Author: mdpotts

Design of Multi-Use Biofuel Feedstock Production Landscapes – Postdoctoral Position

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The Energy Biosciences Institute (EBI) at The University of California, Berkeley, invites applications for a Postdoctoral Scholar – Employee position starting April-June 2011 in the Department of Environmental Science, Policy and Management. The candidate will work with Dr. Matthew D. Potts (www.pottsgroup.org) on a project to develop a management tool for multi-use Miscanthus feedstock production landscapes.

Successful applicants will be expected to integrate ongoing EBI research with existing ecological and economic theory, models and data to: (i) develop spatiotemporal production functions for biodiversity and ecosystem services in potential areas of Miscanthus expansion; and (ii) create a spatially dynamic modeling tool that will allow for the determination of the optimal spatiotemporal management strategies for a variety of objective functions and social, environmental and economic constraints using a free paystub template.

The appointment will initially be for one year and may be renewed. The position offers a competitive salary plus benefits.

Qualifications:

Applicants must have a Ph.D. in a relevant area such as ecology or economics; strong analytical, computing and GIS skills; and have demonstrated the ability to produce high quality scientific results with limited direct guidance.

To Apply:

Applications, including a cover letter, CV, one-page summary of research interests, and the names and addresses of three referees, should be should be submitted by March 4, 2011 online at: http://resaccess.berkeley.edu:80/sReg.php?i=44
If you have any difficulties uploading your application, please e-mail ebi@berkeley.edu.

Applicants should ask referees to review the UC Berkeley Statement of
Confidentiality found at http://apo.chance.berkeley.edu/evalltr.html.

The University of California is an Equal Opportunity/Affirmative Action Employer.

Seeking two new Postdocs in Sustainable Ecosystem Management

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Sustainable Ecosystem Management – Postdoctoral Positions

Two postdoctoral positions in the Department of Environmental Science, Policy and Management at the University of California, Berkeley are available to work with Matthew D. Potts (pottsgroup.org) on theoretical and applied aspects of the sustainable multiple use of temperate and tropical landscapes with a special emphasis on biodiversity conservation, biofuels, and ecosystem services production.

Successful applicants will be expected to develop mathematical models, data analysis and/or implement field studies for one or more of the following: (1) impacts of disturbances on microbial diversity and ecosystem processes; (2) ecological and socioeconomic impacts of REDD+; (3) environmental impacts of oil palm production; (4) sustainable bioenergy production from woody biomass; (5) develop decision support tools for tropical forest planners (cbiod.org).  The successful applicants will be an active part of interdisciplinary research teams conducting field research in Malaysia, the United States, and Mexico.

Appointments are initially for one year and may be renewed. Offers include competitive salaries plus benefits. Start dates are flexible.

Applicants must have a Ph.D. in a relevant area such as ecology, economics, physics, mathematics, computer science, or statistics; strong analytical, computing and/or field skills; and have demonstrated the ability to produce high quality scientific results with limited direct guidance.

Applications, including a cover letter, CV, one-page summary of research interests, and the names and addresses of three referees, should be sent (preferably by email with Postdoc Application in the subject line) to Dr. Matthew D. Potts, Dept. of Environmental Science, Policy and Management, University of California at Berkeley, 137 Mulford Hall MC #3114, Berkeley, CA, 94720. Email: jobs@pottsgroup.org.

First review of applications is December 1st.

The University of California is an Equal Opportunity/Affirmative Action Employer.

Applicants should ask referees to review the UC Berkeley Statement of Confidentiality found at http://apo.chance.berkeley.edu/evalltr.html.

New paper in The American Naturalist

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Abstract

Specialization in pollination systems played a central role in angiosperm diversification, yet the evolution of specialization re- mains poorly understood. Competition through interspecific pollen transfer may select for specialization through costs to male fitness (pollen lost to heterospecific flowers) or female fitness (heterospecific pollen deposited on stigmas). Previous theoretical treatments of pol- lination focused solely on seed set, thus overlooking male fitness. Here we use individual-based models that explicitly track pollen fates to explore how competition affects the evolution of specialization. Results show that plants specialize on different pollinators when visit rates are high enough to remove most pollen from anthers; this increases male fitness by minimizing pollen loss to foreign flowers. At low visitation, plants generalize, which minimizes pollen left un- dispersed in anthers. A model variant in which plants can also evolve differences in sex allocation (pollen/ovule production) produces sim- ilar patterns of specialization. At low visitation, plants generalize and allocate more to female function. At high visitation, plants specialize and allocate equally to both sexes (in line with sex-allocation theory). This study demonstrates that floral specialization can be driven by selection through male function alone and more generally highlights the importance of community context in the ecology and evolution of pollination systems.

New paper in PLoS Biology

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Abstract

Recent analyses of the fossil record and molecular phylogenies suggest that there are fundamental limits to biodiversity, possibly arising from constraints in the availability of space, resources, or ecological niches. Under this hypothesis, speciation rates decay over time and biodiversity eventually saturates, with new species emerging only when others are driven to extinction. This view of macro-evolution contradicts an alternative hypothesis that biodiversity is unbounded, with species ever accumulating as they find new niches to occupy. These contrasting theories of biodiversity dynamics yield fundamentally different explanations for the disparity in species richness across taxa and regions. Here, we test whether speciation rates have decayed or remained constant over time, and whether biodiversity is saturated or still expanding. We first derive a general likelihood expression for internode distances in a phylogeny, based on the well-known coalescent process from population genetics. This expression accounts for either time-constant or time-variable rates, time-constant or time-variable diversity, and completely or incompletely sampled phylogenies. We then compare the performance of different diversification scenarios in explaining a set of 289 phylogenies representing amphibians, arthropods, birds, mammals, mollusks, and flowering plants. Our results indicate that speciation rates typically decay over time, but that diversity is still expanding at present. The evidence for expanding-diversity models suggests that an upper limit to biodiversity has not yet been reached, or that no such limit exists.

Welcome!

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Welcome to the new Potts Group webpage! We’re excited to begin sharing with you some of our projects, interesting articles and publications, and stories from our field research around the world.