APES Ecosystems Study Guide

Organism

A single member of a certain species. Example: a whitetail deer.

Population

All members of a certain species living in an area. Example: All of the whitetail deer living in Tanglewood Park.

Community

All the different populations living in an area. Example: Every type of animal and plant that lives in Tanglewood Park.

Ecosystem

All communities in an area plus the environment. Example: All animals, plants, rocks, climate, pH of Tanglewood Park.

Habitat

The type of place where an organism lives.

Range

The geographical area where an organism lives.

Niche

A species’ role in an ecosystem

Atmosphere

Layer of air surrounding the Earth.

Stratosphere

Layer above troposphere; contains ozone layer.

Lithosphere

Crust and upper part of upper mantle; solid part of Earth that life lives on.

Hydrosphere

All water on Earth.

Heat/Light, Energy for photosynthesis, weather and climate, drives nutrient cycles

4 things sun provides for life on Earth

Degraded into low quality heat in accordance with the 2nd law of thermodynamics.

What eventually happens to solar energy that enters Earth’s atmosphere

Greenhouse effect

GOOD. Gases such as water vapor, carbon dioxide (CO₂), Methane (CH₄), Nitrous Oxide (N₂O), CFCs absorb radiated infrared radiation and release even longer wavelengths of infrared radiation into the troposphere— keeps us warm.

Global warming

BAD. The concept that by increasing the concentration of greenhouse gases, we enhance the warming process.

Biotic factor

Living things — animals, plants, fungi, protists, bacteria

Abiotic factor

Nonliving things — temperature, pH, salinity, humidity, light intensity, air speed

Tolerance range

Range of chemical and physical conditions that must be maintained for a population to function.

Limiting factor

Even if everything else is within the range of tolerance, one factor out of range can limit survivorship.

Zone of physiological stress

Range of tolerance in which a smaller number of individuals can survive.

Zone of intolerance/tolerance limit

The point beyond which none survive.

Optimal zone

Range of tolerance where the greatest number of species survive.

Autotroph

Producers, produce their own food. Ex: Plants through photosynthesis

Producer

Autotrophs, produce their own food. Ex: Plants through photosynthesis

Consumer

Organisms that feed on other organisms.

Primary consumer: eats plants

Secondary consumer: eats meat

Herbivore

Organisms that eat plants. Primary consumer.

Carnivore

Organisms that eat meat. Secondary consumer.

Omnivore

Organisms that eat both plants and meat.

Detritovore

Organisms that eat detritus (dead/decaying plant and animal parts, feces)

Scavenger

Organisms that eat large chunks of recently dead animals.

Decomposer

Animals that are responsible for the final breakdown of organic material into recyclable organic molecules. Fungi, bacteria.

Photosynthesis

Plants do this. The process by which producers make their own food.

Carbon dioxide + water + energy → glucose + oxygen

Respiration

All organisms do this. The process that fuels all of life’s processes.

Glucose + oxygen → carbon dioxide + water + energy

Food chain

A sequence of organisms, each one eating the previous one.

Heterotroph/tertiary consumer = 4th trophic level

Heterotroph/secondary consumer = 3rd trophic level

Heterotroph/primary consumer = 2nd trophic level

Autotroph/producer = 1st trophic level

Food web

A network of food chains.

Biomass

The dry weight of all organic matter contained in organisms on a certain trophic level.

Ecological efficiency

The percentage of usable energy transferred as biomass from one trophic level to the next. It averages 10%.

-Earth could support more people if everyone was a vegetarian

-There’s only 4 trophic levels

-Such a low number of top consumers

3 things that ecological efficiency explains

Gross primary productivity

Total rate at which producers convert and store solar energy into chemical energy via photosynthesis.

Net primary productivity

Rate at which producers store energy from photosynthesis minus the rate at which they use some of this stored energy in respiration. Unit: kcal/m2/y

Growth - respiration

Troposphere

Layer of air closest to Earth’s surface; life and weather take place here.