Old-growth forests/frontier forests
Uncut forests or regenerated forests that have not been seriously disturbed by human activities or natural disasters for at least several hundred years. They provide ecological niches for a multitude of species.
Stands of trees resulting from secondary succession after the trees in an area have been removed by
1) human activities (such as clear-cutting for timber or conversion to cropland) or
2) natural forces (such as fire, hurricanes, or volcanic eruption)
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Tree plantations/tree farms
Managed tracts with uniformly aged trees of one species that are harvested by clear-cutting as soon as they become commercially valuable. Then they are replanted and clear-cut again on regular cycles. These plantations, created mostly by clearing old-growth and second-growth forests, now occupy about 5% of the world’s tree cover area (62% in Asia, mostly China and India) and produce 10% of the world’s wood
What ecological services do forests provide?
1) support energy flow and chemical cycling
2) reduce soil erosion
3) absorb and release water
4) purify water
5) purify air
6) influence local and regional climate
7) store atmospheric carbon
8) provide numerous wildlife habitats
What are economic services that forests provide?
•pulp to make paper
How much land does forests occupy on Earth?
Forests (with 50% or more tree cover) occupy about 32% of the earth’s land surface
What are the four general types of forests based primarily on climate?
Tropical (47% world’s forests), subtropical (9%), temperate (11%), and polar/boreal (33%)
Harvesting pulpwood plantations typically occurs in…
6-10 yr rotations in the tropics and 20-30 yr rotations in temperate regions
Layers of biodiversity in a Douglas fir tree are?
(Top – down)
•Emergent (ex. birds)
•Canopy (ex. reptiles)
•Understory (ex. squirrels)
•Floor (ex. worms)
•Subsoil (ex. nematodes)
Even-aged management/ Industrial Forestry
Involves maintaining trees in a given stand at about the same age and size. A simplified tree plantation replaces a biologically diverse old-growth or second-growth forest. The plantation consists of one or two fast-growing and economically desirable species that can be harvested every 6-100 years, depending on the species.
Involves maintaining a variety of tree species in a stand at many ages and sizes to foster natural regeneration. Here the goals are
1) biological diversity,
2) long-term sustainable production of high-quality timber,
3) selective cutting of individual mature or intermediate-aged trees, and
4) multiple use of the forest for timber, wildlife, watershed protection, and recreation.
A cycle of decisions and events in forest management. Most important steps are:
1) taking inventory of the site,
2) developing a forest management plan,
3) building roads into the site for access and timber removal,
4) preparing the site for harvest,
5) harvesting timber, and
6) regenerating and managing the site until the next harvest.
What plays a role in determining whether forest owners use short-term, even-aged management or longer-term, uneven management?
the rate of economic return
(Before 1960s, it was 2-3%; trees grew at about as fast as the money invested, so owners could afford to wait decades before harvesting them, normally using uneven-management)
Since 1960s, many forest owners have been basing their management decisions based on?
returns of almost 10%, reflecting what they could earn by putting their money into other investments. This means that they can make more money by
1) clear-cutting diverse, uneven-aged forests,
2) investing the profits in something else,
3) growing new even-aged stands of trees as quickly as possible,
4) cutting them down,
5) reinvesting their money, and
6) repeating this process until the soul is exhausted.
List effects of logging.
1) increased soil erosion and sediment runoff into waterways,
2) habitat fragmentation and biodiversity loss,
3) exposure of forests to invasion by nonnative species, and
4) opening of once-inaccessible forests to farmers/miners/ranchers/hunters/ and off-road vehicle users (and in U.S, it disqualified the land for protection as wilderness)
intermediate-aged or mature trees in an uneven-aged forest are cut singly or in small groups. This reduces crowding, encourages growth of younger trees, maintains an uneven-aged stand of trees of diff species, allows natural regeneration from the surrounding trees, can protect the site from soil erosion and wind damage, can be used to remove diseased trees, and allows a forest to be used for multiple purposes.
A form of selective cutting; cutting and removing only the largest and best specimens of the most desirable species
With every large tree felled, 16 or 17 other trees are damaged or pulled down because?
A network of vines usually connects the trees in tropical rainforest canopies. This reduction of forest canopy causes the forest floor to become warmer, drier, and more flammable, and increases erosion of the forest’s thin and usually nutrient-poor soil
A method of harvesting; removes all mature trees in two or three cuttings over a period of 10 yrs
A method of harvesting; harvests nearly all of a stand’s trees in one cutting, leaving a few uniformly distributed seed-producing trees to regenerate the stand
A method of harvesting; removes all trees from an area in a single cutting
Pros of clear-cutting
•increase timber yield p/ hectare
•permits reforesting with genetically improved stocks of fast-growing trees
•shortens time needed to establish a new stand of trees
•takes less skill and planning that other harvesting
•usually provides the maximum economic return in the shortest time
•if done carefully and responsibly, often is the best way to harvest tree plantations and stands of some tree species that need full or moderate sunlight for growth
Cons of clear-cutting
•leaves moderate to large tree openings
•eliminates most recreational value for several decades
•reduces biodiversity, disrupts ecosystem processes, and destroys and fragments some wildlife habitats
•makes nearby trees more vulnerable to being blown down by windstorms
•leads to severe soil erosion , sediment water pollution, and flooding when done on steep slopes
A clear-cutting variation that can allow a sustainable timber yield without widespread destruction; involves clear-cutting a strip of trees along the contour of the land, with the corridor narrow enough to allow natural regeneration within a few years. After regeneration, loggers cut another strip above the first and so on. This allows clear-cutting of a forest in narrow strips over several decades w/ minimal damage.
Human activities have reduced the earth’s original forest cover by…
Almost 50% (some say 20%) over the past 8,000 yrs, and another 30% degraded or fragmented
How much wood harvest comes from developing countries?
About what percentage of the world’s forest is protected legally from ex. logging?
12%, and much of this protection is exists on paper only…
Worldwide, the estimated loss of forests during 1990s was…
16.1 million hectares (40 million acres) per year; Africa lost 20% of its cover, and another 16 nations lost 10-19%. However, b/c of reforestation, the net forest loss in the 1990s was over 9 million hectares (22 mil acres)
Do tree plantations have more or less biodiversity than tropical forests?
Tree plantations have lower biodiversity.
Clearing forests can provide land for:
Crops, livestock, or urban growth
Clearing forests can also:
1) Decrease the overall net primary productivity of the cleared area,
2) reduce the stock of nutrients once stored in trees and leaf littler,
3) diminish biodiversity,
4) make soil more prone to erosion and drying,
5) increase the rate of runoff of water and soil nutrients from the land,
6) reduce the uptake of greenhouse gas CO2 from the atmosphere, and
7) adds CO2 to the atmosphere if cleared trees are burned or allowed to decay.
Deforestation has contributed to how much atmospheric buildup of CO2?
How can forests be managed more sustain-ably?
1) grow more timber on long rotations (generally about 100-200 yrs, depending on the species and soil quality)
2) emphasize selective cutting of individual trees or small groups of most tree species, strip cutting instead of conventional clear-cutting, not clear-cutting (including shelterwood and seed tree and shelterwood cutting) on land that slopes more than 15 degrees.
3) minimize fragmentation of remaining large blocks of forest
4) stop or sharply reduce road building into uncut forest areas
5) use road-building and logging methods that minimize soil erosion and compaction
6) leave most standing dead trees (snags) and fallen timber (boles) to maintain diverse wildlife habitats and to be recycled as nutrients
7) have timber grown by sustainable methods certified and labeled by outside certifying groups
8) includes the estimated ecological services provided by trees and a forest in estimates of their economic value
Implement the following policies if we we were to use tree plantations (to reduce pressures to cut timber in old-growth and second-growth forests and help protect wildlife habitats):
1) banning or sharply reducing the harvesting of the world’s remaining old-growth forests
2) phasing out the harvesting of second-growth forests over a 10-20 yr period as tree plantations are phased in
3) establishing tree plantations only on truly degraded land, not on any newly cleared land or existing cropland
4) phasing out governement subsidies and tax breaks for harvesting timber from old-growth and second-growth forests and phasing in governemnt subsidies and tax breaks for establishing tree plantations on truly degraded areas
How can pathogens and insects affect forests?
