1. Communities: Biodiversity
BIOL 3240 Plant and Animal Ecology
Communities: Biodiversity
 © Getty Images/Taxis
What is biodiversity?
By definition it is the various forms of life
How many species are there anyway?
Estimated 1.4 million already described… perhaps up to 100 million waiting

2. An example from La Selva Field Station (OTS)
How can we measure it?
An example from La Selva Field Station (OTS)
Studied ant species in leaf litter

3. How can we measure it?
Species accumulation curves provide estimates of what remains as well as directs decision about sample size.

4. Is species richness even across the globe?
If not… where would you expect the greatest diversity (i.e. what are the two most diverse ecosystems on the planet)?
Primary productivity likely influences richness (rate of biomass accumulation per unit area as a result of photosynthesis).
Regional stability likely influences richness (what areas have been subjected to glaciation events?)
Climatic stability may influence richness (what areas are the most stable across months, years and longer?)

5. Is species richness even across taxonomic groups?
Name your favorite organism…

6. Why are some taxa richer?
Size limitations…
Adaptive radiation can occur when a novel form is introduced to an established environment (or vice versa).

7. Why should we be concerned about biodiversity?
Habitat loss is the major cause of extinctions/declines
Other anthropogenic causes
Examples for amphibian extinctions
Consequently, we need to know what exists where so that we can best be prepared to protect/save as many species as possible!!!
Hotspots…

8. Why should we be concerned about biodiversity?
Habitat loss is the major cause of extinctions/declines
Other anthropogenic causes

9. # of species (Richness)
How can we measure it?
# of species (Richness)
Relative distribution of species abundance (Evenness)
Type of Bird
Campus A
Campus B
Pigeon 96 20
Robin 1
Starling
Purple grackle
House Sparrow