L14BioticandAbioticPlantsupdated

L14BioticandAbioticPlantsupdated - Different kinds of...

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Individuals Groups of Individuals Different kinds of interacting groups Different kinds of interacting groups across space and time BEHAVIOR POPULATION ECOLOGY COMMUNITY ECOLOGY ECOSYSTEM ECOLOGY
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Fact of the day: Fracking • A method of extracting natural gas by means of injecting water 1 , sand, and chemicals 2 under high pressure into a drilled well. • Pressure fractures the shale and opens fissures that allow the gas to flow out http://www.scientificamerican.com/article.cfm?id=us-fracking-firms 1 millions of gallons 2 596 different chemicals including benzene mediaroots.org
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Fact of the day: Fracking • Exempted from the Safe Drinking Water Act – Don’t need to disclose chemicals • Produces wastewater that may not be properly treated – Threaten drinking water – Contribute to air pollution http://www.scientificamerican.com/article.cfm?id=us-fracking-firms www.gaslandthemovie.com
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Fact of the day: Fracking • Today at 4:30 pm at Endeavour 120 www.gaslandthemovie.com
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Soil, Nutrients and Agriculture
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Meeting increasing demands • Tilman 1999 analyzed the FAO dataset – World food production almost doubled from 1961-1996 • Higher-yielding strains of crops, better practices, more fertilizer, more irrigation and pest control – Accompanied with a 6.87 and 3.48 fold increase in N and P fertilization – Doubling in the amount of irrigated land – 10% increase in cultivated land • If extrapolate these relationships. ..triple the annual rates of N and P, double irrigation and increasing farmland by 18%. ..possible?
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Meeting increasing agricultural demands • Will result in demands placed on habitat – Land use change – Degradation and erosion of soil – Use of fertilizers – Demands of irrigation/water supply
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Land use change • Agriculture replaces high diversity ecosystem with low diversity human constructed ecosystem • Monocultures replaced natural ecosystems, simplifying and homogenizing them. – Maximizes production, maintain quality/quantity – Impacts nutrient cycling, soil processes – Biodiversity loss Tilman 1999
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Degradation and Erosion of Soil • Each year 75 billion tons of soil are removed by wind and water erosion – Degrades arable land • W/W ~10,000 square miles (12 x 10 6 ha) are destroyed and abandoned annually due to nonsustainable farming practices. • ~ 300 m. hectares w/wide = severely degraded • ~additional 1.2 billion = moderately degraded. Pimentel 1997
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Degradation and Erosion of soil • The importance of soil – Plants (roots) – Nutrient cycling • Eroded soil results in decreased plant growth and reduced crop yields because of decreased soil fertility and water availability • Agricultural practices can disrupt the natural processes of soil loss and formation
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Degradation and Erosion of Soil • Within the first 50 years of tilling, 40-70% of the original soil C and N is lost • For sandy soils, the loss can be so great they can’t be sustainably farmed.
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Impacts of Soil Erosion • On Farm – Low fertility, topography alteration, poor
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This note was uploaded on 12/22/2011 for the course BIOLOGY 200 taught by Professor L during the Fall '11 term at SUNY Stony Brook.

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L14BioticandAbioticPlantsupdated - Different kinds of...

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