Adjunct Faculty

Summary of Expertise

My research has evaluated theoretical ecological concepts centered on forest recovery in degraded tropical habitats where I have developed cost-effective strategies to facilitate or accelerate succession under a variety of different conditions. I have conducted both observational and experimental research in Central and South America and established large- and small-scale projects with collaborators and students from multiple institutions. I have tested applied nucleation (or tree islands) extensively, evaluated large (2-4 m tall) vegetative cuttings in a restoration setting as a way to jump-start recovery, and have assessed the potential for utilizing agricultural waste to facilitate recovery in degraded pastures. I also have an interest in tropical forest dynamics, especially in fragmented habitats, and have quantified land use change patterns over long time scales.

Research Interests

• Design and evaluation of cost-effective restoration strategies that facilitate or accelerate forest recovery in degraded habitats, particularly in the Neotropics.

              • Forest dynamics and plant succession in fragmented landscapes.

              • Vegetative propagation of tropical trees.

• Design and implementation of conservation projects in Neotropical regions.

Biography, Education and Training

I am a restoration ecologist and have conducted all my research in the Neotropics where I have evaluated numerous methods to facilitate and jump-start forest recovery processes. I graduated from the University of Texas at Austin with a B.S. degree in Botany and went on to get my M.S. and Ph.D. in Plant Biology from the University of Illinois at Urbana-Champaign. Between 2006-16 I was the Director of the Las Cruces Biological Station and Wilson Botanical Garden in southern Costa Rica - a field research station owned and operated by the Organization for Tropical Studies. More recently I taught as a visiting professor at the American University of Beirut in Lebanon before taking over as Director of Lyon Arboretum, a research unit of the University of Hawai’i at Mānoa.  Since 2021 I took over as the Executive Director of the Charles Darwin Foundation for the Galapagos Islands. 

Honors, Awards and Grants

Awards
2017    Society for Ecological Restoration Theodore M. Sperry Award in recognition of a significant and enduring contribution made toward advancing restoration science or practice through the development of new methods, tools, techniques or strategies.
2016    Editor’s Award for “Tropical forest restoration enriches vascular epiphyte recovery”; article published in Applied Vegetation Science.
2015    Elsevier Publisher’s Atlas Research Award for “Using lightweight unmanned aerial vehicles to monitor tropical forest recovery”; article published in Biological Conservation.

Grants

2020    Research Award, Ecology Cluster, National Science Foundation, $247,109.

2018    Stanley Smith Horticultural Trust, $15,000. 

2017    March Conservation Fund, $10,000.
           World Wildlife Fund, $16,460.
           REU Supplement for Ecology Cluster award, National Science Foundation, $8,158.
2015    Stanley Smith Horticultural Trust, $20,000.
           Field Station & Marine Labs Grant (FSML), National Science Foundation, $186,297.
           Research Award, Ecology Cluster, National Science Foundation, $400,000.
2014    CSBR Supplement, National Science Foundation, $19,942.
2012    Biological Research Collections (CSBR), National Science Foundation, $153,792.
2010    Stanley Smith Horticultural Trust, $20,000.
           Field Station & Marine Labs Grant (FSML), National Science Foundation, $149,405.
2009    Research Award, Ecology Cluster, National Science Foundation, $333,992.
2007    Stanley Smith Horticultural Trust, $20,000.
           Int. Research & Education Workshop, National Science Foundation, $48,099.
           Field Station & Marine Labs Grant (FSML), National Science Foundation, $146,164.
2006    Stanley Smith Horticultural Trust, $20,000.
           Research Award, Earthwatch Institute, $18,500.
2005    Research Award, Ecology Cluster, National Science Foundation, $299,957.
           Research Award, Earthwatch Institute, $18,500.
2003    Research Award, Earthwatch Institute, $18,500.
2003    Summer Fellowship Award, Department of Plant Biology, U. Illinois, $1,680.
2001    Clark Summer Fellowship Award, School of Life Sciences, U. Illinois, $2,500.
           Research Board Award, Graduate College, U. Illinois, $7,000.
1999    Doctoral Dissertation Improvement Grant, National Science Foundation, $9,693.
           Organization for Tropical Studies Research Fellowship, $3,000.
           Research Board Award, Graduate College, U. Illinois, $16,386.
1999    Dissertation Travel Grant, Graduate College, U. Illinois, $4,530.
           Summer Research Fellowship, School of Integrative Biology, U. Illinois, $2,000.
           Clark Research Support Grant, School of Life Sciences, U. Illinois, $775.
1996    Tinker Grant, Center for Latin American & Caribbean Studies, U. Illinois, $1,400.
           Sigma Xi Research Society, $475.
1994    Summer Scholarship Award, Department of Plant Biology, U. Illinois, $2,500.



