Difference between revisions of "Grad-Invited Seminar Nominations for 2009-2010"

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A 24,700-yr paleolimnological history from the Peruvian Andes
 
A 24,700-yr paleolimnological history from the Peruvian Andes
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Quaternary Research, Volume 71, Issue 1, January 2009, Pages 71-82
 
Quaternary Research, Volume 71, Issue 1, January 2009, Pages 71-82
 +
 
Rachel Hillyer, Bryan G. Valencia, Mark B. Bush, Miles R. Silman, Miriam Steinitz-Kannan
 
Rachel Hillyer, Bryan G. Valencia, Mark B. Bush, Miles R. Silman, Miriam Steinitz-Kannan
  
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(II) If on the other hand you are interested in climate change, here is one of Dr. Bush's publications:
 
(II) If on the other hand you are interested in climate change, here is one of Dr. Bush's publications:
 +
 
Fire, climate change and biodiversity in Amazonia: a Late-Holocene perspective
 
Fire, climate change and biodiversity in Amazonia: a Late-Holocene perspective
 +
 
Philosophical Transactions of the Royal Society B 363:1795-1802.
 
Philosophical Transactions of the Royal Society B 363:1795-1802.
 +
 
M.B. Bush, M.R. Silman, C. McMichael & S. Saatchi
 
M.B. Bush, M.R. Silman, C. McMichael & S. Saatchi
  

Revision as of 03:19, 5 February 2009

EEB Graduate Student Association

In order to nominate a speaker for the 2009-2010 Grad-Invited Seminar, create a section heading with that person's name and institution, along with links to their personal webpage, a blurb about their research, etc. See the page from last year for examples. Deadline for nominations will be February 10. Voting will follow, and the decision should be made sometime in February.


Todd Dawson, University of California, Berkeley

Todd Dawson is a Professor in the Integrative Biology Department at UCB, an adjunct Professor in the Environmental Science Policy and Management Department, and is also the Director for Stable Isotope Biogeochemistry at Berkeley. He has large and dynamic lab, with a wide variety of interests and specialties. Broadly, his research focuses on plant ecophysiology, or the interface between plants and their environments. He uses a broad scope of ecological tools, and looks at ecological systems from many perspectives- from the molecular level to the ecosystem level. His research has been instrumental in understanding hydraulic redistribution, and has shown interesting interactions between fog and coastal redwood trees (Sequoia sempervirens- the tallest trees on the planet!!!). He is also a very fun and lively speaker.

Here is a summary of his research interests from the UCB website: "Research in my laboratory focuses on the interface between plants and their environment. The tools of physiological and evolutionary plant ecology and stable isotope biogeochemistry are currently being applied towards the study and interpretation of this interface. Investigations draw upon a variety of physiological methods, modeling and the use of stable isotopes as avenues for improving our understanding of how the ecophysiological characteristics of plants are shaped by and respond to the environments they inhabit. Projects pay special attention to how aspects of plant form and function combine to permit adaptation to environmental variation, whether naturally or anthropogenically imposed, and how plants and their unique traits influence the structure and function of the communities and ecosystems they compose.

"Current research themes include (1) exploring how the ecological and physiological characteristics of plants influence community and ecosystem processes (e.g. how the water, carbon and nutrient relations of plants may influence ecosystem hydrology and biogeochemistry); (2) elucidating the functional evolution and origin of adaptations in plants particularly with regards to how tolerance to low soil nutrient status, periodic drought, or low light and disturbance arises and the importance of evolutionary history in the origins of these adaptations; and (3) examining at the fluxes and exchanges of materials such as carbon, water and nitrogen between organisms and their biotic and abiotic environments using novel stable isotope techniques, Such an approach is proving to be especially powerful in looking at the origin of CO2 from different ecosystems and the exchange of water and nitrogen between plants and their fungal symbionts (mycorrhiza & endophytes) or their neighbors."

Jim Clark, Duke University, Durham, NC

James S. Clark is H.L. Blomquist Professor of the Nicholas School of the Environment, Professor of Biology, and Professor of Statistics and Decision Science. *Clark's experience lies in Ecology of forests and grasslands. Statistics and population dynamics.* Clark’s research focuses on how global change affects forests. Current projects explore consequences of climate, CO2, and disturbance. His lab is using long-term experiments and monitoring studies to determine disturbance and climate controls on the dynamics of 20th century forests in combination with extensive modeling to forecast ecosystem change. Clark has authored over 120 refereed scientific articles and published four books, including Models for Ecological Data (Princeton, 2007), Models for Ecological Data in R (Princeton, 2007), Hierarchical Models of the Environment (Oxford, 2006), and Sediment Records of Biomass Burning and Global Change (Springer, 1997).


Mark Bush, Florida International University, Melbourne, FL

Dr. Mark Bush is a professor in the Biological Sciences department, whose focus is on paleoecology. His research focuses on paleoecology, applied ecology, biodiversity, plant community ecology, tropical forests, and conservation in tropical America.

