Session Themes

Plenary Speakers

There is an explicit thread tying the plenary speaker's talks together. The plenaries emphasize the use of time-series data, either empirical, experimental, or modeled, to define the trajectory of our past environments and project ecosystem behavior into the future.

Further information is listed on the Plenary Speakers page of this web site.  For pdf's for presenters' talks, please go to the Program page and click on each presenter (talks available for names in blue).

Themes For Oral Sessions

  1. Long-term integrated monitoring and modeling
  2. Biosphere-atmosphere interactions and exchanges:  gases and aerosols
  3. The role of extreme events in ecosystem biogeochemistry
  4. Linkages among biogeochemical cycles
  5. Critical unknowns in nitrogen dynamics and reactive N
  6. Biogeochemistry of peatlands
  7. Carbon cycling in well-drained forested soils
  8. Carbon cycling in poorly-drained soils
  9. Experimental manipulations of ecosystems
  10. Trace element biogeochemistry and ecosystem impact
  11. Applications of isotopes and tracers
  12. Bio-energy production impacts in forested systems
  13. The role of biogeochemistry in ecosystem restoration and rehabilitation
  14. Ecosystem management and ecosystem services

Themes for Oral Sessions

1.   Long-term integrated monitoring and modeling

Leader: Jakub Hruska, Czech Geological Survey, CZ

Co-Leader: Filip Moldan, Swedish Environmental Research Institute, SE

Theme Plenary Speaker:  Stephen Norton, University of Maine, US


Biogeochemical modeling provides estimates of ecosystem history and future development. It is a useful method for understanding ecosystem processes and an important tool to summarize scientific understanding for policy decisions. Changes in atmospheric deposition of acidifying compounds were the most important driving force of biogeochemical models for the last several decades. Currently, and for the future, interaction between climate change and land use, resulting in organic carbon and nitrogen transformations, have become increasingly important. Using long-term observations and experiments on catchment and plot scales is vital for understanding processes, and for development and evaluation of new models. Better understanding of nitrogen and organic carbon, cycles of base cations, sulfur, and aluminum, and coupling biogeochemical element interactions cycles with plant biodiversity is a novel and challenging direction in biogeochemical modeling. The main focus of this section will be linking biogeochemical and biodiversity models to long-term monitoring and experimental data sets.



2.   Biosphere-atmosphere interactions and exchanges:  gases and aerosols


Leader: Nancy Dise, Manchester Metropolitan University, GB

Co-Leader: Tobias Eriksson, Swedish University of Agricultural Sciences, SE

Theme Plenary Speaker: TBA


This theme will explore the state of understanding of processes governing the exchange of gases and aerosols between the biosphere and the atmosphere, and the influence of human activities on these processes.   Quantifying biosphere-atmosphere interactions is essential to realistically address global environmental issues such as climate change, atmospheric deposition of pollutants, or troposphere ozone enrichment.  The scale of investigation ranges from laboratory-based studies, through plot- or landscape-scale experiments, to regional or global models that encompass feedbacks between living organisms and the abiotic environment.  Interactions can be instantaneous, such as the microbial production of greenhouse gases, or long-term, such as the response of complex adaptive ecological systems to persistent environmental change.   Current challenges include harmonising across these scales of space and time, and defining feedbacks across components of the Earth system that may strongly influence ecosystem gas/aerosol dynamics.



3.  The role of extreme events in ecosystem biogeochemistry


Leader: Catherine Eimers, Trent University, CA

Co-Leader: Werner Borken, U. Bayreuth, DE

Theme Plenary Speaker: TBA


Climatic change is expected to alter the frequency and intensity of weather extremes, including storms, heat waves and droughts. In addition, increases in temperature during the winter in northern latitudes and high elevations may result in a shorter snow season with more frequent soil frost, freeze-thaw and rain-on-snow events.  These relatively short-duration perturbations can have major impacts on ecosystem biogeochemistry by altering the turnover, transport and stocks of carbon, nitrogen, phosphorus, sulphur and trace contaminants like metals. This session will explore the impact of extreme weather events on biogeochemical cycling in both natural and human-disturbed ecosystems.  Invited are contributions describing the biogeochemical impacts of natural and experimental weather extremes on terrestrial and aquatic ecosystems.



4.   Linkages among biogeochemical cycles


Leader: Christine Goodale, Cornell University, US


Theme Plenary Speaker: TBA


Most elements do not move through ecosystems in isolation. The concept of stoichiometry is central to biogeochemistry, and the concept of limiting nutrients has existed for two centuries.  Yet, the tendency remains for scientific research to focus on the cycling of one, or perhaps two, elements. Earth system models have only recently included nitrogen and carbon; the representation of other elements remains rudimentary or absent. Yet these biogeochemical interactions are critically important: for example, nitrogen limits growth response to elevated CO2; acidification slows carbon turnover; sulphate suppresses methane emissions; phosphorus, iron, and base cations can all limit primary production. Ignoring these interactions may lead to an erroneous understanding of biogeochemical processes. This session will cover these and other examples of linkages among biogeochemical cycles, focusing in particular (but not exclusively) on the role of multiple element (co)limitation, element stoichiometry, redox conditions, and other physico-chemical processes, across a range of spatial scales and ecosystems. 


