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Global change poses a strong challenge to ecologists, environmental scientists, and conservation biologists: even as our natural and managed ecosystems become more stressed by the forces of global change, humans require that they produce both a greater quantity and variety of ecosystem services. For instance, we may expect a forested ecosystem to produce timber, provide clean water, sequester carbon, support wildlife, and provide recreational opportunities, yet at the same time the forest community is being buffeted by climate change, invasive species, and land-use change. In order to ensure that our ecosystems provide the services society demands, we must be able to predict how ecological communities will respond to these global forces, and in turn how changes in community composition will affect ecosystem services. To develop this predictive framework, we employ a mix of observation, experimentation, modeling and synthesis, within a diverse array of biological communities.

Daniel E. Bunker, Principle Investigator

Current positions
Assistant Professor, Departments of Biology and Mathematical Sciences, NJIT
Graduate Faculty, Department of Biology, Rutgers-Newark
Graduate Faculty, Graduate Program in Ecology and Evolution, Rutgers-New Brunswick


433 Colton Hall
New Jersey Institute of Technology
University Heights
Newark, NJ 07102
Office: 973.642.7537
email: dbunker (at) njit (dot) edu
Web: NJIT TraitNet



Post Docs


Farshid Ahrestani

Ph.D.: 2009 Wageningen University, Netherlands

Research Interests

The emerging field of Ecoinformatics is the science of information in ecology that focuses on improving knowledge representation, and facilitating research, in the ecological domain with help of information technology. Areas of ecoinformatics research include: ontologies that clarify ecological semantics; interfacing between ontologies and databases; standardization of data collection and sharing; workflow systems that enables analyses on open-source distributed systems; and the discovery, access, interpretation, integration, and analysis of complex ecological data from highly distributed datasets.

I am currently working with TraitNet , a research coordination network that aims at improving ecological knowledge representation. A major goal of TraitNet is to develop an ecological ontology portal while focusing on a functional plant traits ontology. TraitNet is also involved in research of cross-disciplinary computational tools for merging, disseminating and sharing ecological data; coordinating the standardization of collection and sharing of trait data; and identifying trait data gaps.

My other research interests include foraging and population ecology of Asian large herbivores: how species of varying body size partition forage resources; the relative importance of dietary plant quantity and quality; the impact of the dominating spread of invasive plants on habitat suitability; determining vital life history traits; and population modeling. My scientific interests are closely aligned with my passion for nature conservation. I am also a member of IUCN's Asian Wild Cattle Specialist Group.





440 Colton Hall
(973) 642-7993
email: fa2260 (at) columbia (dot) edu
Web: NJIT TraitNet Columbia University

Grad Students


Caroline DeVan

Research Interests

Pollination ecology and urban ecology

440 Colton Hall
(973) 642-7993
email: cmd26 (at) njit (dot) edu

Sean Fan

Research Interests

Impacts of deer herbivory on plant resistance traits

440 Colton Hall
(973) 642-7993
email: xf24 (at) njit (dot) edu


PhD Rotations


Kimberly Plank

Research interests

Plant-plant interactions have many implications for restoration and in combating invasive species. I am interested in investigating mechanisms to better understand plant coexistence, specifically focusing on classes of plant secondary metabolites that cause chemical interference, known as allelochemicals. Allelochemicals can be volatilized, exuded, or simply present in plant biomass, later expressing toxic effects in decomposing litter. In root-root interactions , allelochemicals have to been shown to function to inhibit seed germination, growth, membrane permeability, ion uptake, nutrient uptake, stomatal opening, photosynthesis, respiration, enzyme activity, and cell division. Further, as we know from classic coevolutionary arms races, some plants have evolved rebuttals to phytotoxins, notably possible is polyphenol oxidase, an enzyme catalyzing the oxidation of phenolic compounds, commonly cited as allelochemical compounds (Holzapfel et al 2010). My research aims to identify mechanisms of allelopathy in plant-plant rhizosphere interactions.

