Local Conditions

How would you describe your climate, or the average, year-after-year conditions of temperature and precipitation where you live?

Does your area receive a great deal of precipitation—rain and snow—or is your area very dry?

Section 4-1

Interest Grabber

Discussion

What is Climate?

• Weather – day-to-day condition of Earth’s atmosphere• Climate – average of daily weather over a period of time

•Factors affecting climate:• Trapping of heat by the atmosphere• Latitude• Ocean currents• Etc.

Sunlight

Some heat escapesinto space

Greenhousegases trapsome heat

Atmosphere

Earth’s surface

Section 4-1

The Greenhouse Effect

Greenhouse Gases

Include:• CO2 (Carbon dioxide)

• Methane• Water vapor

• Similar to a car on a hot day, glass allows light energy in, yet little heat escapes.

The Effect of Latitude on Climate

•Earth is tilted on it’s axis, causing varying degrees of light striking the Earth.

3 main zones of climate:1. polar zones – sun strikes Earth at a very low angle2. temperate zones – angle of the sun varies3. tropical zones – direct or near direct sunlight

Sunlight

Some heatescapesinto space

Greenhousegases trapsome heat

Atmosphere

Earth’s surface

Sunlight

Most direct sunlight

Sunlight

Sunlight

Sunlight

90°N North Pole

66.5°N

23.5°N

0°

23.5°S

66.5°S90°S South Pole

Arctic circle

Tropic of Cancer

Equator

Tropic of Capricorn

Arctic circle

Section 4-1

Figures 4-1 and 4-2 Heating of the Earth’s Surface and Some Factors That Affect Climate

Greenhouse Effect Different Latitudes

4–2 What Shapes an Ecosystem?

A. Biotic and Abiotic FactorsB. The NicheC. Community Interactions

1. Competition2. Predation3. Symbiosis

D. Ecological Succession1. Primary Succession2. Secondary Succession3. Succession in a Marine Ecosystem

Section 4-2

Section Outline

Biotic factors

• Living or once living

Abiotic• Non-living components that influence an ecosystem

• Temperature, Type of soil, Precipitation, Climate

Biotic Factors

ECOSYSTEM

Abiotic Factors

Section 4-2

Abiotic and Biotic Factors

Together they determine the stability of an ecosystem

The Niche• Where an organism fits into its environment

– Place on food chainWhat it eats and what eats it

– How and where it reproduces– Climate it prefers

• No two species can occupy the same niche in the same habitat! Competition? One wins and one loses.

Bay-Breasted WarblerFeeds in the middlepart of the tree

Yellow-Rumped WarblerFeeds in the lower part of the tree andat the bases of the middle branches

Cape May WarblerFeeds at the tips of branchesnear the top of the tree

Spruce tree

Section 4-2

Figure 4-5 Three Species of Warblers and Their Niches

Community Interactions

1.Competition – species attempt to use an ecological resource in the same place at the same time.

2.Predation – one organism captures and feeds on another organism3.Symbiosis – relationship when 2 species live together

• Mutualism – helps both• Commensalism – one benefits, other not harmed• Parasitism – one lives on or in another, harming the host.

Ecological Succession

• Ecosystems are constantly changing in response to human or non-human interactions.

• Could be a rapid change or very gradual (thousands of years).

• Types:• Primary• Secondary

Primary Succession

•Occurs where no soil exists – must start with plants….Why?• Bare rocks• Volcanic areas

• Occurs often due to climatic changes of plate tectonics• After original pioneer species establish area, new organisms begin to inhabit area.

Primary successionafter an eruption

Primary succession

Secondary Succession

• When a drastic climatic event disturbs a particular area and organisms re-establish the ecosystem over time.

• Prairie fires

• Ecosystems typically bounce back from natural disturbances, but struggle to return when human disturbances occur (non-natural).

Secondary successionafter clear-cutting ora fire.

Secondary succession