Activities and events

From/To Units Title Location

2021-06-22

T38

Webinar: The global emergence of hotter-drought drivers of forest disturbance tipping points online
Contact: Henrik Hartmann, Email: hhart@bgc-jena.mpg.de
From/To Units Title Location

2021-05-06

T38

Webinar: Tree mortality modeling – a tool for ecological inference and a challenge for projecting forest dynamics online
Contact: Henrik Hartmann, Email: hhart@bgc-jena.mpg.de
From/To Units Title Location

2021-03-24

T38

Webinar: Rising tree mortality in the Anthropocene online
Contact: Henrik Hartmann, Email: hhart@bgc-jena.mpg.de
From/To Units Title Location

2021-02-23

T38

Webinar: Tree mortality in Australian ecosystems: past, present and future online
Contact: Henrik Hartmann, Email: hhart@bgc-jena.mpg.de
From/To Units Title Location

2021-01-19

T38

Webinar: Tree mortality in the Amazon across local hydrological gradients: how water table depth may save or condemn trees as climate changes online
Contact: Henrik Hartmann, Email: hhart@bgc-jena.mpg.de


Calendar of Meetings

Upcoming events

Webinar: The global emergence of hotter-drought drivers of forest disturbance tipping points;
online; 22 June 2021, 5:00 pm CEST.
Speaker: Dr. Craig D. Allen, Department of Geography & Environmental Studies, University of New Mexico
Current research is presented on global-scale patterns and trends of forest responses to increasingly hotter droughts, particularly extensive tree mortality and forest die-offs involving a range of interactive disturbances (e.g., water stress, insect outbreaks, high-severity wildfire). Diverse cross-scale observations and empirical findings increasingly indicate that amelioration of hotter-drought stress via fertilization of photosynthesis from elevated atmospheric CO2 concentrations may soon be overwhelmed by heat and accelerated atmospheric drought. These findings highlight some current challenges in realistically projecting the future of global forest ecosystems (and their associated carbon pools and fluxes) with process-based Earth system models. In particular there is substantial evidence that forests dominated by larger, older trees may be disproportionately vulnerable to increased growth stress and mortality under hotter-drought conditions. The fates of these old trees in response to global change are of vital importance, given that they are essential as: a) disproportionately large carbon sinks; b) among the most biodiverse and rare terrestrial ecosystems; c) irreplaceable archives of environmental history; and d) venerated for many cultural reasons. Key scientific uncertainties that impede modeling progress are outlined, and examples of promising empirical modeling approaches are illustrated.

Registration: https://zoom.us/webinar/register/8116233165351/WN_ge7sLbEyS16YUUA5FAJ9Ig


Past Events

  • Webinar: Tree mortality modeling – a tool for ecological inference and a challenge for projecting forest dynamics;
    online; 6 May 2021, 5:00 pm CEST
    Speaker: Dr. Lisa Hülsmann, University of Regensburg (Germany)
    Tree death is ubiquitous in forests, even without climate change, and has a lasting impact on forest structure, species composition, biomass, and biodiversity. By relating tree mortality and other vital rates to tree, forest, and environmental conditions, we can therefore identify the mechanisms that govern the shape of forest ecosystems. In turn, these empirical relationships can be useful for projecting future forest dynamics and range limits of tree species. In the talk, I will discuss empirical tree mortality models as a diagnostic opportunity and a modeling challenge through two examples: the role of conspecific negative density dependence (Janzen-Connell effects) for tree diversity and the tighter coupling of dynamic vegetation models to forest data.
    Video Recording of seminar
     
  • Webinar: Rising tree mortality in the Anthropocene; online; 24 March 2021, 09:00 MDT, 16:00 CET, 20:30 IST
    Speaker: Nate McDowell
    Tree mortality is rising in most documented locations but the drivers and mechanisms of this trend are unknown. Changes in atmospheric carbon dioxide, temperature, and vapor pressure deficit, along with drought, are primary potential drivers. Mechanisms linking these drivers to mortality include water, carbon, and pathogen defense processes. These processes are interdependent such that failure of one can lead to failure of the others. Prediction of future mortality is challenged by our understanding of the mechanisms, however, some evidence suggests the growing mortality rates are likely to continue well into the future. The webinar will be concluded with a review of the numerous challenges and opportunities for predicting future tree mortality.
    Video Recording of seminar
     
  • Webinar: Tree mortality in Australian ecosystems: past, present and future; online; 23 February 2021, 09:00 AM in Canberra, Melbourne, Sydney (GTM +11:00).
    Speaker: Prof Belinda Medlyn, Western Sidney University
    Australia is not only the driest inhabited continent, it also experiences high interannual variability in rainfall, and severe multi-year droughts. Tree death from drought is thus a recurring feature of the Australian landscape. In this talk I will review our current understanding of drought mortality in Australian ecosystems, including the historical context, current field research on the extent and mechanisms of drought dieback and recovery, and the development of models to predict future drought mortality risk.
    Video Recording of Seminar
     
  • Tree mortality in the Amazon across local hydrological gradients: how water table depth may save or condemn trees as climate changes; online; 19 January 2021, 16:00 hrs CET.
    Speaker: Speaker: Flávia Costa, Instituto Nacional de Pesquisas da Amazônia (Brazilian Institute of Amazonian Research) - INPA, Brazil
    Dr Costa presented results of 20 years of investigation on patterns of forest response to soil hydrology (more specifically water table depth) during normal and extreme climatic years to examine the hypothesis that shallow water tables buffer forests from droughts and forests in these conditions may even be benefited by droughts. Dr Costa also presented some data on the hydraulic trait distributions along hydrological gradients to analyse the shifting implications to mortality during moderate to strong droughts.
    Video Recording of Seminar             
     
  • Webinar: Global forest monitoring using satellite data; online; 17 November 2020, 17:00 - approx. 18:30 hrs CET.
    Speaker: Matt C. Hansen, University of Maryland
    Earth observation data enable the monitoring of forest extent and change from national to global scales. Consistent processing of time-series images has made possible the operational production of global tree cover extent, loss and gain products.  However, attribution of dynamics in the context 1) reference state, for example forest type, 2) change factor, for example fire or logging, and 3) outcome, for example land use type or natural recovery, is more challenging.   In addition to mapping, the requirement to perform robust sample-based analyses to report on all themes is underappreciated.  This talk will review our work on characterizing forest dynamics at the global scale using multi-source satellite imagery, including mapping and sampling, in the context of current operational versus future aspirational capabilities.
    Report - Video Recording of Seminar         
     
  • Challenges and solutions for merging tree mortality datasets; Würzburg, Germany; 31 March - 2 April 2020. By invitation only
     
  • 2019: Inaugural meeting at the IUFRO World Congress in Curitiba, Brazil.

Send comments to Henrik Hartmann (Task Force Coordinator)