5.  Critical unknowns in nitrogen dynamics and reactive N


Leader: Melanie Vile, Villanova University, US

Co-Leader: Leon P.M. Lamers, Radboud University, NL  

Theme Plenary Speaker: Benjamin Z. Houlton, University of California at Davis, US


Research on N cycling in ecosystems has long fascinated scientists. With recognition that many N cycling processes interact and function at varying temporal and spatial scales, coupled with the knowledge that different ecosystems show high variability in sensitivity to N inputs, it is not surprising that N continues to challenge our understanding. Despite significant advances in our ability to measure rates and pools of reactive nitrogen, critical unknowns in the N cycle remain. This session seeks to apply new insights into N cycling processes to narrow the gap between current paradigms and critical unknowns in N cycling.  Toward this end, we welcome contributions on topics such as the role of organic N in plant nutrition and N cycling, root and mycorrhizal responses associated with elevated N availability (e.g., atmospheric deposition), bedrock as a source of N, rhizospheric N cycling, biological N2-fixation, and recently discovered microbial processes (e.g., Anammox, DNRA).



6.   Biogeochemistry of peatlands


Leader: Kelman Wieder, Villanova University, US

Co-Leader: Lucy Sheppard, Centre for Ecology and Hydrology, UK

Theme Plenary Speaker: Christian Fritz, Radboud University Nijmegen, NL


Peatland ecosystems have long fascinated ecologists, but over the past several decades interest in peatland biogeochemistry has grown dramatically.  The considerable carbon stored in the world’s peatlands, and the role of peatlands as net sinks for atmospheric CO2 and new sources of atmospheric CH4, have energized research on peatland C cycling under past, present, and future climatic conditions. Additionally, anthropogenic disturbances, including wildfire and enhanced atmospheric nitrogen and sulfur deposition, continue to bring new insights into the controls on element cycling in peatlands, and into interactions among element cycles, hydrology, climate, and vegetation change.  This session welcomes contributions that advance our understanding of element cycling in peatlands across the planet derived from descriptive and experimental studies, in the field and in the laboratory, along with modeling efforts.  We especially welcome contributions from large-scale field manipulations designed to test hypotheses related to the biogeochemical functioning of peatlands.



7.   Carbon cycling in well-drained forested soils


Leader: Lucas Nave, University of Michigan, US

Co-Leader: Knute Nadelhoffer, University of Michigan, US

Theme Plenary Speaker: Serita Frey, University of New Hampshire, US


Forest soils hold a globally significant share of the carbon stored in terrestrial ecosystems. Through numerous direct and indirect effects on soil physical, chemical, and biological properties, C storage and cycling in forest soils mediate complex ecosystem functions such as primary production, hydrologic and nutrient cycling, and the resistance/resilience of ecosystem C storage to disturbances. Because of this importance to both the fundamental properties of soils, and processes that are controlled by these properties, C cycling in well-drained forest soils is an important aspect of ecosystem biogeochemistry and management. We seek presentations that address all aspects of soil C cycling in well-drained forest soils, from basic soil C stock characterization to studies of mineralogy and molecular processes. In light of BIOGEOMON's focus on monitoring ecosystem changes over time, we especially encourage presentations that use timeseries datasets, archived soils, chronosequences or monitoring networks to understand temporal patterns in soil C cycling.



8.   Carbon cycling in poorly-drained soils


Leader: Juul Limpens, Wageningen University, NL

Co-Leader: Luca Bragazza, University of Ferrara, IT

Theme Plenary Speaker: Hans Cornelissen, University Amsterdam, NL


Similarities and contrasts across ecosystems and scales

Human activities are dramatically altering the structure and functioning of biomes, worldwide. Climate change, eutrophication, loss of biodiversity, and land use change are affecting the biogeochemistry of our natural ecosystems at unprecedented rates. Predicting the consequences is hampered by the diversity of world ecosystems, study scales, and disciplines, preventing us from seeing common response patterns. In this session we aim to bring together experts on different ecosystems characterized by poorly drained soils in order to explore similarities and dissimilarities of carbon cycling in response to global environmental changes. We welcome contributions focusing on above-ground and below-ground processes and on their interactions. Particular focus will be on the feedbacks between plants and/or soil microbes in response to environmental changes at different spatiotemporal scales.



9.   Experimental manipulations of ecosystems


Leader: Lindsey Rustad, United States Forest Service, US

Co-Leader: Jeff Dukes, Purdue University, US

Theme Plenary Speaker: Claus Beier, Technical University of Denmark, DK


The response of terrestrial ecosystems to a complex suite of natural and anthropogenic perturbations has been the subject of intense scientific scrutiny over the past several decades, and the focus of scores of single- and multi-factor ecosystem-scale manipulation experiments.  Results from these experiments have greatly increased our understanding of the short-term – and in some cases, longer-term or decadal - responses of terrestrial ecosystems and their components to global change drivers such as atmospheric nitrogen and sulfur deposition, elevated atmospheric CO2, warming, and changes in water availability.  The research provides valuable input for dozens of ecosystem-, regional-, and global-scale models that are allowing us to better synthesize current understanding and project future response patterns.  We invite papers on novel results from existing ecosystem-scale manipulative experiments, syntheses of results from suites of experiments, and integrations of results from experiments, observations and models.