>insects and tree diseases can damage and kill trees in natural forests and tree plantations.
>3 deadly diseases caused by parasitic fungi that were accidentally introduced to the U.S from other countries are chestnut blight (from China), Dutch elm disease (from Asia via Europe), and white pine blister rust (from Europe)
List examples of insects that can cause serious damage to certain tree species.
1) bark beetles such as the bronze birch borer and Asian long-horned beetle. They bore channels through the layer beneath the bark of spruce, fir, birch, and pine trees.
2) spruce bud-worm and gypsy moth larvae that was accidentally introduced to the U.S from Europe in 1869, and are now established in 16 states. They can kill trees by eliminating their foliage that the trees need to carry out photosynthesis and produce food.
3) hemlock woolly adelgid, which was accidentally introduced in the U.S from Asia in 1924. During the 1990s, these insect pests have destroyed large areas of hemlock forest throughout the eastern U.S. In 1996, scientists began trying to control this invader by introducing a tiny beetle from Japan that is the natural enemy of the woolly adelgid
List ways to reduce the impacts of tree diseases and of insects.
1) preserve biodiversity
2) ban imported timber that might introduce harmful new pathogens or insect pests
3) remove infected and infested trees or clear-cutting infected/infested areas and burning all debris
4) treat diseased trees w/ antibiotics
5) develop disease-resistant trees
6) apply pesticides
7) use integrated pest management
What do fires help maintain?
Fires, sometimes caused by lightning, helps maintain the vegetation of many ecosystems at a certain stage of ecological succession
What ecosystems/communities need fires to maintain vegetation?
Some fire-maintained communities are: savanna, temperate grasslands, chaparral, southern pine forests, western forests containing giant sequoia trees, and evergreen coniferous forests
What does fire do in fire-maintained ecosystems?
fire burns away much of the low-lying vegetation and small trees. a burst of new vegetation follows
fires that usually only burn undergrowth and leaf litter on the forest floor; natural, low intensity (usually caused by lightning). These fires kill seedlings and small trees but spare most mature trees and allow most wild animals to escape.
List pros of surface fires.
1) burn away flammable ground material and help prevent more destructive fires ex. crown fires by removing flammable ground material
2) release valuable mineral nutrients tied up in slowly decomposing litter and undergrowth
3) increase the activity of underground nitrogen-fixing bacteria
4) stimulate the germination of certain tree seeds (ex. giant sequoia, lodge-pole pine, and jack pine)
5) help control pathogens and insects
6) some wildlife species (ex. deer, elk, woodcock, quail) depend on occasional surface fires to maintain their habitats and provide food in the form of vegetation that sprouts AFTER fires.
an intentionally lit fire designed to burn debris (human-caused); a controlled surface fire to prevent the buildup of flammable ground material in forests; setting controlled ground fires to prevent buildup of flammable material
hot fires that may start on the ground but will eventually burn whole trees and leap from treetop to treetop; fires where the tops of trees burn and can travel from treetops through wind. They usually occur in forests in which no surface fires have occurred for several decades. This allows dead wood, leaves, and other flammable ground litter to build up.
What are the effects of crown fires?
These rapidly burning fires can destroy most vegetation, kill wildlife, and increase soil erosion.
a forest fire that burns the humus and usually does not appear at the surface; occurs when (sometimes) surface fires go underground and burn partially decayed leaves or peat. are common in northern peat bogs. they may smolder for days or weeks and are difficult to detect and extinguish
an out of control, high intensity fire where the entire forest from the ground up is burned; this type of fire has recently occurred frequently due to the buildup of debris that acts as a fuel for fire
early detection and control of fires
fighting fires once they have started
How can we protect forests from fire?
prevention, prescribed burning, presuppression, and suppression
How can we prevent forest fires?
requiring burning permits, closing all or parts of a forest to travel and camping during periods of drought high fire danger, and educating the public
The Smokey Bear educational campaign (of the Forest Service and the National Advertising Council)
>has prevented countless forest fires in the U.S, saved many lives, and prevented billions of dollars in losses
>convinced most members of public that all forest fires are bad and should be prevented or put out
Preventing ALL forest fires can increase what?
the likelihood of highly destructive crown fires because it allows large quantities of highly flammable underbrush and undergrowth and smaller trees to accumulate in some forests; can convert normally harmless surface fires into fires intense enough to destroy the larger fire-resistant species needed for forest regeneration
What principles do ecologists propose to manage forest fires?
1) set carefully controlled prescribed ground fires to keep down flammable ground litter in fire-adapted forests as part of the natural ecological cycle of succession and regeneration
2) allow many fires in national parks, national forests, and wilderness areas to burn as long as they don’t threaten human structures and life
Have government officials listen to ecologists?
Yes. The U.S Park Service and Forest service have set controlled prescribed fires in forests in which ecologists considered occasional fires to be beneficial to trees and various forms of forest life.
What do fires need to prevent them from getting out of control?
fires require careful planning and monitoring to keep them from getting out of control.
ex. spring of 2000- a poorly planned prescribed fire got out of hand in an area managed by the Park Service near Los Alamos, New Mexico. result was a 33-day fire that burned 19,000 hectares (47,000 acres), destroyed or damaged 280 homes, damaged 40 structures at the Los Alamos National Laboratory, and caused an estimated $1 billion in damages.
since 1972, a government policy did what?
allowed most lightning-caused fires in national parks and national forests to burn themselves out as long as they don’t threaten human lives, park or forest service facilities, private property, or endangered wildlife
during the summers of 1988, 1994, and 2000, where did fires break out?
Yellowstone National Park and a number of national forests in the West—> company lobbyists and politicians called for a reversal of the “let-it-burn” policy
Was the fire in Yellowstone ecologically beneficial?
Yes. the meadows and forests (today) have 1) lush growths of regenerating trees and wildflowers and 2) more diverse habitats and better food supplies for many of its natural species because of secondary ecological succession after the fires; biologists say that the fire in Yellowstone and the other fires caused more damage than they should have because they lacked prescribed and natural fires.
Loggers claim that they can prevent crown fires by doing what?
clear-cutting more trees/ selectively removing large trees in national forests and parks (if Congress lets them)
Biologists, in response to these loggers, refute what?
>the most dangerous fuel of all is the unwanted waste material or “slash” left behind after a forest has been cut. Many of the worst fires in U.S history (including those in the 1990s) was burned through cleared forest areas.
>allowing the logging companies to selectively cut or thin larger trees will not reduce the fire hazard because larger trees are difficult to ignite. smaller trees, shrub, slash fuel most fires
How does air pollution and climate change threaten forests?
>forests at high elevations and those downwind from urban and industrial centers are exposed to a variety of air pollutants that can harm trees (esp. conifers) and make them more vulnerable to drought, diseases, and insects.
> solution is to reduce emissions of the offending pollutants from the coal-burning power plants, industrial plants, and motor vehicles
>in the coming decades, regional climate change due to global warming threatens forests, especially temperate and boreal forests)
> this can increase the threat of forest fires in areas that may get less precipitation and cause some types of tree species to die out in some areas
What is the status of forests in the U.S?
forests cover about 30% of the U.S land area, provide habitats for more than 80% of the country’s wildlife species, and supply abour 2/3 of the nation’s total water runoff
Forests among the U.S are among the most what?
