Ecology (Science Olympiad)

Succession

The replacement of one community by another, developing toward a climax

Primary Succession

Succession starting with no soil

Secondary Succession

Succession starting with soil but no vegetation

Extinction

When a species has no more living members

Natural Selection

The differential survival and reproduction of organisms with genetic characteristics that enable them to better utilize environmental resources

Stabilizing Selection

A type of natural selection in which genetic diversity decreases as the population stabilizes on a particular trait

Disruptive Selection

Disruptive selection is a type of natural selection that simultaneously favors individuals at both extremes of the distribution.

Directional Selection

In population genetics, directional selection occurs when natural selection favors a single allele and therefore allele frequency continuously shift in one direction.

Artificial Selection

The process in which breeders choose the traits they want

Limiting Factors

A factor that limits a population's growth; i.e. resources, shelter, food and disease

Biodiversity

The number and variety of organisms within one region (biome)

Type 1 graphs

Type I organisms have lower mortality rate at low ages which gradually increases with age. (ex. Humans, most large mammals)

Type 2 graphs

Type II organisms have mortality rates that stay the same throughout life. (ex. birds, some lizards)

Type 3 graphs

Type III organisms have the largest mortality rates at birth. (fish, oysters, frogs)

Exponential Growth

Occurs when the growth rate remains the same while the population grows. It creates a J shaped curve.

Logistic Growth

Occurs when the growth rate decreases as the population grows due to density-dependent factors (factors increasing mortality rate as population grows such as predation rates, competition, and disease). This creates an S-shaped curve. It is the most common type of population growth.

Greenhouse Effect

When heat is stuck in the atmosphere due to greenhouse gases and Earth is warmed

Invasive Species

A species that has moved into an area and reproduced so aggressively that it has replaced some of the original species.

Acid Rain

rainfall made sufficiently acidic by atmospheric pollution

Wet deposition

acidic rain, fog, and snow

Dry deposition

acidic gases and particles

causes of Acid Rain

Sulfur dioxide (SO2) and nitrogen oxides (NOx)

Environment

the surroundings or conditions in which a person, animal, or plant lives

Biotic Factors

Living components of an ecosystem.

Population

Group of individuals of the same species occupying a common geographical area

Community

Two or more populations of different species occupying the same geographical area.

Population Ecology

The study if how populations interact with their eniornment

Population Size

Number of the individuals making up its gene pool

Population Density

Number of individuals per unit of area or volume

population growth formula

G is growth, r is rate of increase, N is number of individuals. Used to represent population growth mathematically.

K- selected organism:

put most of their energy into growth

Detritivores

decomposers which eat detritus

Logistic growth

a population that at will first rapidly grow but as they near the carrying capacity they will level off

interaction types

Neutral, Commensalism, Mutualism, Parasitism, Predation

Gross Product: Gross primary productivity =

the rate at which the primary producers capture and store energy per unit time. since the primary producers expend energy during respiration the net primary productivity is considerably lower than the gross productivity

Age Structure

pre-reproductive, reproductive, and post-reproductive

Density dependent factors

the growth that is affected by the density of individuals

Density-independent factors

the growth that is not affected by the density of individuals

Potential niche

no competitors and unlimited resources

Niche

the biotic and abiotic resources used by an organism

Realized niche

fundamental niche that a species actually occupies in nature

Climax community

a stable, self-perpetuating array of species in equilibrium with one another and their habitat

Pioneer community

a community that contains the first organisms to occupy an area

Transitional communities

a community that comes and goes

Biotic potential

the maximum growth rate of a population given unlimited resources and space and lack of competition and predators

Carrying capacity

maximum number of individuals of a species or population a given environment can sustain.

Habitat

the physical place where an organism lives, e.g. a pine forest or fresh water lake

Gause's law

all who use same resource can't coexist

Resource partitioning

the resources are divided, and species w/ same need are living together

Climate is dependent upon several factors, name them

Solar radiation

The earth's daily rotation

The earth's rotation around the sun

The distributions of continents and oceans

Ecology

How organisms interact with one another and with their environment. The environment consists of living and nonliving components.

