what is an ecosystem? section 1. interactions of organisms and their environment ecology – the...

Chap. 16 EcosystemsWhat is an Ecosystem?

Section 1

Interactions of Organisms and Their EnvironmentEcology – the study

of the interactions of living organisms with one another and with their physical environment

Habitat – the place where a particular population of a species lives

Levels of OrganizationOrganism – an

individual living thing

Population – a group of the same species that lives in one area

Community – the many different species that live together in a habitat

Ecosystem or ecological system – consists of a community and all the physical aspects of its habitat – complex web of connected biotic & abiotic factors

Biome – a major regional or global community of organisms

Keystone speciesIs a species that has an

unusually large effect on its ecosystem

Form and maintain a complex web of life

Affects all the other species connected to it

Biosphere – living globe – that part of the Earth in which life exists

Extends to as far as 8 kilometers above the Earth’s surface to as far as 8 kilometers below the surface of the ocean

Organisms are not distributed uniformly throughout the biosphere

Physical AspectsTerrainWaterSoil

MineralsCompositionOrganic matterpH

Air atmosphereWeather/climateIntensity of sunlight

Ecosystem Inhabitants of a Pine forestWhich of the six

kingdoms of organisms would be represented if you fenced a square kilometer of the forest?

Ecosystem BoundariesPhysical

boundaries of an ecosystem are not always obvious, also depends of ecosystem being studied

Change of Ecosystems over TimePioneer species – the

first organisms to live in a new habitat where soil is present

Tend to be small, fast-growing plants examples: lichen, mosses – can break down solid rock into smaller pieces

Make the ground more hospitable for other species

SuccessionSuccession –

regular progression of species replacement

Regenerate a damaged community or create a community in a previously uninhabited area

Primary succession –occurs where life has not existed before

Secondary succession – occurs in areas where there has been previous growth

Reestablishment of a damaged ecosystem

Small disturbances start the process

Again & again

Climax Communitywhich populations of

plants or animals remain stable and exist in balance with each other and their environment. A climax community is the final stage of succession, remaining relatively unchanged until destroyed by an event such as fire or human interference

http://glencoe.mcgraw-hill.com/sites/0078802849/student_view0/unit1/chapter3/concepts_in_motion.html#

Pond Successionhttp://www.sabah.edu.m

y/csm07010/Form%204/pond.htm

Pond succession occurs due to the change in depth of the pond. When submerge plants die, it will deposit at the bottom of pond. Over the time, the pond becomes shallow until finally filled in.