Professor, Department of Biology,
University of Hawaii at Hilo
Ph.D. in Botany, University of Florida, Gainesville, FL.
B.A. in Biology, Carleton College, Northfield, MN.
As tropical forest ecologist, my research interests revolve around understanding how tropical forests are structured and how tropical ecosystems function. I have been fortunate to work in both Latin America and Hawai`i.
Current research projects include:
- Designing hybrid ecosystems as a restoration strategy
- Hawaiian forest dynamics using long-term permanent plots (see HIPPNET project)
- Significance of foliar N and P accumulation in tropical forests
- Species invasions and their effects on nutrient cycling
Our lab group works on a variety of ecological studies.
Ostertag, R., F. Inman-Narahari, S. Cordell, C.P. Giardina, L. Sack. 2014. Forest structure in low-diversity tropical forests: a study of Hawaiian wet and dry forests. PLoS ONE 9(8): e103268. doi:10.1371/journal.pone.0103268. PDF
Dudley, B.D., R.F. Hughes, and R. Ostertag. In press. Groundwater availability mediates the ecosystem effects of an invasion of Prosopis pallida (Willd.) Kunth. Ecological Applications, online early. PDF
Dudley, B.D., R.A. MacKenzie, T.S. Sakihara, H. Dulaiova, C.A. Waters, R.F. Hughes and R. Ostertag. In press. Influences of N-fixing and non-N-fixing vegetation and invasive fish on water chemistry of Hawaiian anchialine ponds. Pacific Science 68 (4), online early.
Cavaleri, M.A, R. Ostertag, Cordell, S., and L. Sack. 2014. Native trees show conservative water use relative to invasive: results from a removal experiment in a Hawaiian wet forest. Conservation Physiology 2: 10.1093/conphys/cou016. PDF
Murphy, M. , F. Inman-Narahari, R. Ostertag, and C.M. Litton. 2014. Invasive feral pigs impact native tree ferns and woody seedlings in Hawaiian forest. Biological Invasions 16: 63-71. PDF
Schulten, J.R., T. Colleen Cole, S. Cordell, K.M. Publico, R. Ostertag, J. Enoka, and J.D. Michaud. 2014. Persistence of native trees in an invaded Hawaiian lowland wet forest: experimental evaluation of light and water constraints. Pacific Science 68:267-285. PDF
Cleveland, C., S. Reed, A. Keller, D. Nemergut, S. O’Neill, R. Ostertag, and P.M. Vitousek. 2014. Litter quality versus microbial community controls over decomposition: A quantitative analysis. Oecologia 174: 283-294. PDF
Meyer, III, W.M. , R. Ostertag, and R.H. Cowie. 2013. Influence of terrestrial molluscs on litter decomposition and nutrient release in a young Hawaiian rainforest. Biotropica 45: 719-727.PDF
Inman-Narahari, F., R. Ostertag, S. Cordell, C. Giardina, K. Nelson-Kaula, and L. Sack. 2013. Do seedling recruitment factors shift with ecosystem properties? Tests in low-diversity Hawaiian wet forest and global comparisons among tropical forests. Ecosphere 4(2):24. http://dx.doi.org/10.1890/ES12-00164.1. PDF
Celentano, D., R.A Zahawi, B. Finegan, F. Casanoves, R. Ostertag, R.J. Cole, K.D. Holl. 2011. Restauración ecológica de bosques tropicales en Costa Rica: efecto de varios modelos en la producción, acumulación y descomposición de hojarasca. Revista de Biología Tropical 59: 1323-1336.
Celentano, D., R.A. Zahawi, B. Finegan, R. Ostertag, R.J. Cole, and K.D. Holl. 2011. Litterfall dynamics and nutrient cycling under different tropical forest restoration strategies and young secondary forests. Biotropica 43: 279-287.
Holl, K. D. Holl, R.A. Zahawi, R.J. Cole, R. Ostertag, and S. Cordell. 2011. Planting seedlings in plantations versus tree islands as a large-scale tropical forest restoration strategy. Restoration Ecology 19:470-479.
Meyer, III, W.M., R. Ostertag, and R.H. Cowie. 2011. Macro-invertebrates accelerate litter decomposition and nutrient release in a young Hawaiian rainforest. Soil Biology and Biochemistry 43: 206-211.
