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| Daniel E. Bunker |
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Post-Doctoral Research Scientist
Columbia University
Department of Ecology, Evolution and Environmental Biology
R. 1021 Schermerhorn Extension
1200 Amsterdam Avenue
New York, NY 10027-5557
Phone: 212-854-9881
Fax: 212-854-8188 fax
Email: deb37@columbia.edu
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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, I employ a mix of observation, experimentation, modeling and synthesis, within a diverse array of biological communities.
Active research areas include:
- Global change and ecosystem services:
. Tropical forests and carbon storage
. Nitrogen retention at Cedar Creek
. Neotropical dung beetles, nutrient cycling, seed dispersal and
disease suppression
- Invasive species and biological control
- Competition for light
- Biodiversity and ecosystem function
- Species traits and ecoinformatics |
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| Brenda Lin |
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Research Fellow
Earth Institute at Columbia University
Center for Environmental Research and Conservation
B-16 Hogan Hall
2910 Broadway, MC 3277
New York, NY 10025
Phone: (212) 851-1882
Fax: (212) 854-6309
Email: bl2249@columbia.edu |
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My research primarily looks at the effect of anthropogenic disturbance on natural systems and the subsequent effect of disturbance on ecosystem services within degraded natural ecosystems. Because many societies are inextricably linked to a healthy environment for their livelihoods, the loss of ecosystem services can cause a severe disruption within societal systems as well. Currently, there is a lack of understanding of the ecosystem qualities necessary to maintain certain ecosystem services. Much of my work has concentrated on understanding the ecosystem dynamics that maintain ecosystem services within human dominated landscapes.
My dissertation research investigated various aspects of natural systems agriculture and the effect of management intensity on abiotic and biotic factors important to the overall production success of the crop. Most recently, I have been researching the ability of shaded coffee agroecosystems in Southern Mexico to protect coffee plant production from climate variation and extremes associated with climate change. The results from my work showed that more shade coffee agroforestry systems were capable of mitigating the effects of climate variation on the coffee plant. First, the shaded systems mitigated the variation of microclimate near the crop plant so that the crop plant stayed closer to its ideal temperature and humidity in the shaded systems. This in turn reduced the amount of water lost through evapotranspiration because of lowered VPD in the system. The resulting effect of increased soil moisture allowed for better flowering and fruiting potential of the crop plant in the shaded systems.
Presently, I am researching how differences in management intensity may affect the resilience of agricultural systems to extreme climate events, such as hurricanes. In the same area where I was researching the differences in microclimate and soil moisture among coffee farms, a hurricane passed through in October 2005 causing large-scale damage throughout Southern Mexico and Guatemala. This offered researchers working in this area an opportunity to pool their ecosystem knowledge of pre-hurricane systems to compare with the ecosystem changes post-hurricane. Research of hurricane damage and agroecosystem resilience to extreme climate events will be more important as hurricanes become stronger and more frequent. This type of research can help inform farmers of the types of farming systems that can be implemented in order to protect their crops from damage in case of extreme events.
During to my fellowship with the Earth Institute, I have also begun various projects with a more interdisciplinary scope. First, I will use crop modeling to study the effect of different climate scenarios on the success of the maize crop. I hope to accomplish this in the area of Northeast Brazil, where the farmers are dependent on the seasonal patterns of precipitation for the production of maize. I am also working with other researchers to gain a better understanding of how natural biodiversity and agro-biodiversity may affect nutritional health and societal well-being of villages within the Millennium Village Project. This project will also investigate the scope of diversity on ecosystem services within the villages and the social cost of losing such services. |
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| Liza S. Comita |
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Postdoctoral Research Scientist
Columbia University,
Department of Ecology, Evolution and Environmental Biology
1200 Amsterdam Avenue
New York, NY 10027-5557
Phone: 212-854-8253
Fax: 212-854-8188
Email: lsc2125@columbia.edu
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I am broadly interested in patterns of diversity, dynamics, and species distributions in both pristine and human-altered tropical forests. My current research focuses on the regeneration ecology of tropical tree species and how spatial and temporal variation in seedling dynamics act to maintain diversity and determine species composition in tropical forests. Seedling recruitment, growth and survival are among the most critical demographic rates driving forest regeneration following human or natural disturbance. Nevertheless, determinants of tropical seedling dynamics and the relative importance and interactions of various biotic and environmental drivers are not well understood, even in undisturbed forests.
