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What is a Grassland? A large open area of country covered with grass. Two types: Rangelands and Pastures
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Do Now:
• Forestry multiple choice quiz. 13 questions 10 minutes• Remember: -underline the stem - look for umbrella terms - eliminate absolute statements
Good Luck!
Aim: How Should We Manage and Sustain Grasslands?
What is a Grassland?
• A large open area of country covered with grass.• Two types: Rangelands and Pastures
Rangelands
• Unfenced grasslands in temperate and tropical climates that provide forage for animals
Pastures
• Managed grasslands and fenced meadows used for grazing livestock
Do you understand?
• What is the difference between a rangeland and a pasture?
Ecological Services of Grasslands• Soil formation• Erosion control• Nutrient cycling• Storage of atmospheric carbon dioxide in biomass• Maintenance of diversity
Some Rangelands are Overgrazed • Overgrazing of rangelands• Reduces grass cover• Leads to erosion of soil by water and wind• Soil becomes compacted • Enhances invasion of plant species that cattle won’t eat
Natural Capital Degradation: Overgrazed and Lightly Grazed Rangeland
Fig. 10-20, p. 234
Pause…Think…Write…
• Explain how overgrazing is an example of the tragedy of the commons. Support your answer with an example.
Read A Loud
• The Malpai Borderlands - Arizona-New Mexico border - Management success story
Natural Capital Restoration: San Pedro River in Arizona
Fig. 10-21, p. 235
1980’s 1990’s
Pause…Think…Discuss
• With your table come up with three ways to reduce overgrazing and use rangelands more sustainably.
• Use evidence from the case studies to support your answer.
We Can Manage Rangelands More Sustainably
• Rotational grazing• Replant barren areas• Apply fertilizer• Reduce soil erosion• Suppress growth of invasive species• Herbicides• Mechanical removal• Controlled burning• Controlled short-term trampling
Case Study: Grazing and Urban Development the American West
• American southwest population surge since 1980
• Land trust groups: conservation easements
• Reduce the harmful environmental impact of herds• Rotate cattle away from riparian areas• Use less fertilizers and pesticides• Operate ranch more economically and sustainably
Summary:
• If we fail to protect a much larger percentage of the world’s remaining grasslands, describe three harmful effects that this is likely to have on any children and grandchildren you might have.