Rotation Project: TBA


Anthony Brusa

Research interests

Rotation Project: Development of algorithms to process hemispherical photos for light gap analysis.







Mihir Sanghavi


Mihir is a Computer Science major working on developing the database registry project for TraitNet



Cailin O' Connor Fitzpatrick

Timothy Blockus

Undergrad/Field assistant/UBM Independent Project

Tim worked on the trade-offs project, the deer project, and the urban pollination project. Tim independently researched plant phenolics and plant traits as part of the NJIT UBM program.


Sowmya Thanigaivelu

Masters student/Independent project

Plant traits and urban pollution.


Dominic Evangelista

Undergrad/Field assistant

Dominic worked on the deer project, and the urban pollination project.



Aditya Maddala

Masters student/Field assistant

Aditya assisted on the trade-offs project and general lab maintenance.

Post Docs
We have lots of opportunities for post docs in the lab. I am happy to work with potential post docs to identify and pursue funding sources to support research in my lab. wood stortk
We are always looking for talented undergrads. Opportunities include independent research, research through the NJIT Undergraduate Biology and Math Training Program (UBMTP), or as lab and field technicians. Come by the lab (440 Colton) or drop us an email to learn more!
Graduate students

I am always looking for excellent graduate students. While experience and grades do matter, I am more interested in students that are smart, creative, and motivated. Earning a Ph.D. requires many years of hard, focused work. Prospective students should understand that it is a major, full time commitment.

As an advisor, I strive to enable my students to become independent as rapidly as possible. To that end I encourage my students to develop their own research programs and to compete for independent support right away. While I do expect substantial overlap in the theory and systems with which we work, I am eager to identify potential students that can bring complimentary skills to the lab and with whom I can develop productive collaborations.

Students interested in plant-herbivore interactions (impacts of deer on forest understories), the effects of life history tradeoffs on plant community assembly, and urban ecology are particularly encouraged to apply.

In addition to our small but growing Ecology and Evolution group in the Federated Department of Biology at Rutgers-Newark and NJIT, we are also affiliated with the Department of Ecology, Evolution, and Natural Resources at Rutgers-New Brunswick. Students at NJIT can seemlessly cross register for courses at all three campuses. Details on applying to the graduate program can be found here.

NJIT has outstanding faculty and resources in Mathematics and Computer Science, including the Center for Applied Mathematics and Statistics and a Ph.D. program in Applied Mathematics including Mathematical Biology. NJIT is particularly well suited to prospective students with interests in computational approaches to problems in Ecology and Evolution.

If you are interested in joining my lab for grad school, send me an email and let's chat. I encourage any prospective students to begin the process early, researching graduate programs and potential advisors, and contacting advisors and progarms early in the process.

Advice for grad students (and others)

Grad school is a strenuous and even arduous journey. The rewards are great, but serious work and perseverance are required.

Below are some resources to help get you started in the right direction and keep you on task to thi finish.


Bunker Lab Welocme and Contract - An overview of what you can expect from me as your advisor and what I will expect from you.

Grad student advice from Steve Stearns - A timeless bit of modest advice

Reply to Stearns by Ray Huey - An acynical reply


Cavity nesting bees, their floral resources, and their cletpoparasites

Cavity nesting bees such as Osmia spp are common in forested ecosystems. These bees are solitary and nest in naturally occuring cavities. Osima readily nest in wooden nest boxes placed in the forest. Osimia pollinate many tree and shrub species and are important pollinators of many orchard crops. We are investigating trophic dynamics among these insect pollinators, their floral hosts, and a variety of cleptoparasites (primarily bees, wasps, and beetles) that lay their eggs on the brood provisions that Osmia prepare for their own offspring. In addition, we are investigating impacts of deer herbivory on understory wildflower populations and pursuant impacts on bees and their parasites


Species traits and ecoinformatics
TraitNet Icon

TraitNet, a research coordination network and biological database designed to foster the systematic collection and dissemination of species trait data

Ideally, ecologists eventually will be able to predict many aspects of community interactions and ecosystem functioning from species traits.