 

Selected Publications

Kulikowski II, A.J., R.A. Zahawi, and K.D. Holl. 2021. Effects of insect herbivory on tropical seedling mortality in restored and remnant forest. Restoration Ecology. In press.

Werden, L.K., K.D. Holl, J.M. Chaves-Fallas, F. Oviedo-Brenes, J.A. Rosales, and R.A. Zahawi. 2021. Degree of intervention affects interannual and within-plot heterogeneity of seed arrival in tropical forest restoration. Journal of Applied Ecology. In press.

Sato, A., T. Ticktin, L. Alapai, E. von Allmen, W. Brawner, Y. Carter, K. Carter, R. Keakealani, A. Medeiros, and R.A. Zahawi. 2021. Biocultural restoration of Hawaiian tropical dry forests. Pacific Conservation Biology. In press.

Wilson, S.J, N.S. Alexandre, K.D. Holl, J.L. Reid, R.A. Zahawi, D. Celentano, S.S. Sprenkle Hyppolite, and L. Werden. 2021. Applied nucleation restoration guide for tropical forests. Conservation International. https://www.conservation.org/research/applied-nucleation-report.

Cole, R.J., and R.A. Zahawi. 2021. Coffee pulp accelerates early tropical forest succession on old fields. Ecological Solutions and Evidence. https://doi.org/10.1002/2688-8319.12054.

Fagan, M.E., J.L. Reid, and R.A. Zahawi. 2020. RE: No Bonn Challenge restoration commitment exceeds a country’s potential area. Science e-letter.

Zahawi, R.A., J.L. Reid, and M.E. Fagan. 2020. Potential impacts of COVID-19 on tropical forest recovery. Biotropica. https://doi.org/10.1111/btp.12851.

Powers, J.S., E.M. Bruna, A. Campos-Arceiz, P. Delamonica Sampaio, S.J. DeWalt, L.G. Lohmann, and R.A. Zahawi. 2020. Tropical biology in the time of the COVID-19 pandemic. Biotropica. https://doi.org/10.1111/btp.12802.

Holl, K.D., J.L. Reid, R.J. Cole, F. Oviedo-Brenes, J.A. Rosales, and R.A. Zahawi. 2020. Applied nucleation facilitates tropical forest recovery: lessons learned from a 15-year study. Journal of Applied Ecology. https://doi.org/10.1111/1365-2664.13684.

Werden, L.K., K.D. Holl, J.A. Rosales, J.M. Sylvester, and R.A. Zahawi. 2020. Effects of dispersal- and niche-based factors on tree recruitment in tropical wet forest restoration. Ecological Applications. DOI: https://doi.org/10.1002/eap.2139.

Werden, L.K., N.C. Sugii, L. Weisenberger, M.J. Keir, G. Koop, and R.A. Zahawi. 2020. Ex-situ conservation of threatened plants in island biodiversity hotspots: a case study from Hawai‘i. Biological Conservation. https://doi.org/10.1016/j.biocon.2020.108435.

Fagan, M.E., J.L. Reid, M.B. Holland, J.G. Drew, and R.A. Zahawi. 2020. How feasible are global forest restoration commitments? Conservation Letters. https://doi.org/10.1111/conl.12700.

Fagan, M.E., J.L. Reid, and R.A. Zahawi. 2019. Forests: optimizing carbon uptake. Nature 570:446.

Cadavid-Florez, L., J. Laborde, and R.A. Zahawi. 2019. Using landscape composition and configuration metrics as indicators of woody vegetation attributes in tropical pastures. Ecological Indicators. DOI: https://doi.org/10.1016/j.ecolind.2019.01.072.