My current postdoctoral research focuses on how forests regenerate following large natural disturbances, namely hurricanes, and how regeneration pathways and post-disturbance community composition change as a result of human alterations to landscapes. For this project, I am utilizing a 15-year record of tree and seedling dynamics in the 16-ha Luquillo Forest Dynamics Plot in the Luquillo mountains of northeastern Puerto Rico. The plot encompasses areas of differing intensities of past human disturbance. In addition, the region has been hit by two major hurricanes since 1989. Thus, the site provides an excellent opportunity to study forest regeneration and community stability following large-scale natural and human disturbance. I am currently analyzing patterns of seedling dynamics to assess shifts in the relative importance of land-use history, biotic interactions (e.g., competition, herbivory), and abiotic variables (e.g., light, soil resources) as the forest recovers from hurricane damage. Analyses of this forest plot will be used to predict the future of this forest and will have implications for forests throughout the tropics that will likely experience increases in hurricane disturbance and human impacts in the coming decades.
Past and ongoing research projects include:
-Long-term dynamics of the seedling layer on Barro Colorado Island, Panama
-Cross-site comparisons of tropical forest dynamics
-Effects of spatial and temporal variation in water availability on tropical tree species distributions
-Impacts of long-term research on vegetation dynamics and composition
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| Eleni Nikitipoulos |
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Research Fellow
Columbia University,
Department of Ecology, Evolution and Environmental Biology
R. 609 Schermerhorn
1200 Amsterdam Avenue
New York, NY 10027-5557
Phone: 212-854-9707
Fax: 212-854-8188
Email: en2142@columbia.edu
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I study socio-sexual behavior in non-human primates. As a behavioral ecologist, I am interested in how behavior functions to impact an individual’s direct and indirect fitness. In order to understand social and sexual interactions between individuals it is important to unravel processes in competition and cooperation. My particular fields of study include male and female sexual strategies, collective action and public goods, and cooperation between kin and between non-kin.
My dissertation work focused on female mating preferences and the effects of female sexual strategies on male-male competition. I empirically investigated how female copulation calls and mating preferences influenced male mating success in captive long-tailed macaques (Macaca fascicularis). Traditionally, females were thought to express mate choice by mating selectively with males. However, promiscuous females might exert choice through selection on male ejaculate after copulation. Furthermore, females might mate with multiple partners as a counterstrategy to infanticide by males or to avoid nonviable fertilizations. While promiscuous mating is notable in long-tailed macaques, the alpha male monopolizes copulations with females for at least a portion of the mating period. The proportion of paternity monopolized by the alpha male, however, depends on female cooperation with his mating efforts, female efforts to mate with other males, and the alpha male’s timing of monopolized copulations in relation to the female’s ovulation.
My current research project with Dr. Marina Cords investigates patterns of cooperative behavior in a wild guenon, Cercopithecus mitis, focusing on communal territory defense as a public good and pair-wise grooming as a private exchange. A public good is a behavioral service provided by one or more individuals that benefits the entire group, even group members who don’t participate in its provision. Collective action models offer an approach to investigate how distribution of benefits within a group motivates individual action and decreases cheating. Cheating occurs when individuals contribute less than their fair share toward the collective good, and a collective action problem arises if free-riding results in sub-optimal levels of the collective good. As a commodity, grooming offers hygienic and hedonic value. In the absence of within- and between-group competition, grooming can only be traded for itself and reciprocal grooming bouts are expected. When grooming can be traded for something else, shifts away from reciprocal exchange are expected.
Kin selection, reciprocal altruism, and mutualism have been identified as three major mechanisms that can bring about the evolution of cooperation, and each predicts characteristic patterns of interaction among social partners. In general, the degree to which individuals participate in cooperative activities through any of these mechanisms should reflect a positive balance of benefits minus costs. Predicting who cooperates and when is thus a matter of identifying and assessing those benefits and costs for potential cooperators. |
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