We conduct research on the hydrologic and biogeochemical effects of changing climate. These include long-term measurements and experiments on climate change at Hubbard Brook. Measurments since the 1950s show increases in air temperature and precipitation, loss of snowpack and increases in stream runoff. A focus of this research is on winter climate change, including effects on snowpack accumulation and belowground winter processes. We hypothesize that climate change is driving the northern forest toward a condition of oligiotrophication (decreasing nutrient status). We have submitted a proposal to the National Science Foundation to test this hypothesis. Climate change research at Hubbard Brook has expanded with an NSF-funded project examining the effects of ice storms on the structure and function of the northern forest. Plots were established and experimental icing treatments ice storm conducted during winters 2016 and 2017. A number of papers have been published on this work or are in progress, including effects on the forest nitrogen (Weitzman et al. 2019) and mercury (Yang et al. 2019) cycles; disturbance to the tree canopy (Fahey et al. 2019); and two methods papers addressing the procedures used for the experimental icing treatments and methods for quantifying ice accumulation on trees (Campbell et al. 2020; Rustad et al. in review). I am also leading (with Julia Jones, Oregon State University) a cross site synthesis of climate changes effects for different biomes within the NSF-funded Long-term Ecological Research network.  This will be a series of five papers targeted for the journal BioScience.

Figure Long-term annual trends in air temperature and precipitation by season for different meteorological stations at the Hubbard Brook Experimental Forest, NY

A focus of current is the linkages between air pollution and climate change. In Shen at al. (2019) we examined how climate change exacerbates for formation of ground level ozone and will increase the challenge of states to meet air quality standards, particularly in non-attainment areas across the coterminous U.S. This is initiating a new line of research on the linkages between climate change and air pollution.  There are two initiatives in progress. First is an overview of anticipated future health and ecosystem effects of air pollution which has been submitted to Philosophical Transactions A of the Royal Society (von Schneidemesser et al. in review). The second is an analysis of changes in the supply of nitrogen and eutrophication of coastal waters for the coterminous U.S.

Another component climate change effects research is the application of statistically-downscaled climate projections from global general circulation models (GCMs) as inputs to PnET-BGC to simulate the long-term hydrology and hydrochemical response to forest watersheds to future climate change. Simulations have been conducted at long-term watershed sites across the eastern US (e.g., Hubbard Brook, NH; Huntington Forest, NY; Sleepers River, VT; Fernow Experimental Forest, WV) In recent years we have been conducting similar simulations for western watersheds (Niwot Ridge CO, Loch Vale, CO, H.J. Andrews, OR) (Zheng Dong Ph. D graduate; Dong et al. 2019, Dong et al. in review).

References:

Campbell, J. R., L. E. Rustad, S. Garlick, N. Newman, J. S. Stanovick, I. Halm, C. T. Driscoll, B. Barjenbruch, E. Burakowski, S.  Hilberg, K. Sanders, J. C. Shafer and N. J. Doesken. 2020. Development of a low-cost ice accretion measurement methodology for a volunteer observation network. Agricultural and Forest Meteorology.

Dong, Z., Driscoll, C. T., Baron, J. S., Campbell, J. L., Pourmokhtarian, A., Stoner, A. M. K., Hayhoe, K. In review. A projected transition from temperature to water limiting condition under future climate change in a subalpine forest. Ecological Applications.

Dong, Z., C. T. Driscoll, S. Johnson, J. Campbell, A. Pourmokhtarian, A. Stoner and K. Hayhoe. 2019. Projections of water, carbon, and nitrogen dynamics under future climate change in an old-growth Douglas-fir forest in the western Cascade Range using a biogeochemical model. Science of the Total Environment. 656:608-624. doi:10.1016/j.scitotenv.2018.11.377.

Fahey, R. T., J. Atkins, J. L. Campbell, L. E. Rustad, M. Duffy, C. T. Driscoll, T. J. Fahey and P. G. Schaberg. 2019. Effects of an experimental ice storm on forest canopy structure. Canadian Journal of Forest Research, 136-142. doi:10.1139/cjfr-2019-0276.

Rustad, L., J. Campbell1, C. T. Driscoll, T. Fahey, P.  M. Groffman, P. Schaberg, G. Hawley, I. Halm, F. Bowles, W. Leuenberger, G. Schwaner, G.  Winant and B. Leonardi. In review. An experimental approach to characterize impacts of ice storms on forest ecosystems ice storm impacts. PLOS One.

Shen, H., Y. Chen, A. G. Armistead, Y. Hu, L. R. F.  Henneman, J.Shih, D. Burtraw, S. Shao, M. Qin, A.S. Lawal, G. K. Pavur and C. T. Driscoll. 2019. Relaxing energy policies on top of climate change will significantly undermine states’ efforts to attain U.S. ozone standards. One Earth.1:229-239. doi:10.1016/j.oneear.2019.09.006.

Weitzman, J. N., P. M. Groffman, J. L. Campbell, C. T. Driscoll, R. T. Fahey, T. J. Fahey, P. G. Schaberg and L. E. Rustad. 2019. Ecosystem nitrogen response to a simulated ice storm in a northern hardwood forest. Ecosystems.  doi:10.1007/s10021-019-00463-w.

von Schneidemesser, E., C. T.  Driscoll, H.  E. Rieder, L. D. Schifer. In review. How will air quality effects on human health, crops, and ecosystems change in the future? Philosophical Transactions A.

Yang, Y., L. Meng, R. Yanai, M. Montesdeoca, P. Templer, L. Rustad, H. Asbjornsen and C. T. Driscoll. 2019. Climate change may alter mercury fluxes in northern hardwood forests. Biogeochemistry. 146(1):1-16.doi:10.1007/s10533-019-00605-1.