Chap. 16 EcosystemsChap. 16 Ecosystems

What is an Ecosystem?What is an Ecosystem?

Section 1Section 1

Interactions of Organisms and Interactions of Organisms and Their EnvironmentTheir Environment

EcologyEcology – the study – the study of the interactions of the interactions of living organisms of living organisms with one another with one another and with their and with their physical physical environmentenvironment

HabitatHabitat – the place – the place where a particular where a particular population of a population of a species livesspecies lives

Levels of OrganizationLevels of Organization Organism – an Organism – an

individual living individual living thingthing

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

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

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

BiomeBiome – a major – a major regional or global regional or global community of community of organismsorganisms

Keystone speciesKeystone species

Is a species that Is a species that has an unusually has an unusually large effect on its large effect on its ecosystemecosystem

Form and maintain Form and maintain a complex web of a complex web of lifelife

Affects all the Affects all the other species other species connected to itconnected to it

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

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

Organisms are not Organisms are not distributed uniformly distributed uniformly throughout the throughout the biosphere biosphere

Factors of An Habitat Factors of An Habitat

Abiotic factorsAbiotic factors – physical – physical aspects of a aspects of a habitat –habitat –natural natural nonlivingnonliving

Biotic factorsBiotic factors – – the organisms the organisms in a habitatin a habitat

Physical AspectsPhysical Aspects

TerrainTerrain WaterWater Soil Soil

• MineralsMinerals• CompositionComposition• Organic matterOrganic matter• pHpH

Air atmosphereAir atmosphere Weather/climateWeather/climate Intensity of Intensity of

sunlightsunlight

Diverse Communities in EcosystemsDiverse Communities in Ecosystems BiodiversityBiodiversity – –

the variety of the variety of organisms, organisms, their genetic their genetic differences, differences, and the and the communities communities & & ecosystems ecosystems in which they in which they occuroccur

Ecosystem Inhabitants of a Pine Ecosystem Inhabitants of a Pine forestforest

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

Ecosystem BoundariesEcosystem Boundaries

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

Change of Ecosystems over TimeChange of Ecosystems over Time Pioneer speciesPioneer species – the – the

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

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

Make the ground more Make the ground more hospitable for other hospitable for other speciesspecies

SuccessionSuccession SuccessionSuccession – –

regular progression regular progression of species of species replacementreplacement

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

Primary Primary successionsuccession – –occurs where occurs where life has not life has not existed existed beforebefore

Secondary Secondary successionsuccession – – occurs in areas occurs in areas where there has where there has been previous been previous growthgrowth

Reestablishment Reestablishment of a damaged of a damaged ecosystemecosystem

Small Small disturbances disturbances start the process start the process

Again & againAgain & again

Climax CommunityClimax Community which populations of which populations of

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

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

Pond SuccessionPond Succession http://www.sabah.edu.

my/csm07010/Form%204/pond.htm

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