Benner, J., P.M.Vitousek, and R. Ostertag. 2011. Nutrient cycling and nutrient limitation in tropical montane cloud forest. Pages 90-100 in Tropical Montane Cloud Forests: Science for Conservation and Management, editors. L.A. Bruijnzeel, F.N. Scatena, and L.S. Hamilton. Cambridge University Press, Cambridge, UK.
Inman-Narahari, F., C. Giardina, R. Ostertag, S. Cordell, and L. Sack. 2010. Digital data collection in forest plots. Methods in Ecology and Evolution 1: 274-279. PDF
Ostertag, R. 2010. Foliar nitrogen and phosphorus accumulation responses after fertilization: an example from nutrient-limited Hawaiian forests. Plant and Soil 334: 85-98. PDF
McDaniel, S. and R. Ostertag. 2010. Strategic light manipulation can be a sustainable restoration strategy to suppress alien grasses and encourage native regeneration in Hawaiian mesic forests. Applied Vegetation Science 13: 280-290. PDF
Cordell, S, Ostertag, R., Rowe, B., Sweinhart, L., Vasquez-Radonic, L., Michaud, J., Cole, T.C., Schulten, J.R. 2009. Evaluating barriers to native seedling establishment in an invaded Hawaiian lowland wet forest. Biological Conservation 142: 2997–3004. PDF
Ostertag, R., S. Cordell, J. Michaud, T.C. Cole, J.R. Schulten, K.M. Publico, and J.H. Enoka. 2009. Ecosystem and restoration consequences of invasive woody species removal in Hawaiian lowland wet forest. Ecosystems 12: 503-515. PDF
Marín-Spiotta, E., W. L. Silver, C.W. Swanston, and R. Ostertag. 2009. Soil carbon gain and loss during 80 years of reforestation of tropical pastures. Global Change Biology 15: 1584-1597.
Ostertag, R., E. Marín-Spiotta, W. L. Silver, and J.R. Schulten. 2008. Litterfall and decomposition in relation to soil carbon pools along a secondary forest chronosequence in Puerto Rico. Ecosystems 11: 701-714. PDF
Ostertag, R., C.P. Giardina, and S. Cordell. 2008. Understory colonization of Eucalyptus plantations in Hawaii in relation to light and nutrient Levels. Restoration Ecology 16: 475-485.
Marín-Spiotta, E., D.F. Cusack, R. Ostertag, and W. L. Silver. 2008. Trends in above and belowground carbon with forest regrowth after agricultural abandonment in the Neotropics. Pages 22-72 in R.W. Myster, editor. Post-Agricultural Succession in the Neotropics. Springer, New York. PDF
Zimmerman, N., R.F. Hughes, S. Cordell, P. Hart, H.K. Chang, D. Perez, R.K. Like, and R. Ostertag. 2008. Patterns of primary succession of native and introduced plants in lowland wet forests in Eastern Hawaii. Biotropica 40: 277-284. PDF
Carlson, K.M., G.P. Asner, R. Flint Hughes, R. Ostertag, and R.E. Martin. 2007. Hyperspectral remote sensing of canopy biodiversity in Hawaiian lowland rainforests. Ecosystems 10: 536-549.PDF
Marin-Spiotta, E., R. Ostertag, and W.L. Silver. 2007. Long-term patterns in reforestation of tropical pastures: plant community composition and aboveground biomass accumulation. Ecological Applications 1:828-839. PDF
Ostertag, R., W.L. Silver, and A.E. Lugo. 2005. Factors affecting mortality and resistance to damage following hurricanes in a rehabilitated subtropical moist forest. Biotropica 37: 16-23. PDF
Van Bloem, S. J., P.G. Murphy, A.E. Lugo, R. Ostertag, M. Rivera Costa, I. Ruiz Bernard, S. Molina Colón, and M. Canals Mora. 2005. The influence of hurricane winds on Caribbean dry forest structure and nutrient pools. Biotropica 37: 571-583.
