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STRI talk, long-term ecosystem development and plant diversity

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Presentation of research programme on long-term soil/ecosystem development and patterns of plant species diversity. Tupper Seminar, Smithsonian Tropical Research Institute (STRI), Panama. Jan 8, 2013.

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STRI talk, long-term ecosystem development and plant diversity

  1. 1. Long-term ecosystem development and terrestrial plant diversityEtienne LalibertéSchool of Plant BiologyThe University of Western Australiawww.elaliberte.infoSTRI, January 8, 2013
  2. 2. Outline• Long-term ecosystem development• Soil chronosequences – Jurien Bay dune chronosequence• Nutrient limitation and nutrient-use efficiency• Patterns of plant species diversity – local (alpha) diversity – site-to-site (beta) diversity
  3. 3. Ecosystem developmentEugene Odum(1913-2002) Gross production Peak Biomass standing Net biomass = production ‘climax’ Respiration Odum (1969) Science
  4. 4. What about over longer periods? Gross production ? Biomass Net production Respiration 1000’s Odum (1969) Science
  5. 5. Hawaiian 4.1 million-year island sequenceCrews et al. (1995) Ecology
  6. 6. Long-term soil chronosequences
  7. 7. Wardle et al (2004) Science
  8. 8. Ecosystemdecline orretrogression Wardle et al (2004) Science
  9. 9. Long-term soil chronosequencesBuild-up (progressive) phase Maximal phase Decline (retrogressive) phase Soil age Peltzer et al (2010) Ecol Monogr
  10. 10. Loss of P drives ecosystem decline Apatite (phosphate minerals) Mineral P Total P Organic P Soil age Walker & Syers (1976) Geoderma
  11. 11. South-western Australia Species richness • Ancient, low-P soils • Biodiversity hotspot • ~8000 plant species • ~50% endemic • Highest plant Species endemism diversity in kwongan – small scales (100 m2) – also between sites (β) Jurien Bay dune chronosequenceHopper & Gioia (2004) Ann Rev Ecol Evol Syst
  12. 12. Jurien Bay >2-million-year dune Jurien Bay chronosequence Perth0-7 ky Holocene120-500 ky Middle to late Pleistocene >2000 ky Late Pliocene to Early Pleistocene
  13. 13. Collaborationbetween UWAand STRI (BenTurner)
  14. 14. A Stage 1: very young dunes (10’s—100 years) Photo: Graham Zemunik CVery low N High P Laliberté et al. (2012) J Ecol
  15. 15. Stage 2: young dunes A (100’s-1000’s years) CHighest N High P Laliberté et al. (2012) J Ecol
  16. 16. A Stage 3: young dunes CA C1 (~7000 years) C2 C3Medium N Medium P Laliberté et al. (2012) J Ecol
  17. 17. A Stage 4: old dunesAE E (~120,000 years)B1B2Low N Very low P Laliberté et al. (2012) J Ecol
  18. 18. O Stage 5: very old dunes A (>2,000,000 years) EA ELow N Extremely low P Laliberté et al. (2012) J Ecol
  19. 19. Ecosystem progression and Litterfall traps retrogression Bioassay with canolaLaliberté et al. (2012) J Ecol
  20. 20. Nutrient (co)limitation N limitationLaliberté et al. (2012) J Ecol
  21. 21. Nutrient (co)limitation N limitation Co-limitation Co-limitationLaliberté et al. (2012) J Ecol
  22. 22. Nutrient (co)limitation Strong P N limitation Co-limitation Co-limitation P limitation limitationLaliberté et al. (2012) J Ecol
  23. 23. Plant nutrient-use efficiencyNUE = carbon fixed per unitnutrient taken upGreen leaf nutrient concentration Leaf lifespan Resorption from senescing leaves Photo: Patrick Hayes
  24. 24. Leaf P concentration and resorption Patrick Hayes Honours student
  25. 25. Plant species richness increases during ecosystem development Data from Wardle et al. (2008) Oikos Laliberté et al. (in review)
  26. 26. Random stratified sampling 6 dune systems * 10 plots = 60 Mean distance = 10 km Each plot = 10x10 m
  27. 27. Graham Zemunik(PhD student)• Vegetation surveys • cover • count data • height, diameter
  28. 28. Jurien Bay: alpha diversity All vascular plants All vascular plantsobserved species richness rarefied species richness
  29. 29. Multivariate controls over local plant diversity Time Pedogenic stage Haast, New Zealand Increasing dune ageTurner et al. (2012) Catena
  30. 30. Multivariate controls over local plant diversity Time NitrogenLocal processes Pedogenic stage Diversity of N and P forms Plant resource diversity partitioning (+) Bever et al. (2010) TREE
  31. 31. Multivariate controls over local plant diversity Time PhosphorusLocal processes Pedogenic stage Diversity of N and P forms Turner (2008) J Ecol Plant resource diversity partitioning (+)
  32. 32. Multivariate controls over local plant diversity TimeLocal processes Pedogenic stage Diversity Nutrient of N and availability and Humped-back model P forms stoichiometry Species richness resource-ratio model, productivity- diversity (+/-) Plant resource diversity partitioning (+) Grime (1973) Nature
