Unit 4: Water and Land Use

What percent of land of the US is used for agriculture?

50%

What percent of our water consumption is used for agriculture?

80%

Agriculture

The practice of cultivating soil to grow crops to provide food

Bioaccumulation

The buildup of pesticides at each trophic level resulting in toxic levels in upper level consumers

Bloom

Overgrowth of plant species —> decreases biodiversity and dissolved oxygen levels

Bycatch

Nontarget fish that get caught accidentally in nets, traps, and by other fishing techniques.

~ 7.3 million tons of fish were discarded as bycatch globally between 1992 and 2001. As technologies for catching fish improve and the number of boats in the water increases, more and more marine mammals are being harmed.

Clear-cutting

When an entire forested area is cut down without a single tree left standing. Farmers use it to harvest lumber.

Deforestation

Natural or artificial mass removal of trees in an area by disease, cutting, burning, or erosion.

Desertification

Process where fertile land becomes desert. Typically a result of drought, deforestation, or inappropriate agriculture.

Ecological footprint

The amount of land area that is needed to provide for a population’s needs and dispose of its waste.

Eutrophication

The contamination of a water system with excess nutrients, which stimulates excessive algae growth at the expense of other parts of the ecosystem.

Externality

A cost or benefit produced by profitable actions that impacts the environment. Ex: grazing causes soil erosion —> burning fossil fuels produces pollution —> pollution harms human health —> drives up healthcare costs

Genetically modified organisms

Organism with recombined DNA from other species to produce a chosen trait

Green revolution

The collection of techniques to increase crop yields and the research that established them. Involves irrigation, strategic crop production, genetic engineering, and using fertilizers.

Gross domestic product

Total value of goods and services that a country produces in a year

Heap leaching

A method for extracting metals from ores by pouring a cyanide solution over crushed ore to dissolve and collect it

Hypoxic

When a body of water has low oxygen levels

Maximum sustainable yield

The largest catch that can be taken from a species’ stock over an indefinite period. Figured out in order to re-establish a population

Mining

The extraction of minerals from the Earth. Can be extremely expensive

Monocrops

Large fields of a single species of crop

Old-growth forests

Forests that contain trees that are often several thousand years old that have been undisturbed. Contain dead trees and fallen logs that provide habitats for animals and help recycle nutrients as they decay. Contain healthy soil profiles. Support complex interactions among organisms ranging from plants to animals to fungi.

Ore

Rocks that contain enough minerals and can be economically extracted

Overfishing

Commercial and non-commercial fishing that depletes a fishery (or a fish population) by catching so many fish that too few remain to reproduce and sustain the population. Due to the absence of regulation. Caused the collapse of the Atlantic cod.

Overgrazing

High levels of vegetation consumption by livestock that can lead to erosion

Pesticide

Chemicals that are sprayed on crops to destroy insects that feed or harm the crops

Rangeland

Agricultural land that is used for livestock to graze. Very diverse.

Second-growth forests

Forests that contain younger trees as a result of human or natural destruction.

Selective cutting

Only harvesting small groups of trees that are moderately to fully mature. Least damaging method.

Smelting

Melting ore in a furnace to remove any impurities.

Suburban sprawl

Population shift from urban to suburban areas. Happens in developed countries. People have to drive more since their work and home are in different areas, increasing pollution levels. Spikes in obesity as well due to higher commute times.

Tailings

Toxic waste produced by ore processing. Often stored underground in valleys. Can include arsenic, mercury, cyanide, and sulfuric acid (hazardous to human health)

Tragedy of the commons

Misuse of shared resources due to self-interests that can lead to the collapse of the resource. Can occur with any shared resources; wildlife, land, air.

Urbanization

Population shift from rural to cities.

What is required for human survival?

Proteins, vitamins, minerals.

Undernourished

Not having enough calories

Malnourished

Having enough calories, but not enough nutrients

Overnourished

Having too many calories. Results in obesity.