10. Trace element biogeochemistry and ecosystem impact


Leader: James Kaste, College of William and Mary, US

Co-Leader: Tomas Navratil, Institute of Geology AS CR v.v.i., CZ

Theme Plenary Speaker: Ulf Skyllberg, Swedish University of Agricultural Sciences, SE


Over the last decade, significant advances have occurred in our understanding of how trace metals are distributed and behave in both natural and contaminated environments.  Advances in analytical methods, speciation assessments, and tracing techniques have opened up exciting new avenues of research that help us better measure, model, and predict complex biogeochemical processes.  Our session will examine the distribution, dynamics, cycling, speciation, and uptake of toxic and essential trace elements in ecosystems.  New studies describing trace element fluxes, availability, toxicity, deficiencies, and transport in contaminated and pristine environments are welcome.  We especially encourage original contributions to process modeling, papers describing impacts on soil processes and soil-plant interactions, and works developing new analytical approaches to trace metal research.



11. Applications of isotopes and tracers


Leader: Martin Novak, Czech Geological Survey, CZ

Co-Leader: Tom Bullen, US Geological Survey, Menlo Park, US

Theme Plenary Speaker:  Rich Bindler, Umea University, SE



Isotopes are now commonly used tools in all aspects of biogeochemical science. In recent years, the pace of analytical and conceptual advances concerning isotopes has been dizzying. The use of C, H, N, O, and S stable isotopes, and Pb and Sr radiogenic isotopes has been joined by Ca, Cd, Cr, Cu, Fe, Hg, Mg, Si, Sr, and Zn, stable isotopes, and rare gas isotopes. Foci of the Theme include: multi-tracer approaches, especially as applied to contaminant transport; diagnostic isotope fractionations in natural systems; isotope input-output mass balance in catchments; isotope constraints on global budgets of greenhouse gases; temporal and spatial trends in the abundances of isotopes in forest ecosystems; element cycling along soil chrono-, climo- and pedosequences; and advances in mass spectrometric methods and their application to low-temperature biogeochemistry. We particularly encourage contributions that highlight the power of using isotopes in interdisciplinary research.



12. Bio-energy production impacts in forested systems


Leader: Michael Starr, University of Helsinki, FI

Co-Leader: Liisa Ukonmaanaho, METLA, FI

Theme Plenary Speaker: Bengt Olsson, Swedish University of Agricultural Sciences, SE


With the need to reduce dependence on fossil fuels, forest logging residues are increasingly being used as a source of bio-energy and forest harvesting practices are correspondingly changing. However, the impact and sustainability of intensive logging residue removal on site productivity, nutrient and carbon cycling, and on water quality are unclear. In this session the biogeochemical aspects (e.g. base cation and nutrient removals in biomass; acidification; leaching of DOC, metals and nutrients; replacement of soil nutrients via deposition and weathering) of harvesting and biomass removal for bio-energy will be covered. Empirical and modeling studies dealing with the short and long-term effects of whole tree harvesting, including stump harvesting and logging residue, compared to thinning and conventional stem-only harvesting on soils, soil water and recipient streams and lakes will be welcome.



13. The role of biogeochemistry in ecosystem restoration and rehabilitation


Leader: Stefan Peiffer, University of Beyreuth, DE

Co-Leader: Katherine Walton-Day, US Geological Survey, Denver, US

Theme Plenary Speaker: Curtis J. Richardson, Duke University Wetland Center, USA 


The objective of ecosystem restoration and rehabilitation typically consists of the (re)generation of ecosystem functionality and services. Restoration of wetland systems must consider completely different biogeochemical processes compared to terrestrial systems because of their different hydrological boundary conditions and variable redox state. Hence, the success of restoration and rehabilitation of ecosystems depends on understanding the linkage between hydrology and biogeochemistry. We, therefore, encourage contributions with a clear focus on this relationship in terrestrial and wetland ecosystems.



14. Ecosystem management and ecosystem services


Leader: Curtis J. Richardson, Duke University Wetland Center, US

Co-Leader: Chris Craft, School of Public and Environmental Affairs, Indiana University, US

Theme Plenary Speaker: Brian C. Murray, Nicholas School of the Environment, Duke University, US


The millennium Ecosystem Assessment Report in 2005 concluded that 60% of all ecosystems services (ES) had declined in the past 50 years due to the impact of agriculture, forestry, fisheries, industries, and urban development.  Ecosystem services such as carbon sequestration, air-quality regulation, storm protection, disease control, freshwater supply, or water quality regulation are only recently being considered to have market value by society. This session will examine some of the key ecosystem services and mechanisms currently being designed to link ecological functioning to ecosystem services.  Case study examples that range from wetlands to prairies will be presented along with mechanisms for motivating people to provide or maintain ES on the landscape (e.g., cap and trade, regulation and penalty, or direct payments).



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