THE BIODIVERSITY CRISIS: AGRICULTURE'S EFFECT ON BIODIVERSITY
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What is Biodiversity?
Biodiversity is the variance and interactions of organisms within an ecosystem
How does Agriculture Negatively Effect Biodiversity?
Effects of Pesticides:external image images.jpg
  • Pesticides are chemicals used to reduce the destruction of crops due to pests such as weeds, insects, bacteria and viruses.
  • These pests are destructive to agriculture because they drastically reduce the quality and quantity of yields.
  • In the US over 8 billion dollars is spent each year on pesticides. 70% of total pesticide sales go to agriculture, totaling at 780 million pounds annually.
  • Pesticides have many adverse effects on biodiversity:
    • Other animals besides the targeted pests are harmed often with fatal effects.
    • Drift sprays find their way into local waterways.
    • Much of our food still has traces of pesticides.
    • Ground water is overrun with pesticides which then goes into lakes harming many species of fish and water dwelling organisms.
    • Due to overuse, pests can develop a resistance making it much more destructive.
    • Distribution can cause poisoning hazards if not done carefully.
    (http://www.regional.org.au/au/roc/1992/roc1992031.htm)
(http://www.noticenature.ie/What_effect_does_agriculture_have_on_biodiversity_and_why_take_action_to_protect_it_.htm)
Effects of Monoculture Farms:
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  • Monocultures quickly overuse and ruin soil in a single area. Farmers have to continually move crops over an expanded area to better the soil which leads to more rapid destruction of surrounding natural habitation.
  • Pollution of rivers can occur as soil becomes less fertile because many artificial fertilizers are added to the soil to maintain production
  • From continual cultivation from a single crop, soil can become impacted leading groundwater not to seep in, a cause of flooding
  • Plants, animals, and insects have been in steady decline 95% since the introduction of pesticides in monoculture farms
(http://www.gwll.org.uk/index.asp?page=115)

How big is the agriculture problem?
How much land is lost to Farming?

Demand for farming trends:
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http://image.tutorvista.com/content/management-natural-resources/population-curve-graph.jpeg

  • As the human population increases exponentially, the demand for food also increases.

Trends in biodiversity destruction:
  • As demand for agriculture rises, biodiversity falls.
  • Increasing farmland under cultivation leads to a reduction in biodiversity due to land loss.
    • modern policy attempts to coincide farming and conservation.
(www.ehs.org.uk/ehs/pressbriefings2007/.../hanleypressrelease.doc)

Where/what it most negatively effects?
  • Agriculture most negatively affects habitats which it destroys in order to grow crops
    • Farmers attempt to eliminate wild animals and other species from their land in order to reduce pest predation
    • Agricultural areas can damage protected ecosystems that are near
    • Machinery used in farming can destroy natural plant life such as trees, that serve as natural habitats
  • Agriculture also greatly affects water:
    • pesticides used on crops seep into the ground water and run into streams, ponds, and rivers
    • Most agricultural areas are watered from nearby natural sources, dirtying and using up the natural water source
(www.mekong-protected-areas.org/mekong/docs/tlp-10.pdf)

What Can be Done to Reduce the Effects of Agriculture?
Law: What restrictions are placed on Agriculture?
  • The Endangered Species Act 1973:
    • Prohibits taking, possessing, transportation, and trafficking of listed species.
  • Federal Agriculture Improvement and Reform Act 1996:
    • Protects wildlife habitat as an element of agricultural conservation.
  • Stockholm Convention 2001:
    • International agreement to reduce pesticides such as DDT.
  • The Local Government (Water Pollution Act) 1977 & 1990.
  • The Nitrates Directive and Good Agricultural Practice for Protection of Waters Regulation of 2006.
((( ((((((http://www.ers.usda.gov/publications/agoutlook/dec1996/ao236e.pdf)))

