Fundamentals of Ecology all weeks (1, 2, 3, & 4)

what are the 3 characteristics of biological community?

physical appearance. types ands numbers of species they contain. ecological roles that species play

physical appearance

may refer to size, stratification, and distribution of its populations and species for various terrestrial communities. differences in physical structures and zones of communities in aquatic life zones (such as oceans or lakes)

species diversity

combination of its number of different species (species richness) and abundance of individuals within each of its species (species evenness).

species richness

the number of different species in a community

species evenness

abundance of individuals within each of its species

what are the most species rich areas?

rich in tropical rain forest, coral reefs, deep sea, and large tropical lakes

numbers of species and number of individuals

communities that have large number of different species generally have only few members of each species

what factors affects species diversity?

latitudes. pollution in aquatic system. habitat diversity, NPP, habitat disturbance, and time.

latitudes, species diversity

species diversity. distance from equator in terrestrial communities. species diversity highest in tropics and declines from equator to poles

niche structure

refers to number ecological niches, how they resemble or differ from each other and how species interact with one another

what is ecological niche a term for?

term for position of species within ecosystem, describing both range conditions necessary for persistence of the species and its ecological role in ecosystem

ecological niche subsumes

all of interaction between species and biotic/abiotic environment

what are niche influences?

way species interact w/other species. way species interact w/its environment. migration. extinction. evolution. domination

what are limiting factors in niche structure?

competitive exclusion. resource availability

what are the two types of niches?

fundamental. realized

fundamental niche

potential full niche that a species can occupy. would act as full niche on absence of competition

realized niche

narrower than fundamental niche. formed as result competition (species occupies less space). act as "competitive refuge" (species will fight to maintain)

native species

those that normally live and thrive in particular community

nonnative species

evolved somewhere else and then migrate into or deliberately or accidentally introduced into community (AKA invasive/alien species)

indicator species

serve as early warnings of damage or danger to a community

Why are birds good indicator species?

birds. b/c found almost everywhere and affected quickly by environmental change such as loss/fragmentation of habitats and introduction of chemical pesticides. many bird species declining

why are butterflies good indicator species?

also good indicator and in some areas declining faster than bird species

keystone species

major players who help keep ecosystems running smoothly

what do keystone species help determine?

help determine types and numbers of various other species in a community

what roles do keystone species play?

play critical ecological roles. Ex: pollination, top predators, recycling

foundation species

shape communities by creating and enhancing habitats that can benefit other species in community

elephants and foundation species

elephants push over, break/uproot trees, creating forest openings in savanna grasslands and woodlands in Africa. promotes growth grasses and other forage plants that benefit smaller grazing species such as antelope. also accelerates nutrient cycling rates

species interactions

when different species in community have activites or resources needs in common, they may interact with one another. members of these species may be harmed, helped, or unaffected by interaction.

what are the 5 basic types of species interactions?

interspecific competition. predation. parasitism. mutualism. commensalism

interspecific competition

competition between members of different species

predation

An interaction in which one organism kills another for food.

parasitsm

a relationship in which one organism benefits and the other is harmed

mutualism

A relationship between two species in which both species benefit

commensalism

A relationship between two organisms in which one organism benefits and the other is unaffected

competitive exclusion principle

two species can't occupy same nice in a habitat. different species can't coexist in community if competing all for same resources. b/c resources often limited within habitat and multiple species may compete to obtain

resource partitioning

occurs when species competing similar scare resources. evolve more specialized traits that allow them to sue shared resources @ different times, in different ways, or in different places

niche specialization

fairly broad niches of two competing species can become specialized so thar species can share limited resources

examples of niche specialization

lions and leopards, lions take larger and leopards take smaller prey. hawks and owls, hawks hunts during day and owls and night

ecological succession

refers to gradual change in species composition of given area. all communities change their structure and composition over time in response to changing environmental conditions

communities and stable structures

communities w/stable structures are said to be @ equilibrium. following a disturbance a community may or may not return to equilibrium state

during succession and colonize

during succession some species colonize an area and their populations become more numerous, where as populations of other species decline and may even disappear

what are the two types of succession?

primary and secondary

primary succession

which involves the gradual establishment of biotic communities on nearly lifeless ground

secondary succession

biotic communities are established in area where some type of biotic community already present

when does primary succession occur?

occurs when already present land is formed or rock is exposed. for ex, following eruption of volcanoes

primary succession and length of time

usually takes an extremely long time. one reason is that before community can become est. on land must be soil. depending on climate take natural processes several hundred to several thousand years to produce fertile soil.

soil formation and primary succession

soil formation begins when hardy pioneer species attach themselves to inhospitable patches of bare rock

pioneer species

First species to populate an area during primary succession

example of soil formation/primary succession

wind dispersed lichens and mosses, can withstand lack moisture and soil nutrient and hot/cold temp extremes found in such habitats

where does secondary succession begin?

