Lists for biology, ecology, zoology and botany, 1, 2, 3
- storage of unwanted products.
- plant structure - cell
- 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.
an island of a given size number of species decreases with distance from source
- continual turnover of species where colonizations are balanced by
- Reduces chance of offspring/sibling/parent competition.
- Reduces inbreeding. 3) Increases chance of finding "safe" site.
competition i.e. competition between individuals of same species.
competition makes resources e.g. food unavailable to others.
competition occupying space, defending territory preventing others reaching
- Interspecific competition i.e. competition between different species.
- Abundant in soil seed bank.
- Small seeds.
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.
- 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.
islands rarely have freshwater fish.
- Oceanic island species often lose their powers of
- Oceanic island species may
differ remarkable in size from mainland species.