how farming affects parts of an ecosystem. review questions where does our food come from? how is...
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Food and Ecosystems How farming affects parts of an ecosystem
Review questionsWhere does our food come from?How is our food supply dependent of
ecosystems?How do current agricultural practices affect
public health and the environment?
SoilThe foundation of a farm’s ecosystemFoundation of food supplySustains plants by providing:
WaterNutrientsRoot support
Organisms in the SoilBacteriaArthropodsEarthwormsFungiNematodesProtozoaMammals All play a role in the foundation of soil
Soil Food Web Soil food webs offer many services that
promote and abundant food supply and human healthCycling nutrients which crops can useSoil stores nutrients and releases them slowlySoil stores waterSoil can suppress plant disease Some soils can purify water by breaking down
pollutants
Problems in AgricultureIndustrialization of agriculture changed how
food is grownFrom 1950 to 2000, production of US farms
more than doubled with a fraction of human laborFrom 1950 to 1970 new varieties of grain was
introduced to developing nations- The Green Revolution
The Green RevolutionGenetically engineered rice, grain and corn
was introduced and produced higher yields per acre
These crops needed many nutrients the soil did not provide naturally so fertilizers had to be used
Many of these crops were expensive so poorer farmers could not afford them
Livestock was raised in larger populationsLead to outbreak of disease and trouble handling
that many animals
Problems in AgricultureFertilizers
Nutrient runoff promotes algal blooms and dead zones
Dead zones common in Gulf of Mexico, Chesapeake Bay and other coastal regions
Synthetic nitrogen fertilizers and increased intensity of meat production are among the greatest contributors to nutrient pollution
Pesticides Impact surrounding environmentsCan cause deformities and in fish and
amphibiansDecline pollinator populationsCompromised immunity of sea life
More Problems with AgricultureWild biodiversity loss
Heavy use of insecticides impact pollinators and predators of other pests
Where are all the bees? Monoculture and biodiversity loss
Replaces bio-diverse habitats with fields of genetically uniform organisms – open to disease
Pollinators may not have enough variety of food to survive
Monoculture- only growing one type of crop- Depletes soil of
nutrients- Decreases
amount of pollinators
Strip-cropping – planting multiple crops in alternating rows- Better for the soil
because each crop uses different nutrients
- Allows for more biodiversity
Domestic Biodiversity LossLow genetic diversity in our cropsGlobally, 90% of our food supply is grown from
only 15 plant and 8 animal speciesClimate Change
Changes in temperature and weather patterns affect how, when and where certain crops can be grown
Resource DepletionNatural resources like fertile soil, freshwater
and fossil fuels are being depleted faster than natural rates can restore them
Modern agriculture is dependent on all these resources
Loss of FarmlandEvery minute, more than an acre of American
farmland is loss to developmentWell managed agricultural land provides many
ecosystem services
Loss of Farmer EquityDecisions about food production- who, how and
where- have shifted away from the farmer and into industry More than half of the corn seeds sold in the US are
controlled by 2 companiesFarmers may be pressured into practices
dictated by industry
The Treadmill EffectTarget insects develop resistance to
pesticidesThere is a need to apply more or stronger
chemicals Chemical fertilizers can degrade the soil
quality over time Farmers continually need to apply more
chemicals to achieve the desired results
If they can’t breath it ….do you want to eat it?
Your AssignmentGo through the provided list of problems and
answer the questions on the handoutTomorrow you will work with a group on one
of these issues