Unit 8: Ecology

Abiotic factor

any nonliving factor in an organism's environment

ex: temperature, water, sunlight, soil, oxygen, and carbon dioxide levels, pH levels

Adaptation

A characteristic that improves an individual's ability to survive and reproduce in a particular environment.

Biodiversity

describes any variety in a biological system

includes: genetic, species, and ecosystem diversity

more diversity = more healthy and stable

Biome

A group of ecosystems that share the same climate and have similar types of communities

Biotic factor

any living factor in an organism's environment

ex: producers, consumers, decomposers

Carrying capacity

the sustainable abundance of a species that can be supported by the ecosystem's total available resources (represented by K)

Climate Change

the broad range of changes seen in our planet. Cause: the greenhouse effect

Community

All the populations of species (all biotic factors)

- Live at the same time, same place

Decomposers

non-photosynthetic bacteria and fungi that extract energy from dead matter, including animal wastes in the soil, and make nutrients available

Density-Dependent Factors

the impact of these factors depends on how dense the population is

Detritivores

feed on detritus and the decomposing products of organisms

distribution

how organisms are arranged in a habitat (pop. dist.)

or

how biological data points are spread out (data dist.)

ecological niche

the role or position that an organism has in an ecosystem

ecological pyramids

representations of the flow of energy and matter in an ecosystem

ecological succession

gradual change in living communities that follows a disturbance

ecosystem

all the biotic and abiotic characteristics in an area

endangered species

an organism in immediate danger of extinction throughout all or a significant portion of its natural range

exponential growth

If there is nothing preventing a population from reproduction or limiting their reproduction

only possible when infinite natural resources are available

Food Chain

Follows a single path of energy flow

Food Web

Follows many paths of energy flow

Global Warming

an enhanced greenhouse effect driven by human activity—(fossil fuels, deforestation, etc.) releases greenhouse gases that trap more thermal energy in the atmosphere

Greenhouse effect

the natural process by which specific atmospheric gases trap outgoing infrared heat, maintaining Earth's habitable temperature

greenhouse gasses

Burning of fossil fuels increases concentration of __________ ______, which block more heat from escaping.

Habitat

the area where an organism lives

Interspecific Competition

competition between members of different species

Intraspecific Competition

Competition between members of the same species

introduced species

an organism transported by humans—intentionally or accidentally—outside its natural geographic range

K-selection

a few offspring with high survival rates

Keystone species

an organism that plays a unique and crucial role in the way an ecosystem functions.

Limiting Factor

biotic or abiotic factor that restricts the number, distribution, or reproduction of a population within a community

ex. sunlight, temp, water, nutrients, fire, other plants and animal species

Logistic Growth

occurs when resources are limited and there is a carrying capacity

Migration

animals move from one location to another in a seasonal pattern, triggered by enviro cues such as air temp and day length.

animals can migrate to correct location w/out ever being there.

mortality

the frequency of deaths in a population over a given time

Mutualism

A symbiotic relationship that benefits both members

ex. obligate symbionts (both depent entirely for survival)

Parasite

In parasitism, one organism is harmed and the other benefits. The one that benefits is called the ________.

Photoautotrophs

capture light energy present in sunlight and perform photosynthesis, contributing to primary productivity

Population

A group of organisms of the same species

- Live at the same time, same place

Predator

an organism that hunts, kills, and consumes another organism (its prey) for energy and matter

Primary Consumer

a heterotroph that feeds directly on primary producers (like plants or algae) to obtain energy

r-selection

many offspring with low survival rates

secondary consumer

a heterotroph that feeds on primary consumers

survivorship curve

a graph that shows the proportion of individuals in a population surviving to each age

Symbiosis

any long-term and close relationship between two or more species

the 10% rule

when energy is passed in an ecosystem from one trophic level to the next, only about 10% of the energy is passed on and stored as biomass.

The remaining 90% is lost as metabolic heat, respiration, and undigested waste

trophic efficiency

the percentage of energy transferred from one trophic level to the next

trophic level

an indicator of feeding level or position in the food chain.

ec. primary producer, etc.

Nitrogen fixation

nitrogen gas (N2) is fixed into ammonia (NH3), which ionizes into ammonium (NH4+) by acquiring hydrogen ions from the soil solution

Eutrophication

water pollution from nitrogen-rich and phosphorus-rich substances flowing into waterways, causing algal overgrowth.

biomagnification

higher-level predators (fish, birds, and marine mammals) build up greater and more dangerous amounts of toxic materials than animals lower on the food chain