Obesity

Growing problem in U.S. and other developed countries. 1/3 of American population is obese. Can lead to health problems, such as heart disease, diabetes, stroke, and depression.

My Plate

Tool implemented by U.S. department of agriculture to help consumers make better food choices. Uses age, sex, height, weight, and level of physical activity to build a personalized food plan.

Three main types of crops grown across globe.

Wheat, rice, maize/corn

Wheat and Rice

Make up ~60% of the calories humans consume

Specialized crop production

Potatoes and oats grow at higher altitudes of northern Europe and Asia. Other tubers grow in the tropical climate zones of South America and Africa.

What should 75% of your diet consist of?

Grains, such as wheat and rice, fruits, and vegetables

Irrigation

Controls the rate at which water is sprinkled onto plants to allow for maximum water absorption and reduced runoff.

Agriculture before irrigation

Farmers used water through flood, ditch, or sprinkler irrigation. Led to water logging, increased evaporation, and runoff. Led to soil salinization. Runoff can also harm ecosystems due to the contaminants it carries to aquifers and other reservoirs. Additionally, land and bodies of water can experience desertification if water is consumed irresponsibly. This is what caused the Dust Bowl of the 1930s.

Monocrops

Large fields of a single crop is planted. Allows farmers to harvest more of the crop at the same time.

Negatives to monocropping

Can lead to soil erosion, salinization, and decreased biodiversity. Also more susceptible to loss due to diseases.

Genetic Engineering

Improving the ability for plants to survive. Makes organisms stronger, more tolerant to drought, and resistant to insects.

GMO Process

Scientists extract the genes for certain traits from other species and insert the gene into the DNA of the crop species.

GMO’s in the U.S.

Eliminates the need for chemicals to control weeds and pests. Found in over 60% of all processed foods.

Worries of GMOs

Could they hybridize with other plants to produce superweeds? What other unknown byproducts could GMOs produce? How does consuming GMOs affect human health?

Currently, no peer-reviewed scientific evidence that GMOs are harmful to our health.

Fertilizers

Provide essential nutrients to soil in the form of nitrates and phosphates. But can runoff into waterways and cause problems.

What can the runoff of fertilizer cause?

Algal bloom, which takes over an ecosystem.

Eutrophication

Increased nitrogen and phosphorous in rivers and dams. 50% of lakes in North America, Europe, and Asia are impacted by it.

Hypoxic (dead zones)

Bodies of water with low oxygen

Why are eutrophication and hypoxia are difficult to combat?

caused by non-point source pollution, which is difficult to regulate, and nitrogen and phosphorus, which are difficult to remove from wastewater

What is the growing concern about the health of wild bees?

To protect them from pesticide risk as they are useful as pollinators.

When did researchers begin to notice bee colony losses?

Late 2006

What did the National Research Council report in 2007?

Decline of pollinators and other actions needed to address the issue. 

What do most EPA and USDA scientists think is causing the declining health of bees?

It is related to complex interactions among multiple stressors including: pests, pathogens, and viruses, poor nutrition, pesticide exposure, bee management practices, and lack of genetic diversity.

What is Colony Collapse Disorder, or CCD?

A sudden and widespread disappearances of adult honey bees from beehives in the U.S.

What causes CCD?

A combination of stressors that weaken bee colonies. Can include pathogens, parasites, environmental factors, and poor nutrition

What are the USDA and EPA doing to prevent CCD?

Colony Collapse Disorder Steering Committee, Pollinator Health Research

Factors that limit the growth of crops

Water, temperature, nutrients.

Biological factor that can affect crop growth

Pests such as mosquitoes, cockroaches, and locusts.

What have humans used in the past to combat the negative effects of pests?

Smoke, salt, lime, other insect-repelling plants.

