Environmental Issues Exam #1

Ecology

Study of interrelationships between living things and the environment 

Abiotic factors

non-living elements of an ecosystem

Biotic factors

living elements of an ecosystem

Limiting factors

any resource, condition, or factor that restricts the growth, distribution, or population size of an organism, population, or an organization  

Range of tolerance

 the range of conditions that an organism can withstand 

Indicator species

species which provide information on ecological changes and give early warning signs regarding ecosystem processes

Invasive species

non-native organism that spreads into a new environment and causes ecological, economic, or human health harm by displacing native species, altering and disrupting food webs

Keystone species

an organism that helps define an entire ecosystem

Generalists

species with a wider range of tolerance due to their greater versatility 

Specialists

species that are specifically adapted to a specific niche, making them more vulnerable

Food web

Sun, primary producer, primary consumer, secondary consumer, apex predator, decomposer (energy is lost with every step up the levels)

Primary productivity

the material that plants make through photosynthesis (biomass) 

Niche

a species’ ‘job’ or ‘role’ in the ecosystem

Adaptation

 a tool for survival and reproduction, helps animals and plants exist within their ecosystem

J-Shaped Growth

uncontrolled population growth that continues until the ecosystem can’t sustain it anymore and the population crashes

S-Shaped Growth

sustainable growth, hovers around carrying capacity

Carrying Capacity (K)

number of individuals that an ecosystem can sustain over time without damaging that ecosystem 

“r” species

those species that produce many young but don’t take care of them (rabbits)

“K” species

those species that produce fewer young but take care of them for longer periods (elephants)

Linear economy

“take-make-dispose” system, focuses on the extraction of resources and a non-renewable disposal of waste products. Finite resources are used at unsustainable rates and creation of waste can cause environmental damage.

Circular economy

the focus is on reducing waste by designing products to avoid generating waste and pollution, recapturing waste as a resource.

Estuary

an area where a freshwater river or stream meets the ocean

Watershed

the land area that drains to a stream, lake, or river

Tributary

a river or stream that flows into a larger river or lake

Salt front

where saltwater from the ocean and freshwater meet in the river

The Dust Bowl 

During the 1930s, drought dried out exposed soil that had been plowed up for farming wheat on the central prairies. The soil dried out and simply blew away into the air from the strong prairie winds

The Green Revolution

shift from smaller farms to industrial agriculture, was about growing more as the world population was rapidly expanding post WWII using technology

Pesticides

chemicals designed to kill insects and other pests

Herbicides

 chemicals designed to kill weeds

Fertilizers

chemicals designed to replenish soil nutrients 

Irrigation

provide water to crops so you’re not as dependent on rain

Mechanization

fossil fuel powered machinery built to plow, plant, and harvest vast areas of land and not be dependent on human labor  

Genetically Modified Foods (GMOs)

engineered plants designed to grow more food, increase nutritional value, and not be as dependent on human labor  

Resurgence

pests developed resistance to pesticides and their population numbers rebounded sharply

Monocultures

vast plots of land dedicated to growing only one type of crop. Monocultures require more pesticides, herbicides, fertilizers, and irrigation

Eutrophication

fertilizer run-off. this is too much fertilizer or sewage entering the watershed and depleting oxygen levels in the water.  

Dead Zones

excess fertilizers were used to make up for soil erosion and the resulting loss of soil fertility. Extra nitrogen and phosphorus washed off the ground and then polluted oceans, lakes, wells, and streams. Vast blooms of algae feed on the fertilizer run-off and sometimes produce toxic chemicals (this is called a red tide). The resulting algae eventually die and decay, and are then consumed by bacteria, using up the dissolved oxygen in the water.

Harmful Algal Blooms (HABs)

These occur when sudden growth of mostly blue-green algae appears in a lake or river. These algae can produce toxins that harm fish, wildlife, and people. Can make the water unfit for swimming, fishing, and other recreational activities. 

Green Manure

using clover to help fertilize fields. Clover roots contain a special bacteria that can harvest nitrogen from the air––creating a natural fertilizer.  

Ecological Footprint

 the impact humanity has on the environment compared to how fast nature can produce resources and process waste

Consequences of Pesticides

can harm beneficial insects, wildlife, and people

Consequences of Irrigation

depletes water supplies and creates conflicts between water users

Consequences of Mechanization

promoted soil erosion, able to convert a lot of natural ecosystems into low diversity “monoculture” mega farms