Rangeland

1. Rangeland

2. How Should We Manage and Sustain Grasslands? • Important ecological services of grasslands: • Soil formation • Erosion control • Nutrient cycling • Storage of atmospheric carbon dioxide in biomass • Maintenance of diversity

3. How Should We Manage and Sustain Grasslands? • Almost half of the world’s livestock graze on natural grasslands (Rangelands) and managed grasslands (Pastures). • We can sustain rangeland productivity by controlling the number and distribution of livestock and by restoring degraded rangeland.

4. Some Rangelands Are Overgrazed • Overgrazing occurs when too many animals graze for too long and exceed carrying capacity of a grassland area. • Grass/shrubs are damaged beyond repair • Reduces grass cover • Leads to erosion of soil by water and wind

5. Some Rangelands Are Overgrazed • Desertification - The degradation of land that results in a desert • Caused by overgrazing, deforestation, or overuse • The worlds deserts are getting bigger • Prevention of overgrazing: • Rotational grazing • Replant barren areas • Apply fertilizer • Reduce soil erosion

6. FORESTS

7. Forests Vary in Their Make-up, Age, and Origins • Old-growth forest: Original forests that have not been disturbed for logging, road building, or development • Sometimes called primary, ancient, virgin, or primeval forests • 36% of world’s forest • High biodiversity because of many specialized niches

8. Remaining Old-Growth Forests in the U.S.

9. Forests Vary in Their Make-up, Age, and Origins Second-growth forest: • Area which has re-grown after a major disturbance such as fire, insect, or timber harvest • 60% of world’s forest • The area is reclaimed by the natural process of secondary succession • Small shrubs and trees followed by the larger trees

10. Tree plantation (tree farm): Planted stands of a particular tree species that are maintained, harvested, and replanted • Typically used for paper or particle board

11. Economic and Ecological Services Estimated annual value: Economic services $1.8 trillion Ecological services $4.7 trillion

12. Deforestation

13. Unsustainable Logging is a Major Threat to Forest Ecosystems • Building roads into previously inaccessible forests paves the way for increased erosion, habitat fragmentation, loss of biodiversity, and invasion by non-native species. • For this reason, many federal wilderness areas do not allow the construction of roads.

14. Three major tree harvesting methods: • Selective cutting • Clear-cutting • Strip cutting

15. Selective Cutting: • Mature trees are harvested individually from diverse forests • Younger trees left to harvest later • Reduces crowding • Removes diseased trees • Encourages growth of younger trees

16. Clear-cutting: • Removing all trees in a single pass.

17. Clear-cutting

18. Strip-cutting: • A type of clear cutting that involves clear trees along the contours of the land. • Less erosion

19. Deforestation in the tropical rainforest Amazon and the Congo

20. Tropical Forests Are Disappearing Rapidly • Large areas of tropical forest are burned to make way for cattle ranches and crops. • Soil in the rainforest is very poor • Farmers burn the trees down to provide nutrients for the soil • Heavy rain leaches away the nutrients so they move to another area and burn again

21. Not limited to the tropics

22. USASwift River Valley below

23. Tropical Forests Are Disappearing Rapidly

24. Tropical Forests Are Disappearing Rapidly • At least half of the world’s terrestrial plants and animals live in tropical rain forests. • About 2,100 of the 3,000 plants identified by the National Cancer Institute as sources of cancer-fighting chemicals come from tropical rain forests.

25. The Congo

26. The Congo

27. Logging roads give access to once isolated ecosystems

28. The Congo

29. The Amazon

30. The Amazon

31. The reason Why!!!!

32. Forest Fires

33. We Can Improve the Management of Forest Fires • Fire prevention programs have been very effective…too effective. • Large amounts of highly flammable underbrush have accumulated • Leads to larger, more destructive crown fires • To reduce fire damage: • Set controlled surface fires (Prescribed Fires). • Allow fires to burn on public lands if they don’t threaten life and property. • Clear small areas around property subject to fire.

34. Threats • Logging interests cut down rain forest trees for timber used in flooring, furniture, and other items. • Power plants and other industries cut and burn trees to generate electricity. • The paper industry turns huge tracts of rain forest trees into pulp. • The cattle industry uses slash-and-burn techniques to clear ranch land. • Agricultural interests, particularly the soy industry, clear forests for cropland. • Subsistence farmers slash-and-burn rain forest for firewood and to make room for crops and grazing lands. • Mining operations clear forest to build roads and dig mines. • Governments and industry clear-cut forests to make way for service and transit roads. • Hydroelectric projects flood acres of rain forest.

35. Solutions • Sustainable-logging regimes that selectively cull trees rather than clear-cut them would save millions of acres of rain forest every year. • Campaigns that educate people about the destruction caused by rain forest timber and encourage purchasing of sustainable rain forest products could drive demand down enough to slow deforestation. • Encouraging people who live near rain forests to harvest its bounty (nuts, fruits, medicines) rather than clear-cutting it for farmland would save million of acres. • Government moratoriums on road building and large infrastructure projects in the rain forest would save many acres. • From National geographic