Unit 1 Ecosystems & Community Ecology

Abiotic

Nonliving physical and chemical parts of an environment, such as water, sunlight, temperature, soil, and air

Biotic

Living or once living parts of an environment, such as plants, animals, fungi, and bacteria.

Ecosystem

All the biotic (living) and abiotic (nonliving) factors interacting in a specific area

Biosphere

All of earth’s ecosystems combined; the global system where life exists Materially closed and energetically open

Materially closed

Matter (physical substances like water, carbon, oxygen, nutrients, and minerals) is mostly recycled within earth rather than entering or leaving the biosphere

Energetically open

Energy (such as sunlight and heat) can enter and leave the biosphere- sunlight enters earth and energy eventually leaves as heat

Steady state

A condition where a system stays relativly stable because input( what enters the system) equals output (what leaves the system)

Environmental systems and disturbances

Environmental systems tend toward equilibium (balance), but they can be disturbed by natural events or human activites

Dynamic equilibrium

A system is constantly changing and responding to disturbances while maintaining or returning toward an overall balance.

Negative Feedback loop

A change causes effects that reduce or reverse the original change, helping the system return towards balance

Positive feedback loop

A change causes effects that increase or amplify the original change, helping the system return toward balance.

Global Warming - Positive feedback

increase in output leads to increase in input - GW causes droughts, forest fires, and CO2 release from warming oceans, which add more Co2 to the atmosphere and cause even more warming. ( Positives= amplifies the change; it does NOT mean '“good”)

Global Warming - Negative feedback

Increase in output leads to a decrease in input- Increased CO2 can cause more plant growth, which removes more co2, from the atmosphere through photosynthesis, helping reduce the orginal warming effect (negative= reduces/reverses the change; it does NOT mean “bad”)