Grassland and Rangelands CHAPTER 10. Fig. 12-16, p. 291 TRADE-OFFS Genetically Modified Crops and...
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Transcript of Grassland and Rangelands CHAPTER 10. Fig. 12-16, p. 291 TRADE-OFFS Genetically Modified Crops and...
Grassland and Rangelands
CHAPTER 10
Fig. 12-16, p. 291
TRADE-OFFSGenetically Modified Crops and Foods
Projected Advantages Projected Disadvantages
Irreversible and unpredictable genetic and ecological effects
Need less fertilizer
Need less waterMore resistant to insects, disease, frost, and drought
Harmful toxins in food from possible plant cell mutations
Grow faster New allergens in foodCan grow in slightly salty soils
Lower nutritionIncrease in pesticide- resistant insects, herbicide- resistant weeds, and plant diseases
May need less pesticidesTolerate higher levels of herbicides
Higher yieldsCan harm beneficial insects
Less spoilage Lower genetic diversity
Rangelands-unfenced grassland that supply forage for vegetation.
Fig. 10-15, p. 225
NATURAL CAPITAL DEGRADATION
Major Causes of the Destruction and Degradation of Tropical ForestsBasic Causes Secondary Causes• Not valuing ecological services • Roads • Cattle ranching• Crop and timber exports • Fires • Logging• Government policies • Settler farming • Tree plantations• Poverty • Cash crops
• Population growthCattle ranching
Tree plantations
Logging
Cash crops
Settler farming
FiresRoads
Some Rangelands Are Overgrazed (1)
• Important ecological services of grasslands– Soil formation– Erosion control– Nutrient cycling– Storage of atmospheric carbon dioxide in biomass– Maintenance of diversity
– Rangelands, if not overgrazed, are less destructive than feedlots.
REVIEW: What were the causes and remedies for the great dust bowl in the United States
CAUSES SOLUTIONS
Restoration of Grazing LandsWhat is a riparian area?
We Can Manage Rangelands More Sustainably (1)
• Rotational grazing• Replant barren
• Suppress growth of invasive species– Herbicides– Mechanical removal– Controlled burning– Controlled short-term trampling by livestock
CLASSWORK
• You are a member of a lobby group that is appearing before congress to testify about genetically modified foods. (GMF’s)
• You may argue for OR against.• Compose a well written paragraph providing
four (4) valid supporting sentences that supports your stance.
PAGE 287 IS A GREAT RESOURCE.
Vocabulary review.
• Potable• Municipality• Anthropogenic• Flavr savr tomato• Per capita