Scientific study of the interactions between organisms and their environments

Interaction between organism and environment – determine the distribution of organism and abundance of organism

Distribution of species? Abundance of species?

Interaction occur at a hierarchy of scales, from organismal to global.

4 comprehensive levels of study, from the ecology of individual organisms to the dynamics of ecosystems.- organismal ecology- population- community- ecosystem

Habitat is defined as a place where an organism lives.

Organismal ecology is concerned with the morphological, physical and behavioral ways in which individual organisms meet the challenges posed by their biotic and abiotic environments

Population is defined as groups of individuals or of the same species that tend to mate with each other and living in a particular geographic area. - (second level of study in ecology)- analyzes factor that affects population size and how and why it changes through time.

Community is defined as a group of population of different species in an area.- how interaction between species affect community structure and oragnization

ecosystem

Organism/individual

population

community

Ecosystem is defined as the community of organisms in an area and the physical factor with which those organisms interact.- emphasizes energy flow and chemical cycling between organisms and the environment.

Landscape ecology – mosaic of connected ecosystems.

The interactions between organisms and their environments determine both the distribution and abundance of organisms.

The environment of any organism include abiotic components and biotic components

ClimateSunlight – too little sunlight/to much

sunlightWater/precipitation (rain,snow etc)Temperature Humidity Wind and air currents Soil pH – basic/acidicMineral + trace elementsWater retention + absorption

Geography Salinity – affect osmosisWater current

Topography

competition for food or territory (intraspecific)

interaction between predator and prey, interaction between host and parasite, mutualistic relationship competitive exclusion and resource partitioning (interspecific)

Biomes are defined as "the world's major communities, classified according to the predominant vegetation type in teresstrial biomes or the physical environment in aquatic biomes.

Biomes have changed and moved many times during the history of life on Earth. More recently, human activities have drastically altered these communities

Aquatic biomes – marine and freshwater (salinity)

Terrestrial biomes (forest, tundra, savanna, desert etc)

biosphere is the biological component of earth systems.

defined as zone of air, land and water at the surface of the earth in which living organisms are found. (the global ecosystem)

The earth can be divided into atmosphere, lithosphere and hydrosphere.

Ecological interactions between populations of different species

The kinds of interaction that occur between species in community

Classified by whether help, harm or no effect

Ecological niche -biological role played by a species in its community, or the sum of a species’ use of the biotic and abiotic resource in its environment.

Limiting resources limit the ecological niche of a species.

Fundamental niche - the total range of environmental conditions that are suitable for a species existence without the effects of interspecific competition and predation from other species.

Realized niche -part of the fundamental niche that a species actually occupies. Affected by competition.

Involve the interaction where two or more organisms in the same space require the same resource

Food, water, nesting space, ground space

Interspecific or intraspecific biotic levels.

Result of exploitation or interference.

Interspecific competition – interaction between different species that compete for a limit resources.

Intraspecific competition - Individuals compete with others of their own kind (that is, members of their own species)

When populations grow, and individuals are therefore more closely packed, and/or resources are scarcer.

Resource competition - Occurs when a number of organisms utilize common resources that are in short supply

An intraspecific/interspecific all the individuals “share” the limited resources, affected equally. None of them get sufficient amount of resources

(no winners/losers) (0/0)

Interference competition - Occurs when the organisms seeking a resource harm one another in the process.

Inter/intraspecific Intraspecific competition with dominant

individuals get sufficient supply of the limited resource.

Also known as contest competition (fighting) (+/-)

Competitive Exclusion - a situation where no two competitively interacting species can occupy exactly the same fundamental niche because of resource limitations.

Overlapping niche The outcome - local extinction the

species that is a poorer competitor.

G. F. Gause, demonstrated the effect of competition on niches on two species of single-celled animals, Paramecium aurelia and Paramecium caudatum.

The three graphs showing competition between two species of Paramecium

Resource partitioning - the differentiation of niches that enables similar species to coexist in a community.

the niche is partitioned into separate, minimal overlapping differences in resource use.

Species with reduced niche overlap have reduced competition because they have different requirements for similar resources.

Resource partitioning very often results in species that are specialists.

Result in, a species’ realized niche is often different from its fundamental niche.

7 species of Anolis lizards lived in close proximity, and all feed on insects and small athropods. However, competiton for food is reduced because each lizard species has a different preferred perch, thus occupying a distinct niche.