Less Developed Countries v. Highly Developed Countries
  • According to Jan Bengtsson, "Organic farming is less productive in industrial countries." However, industrial countries use much of their land to produce crops for meat production "rather than for human food directly"
  • In less developed countries Organic farming can double food production with a small amount of investment; this is ideal for small farmers.
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This graph reveals what countries participate in the most organic farming.
(http://www3.interscience.wiley.com/journal/118735203/abstract?CRETRY=1&SRETRY=0)

Gene Banks:
  • Gene banks are repositories for many genes.
  • These hold large amounts of genetic material, often taken from farms.
  • Gene banks are relatively inexpensive and can help protect and study endangered species.
  • They are used to find new genetic material used by breeders targeting certain traits.
  • With genetic diversity as a threat in the farming world, gene banks are essential to preserving biodiversity.
(http://www.ers.usda.gov/publications/agoutlook/dec1996/ao236e.pdf)

Organic Farming/Localized farming:
  • "Organic farming has been shown to increase biodiversity - and more interesting, if there is more organic farming in a landscape there is a higher diversity also on conventional farms." -Jan Bengtsson
  • causes the climate to change, sustainability in biodiversity, enhances the structure of soil, conserves waterexternal image usda20veggies.jpg
    • no use of pesticides, herbicides, or inorganic fertilizers
    • there is usually a more diverse crop rotation
    • increases species richness:
      • average 30% higher diversity in organic farms than in traditional farms
      • abundance of birds, insects and plants usually increases
    • The effect is usually most significant on a large plot scale
      • average 50% more abundant organisms
      • pests and non-predatory insects do not benefit from organic farming which enables the farmer to not use harmful chemicals
    • The effect of organic farming varies with location and season.
    ( http://www3.interscience.wiley.com/journal/118735203/abstract?CRETRY=1&SRETRY=0)
How does this differ from typical agriculture?
  • Organic farming gets rid of the use of pesticides and relies on crop rotations.
  • Some organic farms have animals that giving the farm greater biodiversity.
  • Typical agriculture uses pesticides, herbicides, and insecticides. Most farms focus on one crop, creating a monoculture.
    • This damages biodiversity and pollutes the environment
    • Traditional farms also use Genetically Modified Organisms (GMOs) which pollute the natural gene pool and change the genetics of wild species.
(http://www3.interscience.wiley.com/journal/118735203/abstract?CRETRY=1&SRETRY=0)
Can you have both Biodiversity and thriving Agriculture?
Why does Agriculture require Biodiversity?
  • Humanity depends on the resources that come from biodiversity.
  • Biodiversity allows for natural clean air, rainfall, moderate temperatures, filtration, natural seeding, soil productivity and many more valuable functions.
  • Species diversity is essential to the efficiency of farms.
    • Many crops require pollination by insect populations and bees.
    • Fertile soil only comes from a diverse selection of crops; monoculture farms drain the soil of vital nutrients.
    (http://www.ers.usda.gov/publications/agoutlook/dec1996/ao236e.pdf)

How to find a balance between biodiversity and the demand for food:
  • Organic farming is a viable solution for the present population
    • Jan Bengtsson's ideal solution would be: "a principally organic farm with some minor help from mineral nutrients and herbicides/pesticides when really needed" instead of using "full-scale monocultures" which would destroy biodiversity for farmers
    • For the present population organic farming could produce enough food. However, it is estimated that in the next 50 years "the planet may need 50% more food" (Bengtsson)
      • Organic farming could possibly deal with the increase in population if there were several improvements in the agricultural field in combination with new techniques in animal breeding. (Bengtsson)
  • We must achieve equilibrium between the growing human population and demand for food and the increasing threat to biodiversity because of farming.
    • On-site preservation can provide valuable knowledge of species development and interactions.
    • Off-site preservation removes genetic material from the natural environment for long term conservation: gene banks and botanical gardens.
(http://www3.interscience.wiley.com/journal/118735203/abstract?CRETRY=1&SRETRY=0)