1.   Even the best examples of habitat types can not exist in isolation like islands of richness in a sea of poverty.

2.   The richest centres have the most complicated mosaics of different habitat types reflected in topography, soils and vegetation.

3.   And they have released the fish into those three habitat types.

4.   Another potentially explosive habitat type is a heavily wooded slope below a ridge, where the forest floor has a long-term buildup of pine needles and dead branches.