OOS 11: Trajectories and Tipping Points of Watersheds in Response to Disturbances

Session Organizer(s)

• Emily Graham

  School of Biological Sciences, Washington State University
  Richland, WA, USA

Moderator(s)

• Emily Graham

  School of Biological Sciences, Washington State University
  Richland, WA, USA

Volunteer(s)

• Savannah Fuqua

  Point Reyes National Seashore Association
  Point Reyes, California, United States

Disturbances fundamentally alter ecosystem functions, yet predicting their impacts remains a key scientific challenge. This challenge is paramount to current research in ecology and the environmental sciences, as many disturbances have dramatically increased and/or are predicted to increase with changes in climate in the coming century. Watersheds serve as integrators of the effects of disturbances by encompassing both terrestrial and aquatic landscapes, as well as the highly dynamic interfaces that connect them. For instance, over the last 15 years wildfires in the US alone have burned ~2.8-million ha year-1, which is almost 1-million ha year-1 greater than the 80 year average. The cascade of effects from landscape disturbances into aquatic ecosystems remain largely unknown. Increasing occurrence and severity of other disturbances, like drought, temperature changes, pest outbreaks, pathogens, and other natural hazards affect soil and plant health and also alter stream intermittence, seasonal flow variations, and materials transported into the river corridor. This interconnectivity of terrestrial and aquatic domains is often overlooked in our collective investigations of disturbance drivers and impacts. As a consequence, process-based representations of disturbance impacts on ecosystems remain poorly represented in state-of-science modelling frameworks. Advancing our understanding requires a suite of investigations across sub-daily to multidecadal, as well as molecular to landscape and larger scales. This session explores the ecological ramifications of disturbances spanning terrestrial and aquatic domains and highlights remaining obstacles including: integrating across ecological scales, understanding disturbance interactions, establishing baselines and trajectories of ecosystem functions after disturbances, and developing process-based models and ecological forecasting initiatives. Our session will include speakers that span terrestrial and aquatic domains and/or extend through time, space, or multiple ecoregions.

Presentations:

• ON DEMAND

  Adapting carbon dynamic models to characterize biogeochemical processes across terrestrial-aquatic interfaces
  

  Presenting Author: Jianqiu Zheng – Pacific Northwest National Laboratory
• ON DEMAND

  At what scale do disturbances matter for terrestrial to marine carbon fluxes? Comparing undisturbed aquatic carbon fluxes to disturbance frequency, extent, and associated carbon export at fine and regional scales
  

  Presenting Author: Brian Buma – Natural Science, University of Colorado, Denver
• ON DEMAND

  Fire impacts on river water chemistry, microbial diversity, and watershed hydrological connectivity
  

  Presenting Author: Michelle Newcomer – Lawrence Berkeley National Laboratory
• ON DEMAND

  Linking carbon export to watershed hydrology enables an integrated view of biogeochemistry in fire-affected streams
  

  Presenting Author: Sasha Wagner – Rensselaer Polytechnic Institute
• ON DEMAND

  Salinity gradients in coastal river corridors impact organic matter processes and ecosystem function
  

  Presenting Author: Aditi Sengupta – Biology, California Lutheran University
• ON DEMAND

  Trajectories of ecosystem functions after disturbances spanning terrestrial and aquatic domains in the Intermountain West
  

  Presenting Author: Kathleen A. Lohse – Department of Biological Sciences, Idaho State University