Terrestrial Biodiversity

1. Terrestrial Biodiversity Chapters 11 & 12

2. Biodiversity Decrease Factors Increase Factors • Middle stages of • succession • Moderate environmental • disturbance • Small changes in • environmental conditions • Physically diverse habitat • Evolution • Extreme environ- • mental conditions • Large environmental • disturbance • Intense environ- • mental stress • Severe shortages of • key resources • Nonnative species • introduction • Geographic isolation Figure 11-2Page 195

3. Value • Intrinsic (existence)- value regardless of usefulness to us • Instrumental- value based on usefulness to us • Existence- value whether we see it or get direct use from it (nonuse) • Aesthetic- appreciation of beauty (nonuse) • Bequest- willingness to pay to protect natural capita for future use

4. Conservation Biology • Uses rapid response strategies to stem loss & degradation of biodiversity • Bioinformatics- applied science of managing, analyzing, & communicating biological information • Importance- to understand & sustain biodiversity

5. Public Lands • 35% of U.S. land • 73% (of the 35%) is in Alaska

6. National parks and preserves National forests (and Xs) National wildlife refuges

7. National parks and preserves National forests (and Xs) National wildlife refuges

8. Use of Public Land • Protecting biodiversity, wildlife habitats, & ecological functioning of public land ecosystems • No government subsidies or tax breaks for using or extracting resources on public lands – user-pays approach • American people deserve fair compensation for extraction of any resources from their property

9. All users or extractors of resources on public lands should be responsible for any environmental damage they cause

10. Economist, developers, & resource extractors view public lands for their usefulness in providing timber, mineral, and other resources & ability to increase economic growth

11. Figure 11-7 • 8 important ecological services provided by forests • 7 important economic benefits of forests

12. Forest Growth • Old-growth forest- uncut forest or regenerated forest that has not been seriously disturbed by human activities or natural disasters for at least several hundred years • Second-growth forest- a stand of trees resulting from secondary ecological succession

13. Tree plantation- tree farm- managed tract with uniformly aged trees of 1 species that are harvested by clear-cutting as soon as they are commercially valuable; replanted & recut

14. Weak trees removed Seedlings planted Clear cut 25 15 10 30 Years of growth 5

15. Tree Harvesting • Even-aged- tree farm that consists of 1 or 2 fast-growing & economically desirable species (6-10 yr harvest) • Uneven-aged- variety of tree species at many ages & sizes

16. Trade-Offs Clear-Cutting Forests Advantages Disadvantages Reduces biodiversity Disrupts ecosystem processes Destroys and fragments some wildlife habitats Leaves moderate to large openings Increases soil erosion Increases sediment water pollution and flooding when done on steep slopes Eliminates most recreational value for several decades Higher timber yields Maximum economic return in shortest time Can reforest with genetically improved fast- growing trees Short time to establish new stand of trees Needs less skill and planning Best way to harvest tree plantations Good for tree species needing full or moderate sunlight for growth Figure 11-11Page 203

17. Deforestation • Temporary or permanent removal of large expanses of forest for agricultural use

18. Natural Capital Degradation Deforestation • Decreased soil fertility from erosion • Runoff of eroded soil into aquatic systems • Premature extinction of species with • specialized niches • Loss of habitat for migratory species such as • birds and butterflies • Regional climate change from extensive clearing • Releases CO2 into atmosphere from burning • and tree decay • Accelerates flooding Figure 11-12Page 203

19. Forest Cover • Difficult to estimate due to lack of satellite & radar data, unmonitored land-use change, & different definitions of what constitutes a forest

20. Bad News • Human activities have reduced original forest cover by 20-50% • 40% of remaining forests will be converted to other uses within 10-20 years

21. Good News • Total temperate forests increase slightly due to reforestation • Cut areas of tropical forests have increased tree cover from regrowth & tree farms

22. Forest Value • Estimated economical value - $36 trillion/yr • Economic savings provided by conserving nature vs. immediate profits by exploiting nature • Government subsidies & tax incentives support destruction & degradation

23. Solutions Sustainable Forestry • Grow more timber on long rotations • Rely more on selective cutting and strip cutting • No clear-cutting, seed-tree, or shelterwood cutting • on steeply sloped land • No fragmentation of remaining large blocks of forest • Sharply reduce road building into uncut forest areas • Leave most standing dead trees and fallen timber for • wildlife habitat and nutrient recycling • Certify timber grown by sustainable methods • Include ecological services of trees and forests in • estimating economic value Figure 11-13Page 205

24. Good News • Forest cover more now than in 1920 • Many diverse second-growth forests from cleared or partially cleared between 1620-1920 • Every year, more wood is grown than cut

25. Bad News • Remaining old-growth & diverse second-growth forests have been cut & replaced with tree farms • Disrupts ecosystem processes (energy flows & chemical cycling) • Reduces biodiversity

26. Figure 11-14Page 207 White pine blister rust Hemlock wooly adelgid Pine shoot beetle Sudden oak death Beech bark disease

27. Reduce Harmful Impacts • Ban imported timber • Selectively remove or clear-cut infected or infested trees • Develop tree species that are genetically resistant to common tree diseases • Conventional pesticides & biological controls