Reid, J.L., M.E. Fagan, M.E. Cattau, J. Lucas, and R.A. Zahawi. 2018. The ephemerality of regenerating secondary forests in southern Costa Rica. Conservation Letters. DOI: https://doi.org/10.1111/conl.12607.

Zahawi, R.A. and J.L. Reid. 2018. Tropical secondary forest enrichment with giant stakes of keystone species. PECON. https://doi.org/10.1016/j.pecon.2018.06.001.

Holl, K.D., J.L. Reid, F. Oviedo-Brenes, A.J. Kulikowski, and R.A. Zahawi. 2018. Rules of thumb for predicting tropical forest recovery. Applied Vegetation Science. https://doi.org/10.1111/avsc.12394.

Reid, J.L., M.E. Fagan, and R.A. Zahawi. 2018. Positive site selection bias in meta-analyses comparing natural regeneration to active forest restoration. Science Advances. https://doi.org/10.1126/sciadv.aas9143.

Holl, K.D. and R.A. Zahawi. 2018. Applied nucleation is a straightforward, cost-effective restoration approach: reply to Ramírez-Soto et al. (2018). Restoration Ecology. https://doi.org/10.1111/rec.12701.

Lanuza, O., F. Casanoves, D. Delgado, D. Celentano, R.A. Zahawi, & K.D. Holl. 2018. Litter and nutrient dynamics shift in tropical restoration sites after a decade of recovery. Biotropica https://doi.org/10.1111/btp.12533.

Slik, F. and 172 others. 2018. A phylogenetic classification of the world’s tropical forests. Proceedings of the National Academy of Sciences. https://doi.org/10.1073/pnas.1714977115.

Zahawi, R.A, F. Oviedo-Brenes, and C.J. Peterson. 2017. A degradation debt? Large-scale shifts in community composition and loss of biomass in a tropical forest fragment after 40 years of isolation. PLoS One 12(8): e0183133.

Reid, J.L., S.J. Wilson, G.S. Bloomfield, M.E. Cattau, M.E Fagan, K.D. Holl, and R.A. Zahawi. 2017. How long do restored ecosystems persist? Annals of the Missouri Botanical Garden 102:258-265.

Holl, K.D., J. M. Chaves-Fallas, F. Oviedo-Brenes, J.L. Reid, and R.A. Zahawi. 2017. Tropical forest restoration strategies affect biodiversity recovery more strongly than does landscape forest cover. Journal of Applied Ecology. https://doi.org/10.1111/1365-2664.12814.

Holste, E.K., K.D. Holl, R.A. Zahawi, and R.K. Kobe. 2016. Reduced aboveground tree growth associated with higher arbuscular mycorrhizal fungal diversity in tropical restoration. Ecology and Evolution. https://doi.org/10.1002/ece3.2487.

Cole, R.J., K.D. Holl, R.A. Zahawi, P. Wickey, and A. Townsend. 2016. Leaf litter arthropod responses to tropical forest restoration. Ecology and Evolution 6: 5158–5168. https://doi.org/10.1002/ece3.2220.

Reid, J.L., J. Miguel Chaves-Fallas, K.D. Holl, and R.A. Zahawi. 2016. Tropical forest restoration enriches vascular epiphyte recovery. Applied Vegetation Science 19:508-517.

Holl, K.D. and R.A. Zahawi. 2015. "Ilhas de árvores" como uma estratégia prática para a restauração de florestas tropicais. In Brancalion, P.H.S., Gandolfi, and R.R. Rodrigues. Restauração florestal. Oficina de Textos, São Paulo.

Zahawi, R.A., G. Duran, and U. Kormann. 2015. Sixty-seven years of land use change in southern Costa Rica. PLoS One https://doi.org/10.1371/journal.pone.0143554.

Zahawi, R.A., J.L. Reid, and K.D. Holl. 2015. Passive restoration can be an effective strategy: a reply to Prach and del Moral. Restoration Ecology 23:347-348.

Reid, J.L., C.D. Mendenhall, R.A. Zahawi, and K.D. Holl. 2015. Scale-dependent effects of forest restoration on Neotropical fruit bats. Restoration Ecology https://doi.org/10.1111/rec.12235.

