New research quantifies US forest vulnerability to drought stress expected with climate change
john_harrisonAlthough it is widely recognized that climate change will require a major spatial reorganization of forests, our ability to predict exactly how and where forest characteristics and distributions will change has been limited. Current efforts to predict future distribution of forested ecosystems as a function of climate include species distribution models (for fine scale predictions) and potential vegetation climate envelope models (for coarse-grained, large scale predictions). In this paper, titled U.S. Forest Response to Projected Climate-Related Stress: a Tolerance Perspective (Lienard, Harrison, and Strigul In Press at Global Change Biology), an intermediate approach is developed and applied. In this approach, we use stand-level tolerances of environmental stressors to understand forest distributions and vulnerabilities to anticipated climate change. In contrast to other existing models, this approach can be applied at a continental scale while maintaining a direct link to ecologically relevant, climate-related stressors. We demonstrate that shade, drought, and waterlogging tolerances of forest stands are strongly correlated with climate and edaphic conditions in the conterminous US. This discovery allows the development of a Tolerance Distribution Model (TDM), a novel quantitative tool to assess landscape level impacts of climate change. We then focus on evaluating the implications of the drought TDM. Using an ensemble of 17 climate change models to drive this TDM, we estimate that 18% of US ecosystems are vulnerable to drought-related stress over the coming century. Vulnerable areas include mostly the Midwest US and Northeast US, as well as high elevation areas of the Rocky Mountains. We also infer stress incurred by shifting climate should create an opening for the establishment of forest types not currently seen in the conterminous US.
Link to pre-print of new global coastal hypoxia model
john_harrisonFirst-ever global model linking coastal nutrient loading to hypoxia accepted for publication at Global Biogeochemical Cycles
john_harrisonAn article titled Linking nutrient loading & oxygen in the coastal ocean: a new global scale model (Reed and Harrison 2016) has been accepted for publication in Global Biogeochemical Cycles. This article describes and applies a first-ever global model predicting coastal hypoxia as a function of nutrient loading.
GCWB Postdoc Genevieve Metson to present recent work on phosphorus dynamics in U.S.
john_harrisonDr. Genevieve Metson will give a talk titled Shaping Future Phosphorus Management Pathways by Understanding the Past and Present at next weeks AGU meeting in San Francisco. The talk will be Friday, December 18, 15:10 – 15:25, in 210 Moscone West.
New research on coastal vivianite formation published by Dan Reed and colleagues
john_harrisonA new paper titled Shelf-to-basin iron shuttling enhances vivianite formation in deep Baltic Sea sediments by GCWB postdoc Dan Reed and colleagues has just appeared on-line in Earth and Planetary Science Letters.
New article by Rebecca Bellmore on how climate affects organic matter transport from agricultural soils to streams via tile drainage
john_harrisonRecent GCWB alum (Ph.D.) Rebecca Bellmore and co-authors have published an article titled Hydrologic control of dissolved organic matter concentration and quality in a semiarid artificially drained agricultural catchment examining climate controls on organic matter transfer from agricultural fields to surface waters in Water Resources Research.