Pesticides

Chemicals that kill or repel insects; became more widely used during the Green Revolution

Insecticides

Kill insect pests

Herbicides

Kill plants and weeds

Acaricides

Kill spiders and ticks

Rodenticides

Kill rats and mice

Fungicides

Kill fungi and molds

Inorganic pesticides

Not from living matter

Natural organic pesticides

From living matter

Chlorinated hydrocarbon pesticides

Contains C, H, and Cl

Types of pesticides

Inorganic, not from living matter; Natural organic, from living matter; Fumigant, or gaseous (seen in image above); Chlorinated hydrocarbon, which contains C, H, and Cl; Organophosphates; Carbamates; Microbial

Silent Spring

Book published by Rachel Carson pointing out the hazards of pesticides, including DDT. Consumed by primary consumers that feed on the pesticide-treated crops and build up at each trophic level through bioaccumulation.

Negative effects of pesticides

Can create pesticide-resistant organisms, Decreases biodiversity, Accumulates in water and soil for years, Can cause birth defects and deaths in organisms —> Organisms at the top of the food chain and animals with soft shells, such as amphibians, suffer the most.

Alternate solutions to pesticides

Integrated pest management system: includes pesticides, genetically engineering of crops, mechanical vacuuming of pests, and trap crops.

Trap crops

small plots of crops that are planted before the main crop: heavily sprayed with pesticides to trap and kill pests before the main crop is planted.

EPA focus

Controls the sale and use of pesticides. Studies and reports the risk of pesticides to humans and the environment.

The Federal Insecticide, Fungicide, and Rodenticide Act

1947 .Required all pesticide products to be registered.

The Federal Food, Drug, and Cosmetic Act

Requires the EPA to set acceptable pesticide level limits in foods

The Food Quality Protection Act

Allows the EPA to set limits on pesticide exposure and to examine the effects of inert pesticide ingredients. 1996

USDA

Enforces allowable levels of pesticides

FDA

Enforces allowable levels of pesticides

Which of the following is a major contributing factor to hypoxia in the Gulf of Mexico?

the use of nitrogen-based fertilizers

Forests vs Grasslands

Forests feature a high density of trees, while grasslands are characterized by grasses and herbaceous plants

What percent of land do forests cover?

30%

Temperate rainforest

Wet climates and cool temperatures, Contain conifers, cedars, ferns, and spruces, Ex: Olympic national forest

Tropical dry forest

Near equator, Distinct wet and dry seasons, Trees adapted to withstand high temperatures and seasonal droughts, Ex: Jalisco Dry forests in mexico

Tropical Rainforest

Near equator, High moisture and humidity, Warm temperatures, High biodiversity, About 50% of the Earth's rainforests have been cleared, Ex: Borneo tropical rainforest.

Tongass National Forest

Large old-growth forest of Alaska. Spans 17 million acres. Temperate rainforest. Borders the Pacific Ocean. Filled with islands, salmon streams, and towering mountains. Nation’s largest forest; contains rich biodiversity of trees, fish, and fungi.

Redwood National Park

Has some of the world’s largest trees, redwoods. Over 100 meters tall, resistant to insects and fires. If the trees fall, their roots still sprout seeds. They support the growth of ferns, mosses, and mushrooms which positively impact soil regeneration through the various biogeochemical cycles.

What Percent of the Redwood National Forest remains due to overcutting and deforestation? And why?

5%. Farmers cut down trees for timber to build homes and buildings, protection from predators, and to produce fuel wood and charcoal.

What happens if topsoil is removed?

Layers underneath are more susceptible to erosion by water and wind.

Pros of Clear-Cutting

Farmers use large machines to cut down trees in less time.

Cons of Clear-Cutting

Removes small non-target trees which leads to soil degradation by erosion. Destroys habitats for hundreds of different organisms. Worsens soil erosion

Cons of selective cutting

Promotes growth of weeds and invasive species which reduces biodiversity and carbon sinks.

When was the United States Forest Service established?

Established in 1905