Predation – interaction between species in which one species kills/eat another species.

predator feeds on the prey. Attack strategy

Strategies of Predators:◦Pursuit predators - predators which chase their prey

◦Ambush - camouflaged to avoid notice by their prey

Predators have acute sense – they able to locate and identify their potential preys

Having adaptation – claws, teeth, fangs, stingers or poisons (help in catching the prey)

Fast and agile (predators that pursuit their prey)

Often disguised in environment (ambush their preys)

http://www.youtube.com/watch?v=RJW7oZ2b4XA

Prey – adaptation to avoid being eaten Common behavioral defenses – hiding,

fleeing, forming herds/schools Active self-defense is less common Variety of morphological and physiological

defensive adaptation

Secondary compounds (plants) Nutritional deficiencies (plants) Mechanical defenses (plants) Production of poisons (animals)

(chemical defenses) Mechanical defenses (animals) Running away and hiding (animals)

Fighting back (mostly animals) Coloration

- Cryptic coloration (mostly animals)- aposematic coloration

Mimicking- Batesian mimicry (animals)- Müllerian mimicry (animals)

Aposematic colors: Warn the predator that they (the prey) are distasteful - exhibit bright colors

Cryptic colors: Hide the prey by blending it with its background (camouflage)

Mimetic colors: one species to resemble another species. ◦Batesian mimicry - the mimic (edible)looks

like a species that is not palatable (toxin)◦Mullerian mimicry - mimics are all

inedible, but are too rare for the predator to learn to avoid them

One such study involved deadly coral snakes and their harmless look-alikes, scarlet king snakes.

Batesian mimickry

As a caterpillar the Monarch Butterfly eats Milkweeds with produce a toxin. But

the Monarch has developed a way to counter these toxins and stores them up in its body. As an adult Moarcks tast bad and birds learn not to eat butterflies that

have black and orange wings

The Viceroy Butterfly tastes great (to birds) but the birds who have learned that

butterflies with black and orange wings (Monarchs) taste bad won't eat Viceroys.

The Viceroy is the mimic, and the Monarch is the Model.

Batesian mimickry

Symbiosis (sym-= together, -bio- = life, -sis = process)

MutualismMutualism exists when two species interact to the benefit of both species.

CommensalismCommensalism is a symbiosis in which one partner benefits but the other gains nothing from the association.

ParasitismIn this type of symbiosis, one partner or the parasite benefits at the expense of the other partner or the host.

A process The exploitation of an environment by one

population, followed by the exploitation by a second and third population

Succession can be divided into primary succession and secondary succession

Succession starts with the initial rapid colonizer species which are the pioneer community.

Succession stops when species composition changes no longer occur with time, and this community is said to be a climax community.

Primary succession of bare rock

Secondary succession

Secondary succession is succession that follows primary succession

secondary succession occurs rapidly Human activity such as clearing a climax

forest community to set up a farm field consisting of a cultivated pioneering species, such as corn or oil palm trees replaces climax communities with simpler communities.

Energy flows move through feeding relationships.

Food webs, food chains, and food pyramids are three ways of representing energy flow.

The sun is the ultimate source of energy for almost all living things and ecosystems

During photosynthesis, green plants and certain bacteria (producers) trap sunlight and use it to assemble carbon dioxide and water into carbohydrates.

Producers are autotrophic and usually photosynthetic organisms

Consumers - heterotrophic organisms that eat food produced by another organism

Obtain energy either directly or indirectly from producers

Primary consumers – plant eaters Secondary consumers – consume

primary consumers Tertiary (third-level) or quaternary

(fourth-level) consumers – consume secondary or tertiary consumers respectively

Decomposers or detritivores (heterotrophic organisms)

Feed on detritus such as dead organisms or products of living creatures and waste products

Able to recycle nutrients from nonliving or decaying organic material

Example: omnivorous crow; vultures; lobsters; shrimp; crabs; follicle mites; kingdom Fungi; Eubacteria

 

Trophic (trophe)

Consumer           Trophic Level         Food Source          Herbivores         primary               plants              

Carnivores         secondary higher   animals             

 Omnivores          all levels            plants & animals    

Detritivores       --------------       detritus            

A food chain is the path of food from a given final consumer back to a producer

2 types: detritus and grazing food chain Grass – grasshopper- mouse – snake –

hawk Grazing food chain - based on photosynthesis as a source of energy

Detritus food chain - based on decomposition of detritus as a source of energy

Most food chains are interconnected – formed food webs

Food webs -more realistic; allow individual species to consume at more than one trophic level