glued ecology

Download Glued Ecology

If you can't read please download the document

Upload: bob-ohara

Post on 29-Jun-2015

811 views

Category:

Technology


0 download

DESCRIPTION

Talk given at Joined-Up Ecology workshop, at Microsoft, Cambridge:

TRANSCRIPT

  • 1. Glued Ecology Bob O'Hara University of Helsinki Finland

2. All models are wrong, but some are useful G.E.P. Box 3. Where Statistics Fits in Data Theory Scientific Knowledge 4. Where Statistics Fits In Data Theory Scientific Knowledge 5. Approaches to Statistical Inference 6. Graphics and Summary Stats 7. Traditional Statistical Models http://www.vias.org/science_cartoons/ 8. Mechanistic Modelling http://www.vias.org/science_cartoons/ 9. Which One To Use? http://www.vias.org/science_cartoons/ 10. Whichever Works Best! http://www.vias.org/science_cartoons/ 11. Graphics and Summary Stats Should be simple and easy to follow 12. Traditional Statistical Models Forces the analysisinto (flexible) boxes Fitting and interpretationWell understood 13. Mechanistic Modelling Model behaviour can be difficult to understand Closer link to theoretical models 14. Community Dynamics Real work done by Crispin Mutshinda-Mwanza 15. All Trees Are Equal 16. ... but should some be more equal than others? 17. Use Real Time Series Data 18. Discrete Time Neutral Theory n i,t number of individuals of speciesiat timet N t total community size at timet p i,t=n i,t/ N t So, 19. In Other Words N t t p t N t t p t 20. Sampling Model True N Observed N q 21. Moth Data 22. Fit The Model... 23. CommunitySize Sampling Rate Immigration Rate 24. Impossible Results = possible range (0 to 1) 25. Directly fitting the model to data showed that it is wrong 26. What Next? 27. What Next? Add more mecahnisms! 28. The Environment 29. Competition 30. Other Interactions Between Individuals 31. A Gompertz Model log Abundances Growth rates Density Effects Environmental shocks 32. A 33. A DensityDependence 34. A Between-speciesCompetition DensityDependence 35. e~ N(0,V e ) 36. Decompose the variation Interspecificvariation: off-diagonal Intraspecificvariation:leading diagonal Environmental variation 37. Data 38. Proportions of Environmental Variance Sampling variationalso estimated 39. No Interspecific Interactions Largest Bayes Factor 1.25