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The wet, high elevation limestone forests of Rota in the tropical Pacific are characterized by epiphytic ferns, fern allies and orchids. |
The topic of species diversity is focused upon in this next
episode of a
video series designed to complement the
AP Environmental Science
curriculum. It begins with an exploration
of the scale at which diversity is considered, discussing the concepts of
alpha, beta and gamma diversity. It also
considers the components of diversity- species richness and species evenness.
The video then goes on to examine methods of
computing diversity. It evaluates
the uses and pitfalls of diversity characterization, including the loss of
information that occurs by computing diversity indicies.
Still another diversity-related issue is the edge
effect. The video examines how diversity
responds to the boundary between habitats and how certain species are edge
specialists. It also notes, however, that
edges can have reduced habitat quality as well as higher rates of predator activity.
The video concludes by examining the species-area
effect. It considers the phenomenon of
minimum habitat size and the role of chance in the accumulation of species by
virtue of area.