Textbook Notes (363,237)
Canada (158,278)
Biology (652)
BIOLOGY 1M03 (198)
Jon Stone (41)
Chapter 54

Biology Chapter 54.docx

18 Pages
Unlock Document

McMaster University
Jon Stone

1Biology Chapter 54 EcosystemsAn ecosystem consist of organisms that live in an area together with their physical or abiotic environmentAn ecosystem differs from a community because ecosystems are composed of multiple communities along with their chemical and physical environmentsEx A number of communities within a lake oLake bottom surface shallow waterAdjacent ecosystems river lake surrounding forest can be distinguished because their energy and nutrient flows are selfcontainedOccasionally energy and nutrients can also be transferred between ecosystemsEnergy Flow and Trophic StructureEcosystems have four componentsoThe abiotic environmentoPrimary producersoConsumersoDecomposersFour components are linked by a flow of energyA primary producer is an autotroph meaning an organism that can synthesize its own food from inorganic sourcesMost primary producers use solar energy to manufacture their own food via photosynthesisIn some ecosystems bacteria use chemical energy contained in inorganic compounds such as hydrogen methane or hydrogen sulphide to make foodPrimary producers form basis of ecosystems because they transform energy in sunlight or inorganic compounds into chemical energy stored in sugarsPrimary producers use this chemical energy in two waysoMost supports maintenance or respiratory costsoSome makes growth and reproduction possible2Energy that is invested in new tissue is called net primary productivity NPPNPP represents amount of energy available to second and third components of ecosystem consumers and decomposersConsumers eat living organismsHerbivores are consumers that eat plants carnivores eat animals detritivores or decomposers obtain energy by feeding on dead remains of other organisms or waste products Fourth component of an ecosystem is abiotic environment which includes soil climate atmosphere Sun and particulate matter and solutes in waterFour components are linked because energy moves from Sun or inorganic compounds to consumers decomposers and abiotic environmentUnderstanding NPP is a primary focus of ecosystem ecology because it dictates the amount of energy available to consumers and decomposers and because global warming is altering NPP worldwideGlobal Patterns in ProductivityoTerrestrial ecosystems with highest productivity are located in wet tropicsoWith exception of worlds major deserts NPP on land declines from equator toward the polesoProductivity patterns in marine ecosystems are differentMarine productivity is highest along coastlines and can be as high near the poles at it is in tropicsOceanic zones have extremely low NPPAmong aquatic ecosystems most productive habitats are algal beds and coral reefs wetlands and estuariesMost of the total NPP provided by aquatic ecosystems derives from open ocean howeverEven though NPP per square metre is low in these regions open ocean is so extensive that its total production is highoWhat Limits ProductivityData document that terrestrial productivity is lowest in deserts and arctic regions
More Less

Related notes for BIOLOGY 1M03

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.