environmental science exam 3

ecology

study of the way organisms interact with living things (biotic factors) and their surrounding physical environment (abiotic factors)

abiotic factors

nonliving things/ physical environment (air, water, sun, pH, soil, etc.)

biotic factors

living things (bacteria, plants, fungi, animals)

individual

one organism

population

all organisms of the same species in an area

community

mix of species that interact with each other

ecosystem

mix of species that interact with each other and their physical environment

biome

large geographic areas with similar climate, vegetation, and animal life

biosphere

all portions of earth where life exists

limiting factor

a shortage or absence of a specific limiting factor restricts the success of a species (ex. scarcity of milkweed for butterflies)

niche

the functional role an organism has in its environment

species

a group of organisms that interbreed with viable offspring (shared genetics)

natural selection

organisms are naturally selected by their environments based on their traits; drives evolution and adaptation

evolution

process of developing and diversifying living organisms over time; traits are selected under current environmental conditions and can be useless or detrimental as environmental conditions change

coevolution

2+ species of organisms can influence the evolutionary direction of one another

covergent evolution

unrelated species may evolve similar traits due to exposure to the same conditions

divergent evolution

evolving different traits from a common ancestor (ex. elephants and mammoths)

background extinction

occurs continuously at a low rate because of gradual change

mass extinction

over 75% of species dies out in a short period of time

biodiversity

the variety of life on earth; more of this means better human health and ecological, economic, spiritual and cultural benefits

predator

organism that eats other organisms

prey

organism that is eaten by another organism

predation

process of predator eating and killing prey

traits

different bases on predator or prey; speed strength, ambush etc for predators and keen senses, camouflage, speed, warning patterns, etc for prey

intraspecific competition

competition between members of same species

interspecific competition

competition between members of different species

parasitic relationship

a symbiotic relationship when a parasite lives in/ on a host to derive nourishment; host is harmed but not quickly killed;

ectoparasite

lives on surface of host

endoparasite

lives inside body of host

commenalistic relationship

symbiotic relationship between organisms where one benefits and the other is unaffected

mutualistic relationship

symbiotic relationship beneficial to both species involved; ex. alfalfa and nitrogen fixing bacteria

producer

organisms that use sources of energy to make complex, organic molecules from inorganic substances in the environment

consumer

herbivores, omnivores, carnivores, decomposers

decomposer

use nonliving organic matter as source of energy and to build their bodies; respire and help to recycle organic matter

herbivore

eats plants

carnivore

eats animals

omnivore

eats plants and animals

keystone species

species that has a critical role to play in the maintenance of a specific environment

food chain

series of organisms occupying different trophic levels through which energy passes as a result of one organism consuming another

food web

the intersection of several food chains in a community

biomass

the weight of living material in a given area; can be done by trophic level

trophic level

the steps in the flow of energy through an ecosystem (producer → herbivore → carnivore)

terrestrial primary success

a successional progression that begins with a total lack of organisms and bare mineral surfaces; consists of pioneer stage, intermediate stage, and climax community; initiated by sea level change, tectonic plates, lava flow, glaciers

terrestrial secondary success

occurs much faster than primary succession because soil and seeds remain; starts from agriculture, fires, floods, etc.

pioneer stage

the earliest stage of terrestrial ecosystem primary succession; involves pioneer community which are organisms able to survive with no soil and few nutrients; primarily lichens

intermediate stage

soil continues to thicken in this stage; mainly shrubs, tall grasses, starting to see shade intolerant trees

climax community

a relatively stable, long-lasting, interrelated community of plants, animals, fungi, and bacteria at end of primary succession; shade tolerant trees; takes at least hundreds of years to get to this point

native plants

plants that occur naturally in an ecosystem without human interference

invasive plants

causes harm to human health, economy, or ecology

aquatic primary succession

1. early stages of aquatic vegetation 2. later stages of transition to terrestrial communities

desert

windy and evaporative, large daily temp swings, less than 10in of rain per year; sparce vegetation, small animals low in population

temperate grasslands

hot summer, cool winters, 10-30in rain per year; no trees due to low amnt of precipitation, 60-90% of vegetation is grass, grazing mammals and small mammals, insects, birds

savannah

temp is not seasonal and relatively high; constant; 10-60in rain annually (highly seasonal); fires common, grazer animals like zebra, elephants, large carnivores, insects, reptiles, rodents, birds