What is a growth curve?

A growth curve is the pattern that a population's numbers follow

Zero population growth

Designates a near balance of births and deaths

Exponential growth

If birth and death rates of a population remain constant they can be combined into one variable, r=net reproduction per individual per unit time(rate of increase)

10%

The amount of energy transferred from one trophic level to another.

Abiotic factors

Non-living parts of an environment (ex. sun, temperature)

Autotroph/Producer

An organism that makes its own food through photosynthesis.

Biome

The largest division of the biosphere which includes large regions with similar biotic components and similar abiotic components.

Biosphere

The thin layer of air, land, and water on or near Earth's surface in which all living things on Earth exist. Atmosphere, Lithosphere, and Hydrosphere.

Biotic factors

Living parts of an environment (ex. fungi, animals)

Carnivore

An organism that obtains energy by eating only animals.

Carrying Capacity

Size of a population during the steady state region of a logistic growth curve. It represents the optimum number of organisms of a particular species that can be supported by a particular environment.

Cellular Respiration

Process that occurs at all trophic levels in which glucose and oxygen are broken down to produce carbon dioxide and water.

Commensalism

Type of symbiotic relationship in which one species benefits and the other is unaffected (ex. remora and shark)

Competitive Exclusion Principle

Two species cannot coexist if they are in the same niche.

Consumer/Heterotroph

An organism that acquires energy by feeding on other organisms.

Decomposer

An organism that feeds on and breaks down the remains of dead organisms and recycles those nutrients back into the environment; also known as detrivores.

Density-dependent limiting factors

Limiting factors that operate more strongly on large populations than on small ones (ex. competition, predation, parasitism, crowding, stress).

Density-independent limiting factors

Limiting factors that control population regardless of

how large the population is at the time (ex. natural disasters).

Ecological Niche

An organism's role in an ecosystem - includes things like diet, reproductive method, role in a food web, etc.

Ecological Succession

Process in which an existing community is gradually replaced by another community.

Ecology

The study of the interactions of organisms with one another and with their environments.

Ecosystem

A part of a biome in which biotic and abiotic components interact.

Emigration

Leaving an environment.

Generalists

Species with broad niches (ex. common crow). Environments with lots of this type have low diversity.

Herbivore

An organism that obtains energy by eating only plants.

Immigration

Entering an environment.

Logistic Growth

Growth typically experienced by populations. Five stages: 1) slow initial growth; 2) rapid exponential growth; 3) population growth begins to slow; 4) population slows even more still; 5) Population reaches steady state in which growth rate is zero.

Mortality

Death Rate

Mutualism

Type of symbiotic relationship in which both species benefit (ex. bacteria in our digestive tract, flowers and pollinators)

Natality

Birth rate.

Omnivore

An organism that obtains energy by eating both plants and animals.

Parasitism

Type of symbiotic relationship in which one species benefits and the other is harmed (ex. parasite and host, cuckoo and warbler)

Primary Consumer

An organism that feeds on producers.

Pyramid of Biomass

A pyramid that illustrates the total mass of all the organisms in a trophic level.

Pyramid of Energy

A pyramid that shows the total amount of energy available at each trophic level.

Secondary Consumer

An organism that eats primary consumers.

Specialists

Species with narrow niches (ex. anteater). Environments with lots of this type have high diversity.

Species

A group of closely related organisms that can reproduce with one another.

Steady State

Final stage in logistic growth in which birth rate = death rate.

Symbiosis

Relationship between two different species in which at least one species benefits.

Tertiary Consumer

An organism that eats secondary consumers.

Trophic level

A step in a food chain.

endothermal

organisms that maintain their own body heat internals usually through metabolism

ectothermal

organisms that rely on outside factors to maintain their body heat

homothermal

maintain a constant body temperature

Poikilotherm

body temperature fluctuates based on outside conditions

heterothems

characteristics of both homotherms and poikilotherms, they can switch between the two, usually occurs with animals that hibernate

cohort life table

recording the death of a group of individuals born at relatively the same time

static life table

recording the age of death of a group of individuals assuming they have they experienced the same events