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Sean Michael Gleason

Contact details

Fax:+61-3-9905-5613
E-mail:Sean.Gleason@sci.monash.edu.au
Building/Room:17

Project Title

Nutrient and light use efficiency, GPP, and belowground nutrient retention in an Australian rainforest: effects of tree diversity

PhD Project

Plant-soil interactions and nutrient limitation in an Australian rainforest: effects of soil type and species composition.

General research passions: Complementary resource use in forest systems, plant-soil interactions in terrestrial and wetland forests, diversity-productivity mechanisms, invasive species biology and control, ecophysiology of invasion and plant-plant interactions, rare plant conservation, science-based natural resources management

Project

I am investigating plant-soil and plant-plant interactions in diverse rainforest communities in northeast Queensland. I am particularly interested in mechanisms that drive diversity-productivity relationships. Why are diverse forests more productive than less diverse forests (Hooper et al. 2002, van Ruijven and Berendse 2005)? Do species growing on nutrient-poor soils interact synergistically in a way that conserves belowground nutrients and enhances forest-level productivity?

Complementary resource use may come about through asynchrony of resource utilisation among species – species may differ in where roots and leaves are located and when resource uptake/carbon fixation occurs. Resource use patterns among species may then serve to increase resource interception and/or increase resource use efficiency (RUE) at the forest-level in a way that single-species forest could not (Hiremath and Ewel 2001). The idea of complementary resource use has been tested theoretically (Tilman 1988) and in agroforestry / forestry systems (DeBell et al. 1989, Ewel et al. 1991, Binkley and Giardina 1997, Haggar and Ewel 1997, Khanna 1998, Parrotta 1999, Dommergues and Subba Rao 2000, Kaye et al. 2000, Binkley 2003, Binkley et al. 2003), but rarely in naturally occurring forest communities.

I am measuring tree-level and plot-level net primary productivity (NPP), nutrient uptake, nutrient use efficiency, soil nutrient availability, root density patterns, and leaf patterns, within directly adjacent forests occurring on nutrient poor schist and nutrient rich basalt. This allows me to look at temporal and spatial patterns of resource supply and use among many species occurring on different soils. Additional glasshouse and field fertilization experiments allow me to evaluate the RUE of seedlings and mature tress when nutrient limitation is removed. These experiments should allow me to evaluate the nutrient economy of rainforest species and how these species interact when nutrients are limited and abundant. It is hoped that this research will provide insights into why diverse communities are productive and how soil resources influence species-level and plot-level nutrient economy.
See also
Plant Ecology Lab
  

Publications

  • Gleason, S.M, D.T. Faucette, M.M. Toyofuku, C.A. Torres, C.F. Bagley and S. Cardea 2006. (in review).Assessing and mitigating the effects of windblown soil on rare and common vegetation. Ecological Applications
  • Gleason, S.M. and D.T. Faucette (in review). Drought response of invading Russian thistle (Salsola kali) on the island of Hawaii: implications for management with regards to water and nitrogen availability. Journal of Arid Environments
  • Ares, A., and S.M. Gleason 2006. Foliar nutrient resorption in tree species. In New research on forest ecology, A.K. Scaggs (Ed), Nova Science Publishers, New York, USA (in press).
  • Baskin, J.M., B.H. Davis, C.C. Baskin, S.M. Gleason, and S. Cordell 2003. Physical dormancy in seeds of Dodonaea viscosa (Sapindales, Sapindaceae) from Hawaii. Seed Science Research, 14:81-90.
  • Gleason, S.M. and A. Ares 2002. Photosynthesis, carbohydrate storage, and survival of a native and introduced tree species grown under varied light regimes. Tree Physiology, 24:1087-1057.
  • Gleason, S.M., K.C. Ewel and N.V. Hue 2002. Soil redox conditions and plant-soil relationships in a Micronesian mangrove forest. Estuarine, Coastal and Shelf Science, 56:1-11.
  • Gleason, S.M. and K.C. Ewel 2002. Organic matter dynamics on the forest floor of a Micronesian mangrove forest: an Investigation of Species Composition Shifts. Biotropica 34:190-198.

Literature Cited

  • Binkley D. 2003.  Seven decades of stand development in mixed and pure stands of conifers and nitrogen-fixing red alder.  Canadian Journal of Forest Research 33:2274-2279<
  • Binkley D., Bird S. and Cole T. 2003.  Twenty years of stand development in pure and mixed stands of Eucalyptus saligna and nitrogen-fixing Facaltaria moluccana.  Forest Ecology and Management 182:93-102
  • Binkley D. and Giardina C. 1997.  Biological nitrogen fixation in plantations. In: Nambiar E.K.S. and Brown A. (Eds.), Management of Soil, Water, and Nutrients in Tropical Plantation Forests.  ACIAR Monograph 43, Canberra, Australia, pp. 297–337
  • Dommergues Y.R. and Subba Rao N.S. 2000.  Introduction of N2-fixing trees in non-N2-fixing tropical plantations. In: Subba Rao N.S. and Dommergues Y.R. (Eds.), Microbial Interactions in Agriculture and Forestry, vol. II. Science Publishers, Enfield, NH, USA, pp. 131–154
  • DeBell D.S., Whitesell C.D. Schubert T.H. 1989.  Using N2-fixing Albizia to increase growth of Eucalyptus plantations in Hawaii.  Forest Science 35:64–75
  • Ewel J.J., Mazzarino M.J. and Berish C.W. 1991.  Tropical soil fertility changes under monocultures and successional communities of different structure.  Ecological Applications 1:289-302
  • Haggar J.P. and Ewel J.J. 1997.  Primary productivity and resource partitioning in model tropical ecosystems.  Ecology 78:1211-1221
  • Hiremath A.J. and Ewel J.J. 2001.  Ecosystem nutrient use efficiency, and nutrient accrual in model tropical communities.  Ecosystems 4:669-682
  • Hooper D.U., Solan M., Symstad A., Diaz S., Gessner M.O., Buchmann N., Degrange V., Grime P., Hulot F., Mermillod-Blondin F., Roy J., Spehn E., van Peer L. 2002.  Species diversity, functional diversity, and ecosystem functioning. In: Biodiversity and ecosystem functioning, synthysis and perspectives, Loreau M., Naeem S. and Inchausti P. (Eds). Oxford University Press, UK, pp. 195-281
  • Kaye J.P., Resh S.C., Kaye M.W. and Chimner R.A. 2000.  Nutrient and carbon dynamics in a replacement series of Eucalyptus and Albizia trees.  Ecology 81:3267–3273
  • Khanna P.K., 1998. Nutrient cycling under mixed tree systems in Southeast Asia. Agroforestry Systems 38:99–120
  • Parrotta J. 1999.  Productivity, nutrient cycling, and succession in single- and mixed-species plantations of Casuarina equisetifolia, Eucalyptus robusta, and Leucaena leucocephala in Puerto Rico.  Forest Ecology and Management 124:45–77
  • Tilman D. 1988. Plant strategies and the dynamics and functioning of plant communities. Princeton University Press, Princeton, New Jersey, USA
  • van Ruijven J and Berendse F. 2005.  Diversity-productivity relationships, initial effects, long-term patterns, and underlying mechanisms. PNAS 102:695-700