This grant funded the Hubbard Brook Long Term Ecological Research (LTER) project (HBR) from February 2011 – January 2019. The mission of the HBR program is to improve understanding of the response of Northern Forest ecosystems to natural and anthropogenic disturbances. Our principal research site is the Hubbard Brook Experimental Forest in the White Mountains of NH. The conceptual model guiding our research envisions disturbance playing out on a geophysical and historical template that influences the biogeochemistry, vegetation, hydrology and food webs of the Northern Forest. We organize our research around three drivers of disturbance: (1) changing atmospheric chemistry, (2) changing climate; and (3) changing biota, which includes changes in forest structure and plant and animal species composition. Our long-term measurements and experiments have led to seminal research in trends, impacts and recovery from acid rain and other forms of atmospheric deposition, ecological impacts of forest harvesting practices, long-term vegetation dynamics in forests, and trends in songbird populations.  Our research has evolved in response to results (many surprising) from long-term data collection; future research will emphasize interactions among disturbances and legacies of past disturbance.

Some key results over the past six years of research include patterns of streamwater nitrogen loss that do not conform to expectations based on biogeochemical theory. This mismatch between theory and data has led us to re-examine the role of denitrification, the role of the mineral soil in nitrogen dynamics during succession, and the role of climate change in “tightening” the nitrogen cycle. We have also determined that calcium is a critical nutrient in these acid rain-impacted forests. De-acidification of an entire watershed through application of calcium silicate has led to improved tree growth, health and reproduction;, increased litter decomposition and loss of soil organic matter, decreased root growth, and increased loss of nitrogen in streamwater starting approximately 10 years after the application of calcium silicate. Lack of calcium may be inhibiting the regeneration of sugar maple in harvested watersheds. In biodiversity research, we have determined that songbird populations have declined dramatically since measurements began in 1968, but show signs of stabilizing in recent years. The declines are primarily due to the loss of Neotropical migrant species, particularly in species that nest and forage in mid-successional habitats, which have become less common as the forest has matured. Our long term observations, experimental manipulations and modeling studies show that climate change has extended the growing season and altered conditions during seasonal transitions with significant effects on whole-system carbon and nitrogen fluxes

HBR research is tightly coupled to an extensive program of education and outreach. Highlights over the last six years include a series of “Hubbard Brook Roundtables” which use a facilitated-dialogue model for connecting Hubbard Brook scientists with decision-makers facing complex issues. Roundtable topics have included climate change impacts on forests, the maple industry, and snowmobiling; wood fuel; public engagement with science; forests in a climate economy; biodiversity; and preventing imported forest pests. We also provide essential training, tools, materials, and experiences for the next generation of ecosystem thinkers and their teachers. K-12 classroom resources include more than 20 math and science lessons available for free download; guided and virtual tours of the Hubbard Brook Experimental Forest; and training workshops and summer field research experiences for teachers. Each year approximately 6,000 students and teachers participate in these programs. We have a summer Research Experiences for Undergraduates program at Hubbard Brook for up to 10 environmental science students annually.  We facilitate the linkage of scientific information with public policy through the “Science Links” series of reports and our founding membership in the Science Policy Exchange, a consortium dedicated to the sound use of science in federal policy.

The Information Management System at HBR maintains a catalog of HBR data, with an emphasis on high quality data/documentation and data preservation enabling data discovery/access to serve the HBR, LTER, and broader scientific communities. Our data are available without restriction, citable by Digital Object Identifier, and are discoverable via higher-level data search portals (DataONE). These data support a number of k-12 curricula and synthesis activities within and beyond LTER.

Partnerships are essential at HBR. The USDA Forest Service (USFS) operates the ~3500 ha Hubbard Brook Experimental Forest and its onsite facilities, and provides the foundational data for hydrology and meteorology. The Hubbard Brook Research Foundation (HBRF) is also a key partner, supporting facilities for HBR researchers and leading our education and outreach activities.

Last Modified: 05/30/2019
Modified by: Gary M Lovett