FLUXNET Seminar Series

The FLUXNET Seminar Series is a monthly community event co-sponsored by FLUXNET Early Career Network, AmeriFlux AMP, and members of the AmeriFlux and FLUXNET communities. The theme of the events will alternate between community and science, and data/tech seminars.

Organizers: Christin Buechner, Housen Chu, Gavin McNicol, Fred Otu-Larbi, Gilberto Pastorello, and Gabriela Shirkey. For more information, contact us at: [email protected]

Also check out the AMP webinar series, with AmeriFlux content and tutorials.

FLUXNET-ECN Summer Series

For the summer months, the FLUXNET Early Career Network will lead a series of webinars focusing on the international FLUXNET network and its associated regional networks. If you’re new to FLUXNET and flux science, or are interested in participating within a regional network, these webinars will introduce you to the field and provide an opportunity for questions from some founding members.

Upcoming events

  • Friday, March 5th, 2021
    • Speaker: Lianhong Gu, Oak Ridge National Laboratory
    • Title: The light reactions of photosynthesis and the grand hypothesis of eddy covariance energy imbalance
    • Description: Photosynthesis starts with the excitation of chlorophyll molecules by light. The excitation is then funneled to the reaction centers of photosystems where the energy of excitation is converted to charge separation and electron transport via a chain of redox reactions. The electron transport causes the buildup of protons in the lumen and the formation of electric field across the thylakoid membrane with the positive side in the lumen and the negative side in the stroma. This electric field provides the proton motive force (PMF) that drives the synthesis of high-energy molecule ATP across the membrane. At the end of the electron transport chain, the electrons reduce the lower energy molecule NADP+ to form the higher energy molecule NADPH. ATP and NADPH power the Calvin Cycle to produce sugar which stores some of the initially absorbed light energy in chemical bonds to support essentially all life on Earth. The light energy initially harvested by chlorophyll molecules is much higher than the chemical bond energy eventually stored in sugar because the processes of the formation of PMF and the production of ATP and NADPH also require energy. However, the difference between the light energy initially harvested and the chemical bond energy eventually stored does not appear as heat immediately to be detectable by a heat sensor such as eddy covariance. This is because it takes time for the proton motive force to dissipate and the ATP and NADPH to be consumed. At high light, the PMF may be stronger and the rates of production of ATP and NADPH may be higher than what are needed by the Calvin Cycle. Conversely, at low light, the PMF and the production rates of ATP and NADPH that can be supported by the available light may not be able to satisfy the demand of the Calvin Cycle. Therefore, the oversupply of PMF, ATP and NADPH at high light may compensate the shortage at low light. This compensation cannot be detected as sensible heat in the energy budget equations. I hypothesize that this is the reason why the eddy covariance system cannot close the energy budget. Technological and theoretical developments needed to test this hypothesis are now in place. This hypothesis leads to several predictions that can be experimentally or observationally checked for its falsification or confirmation.
    • Speaker Bio: Lianhong Gu is a Distinguished Research Staff Scientist in the Ecosystem Processes Group, Environmental Sciences Division, Oak Ridge National Laboratory. He conducts research in photosynthesis and ecosystem science with observational, theoretical, and experimental approaches. He is the inventor of the licensed technology Fluorescence Auto-Measurement Equipment (FAME), the software Integrated Measurement And Control System for SIF (IMACSS), and the community online tool leafweb (https://leafweb.org/).
    • Speaker: Jingfeng Xiao, University of New Hampshire
    • Title: Assessing drought impacts on terrestrial photosynthesis with satellite data from OCO-2 and SMAP
    • Description: Solar-induced chlorophyll fluorescence (SIF) measured from space (e.g., the Orbiting Carbon Observatory-2 or OCO-2) and both soil moisture and gross primary production (GPP) estimates from the Soil Moisture Active Passive (SMAP) provide new opportunities for understanding the responses terrestrial photosynthesis to water stress over large regions. In this presentation, we will explore the impacts of drought on photosynthesis using SIF (mainly from OCO-2 and partly from GOME-2), SMAP, and flux data.
    • Speaker Bio: Jingfeng Xiao is a global ecologist whose research is motivated by the compelling need to understand the impacts of climate change and human activities on the Earth’s biosphere and the feedbacks to the climate. He has never established or maintained any flux site but uses flux measurements for almost every project. With expertise in remote sensing and modeling, he has been upscaling AmeriFlux/FLUXNET data to the continental and global scales since 2007 and has also been heavily involved in synthesis and model improvement efforts. More recently, he has been studying carbon/water cycling and high-frequency Earth surface processes using observations from new polar-orbiting satellites (e.g., OCO-2, TROPOMI), International Space Station (e.g., ECOSTRESS, OCO-3), and geostationary satellites in combination with flux measurements.
    • When: Friday, March 5th, 9am PST | 12pm EST | 5pm London | 2am (Sat, Mar 6th) Tokyo
    • Webinar host: Lin Meng, Lawrence Berkeley National Laboratory
    • Contact us: [email protected]
    • Register for this webinar: https://lbnl.zoom.us/meeting/register/tJUvcOyuqDosHNSiyUUW2rHX4rL9TzK8DlUN

