ENVSTY 101 week 4

ecosystems

a set of organisms within a defined area that interact w one another and w/ their environment

ecology

branch of biology that focuses on how living organisms interact w/ living and nonliving parts of the environment

troposphere

extending 11 miles above sea level, the air we breathe

what makes up the troposphere

78% nitrogen 21% oxygen 1% water vapor, carbon dioxide, and methane

stratosphere

11-31 miles above the earth’s surface, contains ozone to protect against UV radiation

hydrosphere

all the water on or near the earth’s surface

geosphere

earth’s rocks, minerals, and soils

biosphere

where life is found

three factors that sustain life on earth

energy from the sun, cycling of nutrients, gravity

energy from the sun

supports plant growth, energy for living organisms, warms us in the greenhouse effect

cycling of nutrients

fixed supply of nutrients cycling through the biosphere to support life

gravity

planet holds onto the atmosphere and enables the movement and cycling of chemicals through the air, water, soil, and organisms

levels of matter

biosphere, ecosystems, communities, populations, organisms

trophic

feeding level

how are organisms classified

producer and consumer

interspecific competitiion

competition between different species

intraspecific competition

competition among members of the same species

predation

member of one species is a predator that feeds directly on all or part of a member of another species

coevolution

overtime as prey species develop adaptations that make them more difficult to hunt, predators face selection pressures that favor traits increasing their ability to catch their prey

parasitism

when one species live in or on another organism

mutuallism

two species interact in ways that benefit both, by providing each with food, shelter, or some other resource

commensalism

the interaction benefits one species, but has very little to no, benefits or harmful effect on the other

terrestrial biodiversity

the variety of life forms on the land surface of the earth

6 major types of terrestrial habitats

desert, tundra, grasslands, coniferous forest, decidious forest, tropical forest

where is terrestrial biodiversity the highest

tropical rainforests

aquatic biodiversity

variety of life forms in the aquatic environment (marine and freshwater systems)

aquatic life zones

aquatic equivalent of biomes, the saltwater and freshwater portions of the biosphere that support life

key factors that determine life in marine zones

temp, dissolved oxygen content, availability of food/light/nutrients needed for photosynthesis

why are freshwater systems so important

surface water is precipitation that does not sink into the ground or evaporate, freshwater that flows or is stored in bodies of water on the earth’s surface

what is salinity

the amounts of various salts such as sodium chloride dissolved in a given vol of water

forest ecosystem services

photosynthesis, oxygen, purify water and reduce runoff and flooding, biodiversity

forest economic services

raw materials, industrial wood, maintaining human health, remove air pollution

HIPPCO

habitat destruction, degradation, and fragmentation; invasive species; population growth and increasing use of resources; pollution; climate change; overexploitation

how are humans degrading marine ecosystems

climate change; ocean acidification; coastal development; runoff of pollutants; overfishing and depletion of commercial fish species; destruction of bottom ocean habitats; invasive species

how are humans degrading freshwater ecosystems

dams and canals that restrict water flow; flood control levees and dikes; cities and farms that add pollutants and excess plant nutrients; inland wetlands being drained

biological extinction

when a species can longer be found anywhere on the earth

background extinction rate

the natural rate of biological extinction

mass extinction

the extinction of many species in a relatively short period of geologic time

5

how many mass extinction events have we had

what is the rate of background extinction rate

loss of 1 species per year/every 1 million species living on earth

1,000x the BER (10,000 species per year)

what is the current mass extinction rate

endangered species

species that are heading towards biological extinction