Competition Between Species
Competitive Exclusion Principle
An ecological community is the different species of organisms living within a habitat. Interspecifc competition (competition between members of different species) exists when the demand for a resource like light, water and nutrients exceeds supply.
The competitive exclusion principle is the idea that two species cannot share the same habitat indefinitely if they had similar requirements/similar niches.
The more similar the niches, the more intense the interspecific competition.
So how can habitats be so biodiverse and have so many different species co-existing in the same habitat? Species are distributed in distinctive ways within the habitat, to reduce the degree to which their niches overlap.
Succession as a Pattern of Species Distribution
There are two types of succession: Primary succession and Secondary succession.
The type of succession currently occurring at Arataki is secondary succession
The main ideas are:
Sequences of communities replace one another. For example, weed/pioneer communities get replaced by woody shrub species, which then get replaced by large, long-lived tree species.
This happens because as each community inhabits the area, they change the physical environment - light availability and soil composition especially.
The change in physical environment makes the habitat increasingly less favourable for themselves, and increasingly more favourable to other species.