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