Chapter 49: Introduction to Ecology

Ecology

The study of how organisms interact with each other and their environment.

Levels of Ecological Study

Organismal, population, community, ecosystem, and global/biome levels, including conservation biology.

Factors Affecting Geographic Distribution and Abundance

Abiotic and biotic factors.

Climate Patterns

Temperature, precipitation, seasonality, and land topology.

Characteristics of Major Aquatic Biomes

Salinity, light, currents, and nutrient availability.

Ecology

Study of how organisms interact with each other and their environment, and increasingly the impact that humans have.

Organismal Ecologists

Explore morphological, physiological, and behavioral adaptations.

Population Ecologists

Focus on how the number and distribution of individuals in a population change over time.

Community Ecologists

Study the nature and consequences of the interactions between species.

Ecosystem Ecologists

Study how nutrients and energy move among organisms and through the surrounding atmosphere and soil or water.

Global/Biome Ecologists

Focus on the effects of human impacts on the biosphere.

Conservation Biology

Study, preserve, and restore threatened populations, communities, and ecosystems.

Niche

Range of conditions a species can tolerate and resources it can use; product of abiotic and biotic factors where a species lives.

Weather

Short-term atmospheric conditions.

Climate

Prevailing long-term weather conditions found in an area.

Hadley Cell

Major cycle in global air circulation.

Seasons

Regular, annual fluctuations in temperature, precipitation, or both.

Biomes

Regions characterized by distinct abiotic characteristics and dominant vegetation types.

Net Primary Productivity (NPP)

Total amount of biomass generated by the carbon that is fixed per year minus the amount oxidized during cellular respiration.

Biomass

Total mass of organisms, primary producers in this case.

Arctic Tundra

Occurs throughout the arctic regions of the Northern Hemisphere.

Boreal Forest (Taiga)

Occurs across most of Canada, Alaska, Russia, and northern Europe.

Temperate Forest

Occurs in eastern North America, Europe, and eastern Asia.

Temperate Grassland

Also called prairie in North America and steppe in central Eurasia.

Desert and Dry Shrubland

Occurs at 30 degrees latitude north and south.

Tropical Wet Forest (Tropical Rain Forest)

Occurs in equatorial regions.

Anthropocene

New epoch of history due to human population explosion.

Simulation Studies

Computer models of weather patterns in local regions.

Observational studies

Long-term monitoring at fixed sites around the globe

Freshwater Wetlands

Shallow-water habitats where the soil is saturated for at least part of the year, including marshes, swamps, and bogs.

Streams

Bodies of water that move constantly in one direction from an area of higher elevation to an area of lower elevation.

Estuaries

Areas where rivers meet the ocean, mixing fresh water with salt water.

Oceans

A vast, continuous body of salt water that is remarkably uniform in chemical composition.

Salinity

Proportion of solutes dissolved in water.

Intertidal Zone

Submerged at high tide, exposed at low tide.

Neritic Zone

From the intertidal zone to about 200m, defined by the continental shelf.

Oceanic Zone

The open ocean; beyond the continental shelf.

Benthic Zone

Bottom of the ocean at all depths.

Photic Zone

Regions that are sunlit.

Aphotic Zone

Areas that do not receive sunlight.

Littoral Zone

Shallow waters along the shore, where plants can take root.

Limnetic Zone

Water that receives enough light to support photosynthesis; but too deep for plants to take root.

rain shadow

area on side of mountain ridge that receives little precipitation

Gyres

massive ocean current cycles that bring warm water to colder latitudes and vice versa

aboveground biomass

total mass of living plants, excluding roots

photosynthesis cannot occur in these conditions

low temperatures or under drought stress

Historical studies

examine factors related to events that occurred millions of years ago

climate change experiments

designed to simulate changed climate conditions and to record organisms’ responses

4 abiotic factors that distinguish streams from oceans

Salinity, Water depth, Water flow, Nutrient availability

Three types of water flow that provide critical nutrients

Coastal runoff, ocean upwelling, lake turnover

Coastal runoff

the flow of freshwater, along with any pollutants it carries, from land into coastal waters, like rivers, estuaries, and oceans

Ocean upwelling

the vertical movement of deep, cold, nutrient-rich water towards the surface

Lake turnover

seasonal mixing of a lake's water column, where the top and bottom layers of water exchange

Winter stratification

dense 4 degree water is nutrient rich at the bottom, while colder water near surface becomes oxygenated

spring turnover

surface water WARMS to 4 degrees and sinks, carrying O2 down and driving nutrients up

(similar to FALL)

summer stratification

dense 4 degree water at the bottom becomes nutrient-rich, warmer water near surface becomes oxygenated

fall turnover

surface water COOLS to 4 degrees and sinks, carrying O2 down and driving nutrients up

(similar to SPRING)

moderate climate

coastal areas have this climate; BUFFER of temp changes

high NPP

near equator

low NPP

near poles

deciduous trees

trees that drop their leaves in the winter

Greenhouse Effect

when gases in the Earth's atmosphere trap the Sun's heat