  33. 33. Multivariate controls over local plant diversity Resource-ratio model Time N?Local processes Pedogenic stage Tilman (1982) Diversity of N and Nutrient availability and P? P forms stoichiometry resource-ratio model, productivity- diversity (+/-) Plant resource diversity partitioning (+)
  34. 34. Multivariate controls over local plant diversity TimeLocal processes Pedogenic stage Diversity Nutrient Soil spatial of N and availability and heterogeneity P forms stoichiometry niche resource-ratio theory (+) model, productivity- diversity (+/-) Plant resource diversity partitioning (+)
  35. 35. Multivariate controls over local plant diversity Bever et al. (2010) TREE TimeLocal processes Pedogenic stage Diversity Nutrient Soil spatial Soil biota of N and availability and heterogeneity P forms stoichiometry niche negative plant- resource-ratio theory (+) soil feedback (+) model, productivity- diversity (+/-) Plant resource diversity Host-specific pathogen partitioning (+)
  36. 36. Multivariate controls over local plant diversity Bever et al. (2010) TREE3-year project Timewith Ben Turner (STRI)and other collaboratorsLocal processes Pedogenic stage Diversity Nutrient Soil spatial Soil biota of N and availability and heterogeneity P forms stoichiometry niche negative plant- resource-ratio theory (+) soil feedback (+) model, productivity- diversity (+/-) Plant resource diversity Host-specific pathogen partitioning (+)
  37. 37. Multivariate controls over local plant diversity ‘Regional’ processes Time Abiotic environmental conditions filtering (-) Stage-Local processes Pedogenic stage specific species pool size Diversity Nutrient Soil spatial Soil biota of N and availability and heterogeneity P forms stoichiometry niche negative plant- resource-ratio theory (+) soil feedback (+) model, productivity- diversity (+/-) Plant resource diversity species pool partitioning (+) hypothesis (+)
  38. 38. Multivariate controls over local plant diversity ‘Regional’ processes Time Abiotic environmental conditions filtering (-) Pedogenic stage Stage- specific species pool size Plant diversity species pool hypothesis (+)Young carbonate dunespH > 8
  39. 39. Multivariate controls over local plant diversity ‘Regional’ processes Time Abiotic environmental conditions filtering (-) Stage-Local processes Pedogenic stage specific species pool size Diversity Nutrient Soil spatial Soil biota of N and availability and heterogeneity P forms stoichiometry niche negative plant- resource-ratio theory (+) soil feedback (+) model, productivity- diversity (+/-) Plant resource diversity species pool partitioning (+) hypothesis (+)
  40. 40. From alpha to beta diversity Dune age0.01 ky 1 ky 7 ky 120 ky 500 ky 2000 ky 10 m X 10 m plot How many plant species? Alpha diversity
  41. 41. From alpha to beta diversity Dune age0.01 ky 1 ky 7 ky 120 ky 500 ky 2000 ky How much variation in species composition between plots within a dune system? Beta diversity Alpha and beta determine gamma diversity (total number of species)
  42. 42. Does beta diversity increase with productivity?Chase (2010) Science
  43. 43. From alpha to beta diversity Dune age0.01 ky 1 ky 7 ky 120 ky 500 ky 2000 ky Productivity peaks in relatively young soils (1-7 ky), then declines in older soils (>120 ky)
  44. 44. Alpha and gamma diversity Stage 2 (~1 ky) Stage 6 (2000 ky)
  45. 45. Beta diversity Stage 2 (~1 ky) Stage 6 (2000 ky)
  46. 46. Spatial autocorrelation?Condit et al. (2002) Science
  47. 47. Spatial autocorrelation?Condit et al. (2002) Science In older dunes, community similarity drops faster with geographical distance
  48. 48. Spatial autocorrelation?Condit et al. (2002) Science Mean distance to centroid = measure of di spatial dispersion
  49. 49. Spatial autocorrelation?Condit et al. (2002) Science In older dunes where beta diversity is greatest, plots are actually closer to each other β = -1.04 Mean distance P ≤ 0.05 to centroid = measure of di spatial dispersion
  50. 50. Differences in sampling effort? After rarefaction, general pattern persists
  51. 51. Environmental heterogeneity? • Total N • Total P • Resin P • pH • CEC • etc...Laliberté et al. (2012) J Ecol
  52. 52. Environmental heterogeneity? but σ quite smallGreater beta diversity in older soils not linked to greater environmental heterogeneity
  53. 53. Summary• Ecosystem progression & ecosystem retrogression• Shifts from N to P limitation• Higher P-use efficiency with soil age• α, β, and γ diversity higher in older soils• Higher β diversity in older soils despite: – plots closer to each other – lower environmental heterogeneity• Contrary to productivity-beta diversity hypothesis?• Chronosequences as ‘natural experiments’ for plant community ecology
  54. 54. • Hans Lambers • Graham Zemunik Acknowledgements • Ben Turner • François Teste• Thanks to STRI for the invitation • Patrick Hayes • Stuart Pearse • Thomas Costes • several field workers...

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