However, we have found that species trait data are at best widely scattered throughout the literature and at worse simply nonexistent. Many other types of data are currently online, including community composition data (e.g., VegBank, CTFS), the phylogenetic relationships of species (e.g., Tree of Life, Phylocom, TreeBASE), and the genetic sequences of species (e.g., GenBank). Yet, in spite of the fact that trait measurements are critical to much ecological and evolutionary research, we know relatively little about species traits.

In response, Shahid Naeem and I are implementing an NSF Research Coordination Network and online database designed to bring together researchers who utilize species traits as a tool for myriad and diverse research efforts. The goal of TraitNet is to build an ecoinformatics backbone that will enable seamless data contributions to a fully searchable, geo-referenced database. This database will allow species trait data to be discovered and shared while protecting the intellectual property rights of data contributors. The network includes more than 40 founding participants, including ecologists and evolutionary biologists as well as ecoinformatics specialists and computer scientists. We believe that species traits are a critical compliment to community, phylogenetic and genetic data, and that TraitNet will foster substantial research that would be otherwise unattainable.

More info on the TraitNet Website


Data Schema

Deer herbivory and forest community composition

Generalist herbivores such as White-Tailed Deer impact plant communities by differentially foraging on particular tree and shrub seedlings and saplings. The deer project is aimed at identifying specific tree and shrub traits that predict which species will be most strongly affected by deer herbivory and how those differences in turn determine the effects of deer on forest understory species composition

Global change, tree species composition and ecosystem function in tropical forests

In collaboration with Shahid Naeem, Fabrice DeClerk and several other BioMERGE participants, I have been working to quantify the effects of tree species extinctions on ecosystem function. Prior efforts to quantify the effect of biodiversity on ecosystem function have used small-scale experiments in relatively simple systems and have also assumed random extinctions. However, most biological systems are far more complex and less amenable to wholesale manipulation, and species' responses will differ among extinction drivers. To evaluate the effects of tree species loss on carbon storage, we simulated several extinction scenarios within a diverse, well-studied tropical forest, and quantified the effects on above-ground carbon storage. We demonstrated that both the magnitude and variability of carbon storage differed greatly between global drivers of extinction such as fragmentation or climate change. We currently are elaborating on this approach by developing more mechanistic models of both extinction risk and ecosystem function.

Because this approach requires substantial species trait data, I have recently begun working with the Species Traits Working Group at the Center for Tropical Forest Science, led by Joe Wright of the Smithsonian Tropical Research Institute, to collect species trait data from the 18 large forest dynamics plots maintained by CTFS.

BEF flowchart
Land-use change and neotropical dung beetle communities
In collaboration with Elizabeth Nichols, Sacha Spector of the American Museum of Natural History, as well as numerous data contributors, I am working to quantify the effects of land use change on dung beetle communities and the ensuing effects on ecosystem function. Dung beetles perform several important ecosystem functions - in addition to dung removal, dung beetles recycle nutrients, disperse seeds, and suppress both flies and pathogens. Dung beetles are also highly diverse and respond differentially to land use change. Utilizing samples of dung beetle community composition collected across seven levels of land use intensity, including intact forest, secondary forests, clear cuts and pasture , we are identifying the traits that predispose dung beetle species to population declines. We also are independently building models of species' contributions to functioning via their functional traits. When combined, we will be able to assess broadly the effects of land use change on a suite of important ecosystem functions.
Dung Beetle
Functional diversity quantified by convex hull volume
Ecosystems perform numerous functions and provide a wide variety of services.  Maximizing the range and magnitude of functions and services requires that communities fill all available niches.  We combine ideas about functional diversity with those of habitat filtering to quantify the proportion of trait space occupied by a given set of species.  Advancing prior work using convex hulls, we employ a hulls-within-hulls approach that sums intraspecific hulls, and thus trait space, as a proportion of the total available trait space (the total hull volume of intact communities or of the candidate species pool).  We find that while a reduced set of species may fill the available functional trait space, this may come at the price of both reduced redundancy and limited ability to respond to environmental change. 