Slik, F. and 170 others. 2015. An estimate of the number of tropical tree species. Proceedings of the National Academy of Sciences. https://doi.org/10.1073/pnas.1423147112.

Reid, J.L., K.D. Holl, and R.A. Zahawi. 2015. Seed dispersal limitations shift over time in tropical forest restoration. Ecological Applications 25:1072-1082.

Paine, C.E.T., and 34 others. 2015. Globally, functional traits are weak predictors of juvenile tree growth, and we do not know why. Journal of Ecology https://doi.org/10.1111/1365-2745.12401.

Zahawi, R.A., J.P. Dandois, K.D. Holl, D. Nadwodny, J.L. Reid, and E.C. Ellis. 2015. Using lightweight unmanned aerial vehicles to monitor tropical forest recovery. Biological Conservation 186:287-295.

Zahawi, R.A., C. Eckert, J.M. Chaves-Fallas, L. Schwanitz, J.A. Rosales, and K.D. Holl. 2015. The effect of restoration treatment soils and parent tree on tropical forest tree seedling growth. Open Journal of Forestry 5(2). https://doi.org/10.4236/ojf.2015.52015.

Zahawi, R.A., J.L. Reid, and K.D. Holl. 2014. Hidden costs of passive restoration. Restoration Ecology 22:284-287.

Zahawi, R.A. and K.D. Holl. 2014. Evaluation of different tree propagation methods in ecological restoration in the Neotropics. Pages 85-96. In Bozzano, M., R. Jalonen, E. Thomas, D. Boshier, L. Gallo, S. Cavers, S. Bordács, P. Smith, & J. Loo (eds). Genetic considerations in ecosystem restoration using native tree species. State of the World’s Forest Genetic Resources – Thematic Study. Rome, FAO and Biodiversity International.

Reid, J.L., C. D. Mendenhall, J.A. Rosales, R.A. Zahawi, and K.D. Holl. 2014. Landscape context mediates avian habitat choice in tropical forest restoration. PLoS One 9:e90573.

Reid, J.L., E.K. Holste, K.D. Holl, and R.A. Zahawi. 2014. Does any bat box facilitate forest recovery? – Reply to Kelm. Biological Conservation 170:330-331.

Holl, K.D. and R.A. Zahawi. 2014. Factors explaining variability in woody above-ground biomass accumulation in restored tropical forest. Forest Ecology and Management 319:36-43.

Holl, K.D., V. M. Stout, J.L. Reid, and R.A. Zahawi. 2013. Does applied nucleation enhance habitat heterogeneity and tree diversity in restored tropical pasture? Oecologia 173:569-578.

Reid, J.L., E.K. Holste, and R.A. Zahawi. 2013. Artificial bat roosts did not accelerate forest recovery in abandoned pastures in southern Costa Rica. Biological Conservation 167:9-16.

Zahawi, R.A., K.D. Holl, R.J. Cole, and J.L. Reid. 2013. Testing applied nucleation as a restoration strategy to facilitate tropical forest recovery. Journal of Applied Ecology 50: 88-96.

Cayuela, L., L. Gálvez-Bravo, F.S. de Albuquerque, R. Pérez-Pérez, D.J. Golicher, R.A. Zahawi, and 47 others. 2012. La red internacional de inventarios forestales (BIOTREE-NET) en Mesoamérica: avances, retos y perspectivas futuras. Ecosistemas 21: 126-135.

Cayuela, L., L. Gálvez-Bravo, R. Pérez-Pérez, F.S. de Albuquerque, D.J. Golicher, R.A. Zahawi, and 45 others. 2012. The tree biodiversity network (BIOTREE-NET): Prospects for biodiversity research and conservation in the tropics. In J. Dengler, J. Oldeland, F. Jansen, M. Chytry, J. Ewald, M. Finckh, F. Glöckler, G. Lopez-Gonzalez, R. K. Peet, J. H. J. Schaminée (eds). Vegetation databases for the 21st century. Biodiversity & Ecology 4: 211–224.

