Ecolgy Unit Chapter 2 Glossary Terms

A group of individuals belonging to a species living in the same region at the same time, and able to successfully reproduce.

• Tend to increase when individuals reproduce at rates faster than what is needed to replace individuals that have left or died
• Example : Elephants
• The size of the population is based on the ecosystems carrying capacity

Very quick and accelerating growth of a species.

• Exponential growth occurs when a species has a lot of resources
• Produces a j-shaped curve when graphed against time
• Examples : algae growing in a new pond, and pressure being removed from elephants
• Cannot be sustained in nature

Environmental restrictions that limit population growth.

• Exponential growth cannot continue forever because no ecosystem has an infinite amount of resources
• As a population increases, each animal has access to less resources, thus limiting their growth
• Includes biotic factors like food and abiotic factors like light and oxygen

The size of the population that can be supported by an ecosystem

• Is decided by the amount of resources
• When a population is maintained at carrying capacity it is at an equilibrium 
• When a necessary resource is being used at a rate faster than the carrying capacity of the ecosystem, the population will drop to a natural equilibrium
• the limiting resource may also be an abiotic factor

The function/place of an organism in its ecosystem

• Every living thing on Earth has a role to play in its environment
• Niche includes how resources are obtained and how an organism survives
• A job in the sense of providing benefits to an ecosystem
• Made up of : the resources used by an organism, abiotic limiting factors and bitotic relationships with other species
• Example: The space a bat takes up while sleeping a part of its ecological niche

An animal that preys on/eats others

• A carnivore or meat-eater 
• An animal on a higher trophic level
• Example: a lion is a predator of a zebra

An animal that is hunted by another for food

• Usually a herbivore or secondary predator
• An animal on a lower trophic level
• Example: a rat is snake's prey

A symbiotic relationship between two species that both species benefit from

• The animals "work together" in a sense
• Organisms in a mutualistic relationship evolved together
• A species may be so dependent that it cannot live without its mutualistic partner
• Examples of mutualisim: coral and algae, bees and flowers, humans and bacteria

Organisms that live on or in host organisms from which they leech nutrients and give nothing in return

• Parasites don't try to kill their hosts because they need the host to survive
• Sometimes the host is harmed and sometimes not
• The impact on the host is always negative
• Examples of parasites: tapeworms, fleas, and barnacles

When two or more organisms compete for the same resource in the same place at the same time

• Can limit the size of a population
• The more energy spent competing is less energy spent growing and reproducing
• When there is now competition a species can occupy a broad niche but when there is competition the niche is narrower 
• Example: When the sparrow population increased, the amount of eggs laid decreased

The use of a resource that doesn't lead to long term depletion or affect the diversity of an ecosystem

• Allows the resource to meet the needs of present and future generations.
• If something is used sustainably it should last forever

The amount of time it takes for a population's size to double.

A measure of the impact an individual or population on the environment

• Measured in terms of energy consumption, land use, and waste production 
• Reflects the behavior of individuals and the communities they live in 
• A measure of land and water that are needed to support an individuals living standard 
• Our ecological footprint shows that 1.5 earths would be needed to meet humanity's demands
• usually measured in hectares

A pattern of activity that leads to a decline on resources and function in the ecosystem

• Not able to be maintained forever
• The opposite of sustainable
• Non-renewable

Using Earth's resources in a sustainable way in which they can last forever

• Involves meeting the needs of the present without compromising the needs of future generations
• Includes land and water being used sustainably as well
• Opposite of unsustainable

The Benefits provided to organisms(including humans) from sustainable ecosystems

• Includes many things like: the provision of food and clean water, the cycling of nutrients. the conversion of atmospheric carbon into biomass,etc.
• A natural result of all the activities in the biosphere
• Ecosystem services allow ecosystems to function

The change of a place that is not a desert into a desert

• May result from climate change and unsustainable farming and water use
• Usually occurs when large forests are cleared and annual precipitation is lowered
• Example: When European settlers clear cut forests the are became deserts

A form of tourism that is sensitive to the ecosystem and involved activities provided by sustainable ecosystems

• A sustainable form of tourism that is now a multi-billion industry
• Focuses on local cultures and wilderness adventures
• Examples: Hiking, snowshoeing,fishing and kayaking