Post on 18-Jan-2016
10-2 How Should We Manage and Sustain Forests?
• Concept 10-2 We can 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.
Solution: Sustainable Forestry• Biodiversity researchers and a growing number of
foresters have called for more sustainable forest management• Identify and protect forest areas
________ in biodiversity• Rely more on _____________ and
_____________ cutting• Stop logging in _________________ forests• Reduce _________ building in uncut forest areas• Leave dead or fallen timber for wildlife
_____________ and nutrient _______________
highselective
strip
old-growthroad
habitat cycling
Solution: Sustainable Forestry
• Put tree plantations only on _________________ or degraded land
• ________________ timber grown bysustainable methods
• Include ____________________ services of forests in estimates of
their economic value
deforested
Certify
ecological
Science Focus: Certifying Sustainably Grown Timber
• Collins Pine is a forests products _____________that owns and manages large areas of timberland in California, Oregon and Pennsylvania • Has used selective cutting since the 1940s
• Each year their land is evaluated by a subsection of the _____________ _______________ Council and they are awarded with a _______ logo on their products• Only ______ of the world’s forest area in 82 countries
has been certified according to FSC standards
company
Forest StewardshipFSC
5%
We Can Improve the Management of Forest Fires
• In the U.S., the _____________ _________ educational campaign has saved many lives and prevented countless forest fires• Downside?…the advertising campaign has convinced
much of the public that all forest fires are ________
• We actually need _________________ to prevent the build up of flammable underbrush which may cause crown fires
• To reduce this risk, one strategy is to conduct _________________ fires…setting small, contained surface fires to reduce the buildup of underbrush
Smokey Bear
bad
surface - fires
prescribed
• A second strategy is to allow some fires on public lands to ____________
• A third strategy is to __________ out a forest zone surrounding _____________ or other fire prone buildings
• A fourth strategy is to thin forest areas vulnerable to fire by removing ____________ trees
burn
thinhouses
small
We Can Reduce the Demand for Harvested Trees
• One way to reduce the pressure on forest ecosystems is to improve the efficiency of wood ________• 60% of U.S. wood consumed is wasted• This results from…• Inefficient use of ____________________ materials• Excess __________________• Overuse of _________ mail• Inadequate paper __________________
use
constructionpackagingjunk
recycling
We Can Reduce the Demand for Harvested Trees
• We can reduce our need to harvest trees by making paper from ______________ resources• China uses
_______________• U.S. uses a small amount
of __________ (kuh-NAHF)
• Other possible options…hemp, kudzu vine
kenaf
tree-free
rice straw
kenaf
• So to reduce our demand for harvesting trees, we need to be…• Reducing ________________• Finding ________________• Embracing _________________ use
waste
alternativessustainable
Case Study: Deforestation and the Fuelwood Crisis
• About _______ of the wood we harvest world-wide is used for __________
• Less-developed countries use fuelwood for _______________ and _______________
• Ex: Haiti was once a tropical paradise , but now it is an ecological _______________ because its trees were harvested for fuelwood
halffuel
heating cooking
disaster
Mangrove Forest in Haiti Chopped Down for Fuelwood
Fig. 10-18, p. 232
Case Study: Deforestation and the Fuelwood Crisis
• Possible solutions• Establish small plantations of _______________
fuelwood trees and shrubs• Burn wood more efficiently with better
_____________ (that also produce less pollution)• Solar or wind-generated electricity• Burn garden ______________
fast-growing
stoves
waste
Governments and Individuals Can Act to Reduce Tropical Deforestation
• Help settlers to develop ____________________ sustainable agriculture and forestry in tropical forest
• Government _________________ for forest land
• Debt-for-nature swaps/conservation concessions• Example: Brazil’s dairy farmers receive _____________
assistance as long as they are reforesting and maintaining their land…____________ milk yields and ______________ their incomes
• Plant trees
• Buy certified lumber and wood products
small-scale
protection
technical
tripled doubled
Fig. 10-19, p. 233
Solutions
Sustaining Tropical Forests
Prevention Restoration
Protect the most diverse and endangered areas
Encourage regrowth through secondary succession
Educate settlers about sustainable agriculture and forestry
Subsidize only sustainable forest use
Rehabilitate degraded areasProtect forests through
debt-for-nature swaps and conservation concessions
Certify sustainably grown timber
Concentrate farming and ranching in already-cleared areas
Reduce poverty
Slow population growth
10-3 How Should We Manage and Sustain Grasslands?
• Concept 10-3 We can sustain the productivity of grasslands by controlling the number and distribution of grazing livestock, and by restoring degraded grasslands.
Some Rangelands Are Overgrazed (1)• After forests, grasslands are the ecosystems most
widely used and altered by humans
• Rangelands• ____________________ grasslands in temperate and
tropical climates that provide forage for animals• Grazing = _________________• Browsing = __________________
• Pastures• ____________________ grasslands and fenced
meadows used for grazing livestock
unfenced
grassshrubs
managed
Some Rangelands Are Overgrazed (2)• Important ecological services of grasslands• ____________________ formation• Erosion _____________________• Nutrient _________________• Storage of atmospheric _______ in biomass• Maintenance of biodiversity
• Cattle and sheep currently graze on about _____ of the world’s grasslands…estimated to increase to _______ by 2050.
Soilcontrol
cyclingCO2
42%
70%
Some Rangelands are Overgrazed (3)• Overgrazing of rangelands occurs when too many
animals graze for too long…damaging the ________ of grasses and exceeding the area’s _____________ _______________• Reduces grass cover• Leads to erosion of soil by water and wind• Soil becomes compacted…diminishes capacity to hold
_____________• Enhances invasion of plant species that cattle won’t
eat
rootscarrying
capacity
water
Natural Capital Degradation: Overgrazed and Lightly Grazed Rangeland
Fig. 10-20, p. 234
Case Study: The Malpai Borderlands• Malpai Borderlands• Grasslands located by the ___________________
__________________ border• For more than a century, ranchers there….• Allowed __________________• _________________ fires….allowed trees and shrubs
to replace grasses• Management success story• Since 1993, ranchers, scientists, environmentalists, and
governing agencies began working together to restore the grasslands – conducted periodic _______________ burns
Arizona -New Mexico
overgrazingsuppressed
controlled
Natural Capital Restoration: San Pedro River in Arizona
Fig. 10-21, p. 235
__________________ zoneriparian
We Can Manage Rangelands More Sustainably (1)
• More sustainable management of rangelands…
• _________________ grazing – cattle are confined by portable fencing to one area for a ____________ time and then moved to a new location
• Suppress growth of ________________ species• Herbicides• Mechanical removal• Controlled burning• Controlled short-term ______________________
• Replant barren areas with ___________ grasses and applying fertilizer…more expensive option
Rotationalshort
invasive
trampling
native
Case Study: Grazing and Urban Development the American West
• American southwest population surge since 1980
• Some ranchers have been selling their land to _________________
• To sustain our remaining grasslands, we have been working to __________________ cattle ranches• Land trust groups pay ranchers for conservation
_________________ - deed restrictions that bar future owners from developing the land
• Pressuring local governments to ___________ the land
developers
preserve
easements
zone
Review Questions
• What does an FSC logo indicate?
• Why are surface fires needed?
• What is meant by the term “fuelwood crisis”?
• What methods will help us to sustain grasslands?
It is certified as sustainably made
To remove flammable underbrush & maintain grasslands
½ of our wood is used for fuel by LDCsand they need alternatives
Rotational Grazing Suppress Invasive Species Replant/Fertilize