Reid, J.L., J.B.C. Harris, and R.A. Zahawi. 2012. Avian habitat preference in tropical forest restoration in southern Costa Rica. Biotropica 44:350-359.

Lindell, C.A., R.J. Cole, K.D. Holl, and R.A. Zahawi. 2012. Migratory bird species in young tropical forest restoration sites: effects of vegetation height, planting design, and season. Bird Conservation International 22:94-105.

Celentano, D., R.A. Zahawi, B. Finegan, F. Casanoves, R. Ostertag, R.J. Cole, and K.D. Holl. 2011. Restauración ecológica de bosques tropicales en Costa Rica: efecto de diferentes modelos en la producción, acumulación y descomposición de hojarasca. Revista de Biología Tropical 59:1323-1336.

Holl, K.D., 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.

Celentano, D., R.A. Zahawi, B. Finegan, R. Ostertag, R.J. Cole, and K.D. Holl. 2011. Litterfall dynamics and nutrient cycling under different strategies for tropical forest restoration. Biotropica 43:279-287.

Cole, R., K.D. Holl, C.L. Keene, and R.A. Zahawi. 2011. Direct seeding of late successional trees to restore tropical montane forest. Forest Ecology and Management 261:1590-1597.

Zahawi, R.A. and K.D. Holl. 2010. Bridging the gap between scientific research and tropical forest restoration: a multi-faceted research, conservation, education, and outreach program in southern Costa Rica. Ecological Restoration 28:143-146.

Sady, G.C., K.D. Holl, R.A. Zahawi, and R.J. Cole. 2010. Germination and survival of four early successional tree species in tropical montane forest restoration. Ecological Restoration 28:121-124.

Cole, R.J., K.D. Holl, and R.A. Zahawi. 2010. Seed rain under different restoration strategies in a complex tropical agricultural landscape. Ecological Applications 20:1255-1269.

Morrison, E., C.A. Lindell, K.D. Holl, and R.A. Zahawi. 2010. Patch-size effects on avian foraging behaviour: implications for tropical forest restoration design. Journal of Applied Ecology 47:130-138.

Zahawi, R.A. and K.D. Holl. 2009. Comparing the performance of tree stakes and seedlings to restore abandoned tropical pastures. Restoration Ecology 17:854-864.

Fink, R.D., C.A. Lindell, E.B. Morrison, R.A. Zahawi and K.D. Holl. 2009. Patch size and tree species influence the number and duration of bird visits in restoration plots in southern Costa Rica. Restoration Ecology 17:479-486.

Zahawi, R.A. and K.D. Holl. 2008. Tropical forest restoration research opportunities in southern Costa Rica. Ecological Restoration 26:299-300.

Reid, J.L., J.B.C. Harris, L.J. Martin, J.R. Barnett, and R.A. Zahawi. 2008. Distribution and abundance of nearctic-neotropical songbird migrants in a forest restoration site in southern Costa Rica. Journal of Tropical Ecology 24:685-688.

Zahawi, R.A. 2008. Instant trees: using giant vegetative stakes in tropical forest restoration. Forest Ecology and Management 255:3013-3016.

Schlawin, J.R. and R.A. Zahawi. 2008. ‘Nucleating’ succession in recovering neotropical wet forests: the legacy of remnant trees. Journal of Vegetation Science 19:485-492.

Goldsmith, G.R. and R.A. Zahawi. 2007. The function of stilt roots in the growth strategy of Socratea exorrhiza (Arecaceae) at two neotropical sites. Revista de Biología Tropical 55:787-793.

García-C.J.M. and R.A. Zahawi. 2006. Predation by a Blue-crowned motmot on a hummingbird. The Wilson Bulletin 118:261-263.

Zahawi, R.A. and C.K. Augspurger. 2006. Tropical forest restoration: tree islands as recruitment foci in degraded lands of Honduras. Ecological Applications 16:464-478.

Zahawi, R.A. 2005. Establishment and growth of living fence species: an overlooked tool for the restoration of degraded areas in the tropics. Restoration Ecology 13:92-102.

Zahawi, R.A. and C.K. Augspurger. 1999. Early plant succession in abandoned pastures in Ecuador. Biotropica 31:540-552.