Chapter 52An Introduction to Ecology and the Biosphere

2.d.1 – All biological systems from cells and organisms to populations, communities, and ecosystems are affected by complex biotic and abiotic interaction involving exchange of matter and free energy (52.2).

Essential Knowledge

The study of the interactions between organisms and their environment

Ecology

All living beings (animals, plants, fungi, etc)

Studied at many different levels

Organisms

1. Organismal Ecology2. Population Ecology3. Community Ecology4. Biome Ecology5. Biosphere Ecology

Ecology - levels

Abiotic Factors: nonliving factors Ex: Temperature, water, wind, humidity

Biotic Factors: living factors Ex: Competition, Predation (plants, animals, fungi,

etc)

Environment

1. Temperature2. Water 3. Sunlight4. Wind5. Rocks and Soil6. Disturbance

Abiotic Factors

Effects cell contents Ex:

◦ Cold – cells will rupture if temperatures drop below a certain point

◦ Hot – many proteins and DNA will denature Point – life can only exist over a fairly

narrow temperature range

Temperature

Review the properties of water from Chapter 3.

Cells must maintain a certain water potential level (keep from exploding or drying out).

Water

Provides energy for Ps, which drives most food webs.

Plants often compete for light because of shading or absorption of light by deep columns of water.

Sunlight

Effects temperature and water conditions for many organisms.

May carry abrasive particles that limit plant growth by killing the SAM areas.◦ SAM??? Shoot apical meristem areas

Wind

Physical structure, pH, mineral composition of rocks and soil limit where plants can grow.

Ex. Se soils. Plants limit what animals can be found in an

area.

Rocks and Soil

Disturbance is often an important part of an environment.

Allows organisms to re-colonize an area. Ex: Fire

Humans Wind

Disturbance

Yellowstone Fire

Shapes environments and what organisms can live in a particular area.

Climatic factors:◦ Solar radiation and latitude◦ Axis tilt/seasons◦ Air/Water circulation patterns

Climate

Changes the amount of light and energy delivered per surface area.

Result:◦ Poles: less light◦ Equator: more light◦ Unequal heating causes air and water to circulate

Solar Radiation and Latitude

Caused by the Earth's tilt. Day length changes over time. Many organisms are restricted in range by

how well they adapt to changing seasons.

Seasons

Air rises when heated, sinks when cools. Zones of rising/sinking are created. Earth's rotation causes zones to "twist”. Result:

◦ Air circulation patterns◦ Rain fall patterns

Rising air: wet areas Descending air: dry areas

Global Air Patterns

Broad geographical regions with characteristic communities of organisms.

Biomes are controlled by:◦ Temperature◦ Water amount and proximity◦ Geography

Biomes

Areas covered with dense/lush growth of trees and vines.

Climate:◦ Warm temperatures.◦ Constant day length.◦ High water.

Vertical layers of autotrophic growth

Tropical Forests

Have the greatest diversity of species of any area on Earth.

Soil is usually very infertile. Most of the nutrients are in the plant life.

One of the most endangered Biomes.

Tropical Forests

Tropical Forests

Grasslands with a few trees. Climate with three growing seasons:

◦ Cool and dry◦ Hot and dry◦ Warm and wet

Rich in herbivores and predator species Only major biome not found in North

America

Savanna

Characterized by plants adapted to dry growing conditions.◦ Cacti, succulents

Climate:◦ Dry (<30cm/yr).◦ May be cold or hot.

Often found in areas of descending air masses.

Low productivity, but still fairly diverse in species.

Desert

Characterized by spiny evergreen shrubs. Climate:

◦ Mild rainy winters◦ Hot summers

Ex: Southern California Maintained by fires Plants adapted to periodic fires by seeds or

re-growing from the roots

Chaparral

Grasses and other herbs are the dominant vegetation.

Indiana could be considered a temp. grassland

Climate:◦ Intermediate water◦ Relatively cold winters

Temperate Grasslands

Very productive for agriculture. (wheat, corn)

Need disturbance (fires) to keep trees out.

Come in several types:◦ Tall grass◦ Short grass

Grasslands

Deciduous trees dominate (often called deciduous forest)

Climate:◦ Relatively high rain◦ Cold winters

Very little natural area left. Good diversity of species. Coniferous forest:

◦ Tall stands of cone-bearing tress

Temperate Forests

Coniferous trees dominate (also called coniferous forests)

Climate:◦ Long cold winters◦ Short wet summers◦ Long summer daylength

Relatively low species diversity Being logged at an alarming rate

(disappearing rapidly!)

Taiga (Boreal forest)

http://www.ultimateungulate.com/Artiodactyla/Rangifer_tarandus.html

Grasses and sedges dominate. Climate:

◦ Very cold and dry◦ Low light in winter

Permafrost present Plants low in height Poor species diversity

Tundra

Mirror each other. Their Biomes are similar because the

environments are similar. Ex: Alpine = Tundra

Altitude and Latitude

Aquatic Biomes

Have <1% salt concentration. Strongly influenced by temperature and

light. Classification – based on water flow

patterns. Flowing: rivers, creeks Non-flowing: ponds, lakes

Fresh water Biomes

Cover 3/4 of the Earth's surface. Average 3% salt. Controlled by light and the distance to the

shore.

Marine Biomes

Photic - Enough light for Ps. Red light lost rapidly as depth increases.

Aphotic - Lacks enough light for Ps and depends on food made in photic zone for energy. Part of the most extensive biome on the planet.

Light Zones

1. Estuaries2. Intertidal3. Coral Reefs4. Pelagic5. Benthos

Marine Biomes

Where a freshwater river meets the ocean.

Salinity variable.

Very productive Biome.

Complex flow patterns

Estuaries

Characterized by coral.

Found in shallow warm waters.

Very productive. High species

diversity. Very sensitive to

temperature changes

Coral Reef

Bottom area. Usually fed by nutrients drifting down from

upper levels. Fairly rich in life.

Benthos

Know what is involved with the study of “Ecology”.

Know the major factors of planet Earth that shape climate.

Know the major terrestrial biomes and the factors that control them.

Know the major types of aquatic biomes and the factors that control them.

Summary