Below is Dr. Bush's description of his research from the paleoecology lab website: "Successful conservation of tropical biodiversity requires that we understand the mechanisms controlling habitat and species distributions. Two potent forces induce changes in these distributions: climate change and human activities. My research uses paleoecology to understand the changing patterns of tropical biodiversity. Through the study of fossil pollen, diatoms and charcoal, we reconstruct the history of habitats in tropical South America. These paleoecological records allow us to reconstruct climate change over the last 200,000 years and relate it to patterns of biodiversity, speciation and human occupation. From these observations, we contribute to the current debate on global climate change and species conservation.

To gain these data, we must locate and visit ancient lakes in the neotropics. The lake sediments hold a history of the surrounding landscape since the formation of the lake. A core of those sediments provides us with a complete history of that location. We raise the cores using a backpackable coring rig. As many of these lakes lie in some of the most remote locations on Earth, the fieldwork is arduous and not for the faint-hearted. Although the coring is an important and exciting facet of our work, the great majority of our time is spent in intensive lab work counting and identifying the fossil pollen and statistically analyzing the resultant data.

Our study sites include Guatemala, Amazonia, the Andes of Peru and Ecuador, and the Galapagos Islands. Although spanning a large geographic area, the linking theme is in trying to understand how climatic events, such as El Niño-Southern Oscillation, and mega-droughts influenced natural and human communities. Our study of Lake Titicaca has provided a 340,000 year (four glacial cycles) record of climate changes and shows how changes in Earth’s orbit around the sun caused changes in climate. Our studies reveal that modern temperature change is happening 10–100 times faster than any parallel event of the last 50,000 years. These data raise serious questions about the ability of species to migrate to counteract current and future climatic change. Studies of younger lakes have provided the earliest documented corn cultivation in Amazonia, evidence of a sequence of megadroughts within the last 11,000 years, and the collapse of native societies at the time of European contact."


SELECTED PUBLICATIONS:

(I) If you are interested in explainatory factors for species distributions and speciation in the tropics, this publication may interest you:

A 24,700-yr paleolimnological history from the Peruvian Andes

Quaternary Research, Volume 71, Issue 1, January 2009, Pages 71-82

Rachel Hillyer, Bryan G. Valencia, Mark B. Bush, Miles R. Silman, Miriam Steinitz-Kannan

Abstract A new paleolimnological dataset from Lake Pacucha (13 °S, 3095 m elevation) in the Peruvian Andes provides evidence of changes in lake level over the past 24,700 yr. A late-glacial highstand in lake level gave way to an early-Holocene lowstand. This transition appears to have paralleled precessional changes that would have reduced insolation during the wet-season. The occurrence of benthic/salt-tolerant diatoms and CaCO3 deposition suggest that the lake had lost much of its volume by c. 10,000 cal yr BP. Pronounced Holocene oscillations in lake level included a second phase of low lake level and heightened volatility lasting from c. 8300 to 5000 cal yr BP. While a polymictic lake formed at c. 5000 cal yr BP. These relatively wet conditions were interrupted by a series of drier events, the most pronounced of which occurred at c. 750 cal yr BP. Paleolimnological changes in the Holocene were more rapid than those of either the last glacial maximum or the deglacial period


(II) If on the other hand you are interested in climate change, here is one of Dr. Bush's publications:

Fire, climate change and biodiversity in Amazonia: a Late-Holocene perspective

Philosophical Transactions of the Royal Society B 363:1795-1802.

M.B. Bush, M.R. Silman, C. McMichael & S. Saatchi

Abstract

Fire is an important and arguably unnatural component of many wet Amazonian and Andean forest systems. Soil charcoal has been used to infer widespread human use of landscapes prior to European Conquest. An analysis of Amazonian soil carbon records reveals that the records have distinct spatial and temporal patterns, suggesting that either fires were only set in moderately seasonal areas of Amazonia or that strongly seasonal and aseasonal areas are undersampled. Synthesizing data from 300 charcoal records, an age-frequency diagram reveals peaks of fire apparently coinciding with some periods of very strong El Niño activity. However, the El Niño record does not always provide an accurate prediction of fire timing, and a better match is found in the record of insolation minima. After the time of European contact, fires became much scarcer within Amazonia. In both the Amazonia and the Andes, modern fire pattern is strongly allied to human activity. On the flank of the Andes, forests that have never burned are being eroded by fire spreading downslope from grasslands. Species of these same forests are being forced to migrate upslope due to warming and will encounter a firm artificial fire boundary of human activity.

(III) If you are interested in the conservation and planning in light of the dynamic nature of tropical climates, check out:

Pdficon small.gif Bush, M.B. and Lovejoy, T.E. 2007. Amazonian conservation: pushing the limits of biogeographical knowledge. "Journal of Biogeography" 34: 1291-1293.