 

Past events

  • Friday, January 29th, 2021
    • Speaker: Gil Bohrer, The Ohio State University
    • Title: The tree-hydrodynamic revolution – how stomata regulation moved from the soil to the trees
    • Description: The tree hydrodynamic hypothesis assumes that stomata regulation is driven by the dynamic balance of water content within the active xylem. This is a very different view of the classical stomata regulation approach, which is present in almost every model – linking stomata conductance to soil water availability through a wilting curve. Decade-long tree hydraulic observations in our forest flux sites in Michigan showed the importance of species-specific hydraulic strategy for the resulting diurnal patterns of transpiration and response to water shortage.
    • Speaker Bio: Gil Bohrer is one of the Ameriflux Core Flux Site PIs (US-UMB site cluster in Michigan). He studies greenhouse gas fluxes from forests and wetlands and runs several long-term flux sites (Michigan forest, Ohio wetland), and short temp flux tower deployments at industrial, agricultural and natural environments. He combines high-resolution models (Large Eddy Simulations, tree fluid dynamics) with multi-scale observations that link ecological state and function with atmospheric dynamics and hydrology. An additional focus of his research is incorporating environmental and remote sensing data in models of animal movement.
    • Speaker: Assaad Mrad, UC Irvine and Wake Forest University
    • Title: Modeling the spread of gas bubbles inside plants and their effect on photosynthesis during drought [slides]
    • Description: In this presentation, embolism spread in plant xylem will be modeled computationally and using network theory. It is established how embolism spread in xylem depends on the connectivity of microscopic water conduits. This process is upscaled to the organ level to give predicted vulnerability to embolism curves. Vulnerability to embolism curves are then further up-scaled to the whole-plant to evaluate the effect of soil water depletion on photosynthesis.
    • Speaker Bio: Assaad Mrad is an environmental scientist and, specifically, an ecohydrologist. He is interested in the role of vegetation in coupling the fluxes of water and carbon between land and atmosphere. His overarching research objective is to connect scientific advances spanning several scales. For example, how does the anatomy of plant xylem drive its behavior to droughts? He is currently a postdoc studying wildfire spread and the vegetation dynamics pre- and post-fire. As an engineer by training, he is interested in applying tools from physics and engineering to his environmental science questions. Such tools are graph theory, percolation theory, and the calculus of variation. He graduated with a Ph.D. in Environmental Science from Duke University in 2020 and a Bachelor’s degree in Mechanical Engineering from the American University of Beirut in 2016.
    • When: Friday, January 29th, 9am PST | 12pm EST | 5pm London | 2am (Sat, Jan 30th) Tokyo
    • Webinar host: Theresia Yazbeck, The Ohio State University
    • Contact us: [email protected]
    • See recording: https://youtu.be/T38z-YF1xRE

2020

  • Monday, November 30th, 2020
    • Speaker: Karina Williams, UK Met Office Hadley Centre and Exeter University
    • Title: Using fluxes to evaluate and improve land-surface models
    • Description: In this presentation, we will explore some of the ways that flux tower data is used to improve process representation within land-surface models, with particular focus on the way that vegetation responds to low levels of soil moisture in the JULES land-surface model.
    • Speaker Bio: Karina Williams is vegetation module leader for the JULES land-surface model. She co-leads a working group to evaluate and improve the process of water stress at all scales in the model, and coordinates a network of modellers of FACE sites within the JULES community. Dr. Williams completed both undergraduate and postgraduate studies in the Physics Department at Durham University, UK, and did a post doctorate at Bonn University, Germany. She joined the Met Office Hadley Centre in 2011. Since September last year, she has also worked part-time as a lecturer at Exeter University.
    • Speaker: Silvano Fares, National Research Council of Italy
    • Title: From flux measurement to a multi-layer canopy model for ecosystem services in urban areas [slides]
    • Description: In this presentation, we will introduce some history of research in flux measurements using enclosure systems and micrometeorological techniques to study plant-atmosphere exchanges. The focus will be in both CO2 and non-CO2 trace gases, with application of a multi-layer canopy model to predict exchanges and delivery of ecosystem services in urban areas.
    • Speaker Bio: Silvano Fares is a research director at the National Research Council of Italy–Institute of Bioeconomy. He joined the FLUXNETcommunity in 2007 during his PhD in Forest Ecology (University of Tuscia, Italy), and later as a Postdoc at the University of California–Environmental Science and Policy Department, USA in 2008-2010. He is currently the designated national coordinator of terrestrial ecosystems for Italy in the EU program ICOS (Integrated Carbon Observation System) and a SSC member of ILEAPS (Integrated Land Ecosystem Process Study). He is an ecophysiologist interested in exchange processes involving ozone, biogenic volatile organic compounds, methane and carbon between plant ecosystems and the atmosphere. With experience in flux measurement using both leaf-level enclosure systems and eddy-covariance techniques, he applies multi-layer canopy models to predict plant-atmosphere interactions under abiotic stress and estimate ecosystem services provided by urban trees.
    • When: Monday, November 30th, 8:30-9:30pm PST | 11:30am-12:30pm EST | 4:30-5:30pm London | 1:30-2:30am (Tue, Dec 1st) Tokyo
    • Webinar host: Fred Otu-Larbi, Lancaster University
    • Contact us: [email protected]
    • See recording on YouTube: https://www.youtube.com/watch?v=CVAItU0Iewg