Diverse in the world; ranging from tropical forest in Hawaii to boreal forest in Alaska
Forests in the U.S now cover more area than they did in 1920. Many ______ that were cleared or partially cleared between 1620 and 1960 have grown back naturally through secondary succession as fairly diverse second-growth (and some cases third-growth) forest.
The ____ was the world’s first country to set aside large areas of forest in protected areas. By 2000, protected forests made up about 40% of the country’s total forest area (Most in National Forest)
Between 1620 and 1998, most of the old-growth forests in the ________ 48 states were cut.
Since ______, an increasing area of the nation’s remaining old-growth and fairly diverse second-growth forests has been clear cut and replaced with biologically simplified tree plantations.
Replacing diverse forests with tree plantations leads to…
>The reduction overall forest biodiversity and disrupts ecosystem processes such and chemical cycling
>can also reduce the pressure to clear-cut more diverse old-growth and second-growth forests
How many forests does the U.S Forest Service manage?
156 national forests
What are some economic benefits of the U.S National Forests?
>contains about 19% of the country’s forest area and supply about 3% of the nation’s softwood timber (down from 15% in the 1980s)
>serve as grazing lands for more than 3 million cattle and sheep each year
>provide about $4 billion worth of minerals, oil, and natural gas per year
>contain a network of more than 612,000 kilometers (380,000 miles) of roads, equal in an area to the country’s entire interstate highway system. Taxpayers pay for building and maintaining these these mostly narrow dirt roads that give private logging companies access to timber stands
What are some ecological benefits of the U.S National Forests?
>provide habitats for almost 200 threatened and endangered species and hundreds of other wild species and fish
>are the principal habitats for thousands of pollinator species that contribute $4 – 7 billion per year in the U.S agriculture
>provide some of the country’s cleanest drinking water (worth about $3.7 billion per year) for more than 60 million Americans in more than 3,400 communities. This single ecological service is worth more than the annual value of the timber harvested from these lands
> contain about one-third of the country’s protected wilderness area
What is a recreational benefit of the U.S National Forests?
> receive more visits for recreation, hunting, and fishing than any other federal public lands, with recreational use rising sharply since 1930
The U.S Forest Service is required by law to….?
manage national forests according to the principles of 1) sustainable yield (states that potentially renewable tree resources should not be harvested or used faster than they are replenished) and 2) multiple use (which says that each of these forests should be managed for a variety of simultaneous uses such as sustainable timber harvesting, recreation, livestock grazing, watershed protection, and wildlife)
The use of forest resources in national forests is controversial. Timber companies want to cut as much timber as possible at low prices. Biodiversity experts and environmentalists call for _____________________________________________________…..?
1) sharply reducing or eliminating tree harvesting in public forests
2) using more sustainable forest management practices for timber cutting in national forests
3) having timber companies pay more for trees they harvest from national forests
4) managing national forests primarily to provide recreation and to sustain their biodiversity, water resources, and other ecological services
What happened between 1930 and 1988
overall timber harvesting from national forests increased sharply, mostly b/c of 1) intense lobbying of Congress by timber company interests, a law that allows the Forest Service to keep most of the money it makes on timber sales (and thus increase its budget), and 3) a 1908 law that gives counties within the boundaries of national forests 25% of the gross receipts from timber sales
By law, the U.S Forest Service must sell timber for no less than the cost of reforesting the cleared land. However, the price does not include what?
the government-subsidized cost of building and maintaining access roads for timber removal by logging companies. Usually, the companies also buy the timber for LESS than they would pay a private landowner for an equivalent amount of timber. —> Forest Service’s timber-cutting program loses money b/c revenue from timber sales doesn’t cover the costs of road building, timber sale preparation, administration, and other overhead costs.—> b/c of government subsidies, timber sales from U.S federal lands have turned a profit for taxpayers in only 3 of the last 100 yrs.
List some effects of logging in national forests.
1) causes more economic harm than good to local communities near forests, 2) costs the nation’s taxpayers about $1.2 billion per yr in logging subsidies , and 3) costs taxpayers and nearby communities billions of dollars more each year from rivers polluted and fisheries damaged by sediments from logged lands, increased flooding, lost recreational opportunities, and degraded scenery
Timber company officials argue that logging:
1) helps satisfy the country’s demand for wood
2) provides cheap timber–> lumber and paper prices cheap
3) improves forest health by removes diseased trees and helps prevent forest fires
4) provides jobs –> economic growth
Environmentalists respond to timber companies by saying that:
1) timber cutting in national forests only provides 3% of the country’s wood
2) ample private forestland is available to meet the country’s demand for wood
3) below-cost timber prices in national forests increases pressure for timber cutting in national & state forests and have little effect on consumer costs of lumber and paper
4) after timber companies deplete the timber and move to other areas, communities relying heavily on 25% of the proceeds from national forest timber sales experience severe economic slumps
5) recreation in national forests provide many more jobs and more income for local communities than logging does.
>ex. (2002 study) recreation, hunting, and fishing in national forests generates about 2.9 million jobs and add about $234 billion to the economy each year; logging, mining, grazing, and other extractive uses in the national forests add about 407,000 jobs and $23 billion to the economy per year
6) eliminating losses from timber sales in the national forest would save taxpayers $1.6 billion over the next 10 years
In 2001, the Bush administration did the following:
> proposed increasing the sale of timber in the national forests by 40%
> moved to reverse decisions by the Clinton administration to block road construction in road-less areas of national forests (which makes them ineligible for protection in the National Wilderness System)
> called for eliminating long-standing requirement that the Forest Service manage national forests to protect the viability of wildlife
> dropped a requirement imposed by the Clinton administration that “ecological sustainability of resources be the overall goal of forest management”
In 2002, the Bush administration proposed that Congress create what?
a new category of national forests called charter forests that would be managed locally instead of by the Forest Service
>timber companies’ goal is to reduce management costs such as preparing complex environmental assessment documents (goal isn’t to increase activities like logging)
conservationists and elected officials worry because:
> this is a way to evade environmental regulations governing use of national forests and make increased timber cutting the primary focus
> local officials are more easily influenced by timber company interests….
How can we cut fewer trees on public and private lands?
1) improve efficiency of wood use
> up to 60% of the wood consumed in the U.S is wasted unnecessarily through inefficient use of construction materials, excess packaging, overuse of junk mail, inadequate paper recycling, and failure to reuse wooden shipping containers
2) switch to non-wood home-building & remodeling materials such as steel framing & floor joists, aluminum framing, concrete slabs instead of wooden floor joists, and carpet instead of finished wood floors
> involves shifting from a potentially renewable resource (wood) to nonrenewable resources (ex. limestone, iron & other minerals, and crude oil) used to make these products
> uses more energy for transportation & manufacture & produces more pollution than using wood and wood products (ex. steel framing uses 13 times more energy than wood framing, aluminum for walls takes 20 times more energy than wood framing…)
3) make paper by using fiber that doesn’t come from trees
>tree-free fibers come from 2 sources: agricultural residues left over from crops such as wheat, rice, & sugar and fast-growing crops such as kenaf and industrial hemp
Only 3% of the total U.S production of ______ comes from the national forests. Thus reducing the waste of wood and paper products by only 3% could eliminate the need to remove any timber from the national forests and allow these lands to be used primarily for biodiversity protection and recreation.
What is the world’s fastest growing use of wood?
producing paper, which is used for writing and printing (30%), newsprint (12%), and paper tissue & towels (about 8%)
Tree-free paper fibers account for about _______ fiber supply for paper, with 97% of it used in developing countries and less than 1% in the U.S. China uses tree-free pulp, such as rice straw, to make 60% of its paper.
