My research focuses on what might be called “biogeochemical ecology,” asking questions about how climate interacts with plant physiology, demography, and ecological processes to influence or control biogeochemical cycling from local to global scales. Just one example of the need for more complete understanding in this area is the lack of species interactions in modern global climate models, even though such interactions can be critically important in controlling ecosystem carbon cycling and hence, feedbacks to climate. Progress has been limited by the difficulty of bridging the gap between local-scale ecological interactions and broader biogeochemical processes. I use multidisciplinary approaches that combine classical techniques of field ecology and forestry with advanced technological methods (e.g., the micrometeorological eddy covariance method, isotopic techniques) and modeling to integrate biogeochemical processes to ecosystem scales. Current CV
Richard “Rick” Wehr
I am a Research Scientist in the Saleska Lab, studying biosphere-atmosphere gas exchange and how it derives from biological processes and physical transport mechanisms in ecosystems. Currently I am focused on methane emissions from arctic peatlands (using isotopic gas measurements to study the subsurface chemistry and transport that underlies those emissions), and on carbon uptake by temperate and tropical forests (using the forest-atmosphere exchange of CO2 isotopologues to study whole-forest photosynthesis and respiration). I have also worked on temperate forest stomatal conductance and transpiration (probed using carbonyl sulfide uptake), tropical forest photosynthetic seasonality, and eddy covariance methodology. I began working in ecology and biogeochemistry after a doctorate in atmospheric physics at the University of Toronto, which informs the approaches I use.
I’m currently a post-doc researcher in Saleska lab. I am broadly interested in understanding the ecological process underlying plant co-existence and niche partitioning in high diverse tropical ecosystem. My research focuses describing plant water use strategies and how do plants cope with extreme drought in Amazon forest in Brazil. Actually, my research goal is to understanding how plant hydraulic traits plasticity affect species survive in water limited ecosystem. I seek to understanding how plants change they physiology along they ontogeny as the individuals change the hydrological niche defining by changes in vapor pressure deficit in vertical forest structure; and seasonal changes soil water moisture in vertical soil profile.
I study how leaf-level light environment affects leaf demography and phenology in the Amazon forest. My research is particularly focused on the relationship between leaf traits, leaf demography, and light environment across spatial and temporal scales. I am broadly interested in the question of how functional traits can be used to improve our understanding of the scaling relationships between leaf, tree, and landscape level ecological processes, and the use of near-remote sensing (e.g. tower mounted cameras) to understand tropical forest phenology patterns. I also specialize in adapting climbing techniques from my rock and industrial climbing experience to enable new canopy research methods.
I am currently a PhD candidate in the Saleska lab. I am broadly interested in understanding the role of organisms and biodiversity in driving biogeochemical cycles, particularly with respect to global change. My doctoral research focuses on tracing carbon transformations and fluxes through Arctic systems across a permafrost thaw gradient. As permafrost thaws, previously frozen carbon and nutrient pools are released. Simultaneously, associated hydrologic changes drive shifts in plant community composition with concurrent changes in microbial communities. I seek to understand how plant and microbial communities interact during these transitions and how they drive pathways of carbon flow within the system and export to other systems. I also teach inquiry-based outdoor science programs to K-12 students at the UA Sky School.
I had the honor of being the first post-doc in the Saleska Lab from 2006-2011. In 2015, I again started working with the Saleska Lab as a research consultant managing the eddy covariance, SIF, thermal and hyperspectral camera measurements at Santarem K67 -our Amazon research site.
Former Lab Members/Affiliates
Loren Albert – Post Doc, Brown University
Loren is a plant ecophysiologist with a focus on scaling between leaf-level function and ecosystem-level processes in forests. Her past research includes studies examining how the timing of leaf production impacts the seasonality of carbon uptake in Amazonian evergreen forests, and how such phenological processes can be incorporated into land surface models. At Brown Loren is investigating how optical signals from leaves can be used to probe photosynthesis at scales from leaves to canopies under a range of conditions. Loren draws upon tools from the fields of ecology, evolution, micrometeorology, plant physiology and remote sensing in her research
Bradley Christoffersen – Assistant Professor, University of Texas Rio Grande Valley
I am a broadly trained ecologist, with extensive experience in tropical forests and soon the thornscrub ecosystems of the Rio Grande Valley. My research focuses on plant physiological ecology, ecosystem ecology, and models which scale up processes from plant tissues to whole ecosystems.
Carrie McCalley – Assistant Professor, Rochester Institute for Technology
Laura Meredith – Assistant Professor, UA
My research team quantifies the microbial imprint on atmospheric composition and climate using an interdisciplinary set of methods, ranging from genomics to micrometeorology. We focus on resolving the genomic underpinnings of microbe-mediated biogeochemical transformations in soils that drive significant atmospheric fluxes. The goal of my work is to determine when and how projections of biogeochemical transformations are improved by better representation of underlying biological drivers
Anthony Garnello – PhD student, N. Arizona University
Anthony is interested in the Explorations into the boundary of ecosystem-climate interactions through the lenses of biogeochemistry and ecology in the face of climate change, with a predominant focus on Arctic peatland and tundra.
Matthew Gold – Undergraduate student, May 2019
Joost van Haren – UA, Assistant Research Professor
My research focuses on understanding biogeochemical cycles of carbon, nitrogen and water in particular in tropical ecosystems. Currently, we work on understanding carbon and water cycling in tropical peatlands, more specifically, methane emissions from these ecosystems and also how land-use change affects methane fluxes and the microbial community responsible for the methane fluxes.
Virginia Rich – Assistant Professor, The Ohio State
My lab studies how microbes respond to, and in turn help shape, environmental change. We are particularly interested in global change interactions with biogeochemical cycling. Our lens into microbial community composition and function is through molecular “meta-omics” tools, which we bring to robust interdisciplinary collaborations with biogoechemists and modelers to generate a systems-level understanding of ecosystems undergoing change.
Marielle Smith – Post Doc, Michigan State University
I am investigating how tropical forest canopy structure responds to seasonal dry periods and anomalous droughts on seasonal and interannual timescales, using data from ground-based LiDAR (Light Detection and Ranging). Combining long-term LiDAR measurements with tree inventory data provides a way to identify the mechanisms (i.e., changes in leaf area and/or woody biomass) responsible for structural changes associated with drought-induced disturbances and subsequent periods of forest recovery.
Scott Stark – Assistant Professor, Michigan State University
Forest–Atmosphere Interactions | Earth Systems | Plant Community, Ecosystem, and Physiological Ecology. My research combines data from traditional forest plots, ecophysiological information, and LiDAR remote sensing to study the combined effects of size structure, light limitation, and phenotypic diversity on tropical forest dynamics and functions, including biosphere–atmosphere interactions and ecoclimate teleconnections.
Tyeen Taylor – Post Doc, University of Michigan
Pilar Vergeli – PhD Student, Arizona State University
Kenia Wiedemann – Post Doc, Harvard University
Jin Wu – Assistant Professor, Hong Kong University
Jin Wu is a broadly trained environmental scientist studying the interaction of forest ecosystems with climate. He shares a very broad research interest in plant physiology, ecosystem science, ecological strategies, biodiversity, and community assembly. Jin is especially keen to advance our understanding of these topics by using multi-discipline approaches (remote sensing, gas exchange measurements, biometry surveys, earth system modeling) undertaken across a wide range of scales (leaf, canopy, landscape, globe). His current research is focused on understanding and model representation of the processes that underlie the response of tropical forest ecosystems to global change. Jin is also involved in promoting science by mentoring undergraduate/graduate students interested in environmental sciences.