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Abstract An ice storm simulation was performed at the Hubbard Brook Experimental Forest to evaluate impacts of these extreme weather events on northern hardwood forests. Water was pumped from the main branch of Hubbard Brook and sprayed above the forest canopy in subfreezing conditions so that it rained down and froze on contact with trees. The experiment consisted of five treatments, including a control (no ice) and three target levels of radial ice accretion: low (6.4 mm), mid (12.7 mm), and high (19.0 mm). Two of the mid-level treatment plots (midx2) were iced in back-to-back years to evaluate impacts of consecutive storms. This dataset consists of hemispherical photographs of the forest canopy with leaves on and off the trees before and after the various ice treatments. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station. 

To assess relative production of fine roots in droughted and reference plots that are part of the Hubbard Brook DroughtNet study, mesh-free root ingrowth (total depth 20cm) were installed during most study years. Multiple subplots for destructive soil measurements were reserved within plots 7 and 8, and just outside reference plots 1 and 2 in 2015. Fine root production is a component of NPP that is often not well measured in global change experiments. The ingrowth core methodology used may not perfectly represent belowground NPP in the surrounding intact soil, but should provide a reliable metric of relative differences among plots and over time. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station. 

The forest drought experiment prototype at Hubbard Brook was constructed in 2015, as part of the International Drought Experiment (IDE) coordinated by the DroughtNet Research Coordination Network. The throughfall exclusion experiment was designed to simulate a 1-in-100-year drought during an average precipitation year by diverting ~50% of forest throughfall from each treatment plot starting in May 2015 (Asbjornsen et al., 2018). Throughfall was intercepted by reinforced polyethylene troughs and diverted passively to the downslope side of each plot. Each throughfall exclusion plot was 15 x 15 meters in area. TFE plots were designated with the labels 7 and 8 to avoid any confusion with the nearby CCASE plots (which are labeled 1-6). Plots were not trenched to isolate them from the surrounding soil.  In May 2019 throughfall removal was increased to approximately 95% (i.e. full coverage but with stemflow not fully excluded). Throughfall exclusion treatments ended in February 2020. Recovery and return to baseline conditions were monitored during 2020 (when a natural drought occurred) and 2021 (a more normal year). These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station. 

Dendrometer bands were installed to measure tree diameter growth in the Hubbard Brook DroughtNet plots in 2014. Changes in stem diameter, basal area, and aboveground biomass can all be calculated from dendrometer band measurements, provided the tree diameter is known for at least one measurement date. Data from nearby CCASE control plots 1 and 2 can be used as references for these data (these will be part of a forthcoming separate package). These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station. 

The ice storm experiment was a novel experimental approach creating a suite of ice storms in a mature hardwood forest in New Hampshire, USA. The experiment included five ice storm intensities (0, 6.4, 12.7, and 19.1 mm radial ice accretion) applied in a single year, and one ice storm intensity (12.7 mm) applied in two consecutive years. This dataset quantifies the coarse woody debris transferred from the forest canopy to the soil under the different icing conditions. In this forest, little damage occurred below 6.4 mm radial ice accretion, moderate damage occurred with up to 12.7 mm of accretion, and significant branch breakage and canopy damage occurred with 19.1 mm of ice. The icing in consecutive years demonstrated an interactive effect of ice storm frequency and severity such that some branches damaged in the first year of icing appeared to remain in the canopy and then fall to the ground in the second year of icing. These results have implications for National Weather Service ice storm warning levels, and they provide a quantitative assessment of ice-load related inputs of forest debris that will be useful to municipalities creating response plans for current and future ice storms. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station. 

An ice storm simulation was performed at the Hubbard Brook Experimental Forest to evaluate impacts of these extreme weather events on northern hardwood forests. Water was pumped from the main branch of Hubbard Brook and sprayed above the forest canopy in subfreezing conditions so that it rained down and froze on contact with trees. The experiment included five ice storm intensities (0, 6.4, 12.7 and 19.1 mm radial ice accretion) applied in a single year, and one ice storm intensity (12.7 mm) applied in two consecutive years. Measurements of soil respiration were made with an infrared gas analyzer during the snow-free season before and after the ice was applied. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station. 