7% of the world’s
Most of the small amount of tree-free paper produced in the U.S is made from the fibers of a rapidly growing woody annual plant called ______. Compared to pulpwood, it needs less insecticide (b/c it grows faster than most weeds), needs less insecticides (b/c its outer fibrous covering is nearly insect proof, does not deplete soil nitrogen (b/c it is a nitrogen fixer), takes fewer chemicals and less energy to break down its fibers, and produces less toxic waste water.
kenaf (pronounced “kuh-NAHF”)
Kenaf paper costs how much more than virgin or recycled paper?
kenaf paper currently costs 3-5 times more.
price will probably go down if demand increases; greater demand allows lower production costs
Why do biologists urge caution against widespread planting of kenaf or industrial hemp?
biologists fear that these rapidly growing plants could take over ecosystems/ crowd out other plant species/ disrupt food webs; and that large plantations of such plants could compete with increasingly scare land that is needed to provide food for the world’s growing population
Tropical forests cover about ______ land area (roughly the size of the lower 48 states of the U.S) and 47% of the world’s forest cover. Tropical forests grow in equatorial Latin America, Africa, and Asia.
6% of the earth’s
Name some varieties of tropical forests.
rain forests (receive rainfall almost daily), deciduous (plants that survive dry season/scold seasons by shedding leaves; ex. oaks) forests w/ 1 or 2 dry seasons each year, dry deciduous forests, and forests on hills and mountains.
Climatic and biological data suggest that mature tropical forests once covered at least twice as much area as they do today, with most of the destruction from 1950. Satellite scans and ground level surveys are used to estimate forest destruction; it indicated that tropical forests are rapidly being clear-cut (reducing local forest areas to 10% or less of the area they originally covered) in parts of ________, ________, _________. Haiti lost 99% of its original forest cover, Philippines 97%, and Madagascar 84% .
South America (esp. Brazil), Africa, and Asia.
What has happened to Brazil’s forests?
Brazil has about half the world’s remaining tropical rain forests in the vast Amazon basin, which is half the size of the U.S. It is an important center of biodiversity, having 30% of the world’s plant and animal species. 1970- deforestation at 1%. 2000- almost 15% had been deforested. Brazil’s rain forests could disappear in 40 – 50 yrs if there is no action to change forest destruction/degradation practices.
Why are rates of tropical deforestation and degradation debatable?
1) difficulties interpreting satellite images,
2) different ways of defining forest, deforestation, and forest degradation
3) political and economic factors that cause countries to hide or exaggerate deforestation
What is the total global tropical forest loss p/ yr?
50,000 square km (19,300 square miles) to 170,000 square kilometers (65,000 square miles) ——0.3 – 1% each yr. however, scientists estimate that each yr, serious degradation and fragmentation affect an equivalent area of these forests; thus tropical forests are being cut/degraded at a rate of 0.6 – 2% p/ yr, high enough to degrade half the world’s remaining tropical forests in 25 – 83 yrs
Why should we care about tropical forests?
1) the important ecological and economic services they provide
2) instrumental values (usefulness to us)
3) intrinsic values (right to exist regardless of their usefulness to people)
Name values of tropical forest ecosystems.
direct use values:
> timber and other building materials, fuel wood, medicinal plants, edible wild fruits and plants, and fiber
indirect use values:
> soil fertility, flood control, water purification, pollution control, recreation and tourism, education, ecological services (ex. pest control, pollination), and genetic information
> future products, medicine, genetic resources, biological insights, food sources, building supplies, and future ecological services
> protection of biological diversity, maintaining cultures of local people, and continuing ecological and evolutionary processes
What happened to Madagascar (aka “crown jewel of biodiversity” ; the world’s fourth largest island that lies in the Indian Ocean off the East African coast) ?
> most species have evolved in near isolation for at least 40 million years. occurred because the continental drift of the plates (found in earth’s lithosphere) moved the island far enough from Africa’s mainland to prevent migrations of species to and from Africa.—> 85% of all plant and animal species on the island are endemic species that are found only on the island. most live in the vanishing eastern rain forests. many plants and animals are endangered, mostly b/c of loss of habitat from slash-and-burn agriculture on poor soils (which is due to rapid population growth). ex. 16 of the 31 primate species on the island face extinction and officials failed (so far) to control illegal smuggling of endangered species. (esp. frogs, chameleons, and lizards) to Europe and Asia.
> humans arrived to Madagascar 1,500 years ago —> 84% tropical seasonal forests and 66%+ of its rain forests have been cut for cropland, fuel, and lumber; what is left is being cleared or burned rapidly——-> erosion from fields and hillsides ——> Madagascar = world’s most eroded country (evidence from huge quantities of eroded sediment flowing in its rivers and emptying into coastal areas)
> since 1984, the government conservation organizations, and scientists worldwide have united to slow the island’s ecological degradation; for such efforts to succeed, the population growth will have to slow dramatically (projected to almost double from 17 million to 31 million between 2002 and 2025); even with this full implementation of this internationally funded effort, Madagascar will probably still lose have its remaining plant and animal species.
An estimated _________ people belong to indigenous cultures found in about 70 countries. Many of these people have been living in and using tropical and other forests sustainably for centuries (ex. Kuana of Panama, the Kenyah in Indonesia, the Yanshe in Peru, and Yanomami in Brazil). They get most of their food from hunting and gathering, trapping, and sustainable slash-and-burn and shifting cultivation.
What is happening to these tribal people as the lands they have lived on for centuries are taken over for economic development?
many of the earth’s remaining tribal people, representing 5,000 cultures, are vanishing—> loss of ecological knowledge and cultural diversity; people in these cultures know how to live sustainably in tropical forests (& in other biomes) and they know which plants are useful and food and medicines. many analysts urge governments to protect the rights of the remaining indigenous cultures by 1) giving them full ownership of the land they have occupied for centuries and 2) protecting their lands from entering and illegal resource extraction
What are primary causes of destruction and degradation of tropical forests?
> rapid population growth
> exploitive government policies
> exports to developed countries
>failure to include ecological services in evaluating forest resources
What are secondary causes of destruction and degradation of tropical forests?
> unsustainable peasant farming
> cash crops
> cattle ranching
> tree plantations
> flooding from dams
> oil drilling
Tropical deforestation results from a number of interconnected causes. These factors are related to the increasing use of the ____ ______ ____ and mineral resources of the earth’s forests for human use as a result of population growth (less jobs —> poverty), poverty (–> subsistence farming), and government policies that encourage deforestation. Population growth + poverty = subsistence farmers and landless poor go to tropical forests, where they try to grow enough food to survive.
net primary productivity
_________ __________ can accelerate deforestation by 1) making timber or other tropical forest resources cheap relative to their full ecological value and 2) encouraging the poor to colonize tropical forests by giving them title to land they clear (done in Indonesia, Mexico and Brazil).
Government subsidies (tax reduction or cash payment)
__________ ________ __________ encourage developing countries to borrow huge sums of money from developed countries to finance projects such as roads, mines, logging operations, oil drilling, and dams in tropical forests.
International lending agencies
How does the process of degrading a tropical forest usually begin?
it usually begins by cutting a logging road deep into a once inaccessible area —-> then the forest experiences factors that can cause forest depletion and degradation
What factors can cause forest depletion and degradation?
1) commercial logging. The largest importers of tropical timber are Japan, Europe, the United States, and China. After Asia’s tropical timber became depleted, cutting is now shifting to Latin America and Africa. Timber exports to developed countries contribute significantly to tropical forest depletion and degradation. Domestic use accounts for more than 80% of the trees cut in developing countries.
2) cattle ranching. ranchers, sometimes supported by government subsidies, often establish cattle ranches on exhausted or abandoned cropland. heavy rain and overgrazing turn the usually thin and nutrient poor tropical rain forest soils into eroded wastelands. ranchers often sell their land to new settlers, move to another area, and repeat this destructive grazing process.