Convex hulls

Click to animate

Identifying the mechanisms of invasive species success and biological control
For much of my dissertation work, I focused on testing the ability of three competing theories of plant competition to predict invasions and biological control. While many researchers have assumed that species successfully invade because escape from natural enemies has made them better resource competitors than the natives they displace, this assumption has never been tested rigorously in the field. Community ecology offers several models of plant competition that may predict invasions and biocontrol success, including Tilman's resource competition model, Goldberg's response to resource availability model, and the plant size model advocated by both Miller and Keddy. All three offer trait-based measures that, in theory, predict competitive ability and thus the invasive potential of an exotic species. In addition, all three models predict that a biocontrol agent (e.g., an insect herbivore) will succeed, short of killing its host outright, only by reducing the competitive ability of its host, for instance by limiting the invader's ability to reduce resource availability to lower levels than its native competitors.
I have been testing these theories experimentally, in collaboration with Walter Carson, with the widespread invasive, Purple Loosestrife, its native competitor, Broad-leaved Cattail, and Galerucella calmariensis, a leaf-feeding beetle widely released in an effort to biologically control purple loosestrife. Our results suggest loosestrife is able to invade cattail through competition for light and possibly soil nitrogen. However, loosestrife also appears to facilitate cattail by allowing cattail to escape its insect herbivores. The mechanism of this facilitation could be either simple density dependent predation or 'apparent facilitation,' whereby cattail's insect herbivores share a predator with loosestrife's herbivores. Although I have completed my dissertation, I am continuing these long-term experiments as we seek definitive competitive outcomes as well as the mechanisms responsible for the facilitation of cattail by loosestrife.





Modeling competition for light among terrestrial plants
Resource competition theory was originally modeled under the assumption that resources, such as soil nitrogen, are distributed homogenously. However, many species compete primarily for light. Because light is directional and declines in availability with depth in a canopy, no single measure of light availability, for instance at the soil surface, adequately describes a species' ability to compete for light. To address this limitation, I have developed, in collaboration with Scott Stark and Walter Carson, a model of competition for light that makes no assumptions about the vertical foliage distribution of competing species, and thus can be applied to real-world species such as loosestrife and cattail. In addition, our model allows for the direct inclusion of effects such as herbivory and leaf litter on competitive dynamics.
cortoon plants