An ice storm simulation was performed at the Hubbard Brook Experimental Forest to evaluate impacts of these extreme weather events on northern hardwood forests. Water was pumped from the main branch of Hubbard Brook and sprayed above the forest canopy in subfreezing conditions so that it rained down and froze on contact with trees. The experiment included five ice storm intensities (0, 6.4, 12.7 and 19.1 mm radial ice accretion) applied in a single year, and one ice storm intensity (12.7 mm) applied in two consecutive years. Samples of soil solution chemistry were collected with lysimeters throughout the year before and after the ice was applied. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station. 

These data are from four separate projects undertaken between 1997 and 2017. The first of these are two snow manipulation (freeze) projects: 1) In 1997, as part of a study of the relationships between snow depth, soil freezing and nutrient cycling, we established eight 10 x 10-m plots located within four stands; two dominated (80%) by sugar maple (SM1 and SM2) and two dominated by yellow birch(YB1 and YB2), with one snow reduction (shoveling) and one reference plot in each stand. 2) In 2001, we established eight new 10-m x 10-m plots (4 treatment, 4 reference) in four new sites; two high elevation, north facing and (East Kineo and West Kineo) two low elevation, south facing (Upper Valley and Lower Valley) maple-beech-birch stands. To establish plots, we cleared minor amounts of understory vegetation from all (both treatment and reference) plots (to facilitate shoveling). Treatments (keeping plots snow free by shoveling through the end of January) were applied in the winters of 1997/98, 1998/99, 2002/2003 and 2003/2004. The Climate Gradient Project was established in October 2010. Here we evaluated relationships between snow depth, soil freezing and nutrient cycling along an elevation/aspect gradient that created variation in climate with little variation in soils or vegetation. We established 6 20 x 20-m plots (intensive plots) and 14 10 x 10-m plots (extensive plots), with eight of the plots facing north and twelve facing south. The Ice Storm project was designed to evaluate the damage and changes ice storms cause to northern hardwood forests in forest structure, nutrient cycling and carbon storage. Ten 20x30 meter plots were established in a predominately sugar maple stand, with 4 icing treatments and 2 control plots. The treatments are as follows: Low (0.25"), Mid (0.5"), Midx2 (0.5") 2 Years in a row, High: (0.75"), Control. The icing treatment was conducted in the winter of 2015-2016, with a second year of icing on the Midx2 treatments plots in the winter of 2016-2017. The treatments are as follows: Low (0.25"), Mid (0.5"), Midx2 (0.5") 2 Years in a row, High: (0.75"), Control. 

Abstract Ice storms are important winter weather events that can have substantial environmental, economic, and social impacts. Mapping and assessment of damage after these events could be improved by making ice accretion measurements at a greater number of sites than is currently available. There is a need for low-cost collectors that can be distributed broadly in volunteer observation networks; however, use of low-cost collectors necessitates understanding of how collector characteristics and configurations influence measurements of ice accretion. A study was conducted at the Hubbard Brook Experimental Forest in New Hampshire that involved spraying water over passive ice collectors during freezing conditions to simulate ice storms of different intensity. The collectors consisted of plates composed of four different materials and installed horizontally; two different types of wires strung horizontally; and rods of three different materials, with three different diameters, and installed at three different inclinations. Results showed that planar ice thickness on plates was 2.5–3 times as great as the radial ice thickness on rods or wires, which is consistent with expectations based on theory and empirical evidence from previous studies. Rods mounted on an angle rather than horizontally reduced the formation of icicles and enabled more consistent measurements. Results such as these provide much needed information for comparing ice accretion data. Understanding of relationships among collector configurations could be refined further by collecting data from natural ice storms under a broader range of weather conditions.