3) unsustainable forms of small-scale farming that deplete soils and destroy large tracts of forests
4) clearing large areas of tropical forest for raising cash crops. Large plantations grow crops such as sugarcane, bananas, pineapples, peppers, strawberries, cotton, tea, and coffee, mostly for export to developed countries.
5) Increasing forest fires. Between 1997 and 1999, huge areas of forest burned in Indonesia, Malaysia, Brazil, Guatemala, Nicaragua, and Mexico. Farmers using fires to prepare fields for planting or cattle grazing and corporations (clearing forests and burning the remaining plant residues to establish pulp, palm oil, and rubber plantations) started most of these fires. —>highly polluted air that: sickened tens of millions of people, killed hundreds, caused billions of dollars in damage, and released large amounts of CO2 into the atmosphere.
6) mining and oil drilling
7) building dams on rivers that flood large areas of tropical forests
What are some effects of tropical deforestation?
> clearing tropical forests can degrade tropical rivers that carry two thirds of the world’s freshwater runoff. clearing tropical forests near rivers causes dramatic increases in soil erosion, often as much as 25-fold. the eroded soil converts normally clear water to muddy water, silts river bottoms and destroys many forms of aquatic life, fills reservoirs, overloads estuaries with nutrients and silt, and smothers offshore coral reefs with silt
> accelerates flooding and reduces the recharging of aquifers by removing the tree cover (that normally slows rainfall runoff and lets it percolate downward into aquifers). for example, China’s Yangtze River basin lost about 85% of its original tree cover. In 1998, this area experienced some of the worst flooding in its history, mostly because of its lack of water-absorbing tree cover
> affects patterns of precipitation. as forest area shrinks, the flow of moisture to downwind areas can drop. for example, deforestation in the eastern and southern provinces of China as an important factor in the decline of rainfall in the northwestern China
How can we reduce degradation and deforestation of tropical forests?
1) establish programs to help new settlers in tropical forests learn how to practice small-scale sustainable agriculture and forestry
2) using debt-for-nature swaps, conservation easements, and conservation concessions to make it financially profitable for countries to protect tropical forests. in a debt-for-nature swap, participating countries act as custodians for protected forest reserves in return for foreign aid or debt relief. More than 20 such agreements, totaling $110 million, have been established in 10 countries. In conservation easement, a private organization, country, or group of countries compensates other countries for protecting selected forest areas. With conservation concession, a nongovernmental conservation organization protects land from logging by renting it from a government. In 2000, Conservation International (CI) purchased the world’s first conservation concession from Guyana. Guyana makes at least as much money as it would from renting the forest area to a logging company and ends up protecting part of its forests. In 2001, CI was negotiating similar renting agreements with six other countries.
3) establishing an international system for evaluating and labeling timber produced by sustainable methods
4) using gentler methods for harvesting trees. for example, cutting canopy vines (lianas) before felling a tree can reduce damage to neighboring trees by 20 – 40% and using the least obstructed paths to remove the logs can halve the damage to other trees
5) supporting national and global efforts to reforest and rehabilitate degraded tropical forests and watersheds. In 1998, China’s government established a 10-yr plan to reduce timber harvests in natural forests, restore natural forests in ecologically sensitive areas, convert marginal (land on edge of cultivated areas/ easily erodible) farmland to forestland, regenerate natural forests in degraded forest areas, and increase timber production in tree plantations
6) reducing the waste and over-consumption of industrial timber, paper, and other resources by consumers, especially in developed countries.
How can we prevent deforestation?
> protect most diverse and endangered areas
> educate settlers about sustainable agriculture and forestry
> phase out subsidies that encourage unsustainable forest use
> add subsidies that encourage sustainable forest use
> protect forests with debt-for-nature swaps, conservation easement, and conservation concessions
> certify sustainably grown timber
> reduce illegal cutting
> reduce poverty
> slow population growth
How can we restore deforested/degraded forests?
> reforestation (renewal of trees and other types of vegetation on land where trees have been removed; can be done naturally by seeds from nearby trees or artificially by planting seeds or seedlings)
> rehabilitation of degraded areas
> concentrate farming and ranching on already-cleared areas
Wood provides ___ of the world’s annual energy supply. In developing countries, wood accounts for 15% of the supply, compared to 3% in developed countries. Burning wood for heat and cooking accounts for 80% of the wood harvested in developing countries.
In 2000, 2.7 billion people in 77 _______ countries didn’t get enough fuel wood to meet their basic needs (800 million people) or were forced to meet their needs by using wood faster than it is replenished.
City dwellers in many developing countries burn ______ b/c it is much lighter than fuel wood and thus is much cheaper to transport. However, burning wood in traditional earthen pits to produce ______ consumes more than half the wood’s energy. Thus each city dweller burning _______ uses TWICE as much wood for a given amount of energy as a rural dweller who burns firewood. This helps explain the expanding deforested land that surrounds many cities in developing countries where ____ is a major fuel source.
charcoal (for all the blanks)
Fuel wood scarcity has the following harmful effects:
> places a burden on the rural poor, especially women and children, who often must walk long distances searching for firewood.
> buying fuel wood or charcoal can take 40% of poor family’s income
> waterborne infectious diseases and deaths can occur as prices rise and burning wood or charcoal to boil water becomes an unaffordable luxury (aka too expensive to boil water)
> an estimated 800 million poor people who cannot get enough fuel wood burn dried animal dung and crop residues for cooking and heating. Not returning these natural fertilizers to the soil reduces cropland productivity and can increase hunger and malnutrition
How can developing countries reduce the severity of the fuel wood crisis?
1) planting more fast-growing fuel wood trees or shrubs
2) burning wood more efficiently
3) switching to other fuels
Could planting fuel wood plantations with eucalyptus tees be the answer?
> they grow fast in poor soils..but there are disadvantages.
In Australia, these trees thrive in areas with good rainfall. However, when planted in arid areas, these trees suck up so much of the scarce soil water that most other plants cannot grow—-> reduces the amount of animal food (fodder) that farmers can give to their livestock and hinders (prevents/stops/delays) replenishment of groundwater
Eucalyptus trees also deplete the soil of nutrients, produce toxic compounds that accumulate in the soil (because low rainfall), and inhibit (prevents) nitrogen uptake.
In Karnata, India, what did the enraged villagers do when the government planted eucalyptus trees?
they uprooted the saplings.
The most successful fuel wood planting projects do what?
1) involve local people in their planning and implementation
2) give village farmers incentives (motivation), such as ownership of the land or ownership of any of trees that grow on village land
3) grow the trees on community woodlots, which are easy to tend and harvest (rather than fuel wood plantations located far from where the wood is needed)
The sun-dried roots of various gourds and squashes could be used as ______. These root-fuel plants 1) regenerate themselves each year, 2) produce large quantities of burnable biomass per unit area on dry, deforested lands, 3) help reduce soil erosion, and 4) produce an edible seed with high protein content.
Using a traditional 3-stone fire to burn wood typically wastes about ___ of the wood’s energy content. New, cheap, more efficient, and less polluting stoves can provide both heat and light while reducing indoor air pollution. The stoves must be easy and cheap to build, and the materials used to make them must be easily accessible locally. Cheap and easily made solar ovens that capture sunlight to provide heat can reduce wood use and air pollution in sunny and warm areas. However, people in cultures that use fires for light and heat at night and as centers for social interaction often do not accept these stoves.
List some countries in which reducing fuel wood shortages was successful.
China, Nepal, Senegal, and South Korea. However, most developing countries suffering from fuel wood shortages have inadequate forestry policies, budgets, and trained foresters. Such countries are cutting trees (for fuel wood and forest products) 10 – 20 times faster than new trees are being planted.
Who is Wangari Maathai?
the first Kenyan woman to earn a Ph.D. (in anatomy) and to head an academic department (veterinary medicine) at the University of Nairobi, organized the internationally acclaimed Green Belt Movement (establish tree nurseries, raise seedlings, and plant & protect a tree for each of Kenya’s 30 million people) in 1977.
