People in Vegetation Dynamics

Lab Director

Alan Taylor - aht1@psu.edu

Lab Director

·  Hometown: Berkeley, California

·  Distractions: Competitive trail riding, hiking, playing guitar, skiing

·  Education: Ph.D. (1987) Geography - University of Colorado, Boulder. M.Sc. (1979) Geography - Oregon State University, Corvallis. B.Sc. (1977) Geography - California State University, Hayward.

Reseach Associate
Soumaya Belmecheri - sub30@psu.edu

Belmecheri cores a tree

• Education: Ph.D. 2008 in geochemistry at the University of Paris XI-Orsay and the Laboratoire des Sciences du Climat et de l’Environement (LSCE).

• Projects:

Estimating Forest Productivity Over Regional and Multi-Decadal Time Scales Using Carbon Isotopes in Tree Rings (NSF-BCS) will test the δ13C relationship between CO2 fluxes and C sequestration. My role as co-PI will be to study the spatial coherence of δ13C from tree-rings collected at 10 forest-sites along a transect that stretches from Harvard Forest to Howland Forest and to develop a long-term δ13C chronology as as proxy for long term carbon sequestration.

Paleoclimate, Paleoenvironment and Other Potential Drivers of Extinction of Mammuthus primigenius, St. Paul Island, Pribilof Islands, Alaska (Arctic System Program). My role in this project as a co-PI is to develop a calibration of the δ18O and D/H for chironomids and  lake water (to account for a potential vital offset) and use the isotopes to reconstruct past precipitation and temperature during the Holocene. 

Do fuel treatments restore ecosystem function? Water use efficiency before and after fire suppression and fuels treatments in fire-prone pine forests in the western United States (USDA)

My role in this project as a co-PI is to use the δ13C from tree-rings to infer water use efficiency and use this proxy as a metric of ecosystem function from 1800 to 2012 at two FFS study sites (AZ, WA). 

 Georgian Ancient Transcaucasia: Environments and Societies (CNRS-France) I am currently working on the Javakheti Plateau in the republic of Georgia to characterize the impact of natural climate variations on the evolution of pre- and proto-historic societies in central Transcaucasia using lake sediments, with a special emphasis on the the transition Paleolithic-Neolithic between 15-8 ky B.P.

• Research Interests:

I am a broadly trained stable isotope geochemist with research interests in climate and environmental reconstructions from lake sediments and tree-rings. My approach is to develop quantitative proxies in an interdisciplinary collaborative setting. Proxy-derived data are essential to evaluate and calibrate climate and carbon cycle models and to improve their predictive ability. I am also involved with research based in the department of Anthropology at PSU to estimate ages and growth rates of tropical hardwood trees from Central America using calcium concentration in wood (measured with LA-ICPMS) which is a proxy of precipitation seasonality. We have tested this technique on both extant trees and structural wood from a Mayan temple.

 Current Students

Catherine Airey - cta5060@psu.edu

M.S. Candidate, Interdepartmental Graduate Program in Ecology

·  Education: BA, Biological Sciences, Northwestern University, Evanston, Illinois

·  Projects: I am working on a study of landscape fire severity patterns in the Cub Creek Research Natural Area of Lassen National Forest, California.

·  Research Interests: My interests include fire disturbance as an ecological process and how fire regime relates to community and species persistence and restoration. These interests have been most strongly shaped by conducting fieldwork and staffing fires in central Florida, the Florida panhandle, and California’s Sierra Nevada range.

Lucas Harris - lbh146@psu.edu

M.S. Candidate in Geography

·  Research Interests:  I am interested in vegetation change at both small and large spatial scales. Plant communities throughout the world are rapidly changing, but this change is complex and nonlinear.  New modeling techniques and improved understanding of interactions between vegetation and various biotic and abiotic factors make this an exciting time to study the dynamics and spatial distrubution of plants. My particular interests include climate change, species distribution modeling, and the impact of fire and other disturbances on plant communities.

Rachel Isaacs - ryi5016@psu.edu

Ph.D. Student in Geography (ABD)

·  Education: B.A. Geography, University of Hawai’i – Hilo, 2001; M.S. Geography, Texas A&M University – College Station, 2007

·  Research Interests: Biogeography, Landscape Ecology, GIS, Remote Sensing, Climate Change, DisturbanceThe focus of my current and past research has been on the analysis and mapping of topographic and biotic patterns of large-scale natural disturbance and climate change, using remote sensing, GIS, and statistics.  In particular, my Master’s thesis explored the spatial patterns of ice storm disturbance in the forested landscape of Ouachita National Forest, AR and OK.  Since that time, I have shifted my focus to examining the pattern and process of tree establishment and growth at “natural” or climate controlled treelines.  My current research incorporates dendroecological techniques and remote sensing to further capture the impacts of climate and local site conditions on alpine tree establishment and growth in Denali National Park and Preserve, Alaska.

Projects: Two recent research project collaborations included Mt. Rainier, WA (fire disturbed) and Denali, AK (undisturbed). I currently intend to explore alpine treeline responses to environmental change in Cairngorms National Park, Scotland, UK. In addition, I am also contributing to a project reconstructing pre-settlement forest structural patterns in the Lake Tahoe Basin, CA and NV.

Amanda B. Youngaby113@psu.edu

Ph.D. Student in Geography
• Education: M.S. (2008) Geography - Texas A&M University, College Station, TX.  B.A. (2003) Biology and Scandinavian Studies – Gustavus Adolphus College, Saint Peter, MN.
• Research Interests: Treeline Dynamics, Biogeography, Forest Ecology, Dendrochronology, Dendroarchaeology, Disturbance Ecology, Climate Change, Paleoclimatology
• Projects: My dissertation research focuses on high elevation deciduous treelines.  In particular I am using Bond’s (1989) slow seedling hypothesis as a framework to examine how angiosperms (deciduous) trees can dominate at treeline over gymnosperms (coniferous) trees in some high elevation forest systems.  This research is being conducted in the Northern Japanese Alps where both deciduous and coniferous trees form the subalpine forest.  In addition to my dissertation research I am working on a climate analysis of shrubs from Greenland and occasionally date historical structures from around Pennsylvania.   
• Hobbies: Ultimate Frisbee, Hiking, Backpacking, Cooking, and Botanizing

• Publications: Cairns, D., Lafon, C., Mouton, M., Stuteville, R., Young, A. B. and J. Moen. "Comparing two methods for aging trees with suppressed, diffuse-porous rings (Betula pubescens ssp. czerepanovii)."  Dendrochronologia. 30(4)252-256.