begins in an area where natural community of organisms been distributed, remove, or destroyed, but some soil or bottom sediment remains

what can be candidates for secondary succession?

candidates for secondary succession include abandoned farmlands, burned or cut forests, heavily polluted streams, and land that has been dammed or flooded

secondary succession and soil/seeds

secondary succession. b/c some soil or sediment is present, new vegetation can usually begin germinate within few weeks. seeds can be present in soils or they can be carried from nearby plants/wind/birds and other animals

what are the three factors affecting how and rate @ which succession occurs?

inhibition. facilitation. tolerance

inhibition secondary succession

The only possibility for new growth/colonization in this successional sequence arises when a disturbance leads to dominating species being destroyed, damaged, or removed.

facilitation secondary succession

the presence of an initial species aids and increases the probability of the growth of a second species.

tolerance secondary succession

in which late successional plants largely unaffected by plants @ earlier stages of succession. may explain why late successional plants can thrive in mature communities w/o eliminating some early successional and mid successional plants

how many types of ecosystems are there and what are they?

2. terrestrial and aquatic

primary consumers

feed on producers (rooted plants & phytoplankton). ex: zooplankton

secondary consumers

feed on primary consumers. ex: fish

tertiary consumers

feed on tertiary consumers. ex: turtle

heterotrophic

Organisms that obtain their nutrients or food from consuming other organisms.

competition in ecosystem

life in ecosystem is often about competition for limited resources

what are other critical factors influencing community dynamics that are both physical and geographic?

habitat's latitude. amount of rainfall. topography (elevation). available species

law of tolerance

existence, abundance, and distribution of species in an ecosystem are determined by whether levels of 1 or more physical/chemical factors fall within range tolerated by that species

species and tolerance range

may have wide range tolerance to some factors and narrow range to others

organisms and tolerance

each organism has tolerance in its physical and chemical environment

limiting factor principle

too much or little of any abiotic factor can limit or prevent growth of a population, even if al other factors are at near optimum range or tolerance

precipitation limiting factor

on land. often limiting factor. lack of H2O in desert limits plant growth

soil nutrients limiting factor

mostly phosphorus limiting and nitrogen to

limiting factors in aquatic ecosystems

temperature. sun. nutrient availability. dissolved oxygen

dissolved oxygen

amount of oxygen dissolved in given volume of H2O @ particular temp and psi

salinity limiting factor

amounts of various inorganic minerals or salts dissolved in given volume of H2O

earth's organisms either...

produce or consume food

producers (autotrophs)

make own food

heterotrophs or "other feeders"

relay on other organisms to get food

decomposers

mostly certain types of bacteria and fungi. specialized consumers that recycle organic matter in ecosystems

biodegrading

breaking down

process of decomposing

releases simpler inorganic compound into soil and H2O, producers can take them up as nutrients

ecosystem dynamics

changes in ecosystem structure caused by changes in environment (disturbances) or by internal forces

environmental disturbances and humans

impact of environmental disturbances caused by human activities is as important as changes brought by natural processes

equilibrium

steady state ecosystem where all organisms in balance w/environment and each other

resistance

ability ecosystem to remain @ equilibrium in spite of disturbances

resilience

speed @ which an ecosystem recovers equilibrium after being disturbed

human impact and resilience/resistance

nature of ecosystem may changes and it could lose resilience entirely. process may lead complete destruction or irreversible altering of an ecosystem

energy required by most...

complex metabolic pathways (often ATP) especially those responsible building large molecules from smaller molecules and life itself is energy driven process

what are the 3 ways energy is acquired by living things?

photosynthesis. chemosynthesis. consumption/digestion other living or previously living organisms by heterotrophs

each organism in ecosystem is...

assigned feeding level (trophic)

how is the flow of energy and matter traced?

through food webs

food chain

sequence organisms, each which is source of food from next. determines how energy and nutrients from 1 organisms to another through ecosystem

food web

complex interconnected through food chains. map of life's interdependence

1st trophic level

producers

2nd trophic level

primary consumers

3rd trophic level

secondary consumers

4th trophic level

tertiary consumers

detritivores

feed on plant and animal remains and other dead matter

energy flow pyramid

trophic or ecological pyramid. graphical representation of energy found within trophic levels of ecosystem

what is the bottom and largest level of the energy flow pyramid?

producers. contain largest amount of energy

trophic level and biomass

each trophic level contains certain amount of biomass, dry weight of all organic matter contained in its organisms

ecological efficiency

% of usable energy is degraded and lost to environment as low quality heat. in accordance w/2nd law of thermodynamics

different ecosystems use...

solar energy to produce and use biomass at different rates