Since 1984, Lalita Balakrishnan and the All-India Women’s Conference have enlisted _______ ______ to spread the use of efficient smokeless wooden stoves (chulhas) across the country.
Today, more than _______ ________ _______ larger than 10 square kilometers (4 square miles) are located in more than 120 countries. These parks cover a total area equal to that of Alaska, Texas, and California combined.
1,100 national parks
The U.S national park system, established in ____, has 55 national parks (aka “crown jewels”), most of them in the West. These national parks are added by state, county, and city parks. Most state parks are located near urban areas and have about twice as many visitors per year as the national parks.
Parks everywhere are under pressure from ______ ___ ______ threats. Only 1% of the parks and wildlife reserves in developing countries receive protection. The other 99% are paper parks that exist in name only and have no protection.
external and internal threats
Most of these paper parks are invaded by 1) local people who need wood, cropland, game animals, and other natural products for daily survival and 2) loggers, miners, and ___________ . Park services in developing countries typically have too little money and too few personnel to fight these invasions, either by force or by education.
wildlife poachers (who kill animals to obtain and sell items such as rhino horns, elephant tusks, and furs)
Most of the ____ ______ ____ are too small to sustain many large animal species, and many suffer from invasions by non-native species that can reduce the populations of native species and cause ecological disruption.
world’s national parks
_______ is one of the biggest problems of national and state parks in the U.S and other developed countries.B/C of increased numbers of roads, cars, and wealthy people, annual recreational visits to major U.S national parks increased more than fourfold between 1950 and 2000, and visits to state parks rose seven-fold.
What do parks provide?
scenery, solitude, and recreational experiences for visitors
Because of a lack of funds, visitors see…..
closed campgrounds, uncollected garbage, debris on trails and beaches, dirty toilets, and fewer nature lectures and tours by park rangers. During the summer, users of the most popular national and state parks often face hour-long entrance backups and experience noise, congestion, and stress instead of peaceful solitude
U.S Park Service rangers spend an increasing amount of time on ______ ________ instead of conservation, management, and education. Currently there is 1 ranger for every 84,200 visitors to the major national parks. Many overworked and underpaid rangers are leaving for better paying jobs.
List some harmful non-native species.
>ex. European wild boars that were imported to North Carolina in 1912 for hunting; threatens vegetation in part of The Great Smoky Mountains National Park
>ex. Brazilian pepper tree has invaded Florida’s Everglades National Park
>ex. Mountain goats in Washington’s Olympic National Park trample native vegetation and accelerate soil erosion
Some non-native species have moved into parks. Meanwhile, some native species (including threatened and endangered species) of plants and animals are…
be killed or removed illegally in almost half of U.S national parks.
What nearby human activities can threaten wildlife and recreational values in national parks?
mining, logging, livestock grazing, coal-burning power plants, water diversion, and urban development
Air pollution affects scenic views in national parks more than ____ of the time.
ex. polluted air kills trees in California’s Sequoia National Park, blots views at Arizona’s Grand Canyon, and car smog damages many plant species in Great Smoky Mountains National Park
Water pollution (WP) and diversion (WD) affect the following national parks (and more!
Padre Island National Seashore in Texas- wp
Death Valley National Monument- Las Vegas wd it
Sequoia and National Park and Kentucky’s Mammoth Cave – wp in parking lot
Florida’s Everglades National Park- wd for urban areas and agriculture–> may dry up
The U.S NPS uses the principle of _____ ______ to manage the 55 major U.S national parks. This means managing the parks as if they were wilderness ecosystems that can adapt and sustain themselves if left alone. Most parks are too small to sustain themselves. Even the biggest ones, such as Yellowstone, cannot be isolated from 1) the harmful effects caused by activities in nearby areas and 2) destruction from within by exploding populations of some native plant-eating species such as the elk and by invading non-native species.
What are the U.S NPS’s two goals that conflict w/ each other?
1) to preserve nature in parks
2) to make nature more available to the public
How can management of the U.S National Parks be improved?
> require integrated management plans for parks and other nearby federal lands
> increase the budget for 1) adding new parkland near the most threatened parks and 2) buying private lands inside parks
> locate all new and some existing commercial facilities and visitor parking areas outside parks and provide shuttle buses for entering and touring most parks, as was done in 2000 in Zion National Park, Utah. Shuttle bus systems are also available to Yosemite, Grand Canyon, and Denali National Parks
> require private concessionaires who provide campgrounds, restaurants, hotels, and other services for park visitors to 1)compete for contracts and 2) pay franchise fees equal to 22% of their gross (not net) receipts. private concessionaires in national parks pay the government only about 6-7% of their gross receipts in franchise fees; many large concessionaires with long-term contracts pay as little as 0.75% of their gross receipts.
> allow concessionaires to rent but not OWN facilities inside parks
> provide more funds for park system maintenance and repairs. currently, there is a $4.9 billion accumulation of maintenance, repairs, and high-priority construction projects at a time when the park usage and external threats to the parks are increasing
> survey the condition and types of wildlife species in parks
> raise entry fees for park visitors and pour receipts back into parks
>Limit the number of visitors to crowded park areas
>increase the number and pay of park rangers
>encourage individuals and corporations to donate money for park and maintenance and repair
What is the best way to preserve biodiversity?
a worldwide network of protected areas
currently, 17,000+ nature reserves, parks, wildlife refugees, wilderness, and other areas provide strict or partial protection for about 10% of the world’s land area; but many are too small to protect their native wild species and receive too little protection to prevent illegal and unsustainable exploitation of their plant and animal resources
Conservation biologists call for strict protection of at least ___ of the earth’s land area in a global system of biodiversity reserves that includes multiple examples of all the earth’s biomes. Doing this will take action and funding by national governments, private groups, and cooperative ventures (journeys) involving governments, businesses, and private conservation groups. (developers and resource extractors oppose the current 10%..)
1997- Brazilian government proposed establishing __ _____ in the Amazon on government owned lands and asked the World Wildlife fund to help it plan the system. This system would be spread over 10% of the Amazon. Mining & logging would not be permitted in the parks, and hunting & fishing would be allowed only for native inhabitants. 2001- project was launched. It is to be phased in over a decade, with funding from a number of international lending and aid organizations.
______ are vital parts of the earth’s natural resources that sustain all life and economies and are centers of evolution.
Reserves/protected areas/ “islands of biodiversity”
The selection, design, and management of biodiversity reserves should be guided by what 3 ecological principles?
1) ecosystems are rarely at a stable point (the “balance of nature” concept) and thus cannot be locked up and protected from human disturbances. Instead, they are mostly in a never-changing non-equilibrium state because of disturbances caused by natural processes and human activities.
2) intermediate disturbance hypothesis: ecosystems and communities that experience fairly frequent but moderate disturbances have the greatest diversity of species
3) we should view most reserves as “habitat islands” surrounded by a “sea” of developed and fragmented land.
Conservation biologists use the _____ __ _____ ________ to help them 1) locate & try to protect areas in greatest danger of losing species diversity, 2) estimate the size of a nature reserve needed to prevent it from losing species, 3) evaluate how closely a series of small wildlife reserves should be spaced to allow immigration from one preserve to another if a species in one reserve becomes locally extinct, and 4) assess the size and numbers of protected corridors needed to connect various reserves and encourage the spread of protected species between them.
theory of island biogeography
What 2 social principles are useful in establishing, managing, and protecting reserves?
1) include local people in the planning and design of a reserve
2) create user-friendly reserves that allow local people to use parts of a reserve or a buffer zone surrounding a reserve for sustainable timber cutting, livestock grazing, growing crops, hunting, and fishing. Also train local people as guides and local wildlife experts and hire them to help restore degraded areas.–> local people = partners in protecting a reserve from unsustainable uses, not destroyers
What is the best shape for nature reserves?
