1. Species Pools Bio 255 Seminar

2. Species Pools  What is a species pool?

3. Species Pools  What is a species pool?  Is there a species pool hypothesis?

4. Species Pools  What is a species pool?  Is there a species pool hypothesis?  Can regional species pools be defined?

5. What is a pool of species?  “Pool can be deathtrap for our native species”  “These organisms are the ‘obligate’ vernal pool species, so called because they must use a vernal pool for various parts of their life cycle.... ‘

6. The species pool defined.  “the set of species that are potentially capable of coexisting in a particular community” ( M. Zobel 1997 TREE )  “the limited set of species capable of growing under certain habitat conditions within a territory” ( Partel et al. 1996 Oikos )

7. Working definitions From M. Zobel 1997 Regional Pool: the set of species occurring in a certain region that is capable of coexisting in the target community A region is a reasonably large area of the Earth’s surface, with a more or less uniform physiography and climate, from which species are expected to reach the target community, and for which there exists a proper list of its flora. A target community is a plant community bound to a certain set of environmental conditions that provide appropriate ecological niches for the occurring species

8. Working definitions From M. Zobel 1997 Local Pool: the set of species occurring in the landscape around a target community that is capable of coexisting in that community. These species are able to migrate to the community relatively rapidly (~within a few years) Actual pool: the set of species present in a target community

9. Zobel’s pool filters From M. Zobel 1997

10. Origins of the Species Pool Hypothesis r/K 1967 r/K 1967 C-S-R 1974 C-S-R 1974 Habitat Templet 1983 Habitat Templet 1983

11. Grime’s triangle and the Southwood-Greenslade Habitat Templet

12. Species Pool Hypothesis Taylor, Aarssen & Loehle 1990 Taylor, Aarssen & Loehle 1990 “On the relationship between r/K selection and environmental carrying capacity: a new habitat templet for plant life history strategies” (Oikos 58:239-250)“On the relationship between r/K selection and environmental carrying capacity: a new habitat templet for plant life history strategies” (Oikos 58:239-250)

13. Taylor et al.’s “species pool hypothesis”

14. Is the species pool hypothesis testable? Partel et al. (1996) devised null hypotheses based upon the fact that inevitably regional diversity must increase with local diversity Ho 1 –any size of the actual species pool is equally probable in the interval between zero and the regional species poolHo 1 –any size of the actual species pool is equally probable in the interval between zero and the regional species pool Ho 2 -any value of species richness per unit area is equally probable in the interval between zero and the size of the actual species poolHo 2 -any value of species richness per unit area is equally probable in the interval between zero and the size of the actual species pool

15. Defining a regional pool of species Regional flora lists Regional flora lists Ellenberg indicator values (Pärtel 1996; Dupre 2002; Ewald 2003) Ellenberg indicator values (Pärtel 1996; Dupre 2002; Ewald 2003) Empirical assessment of viability or occurrence (Gough et al. 1994; Weiher & Keddy 1995; Peet et al. 2003) Empirical assessment of viability or occurrence (Gough et al. 1994; Weiher & Keddy 1995; Peet et al. 2003) Microcosms (Fox et al. 2000) Microcosms (Fox et al. 2000)

16. Pärtel (Ecology 2002) Related soil pH to plant species richness to infer species pool effect Related soil pH to plant species richness to infer species pool effect If the local species pool was biased toward the pH of the dominant soil type during recent evolutionary history, then the regional species pool was likely affecting local richness. If the local species pool was biased toward the pH of the dominant soil type during recent evolutionary history, then the regional species pool was likely affecting local richness.

17. Pärtel (Ecology 2002) Results from meta-analysis: Results from meta-analysis: 38/47 high pH evolutionary centers showed a positive relationship38/47 high pH evolutionary centers showed a positive relationship 21/34 low pH evoultionary center exhibited a negative relationship21/34 low pH evoultionary center exhibited a negative relationship Although only 45 of these 81 relationships were significant. (It was not specified with respect to which of the above were significant; just that 35 were positive and 10 were negative) Although only 45 of these 81 relationships were significant. (It was not specified with respect to which of the above were significant; just that 35 were positive and 10 were negative)

18. Hillebrand &Blenckner (Oikos 2002) Can local vs. regional richness plots be used to interpret ecological vs. regional processes? Can local vs. regional richness plots be used to interpret ecological vs. regional processes? Suggest that body size and its relation to dispersal limitation may bias some studies toward a linear (unsaturated) relationship.Suggest that body size and its relation to dispersal limitation may bias some studies toward a linear (unsaturated) relationship. Argue that spatial autocorrelation is too strong to ignore when local areas are large or makeup a large proportion of the defined region.Argue that spatial autocorrelation is too strong to ignore when local areas are large or makeup a large proportion of the defined region.

19. Hillebrand &Blenckner (Oikos 2002) Results from meta-analysis: Body size does not seems to drive linear relationships between local and regional diversity as proposedBody size does not seems to drive linear relationships between local and regional diversity as proposed Local sampling size seems to bias local vs. regional plots as suspectedLocal sampling size seems to bias local vs. regional plots as suspected Local vs. regional plots are a poor way of getting at local ecological processes and their common application lacks a good method for differentiating between local and regional effectsLocal vs. regional plots are a poor way of getting at local ecological processes and their common application lacks a good method for differentiating between local and regional effects

20. Discussion…