Search for notes by fellow students, in your own course and all over the country.
Browse our notes for titles which look like what you need, you can preview any of the notes via a sample of the contents. After you're happy these are the notes you're after simply pop them into your shopping cart.
Title: Chapter 7 AQA Biology A2 Unit 4
Description: There are comprehensive notes for all of chapter 7 in unit 4 biology, AQA A2. They cover every learning objective with detailed diagrams and explanations of all features within this section of the course. Being highly in-depth, these are suitable for any ability student studying A2 biology.
Description: There are comprehensive notes for all of chapter 7 in unit 4 biology, AQA A2. They cover every learning objective with detailed diagrams and explanations of all features within this section of the course. Being highly in-depth, these are suitable for any ability student studying A2 biology.
Document Preview
Extracts from the notes are below, to see the PDF you'll receive please use the links above
Chapter 7 – Succession
What changes occur in the variety of species that occupy an area over time? What are meant by the terms
succession and climax community?
The variety of species that occupy an area increases over time, as the presence of more
species often increases how favourable the environment is
...
The first species able to occupy a bleak environment is a pioneer species, which have several
properties:
Are able to photosynthesise, as there are few other food sources
Tolerate extreme conditions e
...
temperature fluctuations
Can fix nitrogen from the atmosphere
Produce vast quantities of wind dispersed seeds
A pioneer species such as lichen may colonise a surface of bare rock
...
Eventually as these organisms die the soil thickens and larger plants grow
...
Eventually a stable state of species with very few being
replaced is produced – climax community
...
g
...
Succession will usually occur more quickly in these cases, as spores
and seeds are already in place in the environment and animals can migrate from
surrounding areas
...
There are several reasons for conservation:
Ethics – respect for other living organisms should be shown
Economics – some organisms can economically benefit humans e
...
the ability to
produce substances such as food and hormones
Cultural/aesthetics – habitats and organisms add variety and interest to our lives
How can managing succession help conservation of habitats?
When left unmanaged, an environment will always develop into a climax community
through a series of succession stages
...
Artificially preventing the next stage of succession occurring in an environment prevents it
from reaching climax community
...
If the conservation is stopped then secondary succession occurs where the environment
eventually reaches climax community, because the factors which limited this development
have been removed
Title: Chapter 7 AQA Biology A2 Unit 4
Description: There are comprehensive notes for all of chapter 7 in unit 4 biology, AQA A2. They cover every learning objective with detailed diagrams and explanations of all features within this section of the course. Being highly in-depth, these are suitable for any ability student studying A2 biology.
Description: There are comprehensive notes for all of chapter 7 in unit 4 biology, AQA A2. They cover every learning objective with detailed diagrams and explanations of all features within this section of the course. Being highly in-depth, these are suitable for any ability student studying A2 biology.