Ideally, a circular reserve is better than an elongated reserve because the circular shape allows for more protection of the interior area that is further away from the edges of the reserve. A long, linear reserve has the most edge, and ALL of its interior space is close to the edge. most reserves have irregular shapes b/c they depend on what land is available.
Is it better to have a Single Large Or Several Small reserves of an equal area? (aka “SLOSS” debate)
general agreement is that large reserves 1) are the only way to maintain viable populations of large, wide-ranging species such as panthers, elephants, and grizzly bears, 2) sustain more species based on the species-area curve, 3) minimize the area of outside edges exposed to natural disturbances (ex. fires), invading species, and human disturbances from nearby developed areas, and 4) provide greater habitat diversity than small reserves.
however, in some locales, several well-placed, medium sized, isolated reserves 1) may have a wider variety of habitats and thus preserve more biodiversity than a single large reserve of the same area, 2) may better protect more populations of endemic species with small ranges than a single large reserve, and 3) are less likely to be simultaneously devastated by a single event such as a flood, fire, disease, or invasion by a non-native species than a single large reserve
a mixture of both large and small reserves may be the best way to protect a variety of species and communities against a number of different threats
Is it better to have a heterogeneous (diverse) reserve w/ a variety of habitats or a homogeneous (alike) reserve?
a heterogeneous reserve generally is better b/c nature is rarely at equilibrium state and undergoes continuous change. a heterogeneous reserve 1) provides a variety of habitat patches (patch dynamics) of different sizes, shapes, and successional stages and 2) can allow species in disturbed patches to undisturbed patches
Should several small reserves in the same area be isolated from one another or connected by corridors?
establishing habitat corridors between reserves can 1) help support more species, 2) allow migration of vertebrates that need large ranges, 3) permit migration of individuals and populations when environmental conditions in a reserve deteriorate, 4) help preserve animals that must make seasonal migrations to obtain food, and 5) enable some species to shift their ranges if global warming makes their current ranges uninhabitable.
BUT! corridors can 1) threaten one-isolated populations by allowing the movement of pest species, disease, fire, and exotic species between reserves, 2) increase exposure of migrating species to natural predators, human hunters, and pollution, and 3) be costly to acquire, protect, and manage.
What should be the role of buffer zones in establishing nature reserves?
whenever possible, it is important to use the buffer zone concept. this means protecting an inner core of a reserve by two buffer zones in which local people can extract resources (from buffer zones) in ways that are sustainable and do not harm the inner core. The United Nations uses this principle in establishing its global network of biosphere reserves.
used to determine whether existing networks of nature reserves provide enough protection for native plant and animal species and natural communities.
can occur in parts of reserve networks where species and communities lack adequate protection
What are the steps of gap analysis?
1) combine existing vegetation data w/ satellite (remote-sensing) data to produce computerized GIS maps of the topography, vegetation, hydrology, land ownership, and existing or proposed nature reserves of a region
2) use bioinformatics (databases of biological information) and other sources of data to show the known or estimated geographic distribution of the region’s plant and animal species
3) place (superimpose) the species distribution maps onto the GIS maps of existing vegetation and protected areas to determine 1. unprotected areas, 2. gaps w/ very high species diversity, or 3. unprotected pockets of rare species.
4) use this information to close the gaps by 1. establishing new nature reserves, 2. expanding the size and shape of existing reserves, 3. adding corridors, or 4. persuading private landowners or developers to modify their existing or proposed patterns of land use
The Biological Resources Division of the U.S Geological Survey has initiated a _______ ___ _______ ______ to provide broad geographic information on the status of biodiversity protection throughout the United States
National Gap Analysis Program (GAP)
B/C there won’t be enough money or political support to protect most of the world’s terrestrial biodiversity, ecologists suggest using two approaches— what are they?
1) a prevention strategy designed to reduce the future loss of biodiversity. it focuses international efforts on establishing a variety of large and small reserves in the world’s most bio-diverse countries and threatened species-rich areas
2) a emergency action strategy that identifies and quickly protects biodiversity hot spots. they are areas especially rich in plant and animal species that are found no where else and are in great danger of extinction or serious ecological disruption.
The 25 hot spots so far (ex. Central Chile) 1) cover only ___ of the land area of the earth, 2) consist mostly of tropical rain forests, 3) contain about 60% of the earth’s terrestrial biodiversity, and 4) are the only locations for more than 1/3 of the planet’s known terrestrial plant and animal species(including 55% primate species and 22% of all carnivore species)
Currently, 1.1 billion people who live in or near these hot spots suffer from extreme __________, and in 19 of the 25 hot spots the human population is growing more rapidly than world population.
malnutrition (lack of nutrients that is required for good health)
According to conservation biologists, spending about $500 million annually over a 5-year period could go far in safeguarding these endangered centers of biodiversity; this use of for protecting at least a third of the world’s threatened species is equivalent to about what the world’s nations spend on ______ every 8 hours.
What are earth’s 19 most bio-diverse countries?
Mexico, Costa Rica, Colombia, Ecuador, Peru, Brazil, Venezuela, Cameroon, Zaire, South Africa, Ethiopia, Madagascar, India, China, Myanmar, Philippines, Malaysia, Indonesia, and Australia
What should the goals of managing a nature reserve be?
> maintain its variety of native ecosystem types
> sustain viable populations of its major native species and prevent or control populations of invasive species
> sustain its essential ecological processes such as energy flow, nutrient cycling, and succession
> maintain the evolutionary potential of its species and ecosystems
> allow sustainable human use of all or part of its area in ways that don’t harm its functioning and long-term sustainability
these goals are difficult to achieve b/c 1) nature reserves are affected by mostly unpredictable biological, cultural, economic, and political changes, and 2) their size, shape, and biological makeup often are determined by political, legal, and economic factors that depend on land ownership and conflicting public demands rather than by ecological principles and considerations
What is adaptive ecosystem management?
> integrates ecological, economic, and social principles to help maintain and restore the sustainability and biological diversity of ecosystems while supporting sustainable economies and communities
> seeks ways to get government agencies, private conservation organizations, scientists, business interests, and private landowners to reach a consensus on how to achieve common conservation objectives
> views all decisions and strategies as scientific and social experiments and uses failures as opportunities for learning and improvement
> emphasizes continual information gathering, monitoring, reassessment, flexibility, adaptation, and innovation in the face of uncertainty and usually unpredictable change
to get conflicting interests to cooperate in achieving ecological and economic sustainability is not easy and takes time, effort, and patience; but human and ecological rewards are worth the effort.
What is wilderness?
-(can be a way to protect undeveloped land from human exploitation fyi)
-The U.S Wilderness Act of 1964 states that a wilderness consists of areas “of undeveloped land affected primarily by the forces of nature, where man is a visitor who does not remain.”
-U.S president Theodore Roosevelt summarized what should be done w/ wilderness: “Leave it as it is. You cannot improve it.”
-U.S Wilderness Society estimates that a wilderness area should contain at least 4,000 square kilometers (1,500 square miles); otherwise it can be affected by air, water, and noise pollution from nearby human activities.
Why should we preserve wildernesses?
> we need places where people can 1) experience the beauty of nature and observe natural biological diversity and 2) enhance their mental and physical health by getting away from noise, stress, development, and large numbers of people
> (most important reasons:) 1) to preserve the biodiversity they contribute as a vital part of earth’s natural capital and 2) to protect them as centers for evolution in response to mostly unpredictable changes in environmental conditions
> 1) provide mostly undisturbed habitats for wild plants and animals, especially those that need a large range, 2) help protect diverse biomes from damage, and 3) provide a natural laboratory in which we can discover more about how nature works in the few remaining areas not seriously disturbed by human activities (aka, wilderness= biodiversity and wilderness bank and an eco-insurance policy)
> some analysts believe that wildernesses should be preserved because the wild species it contains has an ethical right to 1) exist (or struggle to exist) and 2) play their roles in the earth’s ongoing biological evolution and ecological processes, without human interference; aka species have intrinsic value, regardless of their usefulness to us
John Muir was a _________.
