Time scales of ecological processes at LUQ LTER

1. Time scales of ecological processes at LUQ LTER

2. TOPIC OUTLINE Introduction Study Site Methods of analysis Results Future Directions Acknowledgements References

3. Introduction Regional landscape has ** little climatic seasonality ** strong climate gradient up the mountain ** high inter-annual variability due to storms ** geology of Tabonuco forest constant

11. Methods of analysis Turn over time = material quantity in reservoir / annual average flux � Recovery time = post disturbance time for a structure or flux to return to pre-disturbance condition � Relative disturbance effectiveness = disturbance flux / average long term flux

16. More about the forest canopy Recovery time of closedness @ 1 m (hurricane) = ~ 3 years Turnover time of leaf biomass (background) = 0.99 to 1.3 yrs Turnover time of leaf biomass (hurricane) = 50 yrs Relative effectiveness ( hurricane / background) 700/1.54=455

17. DISCUSSION 160 Turnover times & 55 recovery times � span 12 orders of magnitude Mountains slowest Land forms next slowest Turn over of forest biomass - decades Water and nutrients � cycled in scales of days to years �Significance of these findings for Ecosystem science Resource Management

18. Conclusion: Luquillo Landscape Dynamic complex of subsystems in which recovery times increase as the turn over times increase. Component responses to disturbances and recovery occur at different rates Steady state conditions are rarely achieved between all abiotic and biotic components. Comparisons of turn over times, recovery times and relative effectiveness following disturbances in different LTER sites are likely to be instructive

19. QUESTIONS FOR FUTURE RESEARCH Stoichiometry of turnover times , recovery times, and relative disturbance effectiveness ( See Sterner & Elser. 2002; Wardle et al. 2004 ) If stoichiometries exist, what are underlying causes? LTER network wide investigation and synthesis

20. ACNOWLEDGEMENTS NSF BSR-8811902 International Institute of Tropical Forestry Institute for Tropical Ecosystem Studies University of Puerto Rico Plant Biology Dept. University of Georgia

21. References Haines et al. 2005.Time scales of ecological processes at LUQ LTER � this PowerPoint presentation available at .www.plantbio.uga.edu/~haines/haines.html Haines, B.L. and N. Brokaw (unpubl) Canopy recovery after hurricane disturbance in the Luquillo Experimental Forest, Puerto Rico Scatena, F.N. 1995. Relative scales of time and effectiveness of watershed processes in a tropical montane rain forest in Puerto Rico. American Geophysical Union, Geophysical Monographs 89: 103-111. Sterner, W & J. Elser. 2002. Ecological Stoichiometry. Princeton Univ Wardle et al. 2004. Ecosystem properties and forest decline in contrasting long-term chronosequences. Science 305:509-513

22. archived on jump drive of hainesthis frame not for public consumption- it is Haines file archive information. File stored on computer named MIMOSA c:\_Haines\ESA-INTECOL-2005file name = LUQ LTER TIME SCALES 6 AUG 05 EDITION AAAALSO STORED ON HAINES 65 MB JUMP DRIVEales of ecological processes at LUQ LTERalso stored on 2 compact disks.