As populations grow, the need for increased food production is greater On a global scale we produce...
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Transcript of As populations grow, the need for increased food production is greater On a global scale we produce...
As populations grow, the need for increased food production is greater
On a global scale we produce enough food to adequately feed all of the world’s population
Tens of millions continue to suffer from starvation and undernourishment each day minimum critical diet 9900 J = approx
2200 cal
Causes of world hunger are complexsome regions of world have fertile
soils and favourable climatesothers have poor soil conditionsdroughtfloodingand other harsh conditions that limit
the ability to grow foodpoverty
Humans depend on...grain products livestockocean fisheries It is estimated by the Worldwatch
Institute that yield thresholds are being met.
Within the oceans, over fishing has depleted stocks beyond estimated sustainable yields Populations may not recover If significant reductions are not met
globally, can cause a severe prolonged collapse of stocks
10 billion animals used for livestock! Livestock ranching has led to forest
degradation 36% of world’s grain goes to feed livestock livestock wastes are implicated in the
pollution of waterways▪ proliferation of toxic algal blooms▪ loss of fish species▪ water loss (to livestock, and to fresh water
supplies)
Being converted to non-agricultural uses....▪ Housing, industry
soil degradation▪ deforestation exposes soil▪ loss of roots of living plants that would
retrieve nutrients from deeper layers of soil disrupt nutrient cycles▪ salinization▪ accumulation of excess of salts in soil that restricts
water and essential nutrients that plants can withdraw from the soil
Ecologists often use energy pyramids to visualize transfer of food energy from one trophic level to the next through a food chain
Much of the energy is lost at each trophic level and this energy cannot be recaptured
Approximately only 10% of energy in one organism is transferred to an organism in the next trophic level
Top consumers receive a small fraction of available energy from the producers
Urban Sprawl Growth of low density development on
the edges of cities and townsAquifers
Porous, water-saturated layers of sand, gravel, or bedrock that can store and yield significant volumes of water
Precipitation and runoff enter recharge zones and percolate gradually down to an aquifer
Despite it’s recognized ecological importance to southern Ontario, the moraine is at risk from having to accommodate housing developments
supply is not limitless less that 1% of Earth’s water is fresh
waterhuman activities negatively
affect the supply that does exist livestock operations have been
introduced into rural Canadacontamination from livestock wastes
and poor regulation of monitoring procedures and chlorination equipment has led to tragedies (Walkerton)
water supplies polluted by fertilization of cropland, pesticides, acid precipitation, and runoff from storm water off of soiled pavement, industrial wastes (most of which are toxic), mine tailings, household waste water, and raw sewage all lead to critical health concerns regarding the scarcity of clean water for drinking and irrigation.
Cellular respiration of bacterial populations increases, depleting oxygen from the water. This harms other aquatic organisms
Phosphates and nitrates from fertilizers and sulfates from laundry detergent support cellular respiration of some algae and plants, (algal bloom) further depleting oxygen sources for other organisms
Heat produced by power plants and other industrial processes also reduces the amount of dissolved oxygen that can exist in water
(aka) Acid deposition A mixture of Sulfur
dioxide and nitrogen oxide pollutants that can reach earth’s surface in the form of rain, gas, or solid particles.