Silver, W.L., L.M. Kueppers, A.E. Lugo, R. Ostertag, and V. Matzek. 2004. Carbon sequestration and plant community dynamics following reforestation of tropical pasture. Ecological Applications 14: 1115-1127. PDF
Ostertag, R., F.N. Scatena, and W.L. Silver. 2003. Forest floor decomposition following hurricane litter inputs in several Puerto Rican forests. Ecosystems 6: 261-273. PDF
Ostertag, R. and J.H. Verville. 2002. Effects of N and P fertilization on invasion by non-native species in Hawaiian montane forests. Plant Ecology 162: 77-90. PDF
Ostertag, R. 2001. The effects of nitrogen and phosphorus availability on fine root dynamics in Hawaiian montane forests. Ecology 82: 485-499. PDF
Guariguata, M.R. and R. Ostertag. 2001. Neotropical secondary succession: changes in structural and functional characteristics. Forest Ecology and Management 148: 185-206. PDF
Silver, W.L., R. Ostertag, and A.E. Lugo. 2000. The potential for carbon sequestration through reforestation of abandoned tropical agricultural and pasture lands. Restoration Ecology 8: 394-407.
Ostertag, R. and S.E. Hobbie. 1999. Early stages of root and leaf decomposition in Hawaiian forests: effects of nutrient availability. Oecologia 121: 564-573. PDF
Ostertag, R. 1998. Belowground effects of canopy gaps in a lowland tropical wet forest. Ecology 79: 1294-1304. PDF
- Department of Defense, SERDP Program, “Developing Novel Ecosystems that Enhance Carbon Storage, Native Biodiversity, and Human Mobility in Lowland Forests”, 2011-2016, PI.
- NSF Ecosystem Studies, “CAREER: Significance of Foliar Nitrogen and Phosphorus Accumulation in Tropical Forests”, August 2006-Sep 2012, PI.
- NSF Ecosystem Studies, “Effects of Multiple Species Invasions: Albizia Tree and Coqui Frog Colonization of Hawai`i”, July 2005-August 2008, co-PI.
- NSF Ecosystem Studies, "Controls on the Storage and Loss of Soil Organic Carbon with Reforestation of Abandoned Pastures", March 2002-Feb 2005, Senior Personnel,
- NSF TCUP Program, “Hawaiian Values, Science, and Technology: Advancing a New Paradigm for STEM Education”, Sept. 2002-2007. Senior Personnel.
- NASA/Earth System Science Education, “Teaching Global Environmental Change from Mountain to Ocean: The `Ahupua`a Way”, 2003-2005, Co-PI.
- UHH Seed Grant, “Nitrogen and Phosphorus Limitation of Hawaiian Forest Communities”, May 2002-June 2003, PI.
- UHH EPSCoR REAP Grant, “Nitrogen, Phosphorus, and Aluminum Relationships in Hawaiian Forest Communities”, 2003-2004, PI.
- UHH REAP EPSCoR grant entitled “The Impact of Non-Native Species on Resource Availability and Community Structure in a Hawaiian Lowland Wet Forest”, 2002, PI
- Natural History & Conservation of Hawaiian Islands (Biology/Marine Science 156 and 156L)
- Biostatistics (Biology 280)
- General Ecology (Biology 281)
- General Ecology Laboratory (Biology 281L)
- Conservation Biology (Biology 381)
- Advanced Ecology and Evolution (Biology 481)
- Ecology and Evolution Research Methods (Biology 481L)
- Tropical Conservation Biology and Environmental Science (TCBES 600, 601, 602)
I currently teach ecology courses at both lower and upper levels. In lower level courses, the emphasis is on developing a solid foundation based on ecological theory and to understand how that theory can be applied to present environmental issues, particularly related to global change. In upper level courses, the focus is on learning about the "art" of science, including reading primary literature, discussion of new analytical tools, and development of independent hypotheses and research proposals. All laboratory courses that I teach are field based, and take advantage of the extraordinary landscape diversity of the Big Island of Hawai`i.
Career Resources for UH Hilo Students
I am involved in an NSF grant (DEB, Ecosystem Studies, # 0546868) in which I am developing career resources for students interested in the environmental sciences.
Check out our website: www.environmentalcareerresources.uhh.hawaii.edu
How to Find a Summer Opportunity in the Environmental Sciences
Click on these links for handouts and helpful information.
- EnvironmentalJobResources handout with lots of information about opportunities in Hawaii and beyond
- HowtoFindaSummerOpportunityintheEnvironmentalSciences1.31.07 PowerPoint