments wildlife habitats, increases water pollution, flooding and erosion on steep slopes, eliminates most recreational value
Strip cutting
variation of clear-cutting, narrow strip of trees is clear cut to allow natural forest regeneration, after regeneration another strip is cut
Selective cutting
intermediate-aged or mature trees cut singly or in small groups (not clearing a whole area at a time)
Surface fires
burns undergrowth and leave litter on the forest floor; may kill seedlings and small trees but they spare most mature trees and allow most wild animals to escape, they burn away flammable ground material to prevent a more destructive fire, they release seeds from the cones of tree species, they stimulate the germination of certain tree seeds (sequoia or jack pine), they help to control tree diseases and insects
Crown fires
an extremely hot fire that leaps from tree top treetop to treetop, burning whole trees -increasing soil erosion
Global warming
rises temperature, trees are more susceptible to diseases and pests, drier forests result in more fires, more greenhouses gases
Tropical Forests are Disappearing Rapidly
Majority of loss since 1950, Losses concentrated in Africa southeast Asia south America, At current rate of deforestation 98% will be gone by 2022, Role of deforestation in species' extinction -more than half of known terrestrial plants, animals, and insects live in tropical forests, Secondary forests can grow back in 15-20 years
Ways to reduce the harmful impacts of tree diseases and insect pests on forests
Ban imported timber that might carry harmful diseases or insects, remove infected and infested trees, develop tree species that are generally resistant to common tree diseases, apply pesticides
the temporary or permanent removal of large expanses of forest for agriculture, settlements or other large expanses
Major causes of the destruction and degradation of tropical rainforests
not valuing ecological services, crop and timber exports, poverty, population growth, building roads, fires, settler farming, cattle ranching, logging, tree-plantation
How should we manage and sustain forests?
by emphasizing the economic value of their ecological services, removing government subsidies that hasten their destruction, protecting old-growth forests, harvesting trees no faster than they are replenished, and planting trees
Solutions to a more sustainable forestry
Identify and protect forest areas high in biodiversity, rely more on selective cutting and strip cutting, stop logging in old-growth forests, sharply reduce road building in uncut forests areas, leave most standing dead trees and fallen timber of wildlife habitat and nutrient cycling, put tree plantation only on deforested and degraded land, certify timber grown by sustainable methods, include ecological services of forests in estimates of their economic value
highly flammable logging debris
Approach to reducing fire-related harm to forests
remove flammable small trees and underbrush in the highest-risk forest areas; Allow some fires on public lands to burn, thereby removing flammable underbrush and smaller trees; Protect houses and other buildings in fires; The Smokey Bear educational campaign
Reducing the Demand for Harvested Trees
Improve the efficiency of wood use (60% of US wood is wasted) or Make tree-free paper (kenaf or hemp)
Deforestation and Fuelwood Crisis
One half of world wood harvest is for fuel
Possible solution: establish small plantations of fast-growing fuelwood trees and shrubs, burn wood more efficiently, solar or wind-generated electricity, burn garden waste
Governments can act to reduce deforestation by
Reduce fuelwood demand, practice small-scale sustainable agriculture and forestry in tropical forest, government protection, plant trees, buy certified lumber and wood products
protect the most diverse and endangered areas, educate settles about sustainable agriculture and forestry, subsidize only sustainable forest use, protect forests through debt-for-nature swaps and conservation concessions, certify sustainably grown timber, reduce poverty, slow population growth
encourage regrowth through secondary succession, rehabilitate degraded areas, concentrate farming and ranching in already-cleared areas
Green Belt Movement
its main goal was to organize poor women in Kenya to plant and protect trees in order to fight deforestation and provide fuelwood
What are three ecological and three economic benefits provided by forests?
Supporting energy flow or chemical cycling, reducing soil erosion and absorbing and releasing water are ecological benefits that forests provide. Wood for fuel, pulp to make paper and employment are economical benefits.
Why is there recent effort to put a price tag on the major ecological services provided by forests and other ecosystems?
Ecologists recently estimated the total cost of the earth's ecological services, which is around 33.2 trillion per year. It alerts people to be aware of the earth's ecosystem, the value of forests, and the continuous income of sustainable forests
Describe the connection between climate change and forest fires.
drier forests + more dead trees= more greenhouse gas CO2 = more fires
Underlying causes of deforestation
not valuing ecological services, crop and timber exports, government policies, poverty, and population growth.
Direct causes of deforestation
the building of roads, fires, settler farming, cattle ranching, logging and tree plantations.
4 ways in which forests can BE MANAGED more sustainably.
rely more on selective cutting and strip cutting, no logging of old-growth forests, plant tree plantations primarily on deforested and degraded land and certify timber grown by sustainable methods.
