Transcript Ecosystems and Communities

Ecosystems and Communities
Role of Climate
• Weather: day-to-day condition of Earth’s
atmosphere at a particular time and place.
• Climate: the average year-after-year
conditions of temperature and precipitation
in a particular region.
Earth’s Temperature
• Co2, methane, water vapor, and other
gases trap heat energy and maintain
Earth’s temperature.
• Greenhouse effect: the natural situation in
which heat is retained by the layer of
greenhouse gases.
Climate Zones
• Different because of latitude and angle of
heating.
• Polar zones: cold areas; sun’s rays strike
at very low angle.
• Temperate zones: sit between the polar
zones and tropics.
• Tropical zone: near the equator; climate
almost always warm
Biotic Factors
• The living influences on organisms within
an ecosystem.
• Ex: birds, trees, bacteria
Abiotic Factors
• Physical, or nonliving factors that shape
ecosystems.
• Ex: soil, water, temperature
• Together biotic and abiotic factors
determine the survival and growth of an
organism and how productive that
ecosystem is.
Habitat
• The area where an organism lives.
• Niche: role in the ecosystem.
– Ex: place in the food chain, temps for survival,
how reproduces, types of food eaten.
– No two species share the exact same niche
Community Interactions
• Competition
• Predation
• Symbiosis
Competition
• Occurs when organisms attempt to use
ecological resources in the same place at
the same time.
• Resource: any necessity of life, such as
water, nutrients, food, or space.
• Usually a winner and a loser, with the
loser failing to survive.
Predation
• An interaction in which one organism
captures and feeds on another organism.
• Predator: the organism that does the
killing.
• Prey: the organism being hunted.
• Any relationship in which two species live
closely together.
• Mutualism
• Commensalism
• Parasitism
Mutualism
• Both species benefit from the relationship.
• +/+
• Ex: flowers and insects
Commensalism
• One member of the association benefits
and the other is neither harmed nor
helped.
• +/0
• Ex: shark and fish, barnacles and whales.
Parasitism
• One organism lives on or inside another
organism and harms it.
• The host organism is harmed.
• +/• Ex: fleas and ticks
Succession
• As an ecosystem changes, older inhabitants
gradually die out and new organisms move in,
causing changes in the community.
• Primary succession: succession that occurs on
surfaces where no soil exists.
• Pioneer species: first species to populate the
area.
• Secondary succession: occurs when land
cleared and plowed for farming is abandoned; or
after fires.