  • Nichols, E., Uriarte, M., Bunker, D. E., Louzada, J. N.C, Larsen, T., Vaz de Mello, F., Vulinec, K., Favila, M., Slade, E., Naeem, S., Spector, S. H. (in review) Trait-dependent response of dung beetle populations to tropical forest conversion at local to global scales. Ecology Letters.
  • Perrings, C., Naeem, S., Ahrestani, F., Bunker, D. E., Burkill, P., Canziana, G., Elmqvist, T., Ferrati, R., Fuhrman, J., Jaksic, F., Kawabata, Z., Kinzig, A., Mace, G., Milano, F., Mooney, H., Prieur Richard, A.-H., Tschirhart, J., Weisser, W. (2011). Ecosystem services, targets, and indicators for the conservation and sustainable use of biodiversity. Frontiers in Ecology and the Environment, 9(9), 512-520. doi: 10.1890/100212
  • Kattge, J., … Bunker, D. E., et al. (2011). TRY – a global database of plant traits. Global Change Biology, 17(9), 2905-2935. doi: 10.1111/j.1365-2486.2011.02451.x
  • Lin, B. B., Flynn, D. F.B., Bunker, D. E., Uriarte, M., Naeem, S. (2011). The effect of agricultural diversity and crop choice on functional capacity change in grassland conversions. Journal of Applied Ecology, 48, 609–618. DOI: 10.1111/j.1365-2664.2010.01944.x
  • Hovick, S. M., Bunker, D. E., Peterson, C. J., Carson, W. P. (2011). Purple loosestrife suppresses plant species colonization far more than broad-leaved cattail: experimental evidence with plant community implications. Journal of Ecology, 99, 225-234. doi: 10.1111/j.1365-2745.2010.01754.x
  • Wright, S. J., Kitajima, K., Kraft, N., Reich, P., Wright, I., Bunker, D. E., Condit, R., Dalling, J., Davies, S., Diaz, S., Engelbrecht, B., Harms, K., Hubbell, S., Marks, C., Ruiz-Jaen, M., Salvador, C., Zanne, A. (2010). Functional traits and the growth-mortality tradeoff in tropical trees. Ecology, 91(12), 3644-3674. doi: 10.1890/09-2335.1
  • Perrings, C., Naeem, S., Ahrestani, F., Bunker, D. E., Burkill, P., Canziana, G., Elmqvist, T., Ferrati, R., Fuhrman, J., Jasic, F., Kawabata, Z., Kinzig, A., Mace, G., Milano, F., Mooney', H., Prieur Richard, A.-H., Tschirhart, J., Weisser, W. (2010). Letter to the editor – Response. Biodiversity Transcends Services. Science, 330(6002), 324-324. http://www.sciencemag.org/content/330/6012/1745.full
  • Perrings, C., Naeem, S., Ahrestani, F., Bunker, D. E., Burkill, P., Canziana, G., Elmqvist, T., Ferrati, R., Fuhrman, J., Jaksic, F., Kawabata, Z., Kinzig, A., Mace, G., Milano, F., Mooney, H., Prieur Richard, A.-H., Tschirhart, J., Weisser, W. (2010). Ecosystem Services for 2020. Science, 330(6002), 324-324. http://www.sciencemag.org/cgi/content/full/330/6002/323
  • Perrings, C., Naeem, S., Ahrestani, F., Bunker, D. E., Burkill, P., Canziana, G., Elmqvist, T., Ferrati, R., Fuhrman, J., Jaksic, F., Kawabata, Z., Kinzig, A., Mace, G., Milano, F., Mooney, H., Prieur Richard, A.-H., Tschirhart, J., Weisser, W. (2010). Ecosystem services and target-setting for the conservation and sustainable use of biodiversity. Nairobi: Ecosystem Services Economics, United Nations Environment Program.
  • Carson, W., Hovick, S., Baumert, A., Bunker, D. E., Pendergast, T. (2008). Evaluating the post-release efficacy of invasive plant biocontrol by insects: A comprehensive approach. Arthropod-Plant Interactions, 2(2), 77-86.
  • Bunker, D.E., and S. Naeem.  2006.  Species diversity and ecosystem functioning. Letter to the editor in Science. 312: 846-847. PDF
  • Stark, S.C., D.E. Bunker, and W.P. Carson. 2006. A null model of exotic plant diversity tested with exotic and native species-area relationships. Ecology Letters. PDF
  • Bunker, D.E., F. DeClerck, J.C. Bradford, R.K. Colwell, I. Perfecto,O. L. Phillips, M. Sankaran and S. Naeem. 2005. Species Loss and Above-ground Carbon Storage in a Tropical Forest. Science 310:1029-1031. PDF and the Supplement