mediterranean shrublands (chaparral/ scrub)

wet mild winters, hot dry summers; woody shrubs adapted to withstand hot, dry summers and fires, insects, birds, mammals, reptiles; california

tropical dry forest

20-80in rain annually, monsoons (months of rainfall followed by months of dry periods), trees adapted to extensive drought; monkeys, jaguar, deer

tropical rainforest

80-200in rain annually (low seasonality because its constant), constant warm temps; equator; highest species diversity of any biome

temperate deciduous forest

30-60in rain annually; warm summers and cold winters (high seasonality); species of trees that drop leaves in fall; flowering plants bloom in spring; deer, squirrels, raccoons, insects

temperate rainforest

50-120+in rain annually, mild/warm summers, cool winters; coastal areas that receive moist air, damp, high humidity; oregon; coniferous/ evergreen trees that dont drop leaves, lots of insects and decomposers

taiga/ boreal

10-40in precipitation, snowfall common, soil freezes in winter, short cool humid summers, long cold dry winters; moscow, russia; evergreen trees; organisms mostly active in summer; migratory birds

tundra

10in precipitation annually; extremely cold (8-10 months of winter); massive seasonal temp swings; permafrost; low evaporation and lots of surface water, dry winters; grasses, lichens, shrubs, no trees bc of permafrost; insect swarms (mosquitos), migratory birds, wolves

pelagic

type of marine ecosystem; open ocean

benthic

type of marine ecosystem; ocean floor; substrate greatly influences what plants and animals can thrive

euphotic zone

upper layer of ocean where sunlight penetrates; allows for photosynthesis

abyssal zone

benthic ecosystem at great depths in ocean; organisms are scavengers that rely on rain of dead organic matter from euphotic zone; organisms adapted to low light

phytoplankton

pelagic organisms that photosynthesize and form the base of the marine food web

estuary

shallow areas where freshwater enters the ocean; saltiness changes w tides and volume of freshwater; very productive due to nutrients in river and used as reproductive site by fish

littoral

region of lake with rooted plants

limnetic

region of lake without rooted plants

swamps

wetlands containing trees that can withstand near permanent flooding

marshes

wetlands dominated by grasses and reeds that can withstand near permanent flooding

bogs

soft, spongy, wet ground that can support tall plants; accumulates peat from mosses

oligotrophic

low lake productivity; very clear water bc of low nutrients

mesotrophic

medium lake productivity

eutrophic

high lake productivity

straight, meandering, braided

types of channels

sexual reproduction

requires multiple organisms of same species and produces genetically different offspring; oviparous- egg laying; viviparous- give birth

asexual reproduction

reproduction by a single individual that results in a genetic copy of that organism; low genetic variability

birthrate

number of individuals born per 1000 individual people in population per year

deathrate

number of people who die per 1000 individuals in population per year

population growth rate

(birthrate - deathrate) / 1000 × 100 = x%

survivorship curve

number of individuals of a population that will survive to a given age

sex ratio

the ratio of males to females in a population; females are limiting factor in most species as they give birth

population density

number of individual organisms per unit area; high density: urban; low density: rural

immigration

movement into a specific area

emmigration

movement away from a specific area

dispersal

movement away from a densely populated area into a new one

biotic potential

reproductive capacity of a species under ideal conditions; varies widely between species due to birth potential and breeding frequency

population growth curve

lag→exponential→deceleration→equilibrium

lag phase

slow initial growth due to few organisms reproducing

exponential growth phase

more organisms reproducing leads to rapid growth

deceleration phase

growth rate slows as death rate and birth rate becomes more similar

equilibrium phase

birth rate and death rate equalize; stops growing due to limiting factors

extrinsic limiting factor

factors from outside the population

intrinsic limiting factor

factors from within population

density dependent limiting factor

factors that become more influential with increasing population density

density independent limiting factor

factors not related to population density

k-strategist

reproductive strategy: low biotic potential but high survivability (chimpanzee, puma, etc)

r-stratigist

reproductive strategy: high biotic potential but low survivability (oysters, fish, etc)

population doubling time

~1.2% or doubling every 58 years

developed countries

countries with stronger economies, industrialization, per capita income of 25k USD