Ecology Unit Study Guide: Ch.52-55

What is the relationship between ecology & evolution?
-natural selection
-adaptation to habitat

What is the relationship between ecology & environmental policy?
-ecology provides a scientific basis for understanding enviromental issues & making political decisions about them

What are the levels on which ecology can be studied?

Biotic Factor
living factors (all organisms that are part of the individual’s enviroment)
ex. tree

Abiotic Factor
nonliving factors (all the chemical and physical factors)
ex. temperature, light, water, and nutrients

How do biotic and abiotic factors influence aquatic and terrestrial ecosystem?
interaction with the enviroment determines distribution & abundance of organisms
– study powerpoint as well

Effect of solar radiation on weather patterns
-global warming
-ozone depletion
–reduction in plant growth
find more in book

Biogeography and What factors limit organism distribution around the planet?
biotic and abiotic factors

Biogeographic Realms
six vast land areas on Earth, each with distinguishing plants and animals

Biomes: Terrestrial and Aquatic- review descriptions and know general characteristics
on powerpoint

Population Ecology

a group of organisms of the same species populating a given area

How are populations characterized?
their boundaries and size (# of individuals living within those boundaries)

What is Exponential Growth?
occurs under ideal conditions; growth only constrained by life history of the species

Biotic Potential
the maximum reproductive rate of an organism, given unlimited resources and ideal environmental conditions

Limiting Factors
any biotic or abiotic factor that restricts the existence, numbers, reproduction, or distribution of organisms

Carrying Capacity
largest number of individuals of a population that a environment can support

What is Logistic Growth?
growth pattern in which a population’s growth rate slows or stops following a period of exponential growth

Examples of Density Dependent & Density Independent Limiting Factors
dependent: competition for resources, predation, toxic waste, intrinsic factors, territoriality, disease
independent: drought stress that arouses when the roots of the grass are uncovered by shifting sands

Survivorship Curves
A plot of the number of members of a cohort that are still alive at each age; one way to represent age-specific mortality

Issue surrounding Human Population Growth and Ecological Footprint
dealing with the amount of resources available on the planet compared to the amount of resources being used
ex. the usa is using more resources than it has and has to buy from other countries

Community Ecology

any assemblage of populations in an area or habitat

the type of environment in which an organism or group normally lives or occurs

an organism’s profession (how it makes a living)
-fundamental niche= area where species could use
-realized niche= what they use due to competition

What are the categories of Species Interactions and can you give some examples?

-competition= a -/- interaction taht occurs when individuals of different species compete for a resource that limits their growth and survival (ex. weeds growing in a garden compete w/ garden plants for soil nutrients and water)

a +/- interaction between species in which one species (the predator), kills and eats the other (the prey)
(ex. lion attacking and eating an antelope)

a +/- interaction in which an organism eats parts of a plant or algae
(ex. cattle, sheep, water buffalo, grasshopper, beetles)

a +/- symbiotic interaction in which one organism (parasite) derives its nourishment from another organism (host) which is harmed in the process
(ex. tapeworm, tick, lice)

an impairment of health or a condition of abnormal functioning

or mutualistic symbiosis; an interspecific +/+ interaction that benefits both species
(ex. the digestion of cellulose by microorganisms in the digestive systems of termites and ruminant mammals)

an interaction btwn species that benefits one of the species but neither harms nor helps the other (+/o)
(ex. “hitchhiking species” algae on shells or barnacles attatched to whales)

Trophic Structure
The different feeding relationships in an ecosystem, which determine the route of energy flow and the pattern of chemical cycling

Competitive Exclusion
if you have two species with exactly the same needs only one is going to survive the competition (at direct odds w/ each other)

Resource Partitioning
in a biological community various populations sharing environmental resources through specialization thereby reducing direct competition (1 of the species can use a different species to survive)

The evolution of two or more species that is due to mutual influence, often in a way that makes the relationship more mutually beneficial

Community Stability
Communities are assemblages of many different species occupying the same geographical area; Communities are not static, they gradually change over time (communities are in a state of equlibrium) b/c the environment changes and species themselves tend to also change the habitats

Pioneer Species
first organisms into an area; improve conditions for other species; often organisms like lichens, mosses, small plants, insects.

Primary Succession
an ecological succession that begins in a an area where no biotic community previously existed and soil has not yet formed (ex. new volcanic island or the rubble (moraine) left by retreating glaciers)

Secondary Succession
the process by which one community replaces another community that has been partially or totally destroyed but the soil is still intact
(ex. forest fire)

Climax Community
a relatively stable long-lasting community reached in a successional series; usually determined by climax and soil type, Fairly stable, self-sustaining community in an advanced stage of ecological succession; usually has a diverse array of species and ecological niches; captures and uses energy and cycles critical chemicals more efficiently than simpler, immature communities

A discrete event that disrupts an ecosystem or community.
(ex. fires, hurricanes, tornadoes, droughts, and floods)(ex. human-caused disturbances: deforestation, overgrazing, and plowing)

species diversity, dependent on size and geographic location


all organisms living in a community as well as all the abiotic factors with which they interact

Food chain
the pathway along which food energy is transferred from from tropic level to trophic level, beginning with producers

Food Web
the interconnected feeding relationships in an ecosystem

Primary Producer
an autotroph, usually a photosynthetic organism. collectively, autotrophs make up the trophic level of an ecosystem that ultimately supports all other levels they transfer light energy into chemical energy

plant capable of synthesizing its own food from simple organic substances

organism that relies on other organisms (primary producers) for its energy and food supply; also called a heterotroph
a.k.a secondary consumer

an organism that depends on complex organic substances for nutrition

any animal that feeds chiefly on grass and other plants
a.k.a primary consumer

any animal that feeds on flesh

an animal that feeds on both animal and vegetable substances

organism that feeds on plant and animal remains and other dead matter and waste

Energy Flows through an ecosystem; Nutrients Cycle
the process that moves nutrients back and forth between the boitic and aboitic environment while energy is being lost between each trophic level in the form of heat

Trophic Level
step in the movement of energy through an ecosystem; an organism’s feeding status in an ecosystem.

Primary Production
The amount of light energy converted to chemical energy (organic compounds) by autotrophs in an ecosystem

Ecological Pyramids
show the relative amount of energy or matter contained within each trophic level in a given food chain or food web

Biogeochemical Cycle
ions or molecules of a nutrient are transferred from the environment into organisms and then back to the environment.

Biological Magnification
accumulation of non-degradable substances becomes more concentrated in the tissues of organisms at higher trophic levels.

Conservation Biology

the diversity of plant and animal life in a particular habitat (or in the world as a whole)

Approaches to reducing human impacts & restoring ecosystems
-population conservation
-landscape conservation
-restoration ecology
-sustainable development
(all help maintain biodiversity)

3 Levels of Biodiversity
-genetic diversity
-species diversity
-ecosystem diversity

3 Threats to Biodiversity
-habitat loss
-introduced species