David Brower was a _________.
Wilderness supporters call for….
> protecting more wilderness in 1) the world’s most endangered hot spots in species-rich countries and 2) the United States
> 1) emphasis on wilderness protection of grasslands lowland forests, and wetland that are largely absent from the current system and 2) allowing some degraded areas to return to a more wild state
To protect the most popular areas from damage, wilderness managers 1) designate areas where camping is allowed, 2) limit the number of people using these sites at any one time, 3) use wilderness rangers to patrol vulnerable areas, and 4) enlist volunteers to pick up trash discarded by thoughtless users who do not follow the __________ wilderness ethic.
Leave No Trace (LNT)
Environmentalist Roderick Nash suggests dividing wilderness areas into what 3 categories?
1) easily accessible, popular areas that have trails, bridges, hikers’ huts, outhouses, assigned campsites, and extensive ranger patrols
2) large, remote wilderness areas used only by people who get a permit by demonstrating their wilderness skills
3) undisturbed biologically unique areas with no human entry allowed
Almost every place on the earth has been degraded to some degree by human activities. The good news is that _______ ________ can partially reverse much of the environmental damage we have inflicted on nature.
Scientists have developed the following methods to speed up the natural repair of degraded ecosystems:
> restoration, which involves trying to return a particular degraded habitat or ecosystem to a condition as similar as possible to its pre-degraded state. 3 difficulties are 1) lack of knowledge about the previous composition of a system, 2) changes in climate, soil, and species composition that may make it impossible to restore an area to an earlier state, and 3) ecosystems are always undergoing change (basically try to return it to how it was)
> rehabilitation, which involves any attempt to restore at least some of a degraded system’s natural species and ecosystem functions. ex. removing pollutants and replanting areas such as mining sites, landfills, and clear-cut forests to reduce soil erosion (basically to make it functional again, not to its original state)
> replacement, which involves replacing a degraded ecosystem with another type of ecosystem. ex. a productive pasture or tree plantation may replace a degraded forest.
> creating artificial ecosystems. ex. 1) the ecological waste water treatment systems developed by John Todd and 2) artificial wetlands developed to treat sewage in Arcata, California
Researchers suggested the following principles for carrying out ecological restoration:
– mimic nature and natural processes and let nature do most of the work, wherever possible
– recreate important ecological niches that have been lost
– rely on pioneer species and natural ecological succession to make easier the restoration process
– control or remove harmful non-native species
What are basic steps used in ecological restoration and rehabilitation?
– identify what caused the degradation (such as pollution, farming, overgrazing, mining, or invading species)
– eliminate or sharply reduce those factors. ex. remove toxic soil pollutants, add nutrients to the depleted soil, adding new topsoil, and eliminating disruptive non-native species.
– if necessary, reintroduce species (especially keystone species) to restore natural ecological processes
– protect the area from further degradation and from the disruptive effects of fire
– monitor restoration efforts, assess success, and use adaptive ecosystem management to modify strategies as needed.
Most attempts to restore degraded land involve the use of secondary ecological succession. They include:
– trying to hold an ecosystem at a particular desirable stage of secondary succession. ex. 1. using controlled burning to eliminate non-native grass and 2. removing trees to restore grassland to an early successional stage
– speeding up natural secondary ecological succession. ex. 1. planting young trees in a clear-cut forest area and 2. preventing fires that can set back succession in areas such as degraded tropical seasonal forests
– allowing natural secondary succession to proceed. ex. much of the land set aside in 1935 as the Shenandoah National Park in Virginia in 1935 had suffered from over 200 yrs of grazing, mining, logging, and burning. Primarily by protection and allowing nature to take its course through secondary succession, most of the area is now a diverse temperate forest dominated by oak and hickory trees.
Repairing ecosystems requires that a pool of suitable existing ______ ______ ______ ______ _____ be available. ex. recovery of Shenandoah National Park took place mostly because there was enough seeds (mostly underground) and patches of uncut diverse segments left for natural regeneration to take place. Thus an important step in restoration efforts is to identify the remaining native species found above and below the ground of the site or in nearby areas.
plant species and soil organisms
________ _______ is getting into ecological restoration. In May 2000, the Australian Stock Exchange listed an Australian firm called Earth Sanctuaries, Ltd; this firm buys degraded land, restores it, and earns income from ecotourism and consulting on ecosystem assessment and ecological restoration
Why are prairies ideal subjects for ecological restoration?
> many residual or transplanted native plant species can be established in a few years
> the technology involved is similar to that in gardening and agriculture
> the process is well suited for volunteer labor needed to plant native species and weed out invasive species (until the natural species can take over)
The Ferni National Accelerator Laboratory in Batavia, Illinois, is the site for one of the world’s largest tall-grass prairie restoration projects. It was created by Ray Schulenberg and Robert Betz, who began by locating remnants of _____ Illinois prairie in old cemeteries, on embankments, and on other patches of land. In 1972, they transplanted these remnants (remains) by hand to a 4-hectare (10-acre) patch at the Ferni Laboratory site. Each year since then, volunteers have carefully prepared more land, sowed it with native prairie plants, weeded it by hand, and used controlled burning to maintain established communities. The result is more than 180 hectares (445 acres) of restored prairie. New native species are introduced each yr, with the goal of establishing the 150 – 200 species that once flourished on the site.
Why do analysts worry about environmental restoration?
it can encourage continuing environmental destruction and degradation by suggesting any ecological harm we do can be reversed/undone
> however, ecologists point out that preventing ecosystem damage in the first place is cheaper and more effective than any form of ecological restoration
What do government policies allow developers to do?
allows them to destroy one ecosystem or wetland if they (developers) protect, restore, or “create” a similar one of roughly the same size. This trade off, called mitigation, approach is preferable to wanton (evil) destruction of ecosystems
Ecological restoration expert John Berger says:
“The purpose of ecological restoration is to repair previous damage, not legitimize further destruction.”
2002- Edward Wilson, an expert on biodiversity, published a book called “The Future of Life”. In his book, he proposed the following priorities for protecting most of the world’s remaining ecosystems and species:
> take immediate action to preserve the world’s 25 biological hot spots
> keep intact the world’s five remaining frontier forests, which are the earth’s last remaining true wilderness areas. they are the remaining 1) rain forests of the Amazon, central Africa, and New Guinea, and 2) temperate coniferous forests (has cone-bearing trees, mostly evergreens, that have needle-shaped or scale-like leaves) of North America, Russia, Finland, and Scandinavia.
> cease all logging of old-growth forests everywhere
> concentrate on protecting and restoring everywhere the world’s lakes and river systems, which are the most threatened ecosystems of all
> determine precisely the world’s marine hot spots, and assign them the same priority for immediate action as for those on land
> complete the mapping of the world’s terrestrial and aquatic biodiversity so we know what we have and can make conservation efforts more precise and cost-effective
> ensure the full range of the earth’s terrestrial and aquatic ecosystems are included in a global conservation strategy
>make conservation profitable. this involves 1) finding ways to raise the income of people who live in or near nature reserves so they can become partners in their protection and sustainable use, 2) providing financial help from private and government sources to governments that protect their forests and other nature reserves, and 3) helping governments understand that ecotourism, bioprospecting, and eventually greenhouse gas (carbon) trading credits for protecting remaining wild land can yield more income than logging or clearing such land for agriculture.
This strategy for protecting the earth’s precious biodiversity will not be implemented (applied) without political pressure on elected officials by _______ ______ and groups of such citizens.