Summary
OCR A-Level Biology Ecosystems Summary
- Course
- Institution
Handwritten Summary by an Oxford Medical Student which covers all content necessary for an A* in Ecosystems at OCR Biology A-Level.
[Show more]
Seller
Follow
faithcortis
Content preview
Biotic factors foodLiving factors that affect an ecosystem space competition breeding partners
:
, ,
,
Abiotic factors Non-living factors that offect an ecosystem
:
↳
Light temperature water/oxygen availibility edaphic factors
, , ,
Biomass mass of
living
material present
:
↳ Biomass at a no
trophic level biomass present =
x .
organisms
measuring biomass Water must be discounted :
so
dry samples (dead) are often uses
Efficiency of biomass transfer Only:
a small proportion of food is converted to biomass
↳ Producers Not used for photosynthesis energy lost
au solar
energy is in reactions,
limiting factors
:
,
↳ Consumers Not all :
biomass (bones) is eaten , metabolic waste in heat and excretions
Ecological Efficiency :
Biomass available after transfer/biomass availible before transfer
Nitrogen Fixation Nitrogen fixing bacteria ie
:
· .
aztobacter and Rhizobium convert Ne-NH3
·
Nitrification :
Nitrifying bacteria is .
Nitrosomonas
and Nitrobacter Convert NHz-NO ? -
NO
·
Denitrification :
Anaerobic conditions NO ?-N2 :
·
Ammonification Decomposers :
convert
nitrogen
rich molecules into ammonium compounds
Photosynthesis Converts CO2 to molecules
:
·
containing carbon in plants
Respiration Releases CO2 gas to the atmosphere
·
:
feeding Carbon molecules transferred from producers
·
:
are
to consumers
·
Decomposition :
CO2 is released
fluctuations in CO2 No :
photosynthesis at
night and
increased human activity causes CO2 levels to fluctuate
Primary succession Bare
newly formed rock
Secondary succession Soil but no
organisms
:
or
:
Pioneer Arrives seeds ie lichen
Community or
Algae
as
spores or
:
.Reproduce
↳ nitrogen withstand harsh conditions , can fix
quickly photosynthesise , ,
Intermediate community Species that thrive on the rich soil produced by decomposed pioneer species
:
Climax Community Stable community displaying little change over time
:
Plagiodimax Artificially deflected :
succession is by human activity
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller faithcortis. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $3.86. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
67474 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now