Ecology

Ecology

the study of interactions between organisms and the enviorment

What is the enviroment

enviorment refers to the physical surroundings and other organisms

Population

A group of individuals of the same species in the same area

Community

Group of populations living in the same area

All of the living organisms in one area

Ecosystem

All living organisms and the physical enviorment they interact with

Habitat

Physical surroundings where an organism usally lives without the living organisms

Biosphere

global ecosystem including all of the planets ecosystem atmoshpehere and landscape

Biotic

Living organisms or anything alive

Abiotic

Non living such as water climate

Biotic and Abiotic factors limit

population distributions

Niche

tells you where an organism lives, what it uses to survive, and how it interacts

Two species cant occupy the same

niche

Fundamental niche

full range an organism can live in with no constraints

Realized Niche

where an organism can actually live

Population Ecology

Size - total number of individuals in population

Density - Total number of indiviudals per area

Dispersion - pattern or spacing among individuals in populaton

Determination of Geographic Distribution

Dispersal - can they access this area

Behavioral limits - does animal prefer to live here

Biotic Factors - do predators or competition prevent animal from living here

Abiotic Factors - do the factors allow it to live there

Biotic Potential

the maximum growth rate or how quickly a population can grow under ideal conditions

What affects biotic potential

number of offspring

frequency of reproduction

Suvivorship of offspring

Reproductive Lifetime

Age of reproductive maturity

Carrying Capacity

Maxinum number of individuals that a habitat can sustain

Limiting Factors

Elements that prevent a population from reaching biotic potential

Density Dependent Factors

Increase with the density of the population

Examples of density dependent

disease, competition, and predation

Density Dependent factors are subject ot

negative feedback

Density independent factors

not impacted by the density of population

Examples of density independent factors

natural disasters and climate

Are density indepedent factor subject to negative feedback

No they are not subject to negative feedback

Exponential Growth

Hypothetical unlimited growth of population

Logistic Growth

When limiting factors restrict population size and the growth rate decreases and reach a carrying capacity

Bacterial Growth

Lag phase - no change because bacteria is just no adapting to conditions

Exponential phase or log phase - grow at increaing exponential rate growth rate > death rate

Stationary Phase - Growth rate = death rate due to growth limiting factor

Death Phase - Bacteria die off and death rate > growth rate

Survivorship Curve

show how many individuals survive at stages of life

Type 1 Survivorship Curve

very high survival at beginning in middle and near the older age they die

Type 2 Suvivorship Curve

Suvivorship is random and death chance is consistent throughout

Type 3 survivorship curve

Many of these organisms die young and few survive to reproductive age

K Selected species

Low Number of offspring

High parental care

Low population growth

Longer lifespan

stable enviorment

reach reproductive maturity slower

Stable population size

larger offspring

Lower mortality rates

Type 1 Curve

R Sekected species

High number of offspring

low parental care

high population growth rate

short lifespan

unstable enviorment

reach reproductive maturity quickly

poplation fluctuates

smaller offspring

higher mortality rates

Type 3 Curve

Reproductive Stradegies exist on spectrum of K to R

Exist as spectrum and reflect the reproductive rate and growth patterns

Per Capita Birth Rate

Measures the number of births per individual in a population over a give time

Per Capita Birth rate equation

b = B/n or total number of birth /total population size

Species Diversity

Overall Variety of different organisms in a community

Species Diversity two Components

Species Richness

Relative Abundance

Species richness

total number of different species in a community

What is species richness directly related to

community geographic size meaning more geographic area the greater number of species

Relative Abundance

the proportion each species represent out of all individuals in a community

Maximize the diversity meaning having a high

relative abudnace or a balance of species

Community Ecology

Examines how interactions between species affect community organizations

Interspecific Competition

Competition between different species

Intraspecific competiton

competition for resources between individuals of the same species

Competitive exclusion principle

two species competitng for the same limited resource cannot coexist in the same niche and over time one species will win out

either one species dies or it moves to another community

Resource Partitioning

Resource partitioning occurs when species that compete for the same resource divide the resource in different ways, reducing competition and allowing them to coexist.

