Environmental Problems, Their Causes, and Sustainability 1

AdvantagesHelps meetcountry’s timberneedsCut areas growbackTrade-OffsLogging in U.S. National ForestsKeeps lumberand paper pricesdownProvides jobs innearbycommunitiesPromoteseconomic growthin nearbycommunitiesDisadvantagesProvides only 4% oftimber needsAmple privateforest land to meettimber needsHas little effect ontimber and paperpricesDamages nearbyrivers and fisheriesRecreation innational forestsprovides more localjobs and incomefor localcommunities thanloggingDecreasesrecreationalopportunitiesOne way to reduce the pressure to harvest trees forpaper production in national and private forests is tomake paper by using fiber that does not come fromtrees. Tree-free fibers for making paper come from twosources: agricultural residues left over from crops (suchas wheat, rice, and sugar) and fast-growing crops (such askenaf and industrial hemp).China uses tree-free pulp from rice straw andother agricultural wastes left after harvest to make almosttwo-thirds of its paper. Most of the small amountof tree-free paper produced in the United States ismade from the fibers of a rapidly growing woody annualplant called kenaf (pronounced “kuh-NAHF”; seephoto on p. vii).Compared to pulpwood, kenaf needs less herbicidebecause it grows faster than most weeds and reducesinsecticide use because its outer fibrous coveringis nearly insect proof. Growing kenaf does not depletesoil nitrogen because it is a nitrogen fixer. And breakingdown kenaf fibers takes less energy and fewerchemicals and thus produces less toxic wastewaterthan using conventional trees. According to the USDAkenaf is “the best option for tree-free papermaking inthe United States” and could replace wood-based paperwithin 20–30 years.Figure 11-16 Trade-offs: advantages and disadvantages ofallowing logging in U.S. national forests. Pick the single advantageand disadvantage that you think are the most important.Explain.How Can We Reduce the Need to HarvestTrees for Timber and Papermaking?Stop Waste and Make Paper fromTree-Free FibersAlmost two-thirds of the wood consumed in theUnited States is wasted, and much of the paper weuse could be made from agricultural residues andfast-growing crops such as kenaf.One way to reduce the pressure to harvest trees onpublic and private land in the United States (and elsewhere)is to improve the efficiency of wood use. Accordingto the Worldwatch Institute and forestry analysts,up to 60% of the wood consumed in the United Statesis wasted unnecessarily. This occurs because of inefficientuse of construction materials, excess packaging,overuse of junk mail, inadequate paper recycling, andfailure to reuse wooden shipping containers.Only 4% of the total U.S. production of softwoodtimber comes from the national forests. Thus, reducingthe waste of wood and paper products by only 4%could eliminate the need to remove any timber from nationalforests. This would allow these lands to be usedprimarily for recreation and biodiversity protection.11-6 TROPICAL DEFORESTATIONHow Fast Are Tropical Forests BeingCleared and Degraded and Why ShouldWe Care? Protecting the PricelessLarge areas of ecologically and economicallyimportant tropical forests are being cleared anddegraded at a fast rate.Tropical forests cover about 6% of the earth’s landarea—roughly the area of the lower 48 states. Climaticand biological data suggest that mature tropical forestsonce covered at least twice as much area as they do today,with most of the destruction occurring since 1950.Satellite scans and ground-level surveys used to estimateforest destruction indicate that large areas oftropical forests are being cut rapidly in parts of SouthAmerica (especially Brazil), Africa, and Asia.Studies indicate that more than half of the world’sspecies of terrestrial plants and animals live in tropicalrain forests. Brazil has about 40% the world’s remainingtropical rain forest in the vast Amazon basin,which is about two-thirds the size of the continentalUnited States. In 1970, deforestation affected only 1%of the area of the Amazon basin. By 2003, almost 20%had been deforested or degraded.According to a 2001 study by Penn State researcherJames Alcock, without immediate and aggressiveaction to reduce current forest destruction210 CHAPTER 11 Sustaining Terrestrial Biodiversity: Managing and Protecting Ecosystems