28. Surface fire- burns undergrowth & leaf litter Crown fire- extremely hot fire; burns whole trees & leaps from treetop to treetop Ground fire- surface fire that goes underground & burns partially decayed leaves & peat Forest Fires

29. Protection From Fire • Prevention • Prescribed burning (setting controlled ground fires to prevent buildup of flammable material)

30. Benefits of fires • To plants & animals: • Stimulate germination of certain tree seeds • Helps control pathogens & insects

31. Crown Fires • Advantages- clears out flammable small trees & underbrush in high-risk areas Disadvantages-???

32. Advantages Medium & large trees are cut down Reduces ground-level fuel & vegetation in dry forests Clears flammable vegetation around homes & buildings Disadvantages Removal of tress encourages dense growths of highly flammable young trees & rapidly growing underbrush Leaves behind highly flammable slash (debris) Healthy Forest Initiative Law

33. Timber Harvesting • Pressure on Congress by timber companies • Forestry Service keeps money from timber harvest • Government subsidies • Revenue from timber sales does not cover the cost of road building, timber sale preparation, administration & other overhead costs

34. Trade-Offs Logging in U.S. National Forests Advantages Disadvantages Provides only 4% of timber needs Ample private forest land to meet timber needs Has little effect on timber and paper prices Damages nearby rivers and fisheries Recreation in national forests provides more local jobs and income for local communities than logging Decreases recreational opportunities Helps meet country’s timber needs Cut areas grow back Keeps lumber and paper prices down Provides jobs in nearby communities Promotes economic growth in nearby communities Figure 11-16Page 210

35. Tree-free paper • Advantages- faster growth; less pesticides; nitrogen-fixing • Disadvantages- ???

36. Tropical Forests • Being cleared – FAST! • 50,000 to 170,000 km2 / year • Problem- important ecological & economic services provided by forests

37. Oil drilling • Mining • Flooding from dams • Tree plantations • Cattle ranching • Cash crops • Settler farming • Fires • Logging • Roads Secondary Causes • Not valuing • ecological services • Exports • Government policies • Poverty • Population growth • Roads Basic Causes

38. Figure 11-19Page 213 Solutions Sustaining Tropical Forests Prevention Restoration Reforestation Rehabilitation of degraded areas Concentrate farming and ranching on already-cleared areas 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 easements, and conservation concessions Certify sustainably grown timber Reduce illegal cutting Reduce poverty Slow population growth

39. Debt-for-nature Swap • Goal is to make it profitable for countries to protect tropical forests countries act as custodians of protected forest reserves in return for foreign aid or debt relief

40. Sustainable farming & logging • Tropical forests- help new settlers learn how to practice small-scale sustainable agriculture & forestry; multi-layered system of agroforestry – cultivate as many as 75 species on 2.5 acres • Kenya’s Green Belt Movement- women’s self-help group establish tree nurseries raise seedlings & plant/protect a trees for each of Kenya’s people

41. Threats to National Parks • Loggers • Miners • Poachers • Too little money • Too few employees • Too small to sustain many large animal species • Invasion by nonnative species

42. Solutions National Parks • Integrate plans for managing parks and nearby federal lands • Add new parkland near threatened parks • Buy private land inside parks • Locate visitor paring outside parks and use shuttle buses for entering and touring heavily used parks • Increase funds for park maintenance and repairs • Survey wildlife in parks • Raise entry fees for visitors and use funds for park management and maintenance • Limit number of visitors to crowded park rangers • Increase number and pay of park rangers • Encourage volunteers to give visitor lectures and tours • Seek private donations for park maitenance and repairs Figure 11-20Page 215

43. Protected Land • SHOULD protect at least 20% • Only 7%is strictly protected

44. Costa Rica • By mid-1970s had established parks & reserves for ¼ of land (6% for indigenous people) • Parks & reserves are consolidated into 8 mega-reserves designed to sustain 80% of biodiversity • Eco-tourism is now the country’s largest source of income

45. Large Reserves • Advantages- sustain more species & provide greater habitat diversity; minimize area of outside edges exposed to natural disturbances, invading species, & human disturbances • Disadvantages- ??

46. Corridors between Reserves • Advantages- help support more species & allow migration of vertebrates; seasonal migrations; allow for shifts in rage to accommodate global climate change • Disadvantages- ???

47. Biosphere Reserve Core area Buffer zone 1 Buffer zone 2 Tourism and education center Human settlements Research station

48. Biosphere Reserve • Core area- important ecosystem hat the government legally protects from all human activities except non-destructive research & monitoring • Buffer zone- surrounds & protects core area; emphasis on non-destructive research, education, & recreation

49. Transition zone (2nd buffer)- surrounds inner buffer zone; local people can engage in more intensive sustainable forestry, grazing, hunting, fishing, agriculture & recreation

50. Adaptive Ecosystem Management • Maintain & restore sustainability & biological diversity • Seek government consensus on how to achieve common conservation objectives • Use failures as opportunities for learning & improvement • Continual information gathering