Download Ecosystems and Communities

Ecosystems and
Communities
Chapter 4
4-1 The Role of Climate
• What is climate?
– Weather is temperature, precipitation,
other environmental factors
– It usually refers to a specific area
– Climate is the weather of a given area
over a period of time
• Ex. – Artic Climate versus Tropical
Climate
Greenhouse Effect
• This is a natural
situation!!
• Carbon dioxide,
methane, water
vapor and other
gases trap heat
energy and
maintain the Earth’s
temperature range
The Effect of Latitude
on Climate
• How does the position of the sun in the
sky effect climate? (see the next slide
for the answer)
The Earth has three main climate zones:
Polar
Temperate
Tropical
Different latitudes have different
angles of heating, affecting climate
Heat Transport in the Biosphere
• Unequal heating and cooling drives winds and
ocean currents.
What Shapes an Ecosystem?
• Key Concept: Biotic and abiotic
factors determine the survival and
growth of an organism and the
productivity of the ecosystem in which
the organism lives.
• Biotic Factors
– All living things in an
ecosystem
• Abiotic Factors
–
–
–
–
–
–
–
Temperature,
Precipitation
Humidity
Wind
Nutrient availability
Soil type
Sunlight
The Niche
• An organisms occupation in its
environment is it’s niche.
• This includes the following factors
– Type of food
– How it obtains food
– Which other species use the organism as
food
– Physical conditions.
WARNING WARNING
No two species can
share the same
niche in the same
habitat.
Resource Sharing
Community Interactions
• Community interaction, such as
competition, predation and various
forms of symbiosis can powerfully
affect an ecosystem
• Competition
– Happen when two
organisms try to use
the same resource
in the same place at
the same time
– A Resource is:
water, nutrients,
light, food, or space.
• Competitive
Exclusion Principle
– No two species can
occupy the same
niche in the same
habitat at the same
time!!!
Predation
• An interaction in which one organism
captures and feeds on another.
Symbiosis: Living together closely
• Mutualism:
both species
benefit
• +/+
Commensalism
• One member benefits and the other
is neither helped nor harmed
• +/0
Parasitism
• One organism
lives on or
inside another
organism and
harms it.
• +/-
Ecological Succession
• Ecosystems are constantly changing in
response to natural and human
disturbances.
• As an ecosystem changes, older
inhabitants gradually die out and new
organisms move in, causing further
changes in the community
The series of predictable changes that
occur in a community over time.
• Primary Succession
– Succession that
occurs on surfaces
where no soil exists.
Primary Succession
• Occurs on the surfaces formed as
volcanic activity builds new islands or
covers the land with lava or volcanic
ash.
• Also occurs on bare rock exposed
when glaciers melt.
• The first species to populate an area:
pioneer species
Secondary Succession



A disturbance of some kind that changes
an existing community without removing
the soil.
Caused by farming, wildfires
The series of predictable changes ends
with a mature, stable community called a
climax community
Secondary Succession
Climax Community
Temperate Rain Forest
Biomes
• There are at least 10 different biomes.
• Each of these biomes is defined by a
unique set of abiotic factors and has a
characteristic ecological community
The Effect of Coastal Mountains
Biomes
#1 - What is this Biome?
#2 - What Biome is this?
#3 - Name That Biome!!
#4 - What Biome is this?
Last but not least… #5
Water, water everywhere…
• Aquatic ecosystems are determined
primarily by the depth, temperature,
flow, and chemistry of the overlying
water.
Freshwater Ecosystems
•
•
•
•
Flowing water: rivers and streams
Standing water: lakes and ponds
Wetlands: marshes and swamps
Estuaries: where rivers meet the sea.
– Contain a mixture of fresh and salt water
– Serve as spawning and nursery grounds
for many fish and shellfish species.
Estuary
River Delta –
Lena, Russia
Marine Ecosystems
• Divided into two zones based on the
amount of light penetration.
– Photic Zone: well-lit upper layer down to
about 200 meters. Photosynthesis
possible.
– Aphotic Zone: permanently dark. Only
producers in this zone are
chemoautotrophs.
Marine Ecosystems (cont.)
• Scientists also divide the ocean into
zones based on the depth and
distance from shore.
– Intertidal: subject to tides
– Coastal ocean: from the low tide mark to
the edge of the continental shelf. Contain
coral reefs in tropical areas.
Marine Ecosystems (cont.)
• Open Ocean: from the continental
shelf and extends outward
– Largest marine zone
– Organisms in the deep open ocean have
adapted to great pressure, freezing
temperatures and no light
Benthic Zone: the ocean floor.
Continental Shelf
Ocean Zones