  • Thursday, September 10th, 2020
    • Speaker: Jason Beringer, School of Agriculture and Environment, University of Western Australia
    • Title: OzFlux: from little things big things grow
    • Speaker Bio: Professor Jason Beringer studies how ecosystems, and the services they provide, will respond to climate change and future disturbances. He has conducted extensive research in Australia’s dry land ecosystems, considering interactions among fire, precipitation, and ecosystem productivity. As founding member and current Director of TERN OzFlux, he has overseen the growth of the network and co-hosted the 20th anniversary OzFlux meeting in the summer of 2020. View his biography here.
    • Speaker: David Campbell, Earth Sciences, University of Waikato, New Zealand
    • Title: The Kiwi EC connection – from peat to pasture
    • Speaker Bio: Associate Professor David Campbell joins us from the Waikato Biogeochemistry and Ecohydrology Group where he studies the carbon balance of New Zealand’s distinctive peatland and agricultural ecosystems. He was an early adopter of micrometeorological methods for measuring exchange of both carbon dioxide as well as methane. He is lead investigator at the only temperate bog site compiled as part of the FLUXNET methane synthesis from the southern hemisphere. View his full biography here.
    • Speaker: Caitlin Moore, School of Agriculture and Environment, University of Western Australia
    • Title: An early career researcher perspective of OzFlux
    • Speaker Bio: Dr. Caitlin Moore is a research fellow in the School of Agriculture and Environment, at the University of Western Australia. Caitlin got her PhD at Monash University studying tropical savanna productivity using a combination of eddy covariance and phenocam data, then completed a postdoctoral position studying bioenergy crops at the University of Illinois at Urbana-Champaign. Currently, she is bringing together new measurements and modeling techniques to better predict crop and native ecosystem stress in Western Australia. Caitlin serves as External Communications officer on OzFlux’s steering committee. View her full biography here.
    • When: Thursday, September 10th, 4:30-5:30pm PDT | 7:30-8-30pm EDT | 12:30-1:30am (Friday, 11th) London | 8:30-9:30am (Friday, 11th) Tokyo | 9:30-10:30am (Friday, 11th) Sydney | 11:30am-12:30pm (Friday, 11th) Auckland
    • Webinar host: Gavin McNicol, Stanford University
    • Contact us: [email protected]

  • Thursday, August 6th, 2020
    • Speaker: Takashi Hirano, Hokkaido University, Japan; Vice President of AsiaFlux and the former President of JapanFlux
    • Title: History and activities of AsiaFlux and JapanFlux
    • Speaker Bio: Professor Takashi Hirano from the Graduate School of Agriculture, Hokkaido University, Japan is the Vice President of AsiaFlux and former President of JapanFlux. He will share the history and activities of both AsiaFlux and JapanFlux in his experience as a senior scientist. Biometerology and ecosystem functions are his specialty, and his interests include the eddy flux technique in forest ecosystems, land use change, tropical and northern peatlands, agricultural meteorology and more. View his biography here.
    • Speaker: Masahito Ueyama, Osaka Prefecture University, Japan
    • Title: Expanding research interests with collaborations through surviving young days
    • Speaker Bio: Associate Professor Masahito Ueyama joins us from the Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Japan. He will speak on experiences as an early career professional within AsiaFlux and JapanFlux, which lead him to a position in ecological meteorology. He serves on the AsiaFlux and JapanFlux steering committees, amongst others, and currently researches methane fluxes and greenhouse gas emissions. View his full biography here.
    • When: Thursday, August 6th, 4:30-5:30pm PDT | 7:30-8-30pm EDT | 12:30-1:30am (Friday, 7th) London | 8:30-9:30am (Friday, 7th) Tokyo time
    • Webinar host: Gabriela Shirkey, Michigan State University
    • Contact us: [email protected]

 

  • Friday, June 26th, 2020
    • Speaker: Dennis Baldocchi, UC Berkeley
    • Title: Introducing FLUXNET: History and Founding
    • Description: Our inaugural meeting will feature Dennis Baldocchi, Professor of Biometeorology at University of California, Berkeley, who will speak about the history of eddy covariance flux measurements, it’s changing theory, methods, and applications, and the eventual establishment of FLUXNET. Professor Baldocchi helped pioneer the eddy covariance method and his research approach involves the coordinated use of long-term, quasi-continuous flux measurements and theoretical models to study biosphere-atmosphere interactions. Today, he is a co-investigator of the AmeriFlux Management Project, helping support the AmeriFlux and FLUXNET networks. Read his bio here.
    • When: Friday, June 26th, 8-9am PDT | 11a-12pm EDT | 4-5pm London | 12-1 am (27th) Tokyo time
    • Webinar host: Gabriela Shirkey, Michigan State University
    • Contact us: [email protected]