5 ways TO PROTECT tropical forests and to use them more sustainably.
help new settlers learn how to practice small-scale sustainable agriculture and forestry, harvest renewable resources on a sustainable basis, reducing poverty and slowing population growth could help protect these forests too, rehabilitate degraded areas and encourage regrowth through secondary succession, subsidizing only sustainable forests
deforestation, soil erosion, water shortages, loss of biodiversity, degradation of the marine ecosystem and poverty
Ecological services of grasslands
soil formation, erosion control, nutrient cycling, storing CO2 in biomass, maintaining biodiversity
unfenced grasslands in temperate and tropical climates that supply vegetation
are managed grasslands and fenced in meadows used for grazing livestock (relatively small to the rangeland; aka an area with lush green grass)
Overgrazing of rangelands
occurs when too many animals graze for too long, damaging the grasses and their roots and exceeds the carrying capacity of a rangeland area
Ways we can manages rangelands more sustainably
1) Control the number of grazing animals and the duration of their grazing 2) protect riparian zones by fencing off areas 3) Suppress growth of invasive species by using herbicides, mechanical removal, controlled burning, controlled short-term trampling 4) Replant barren areas 5) Apply fertilizer 6) Reduce soil erosion
Rational grazing
cattle are confined by portable fencing to one area for a short time then moved to a new location
Riparian zones
areas of lush vegetation by streams or rivers
National Parks threatened by
invasions by nonnative species that compete and reduce the populations of native species, (popularity) many people in less-developed countries enter the parks illegally in search of wood, cropland, animals, other natural products; Loggers and miners, wildlife poachers, operate illegally creating decline in populations or habitat loss
Gray Wolf in Yellowstone NP
Keystone species, species depended on it, listed as endangered by the ESA in 1974, 1995 was reintroduced,
prey on elk and pushed them to a higher elevation resulted in a regrowth of aspen, cottonwoods and willows that stabilizes stream and riverbank areas, creating more beaver dams, more wetlands, more aspens. Reduced the number of coyotes which increased cattle population and increased smaller mammals
Solutions to National Parks
Integrate for managing parks, add new parkland near threatened parks, buy private land inside parks, increase federal funds for park maintenance and repairs, increase the number of park rangers and their pay
Nature Reserves
Currently less than 13% of land is protected; Conservationists goal is to protect 20%
Nature Conservancy
created largest system of privately held reserves and wildlife sanctuaries in 30 counties- includes land in all 50 US states
Buffer zone concept
has to do with national parks and trying to protect parks areas; by creating this you are creating an area in which ppl are not going to live here, eliminating a lot of pollution that is happening, trying to stabilize and reduce the impact such as congestion and pollution. establishing two buffer zones in which local people can extract resources sustainably without harming the inner core
habitat corridors
connects wildlife populations separated by human activities or structures; allows an exchange of individuals between populations, which may help prevent the negative effects of inbreeding and reduced genetic diversity
Costa Rica
A Global Conservation Leader; 1986-2006 forest grew from 26% to 51% accomplished through a system of nature serves and national parks. Goal: net carbon dioxide emissions to zero by 2021; government has eliminated subsidies for converting forest to rangeland and pays landowners to maintain tree cover; earns 1 billion dollars per year in tourism; Each of their reserves contain a protected inner core surrounded by two buffer zones that local and indigenous people can use for sustainable logging, crop farming, cattle grazing, hunting, fishing and ecotourism
land officially designated as an area where natural communities have not been seriously disturbed by humans and where human activities are limited by law
Wilderness Act of 1964
• Protect undeveloped lands in US
• 2% of lower 48 states protected mostly in West
• 10-fold increase from 1970-2010
o Controversial -some want all land available for economic purposes
4-Point Strategy to Protect Ecosystems
1.Map the world's terrestrial ecosystems and create an inventory of the species contained in each of them.
2.Locate and protect the most endangered ecosystems and species.
3.Seek to restore as many degraded ecosystems as possible.
4.Development must be biodiversity-friendly by providing significant financial incentives and technical help to private landowners who agree to protect endangered ecosystems.
Biodiversity hotspots
areas especially rich in plant species that are found nowhere else and are in great danger of extinction
Why should we protect hotspots?
• covers 2% of earths surface, but contains 50% of flowering plant species and 42% of terrestrial vertebrates
• home to most endangered or critically endangered species as well as 1.2 billion people
UN Millennium Ecosystem Assessment
• Identify key ecosystem services
• Human activities degrade or over use 60% of the earths natural services
• Identify highly stressed life raft ecosystems
Foster cooperation among residents, government and scientists to protect people and biodiversity
• Life raft ecosystems
areas where poverty levels are high and where a large part of the economy depends on various ecosystem services that are being degraded severely enough to threaten the well-being of people and other forms of life
how can we rehabilitate and restore ecosystems that we have damaged
1.Restoration: returning a degraded habitat or ecosystem to a condition as similar as possible to its natural state
2.Rehabilitation: turning a degraded ecosystem into a functional or useful ecosystem without trying to restore it to its original conditions (removing pollutants and replanting to reduce soil erosion)
3.Replacement: replacing a degraded ecosystem with another type of ecosystem (degraded forest could be repaved by a proactive pasture or tree plantation)
4.Creating artificial ecosystems: creating a artificial wetland to help reduce flooding or to treat sewage
How to carry out most forms of ecological restoration and rehabilitation
1.identify what caused the degradation
2.stop the abuse
3.reintroduce species
4.protect from further degradation
Reconciliation ecology
focuses on inventing, establishing, ad maintaining new habitats to conserve species diversity in places were people work, live or play. We need to learn how to share with other species some of the spaces we dominate
1970s: Blackfoot River Valley in Montana threatened by
poor mining, logging, and grazing practices, water and air pollution, unsustainable commercial and residential development. Community meetings led to weed-pulling parties nesting structures for waterfowl, developed sustainable grazing systems
rehabilitation ecology
Where it is impossible to restore a site to its original condition, the establishment on it of a community which is similar to the original.
3 examples of reconciliation ecology
protecting local wildlife and ecosystems that provide economic resources, protecting vital insect pollinators that are vulnerable to insecticides and habitat loss, protecting certain birds that have declined in population because humans have damaged or destroyed their nests