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Lists for biology, ecology, zoology and botany, 1, 2 , 3
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storage of unwanted products.
plant structure - cell
walls.
plant colour and smell.
defence against physical factors e.g. cold,
salinity, UV light.
defence against herbivores.
Essential features of the theory of island biogeography
number of species increases with increase in island area.
for
an island of a given size number of species decreases with distance from source
area.
continual turnover of species where colonizations are balanced by
extinctions.
Reduces chance of offspring/sibling/parent competition.
Reduces inbreeding. 3) Increases chance of finding "safe" site.
Intraspecific
competition i.e. competition between individuals of same species.
Exploitation
competition makes resources e.g. food unavailable to others.
Interference
competition occupying space, defending territory preventing others reaching
resource.
Interspecific competition i.e. competition between different species.
Abundant in soil seed bank.
Small seeds.
Shade
intolerant. Germination only in open sites. Dormancy broken or germination
enhanced by high light intensity, high R/FR ratio light, fluctuating or high
temp. and/or moisture, high NO3
Rapid growth.
Early
reproduction.
Large investment of resources in reproduction (r-selected).
Reproduction continuous or frequent.
Mechanisms for distant seed dispersal
(birds, insects, wind).
Short lived.
Genetically diverse.
Phenotypically plastic.
Low density wood, in trees.
Leaves not robust
and short lived.
Continental islands usually
have more species for their size
Continental islands usually have a subset of mainland species; oceanic islands have a subset of those that are good at dispersal
Oceanic islands contain a greater
number of endemic species.
Oceanic
islands rarely have freshwater fish.
Oceanic island species often lose their powers of
dispersal.
Oceanic island species may
differ remarkable in size from mainland species.