ECHS Ecology Study Guide

what is ecology

the study of interactions between organisms and their environment

what conditions does life require

nutrients, energy, liquid water, apprpriate temperature

what are the ecological levels of organization from the smallest to largest

individual, population, community, ecosystem, biome, biosphere

what are the two basic laws underlie ecosystem function

nuterients constantly cycle and recycle

energy moves through communities in a continuous one way flow

what is primary production rate

rate at which all the plants in an ecosystem produce net useful chemical energy

what are trophic levels

energy level and position in a food chain

what is a primary producer

organisms that use energy from the sun to make food aka photosynthesizers or autotrophs

what are consumers

heterotrophs - rely on other organisms for energy and nutrients

detrinvore

digests decaying matter in soil

what is the 10% rule

10% of energy is passed on each level, 90% is used by the organism for life processes, and the rest is given off as body heat

what is the energy pyramid

they show relative amounts of energy available at each trophic level of the food chain

what is biological magnification

consequence of food webs

what are the other types of pyramids used in ecology and what do they tell us

1. pyramid of biomass - amount of living matter available at each trophic level

2. pyramid of numbers - number of individual organisms at each trophic level

macronutrients

a substance required in relatively large amounts by living organisms

micronutrients

a chemical element or substance required in trace amounts for the normal growth and development of living organisms - vitamins

biogeochemical cycles

recycling of inorganic matter between living organisms and their nonliving environment

reservoirs

storage of inorganic components

water cycle

can continue without living organisms. water from land and oceans enters the atmosphere by evaporation or sublimation, where it condenses into cloud and falls as rain or snow. precipitation water may enter freshwater bodies or infilltrate the soil. the cycle is complete when the surface of groundwater reenters the ocean. reservoir - ocean

carbon cycle

carbon dioxide gas exists in the atmosphere and is dissolved in water. photosynthesis converts carbon dioxide gas into organic carbon, and respiration cycles the organic carbon back into carbon dioxide gas. long-term storage of organic carbon occurs when matter from living organisms is burried deep underground and becomes fossilized. volcanic activity and human emmisions bring stored carbon back into the carbon cycle. reservoir - carbon dioxide in the atmosphere

Nitrogen cycle

nitrogen enters the living world from the atmosphere through nitrogen and nitrogenous waste from animals then processed back into gaseous nitrogen by soil bacteria, which also supply terrestrial food webs with the organic nitrogen that they need. reservoir - nitrogenus gas

Phosphorous cycle

the only biochemical cycle that doesn’t involve the atmosphere. phosphorous exists as the phosphorous ion. weathering of rocks and volcanic activity releases phosphates into the soil, water, and air where it becomes available to enter the terrestrial food webs. phosphates enter the oceans in surface runoff, groundwater, and riverflow. Phosphates dissolved in the oceans enters the marine food webs where it is available to fall to the ocean floor and form sediment. reservoir - sedimentary rock

what is succession

a series of gradual changes that occur in a community and its nonliving environment following a distrubance

what proceeds succession

a distrubance such as fire, volcanic activity, or argricultural distribution

what is a climax community

an equilibrium state; stable communities formed by characteristic assortment of plant and animal species; replace in predicatable manners with a stable, self-sustaining. this is

what is primary succession

succession that occurs in an area with no trace of previous community; pionear species. climax community is reached. tak longer to reach climax community

secondary succession

part of the ecosystem is disturbed and remnants of the previous community remained. often follow some event like a fire or a huricane or human activies. faster than primary

what is subclimax

if vegitation doesn’t reach climax as a result g interruptios by local factors such as soilchanges of differences in parent rock interruptions known as aresting factors

what is a keystone species

one whose presence hasinfluence in maintaining the prevalence of various species in an ecosystem

what happens when a keystone species is removed

compositio is altered/biodiversity is reduced - chang or calapse of ecosystem

what are the greenhouse gases

carbon dioxide, methane, and water vapor

what is a biome

large naturaly occuring communites of living organsims occupying a major abitat

tropical

found in equaltorial regions

savanahas

grasslands with scattered trees found in Africa, South America, and Nothern Australia

deserts

exist between 15* and * north and south of the equator

chapparal

found in California, along the Mediteranean sea

temperate grasslands

found throughout central America and in Eurasia

temperate forests

most common biome in eastern north america, western europe, eastern chile, and New zeland

boreal forests

found between 50* and 60* N laitude across Canada, Alaska, Russia, and N europe

artic tundra

located througout the artic regions of the northern hemisphere

how are aqatic biomes different from terrestrial biomes

more dependent on light and less temperture

three types of aquatic biomes

1. freshwater

2. saltwater

3. estuaries - where oceans meet freshwater

niche

way of life

how is a niche defined

organisms physical home or habitat, all pyhsical environmental conditons needed for an organism to survive, entire role speces preforms with an ecosystem

competitive eclusion

no two species can occupy the same nice in the same habitat at the same time

resource partitioning

instead of competing for smilar resources, species usually divide them

intraspecific comptition

competition among two members of the same species

mutualism

both species benefit

parasitism

one organism benefits, and the other is harmed

commensalism

one organism benefits and the other is neither

what is biotic potential

the abilty of a population of a living species to increase the ideal environmental conditions.

what factors influence biotic potential

age of first reproduction, frequency of reproduction, average number of offspring, reproduction life span, death rate under ideal conditions

carrying capacity

maximum number of individuals an environment can support

density independent

time, weather, pesticides, habitt destruction

density dependent

parasites and diseases, competition, predation, herbivory, stress from overcrowding

scramble competition

who gets there first

contest competition

social or chemical interactions determine access;territorial species

what factors generate environmental resistance

density deoendent and density independent factors interact to regulate population size

what is surivivorship curve

graph of the number of individuals surviving at each interval v.s. time - allows us to compare life histories of different populations

types of loss seen on surviviorship curves

• late loss - mortality is low in early middle years (humans/mammals)

• constant loss - mortality is relatively constant throughout lifespan (birds)

• early loss - mortality is highest at early ages (trees)

what advances have we made to increase the carrying capacity

fire, invented tools and weapons, built shelters and protective clothing, domesticated crops and animals, medical advancements, major industry advancements

conservation biology

the management of nature and earth’s biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction and the erosion of biotic factors

what are the goals of conservation biology

understand the impact of human activites, reserve and restore natural communities, reverse the loss of earth’s biodiversity, fostor sustainable use of earth’s resources

what are the three types of biodiversity

ecosystem, species, and genetic

what are the benefits of biodiversity

medicine - orignal sources of many medicines, agriculture - genetic engineering, ecosystems - stability, productivity, and value of humans

how can we conserve biodiversity

protecting local individual species, preserving habitats with arks and reserves, considering local interests, individuals change their habits with things such as recycling, car pooling, and the use of renewable resources

what is an ecological hotspot

significant numbers of species and habitats are in immediate danger of extinction

what is an ecological footprint

it describes the total area of functioning land and water ecosystems needed to provide the resources an individual or population uses to absorb the wastes generated