Character Displacement

The tendency for traits to become more divergent due to competition in the same enviorment

what does character displacement lead to

less competition due to divergent of species

Interference competition

Aggression directly between individuals

Exploitation Competition

Occurs inderectly through deplletion of a common rescource and one population is reduced

Apparent Competition

Apparent competition occurs when two species are preyed upon by the same predator, indirectly affecting each other’s survival. Although they are not directly competing for resources, one species can increase predator numbers, which in turn harms the other species.

Exploitation

Exploitative competition occurs when species indirectly compete by depleting a shared resource.

Predator

kills and eat another organism

Parasites

Requires a host to complete life cycle

feed off the host

Parasitoids

live in close association with the host but eventually kill the host

Herbivores

Consume plants

Symbiosis

Association between two organisms that may or may not be beneficial

Commenalism

One benefits and one is unaffected

Mutualism

Both organsims benefit P

Paratisitsm

Organism befnifts at the expense of the host

Indirect Interactions

species where an organism impact on antoher are mediated by a third organism and never interact

Indirect commensalism

Indirect commensalism occurs when one species benefits from another without direct interaction between them.

Facilitation

Species indirectly has a postive effect on another without close contact by altering the enviroment

Common in plant ecology

Saprophytes

organisms that decompose dead organic matter

Scavengers

consume dead animals directly

Ecological Succession

Change in composition of species over time

one community is replaced by another gradually over time

Pioneer Species

the first speices to take over and start ecosystem

Intermediate species

Are not limited by the bad soil but now better soil can support better animals and plants

Climax Community

Final stage where there is constant species composition unless catastrophic event

Primary Succession

Occurs in area that have never previously supported living things

Essential process of soil building

Prinary Succession

Lifeless rock exposed by natural changes

Life starts to develop from Lichens or Pioneer Species and form soil

Soil Accumhlates and develips as rock weather

Bacteria and other pioneer species appear

Inscets begin to appear and contribute to cycle

Soil gets deeper and richer and plants begin to grow

Eventually r relate species get replaced by K selected species

Secondary Succession

Begins in habitats where communiteis were entirely or partially destroyed by a fire or flood

Which is faster primary or secondary succession

secondary because soil is already present

Secondary Succession timeline

ponds form after natural disaster

species begin to establish in the pond

Shallow water pond fills in

more plants begin to grow and create Moist Land

Finally climax community creates a Woodland

Ecological Succession factors

Substrate Texture - can change via plant and animal decomposition

Soil pH- how acidic or basic and base off what grows

soil water potential - ability of soil to retain water

Light avaliability - full sun shady or darkness can decrease or increase coverage

Crowding

increase with population growth but more developed more dense and more competition

Pioneer species

plants and animals first to colonize a new habitat

usally are R selected and can tolerate harsher conditions

factors that influence ecological succession

Light, Crowding, soil water potential, substrate texturem pioneer species, soil ph

Ecological Footprint

Aggregate amount of natural resources required to sustain organism or population

Ecosystem Organization

all the living organisms in a given area and the physical enviornnt they interact with

Ecological Pyramid

Show the energy conversion and biomass

organisms at the bottom have the most energy and biomass

Trophic Levels

Primary Producers

Primary Consumers

Secondary Consumers

Tertiary Consumer

Primary Producers

bottom of pyramid

autotrophs that convert sun energy into chemical energy

normally are plants

Primary Consumer

Herbivotes

eat primary producers

Secondary Consumer

Primary Carnivote

eat primary consumers

Tertiary Consumer

Secondary Carnivote

eat secondary consumers

Decomposers/Detrivotes

Organisms that absorb nutrients from non living organic material

convert dead matter and waste into inorganic forms

Trophic Effiiciency

Describes the proportion of energy at one trophic level transferred to the next

How is energy lost

as heat or as part of waste or metabolism

Higher Trophic levels are

less stable and most sensitive to population fluctuations

what are the average transfer of energy between trophic levels

aboyt 10 percent energy loss

Energy and Biomass is highest where

at the bottom or primary producer

Food Chain

Linear flow chart of who eats who

Food Web

Complex and expanded but more accurate with greater number of food pathways

Consumers

consumers must eat to gain energy

Omnivores

organisms that consume both animals and plants

Carnivores

Organims that eat other animals