(Week 8) Population and Community Ecology BSC 101 ISU

Ecology

The science of the relationships between organisms and their environment

Individual Level Ecology

The study of how an individual organism interacts with their environment

Population Ecology

A group of individuals of the same species living and interacting in the same region

Community Ecology

The study of how interacting populations of different species living in the same area at the same time

Ecosystem

Species (biotic) interacting with other species and the environment (abiotic). Focus on the flow of energy and cycling of nutrients

Random Distribution

Individuals are equally likely to appear anywhere within an area

Clumped Distribution

High-density clumps of individuals are separated by areas of low abundance

Uniform Distribution

Individuals maximize space between them by being uniformly spaced

Growth Rate

Birth rate - death Rate

Exponential growth

Rapid 'unchecked' growth of a population

Logistic growth

The pattern of growth observed when individuals are limited by environmental factors

Carrying Capacity

The maximum number of individuals that can be supported in an environment based on space and resources

Abiotic Factors

Nonliving components of environment. Can influence organisms in a given environment. Density independent

Biotic Factors

Living components of an environment. Can influence organisms in a given environment. Density dependent

Parasitism

One species benefits and another is harmed

Predation

One species benefits and another is harmed. Typically involves herbivory and carnivory

Commensalism

One species benefits and the other is unharmed

Mutualism

Both species benefit

Stamen

Male, pollen-bearing structures (in flowers)

Anther

The structure that produces and releases pollen (in flowers)

Filament

The thin structure that extends and supports the anther so it is accessible to pollinators (in flowers)

Carpel

Female, egg-bearing structures (in flowers)

Stigma

Sticky surface that traps pollen (in flowers)

Style

The tube connecting the stigma to the ovary (in flowers)

Ovary

The protective structure that contains the ovules, where eggs develop and are fertilized. The ovary becomes the seed-containing fruit after fertilization (in flowers)

Ovule

The egg-producing structure within the ovary

Pollination

The transfer of pollen from male reproductive structures to female reproductive structures in plants

Competition

Typically a minus/minus (neither species immediately benefits and may be harmed). Occurs when two species have overlapping niches

Niche

The combination of physical space, environmental conditions and resources that species require

Generalist

A species whose niche is large ie the species can survive in different environments

Specialist

A species whose niche is small ie the species can survive in a few select environments tailored to their needs

Competitive Exclusion

A form of competition. Occurs when one species outcompetes another

Resource Partitioning

A form of competition. Occurs when resources are divided (partitioned) to reduce competition

Food Web

Representation or model of feeding relationships in a community

Producers

Autotrophs. Produce energy by harnessing

Consumers

Heterotrophs. Eat other producers or consumers

Herbivore

Predator of plants

Carnivore

Predator of animals

Trophic Pyramid

Illustrate feeding levels. Also illustrates how energy is lost as it flows through a food chain