  • Bunker, D.E., and W.P. Carson. 2005. Drought stress and tropical forest woody seedlings: effect on community structure and composition. Journal of Ecology. 93: 794-806. PDF
  • Stevens, M.H.H, D.E. Bunker, S. Schnitzer, and W.P. Carson. 2004. Establishment limitation reduces species recruitment and species richness as soil resources rise. Journal of Ecology. 92: 339-347. PDF
  • Stevens, M., Z.T. Long, S.A. Schnitzer, D.E. Bunker, R. Collins, A. Bledsoe, W.P. Carson. 2003. Testing Ecological Theory - Lab manual for Ecology Laboratory. University of Pittsburgh. Pittsburgh, PA. PDF not available
  • D'Arrigo, R.D., C.M. Malmstrom, G.C. Jacoby, S.O. Los and D.E. Bunker. 2001. Correlation between maximum latewood density of annual tree rings and NDVI based estimates of forest productivity. International Journal of Remote Sensing. 21: 2329-2336. PDF
  • Yamaguchi, D.K., B.F. Atwater, D.E. Bunker, B.E. Benson, and M.S. Reid. 1997. Tree-ring dating the 1700 Cascadia earthquake. Nature 389: (6654) 922-923. PDF
  • Jacoby, G.C., D.E. Bunker, B.E. Benson. 1997. Tree-ring evidence for an AD 1700 Cascadia earthquake in Washington and northern Oregon. Geology 25: (11) 999-1002. PDF
  • Naeem, S., D.E. Bunker, A. Hector, M. Loreau and C. Perrings, editors. In press. 2009. Biodiversity, Ecosystem Functioning, and Human Wellbeing: An Ecological and Economic Perspective. Oxford University Press, Oxford. --> OUP website
  • Naeem, S., D.E. Bunker, A. Hector, M. Loreau, and C. Perrings. In press. 2009. The ecological and social implications of changing biodiversity: An overview of a decade of biodiversity and ecosystem functioning research. In Naeem, et al., editors. Biodiversity, Ecosystem Functioning, and Human Wellbeing: An Ecological and Economic Perspective. Oxford University Press, Oxford.
  • Solan, M., J. Godbold, D.F.B. Flynn, A. Symstad, and D.E. Bunker. Biodiversity-ecosystem function research and biodiversity futures: Early bird catches the worm or a day late and a dollar short? In press. 2009. In Naeem, et al., editors. Biodiversity, Ecosystem Functioning, and Human Wellbeing: An Ecological and Economic Perspective. Oxford University Press, Oxford.
  • Engelhardt, K., A. Symstad, A. Prieur-Richard, M. Thomas, and D.E. Bunker. In press. 2009. Opening communities to colonization –The impacts of invaders on biodiversity and ecosystem functioning. In Naeem, et al., editors. Biodiversity, Ecosystem Functioning, and Human Wellbeing: An Ecological and Economic Perspective. Oxford University Press, Oxford.
  • Naeem, S., and D.E. Bunker. In press. 2009. TraitNet: Furthering biodiversity research through the curation, discovery, and sharing of species trait data. In Naeem, et al., editors. Biodiversity, Ecosystem Functioning, and Human Wellbeing: An Ecological and Economic Perspective. Oxford University Press, Oxford.
  • Naeem, S., D.E. Bunker, A. Hector, M. Loreau, and C. Perrings. In press. 2009. Can we predict the effects of global change on biodiversity loss and ecosystem functioning? In Naeem, et al., editors. Biodiversity, Ecosystem Functioning, and Human Wellbeing: An Ecological and Economic Perspective. Oxford University Press, Oxford.

R Tutorial

Click on the streencast below to view an introductory tutorial on R, a language and environment for statistical computing and graphics

Download the data files (.csv) and the R script (.R) to a single directory to follow along on your own machine.

R Tutorial ScreenCast

R script for PC

R scrip for mac

Species trait file

Species abundance file

Environmental file


Daniel E. Bunker

433 Colton Hall
Department of Biological Sciences

New Jersey Institute of Technology
University Heights
Newark, NJ 07102

Office: 973.642.7537
Lab: 973.642.7993
email: dbunker (at) njit (dot) edu

Web: NJIT TraitNet