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As the interface between plants and soil, the organic horizon is the foundation of forest ecosystems. Two potential predictors of O-layer properties, vegetation and mineral soil type, are difficult to separate because they typically covary. We conducted a factorial study involving four canopy tree species and two soil types with distinctly different hydrology and topographic position to parse patterns in chemistry and microbiota of the O-layer in a north-temperate deciduous forest. 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. 

Hydrologic behavior and soil properties across forested landscapes with complex topography exhibit high variability. The interaction of groundwater with spatially distinct soils produces and transports solutes across catchments, however, the spatiotemporal relationships between groundwater dynamics and soil solute fluxes are difficult to directly evaluate. While whole-catchment export of solutes by shallow subsurface flow represents an integration of soil environments and conditions but many studies compartmentalize soil solute fluxes as hillslope vs. riparian, deep vs. shallow, or as individual soil horizon contributions. This potentially obscures and underestimates the hillslope variation and magnitude of solute fluxes and soil development across the landscape. This study determined the spatial variation and of shallow soil base cation fluxes associated with weathering reactions (Ca, Mg, and Na), soil elemental depletion, and soil saturation dynamics in upland soils within a small, forested watershed at the Hubbard Brook Experimental Forest, NH. Base cation fluxes were calculated using a combination of ion-exchange resins placed in shallow groundwater wells (0.3 – 1 m depth) located across hillslope transects (ridges to lower backslopes) and measurements of groundwater levels. Groundwater levels were also used to create metrics of annual soil saturation. Base cation fluxes were positively correlated with soil saturation frequency and were greatest in soil profiles where primary minerals were most depleted of base cations (i.e., highly weathered). Spatial differences in soil saturation across the catchment were strongly related to topographic properties of the upslope drainage area and are interpreted to result from spatial variations in transient groundwater dynamics. Results from this work suggest that the structure of a catchment defines the spatial architecture of base cation fluxes, likely reflecting the mediation of subsurface stormflow dynamics on soil development. Furthermore, this work highlights the importance of further compartmentalizing solute fluxes along hillslopes, where certain areas may disproportionately contribute solutes to the whole catchment. Refining catchment controls on base cation generation and transport could be an important tool for opening the black box of catchment elemental cycling. 

Cone Pond Watershed: Soil Profiles (Pedons), 1988-2023 This dataset documents pedons (soil profiles) sampled at Cone Pond Watershed, Thornton, New Hampshire. Since the early 1980’s, Cone Pond, on the Pemigewasset District of the White Mountain National Forest, has been an active research satellite site to the nearby Hubbard Brook Experimental Forest. In 1988, intensive monitoring began as part of a comprehensive watershed scale ecosystem study. A weir was built on the main inlet stream, just above its mouth at Cone Pond, to monitor streamflow. Two rain gages were installed to monitor atmospheric deposition and multiple studies of major ecosystem components were initiated. Soil profiles documented in this dataset were sampled between 1988 and 2003. All descriptive profile and horizon data as well as chemical analyses of samples of genetic horizons are included in this dataset. Samples from 123 of these horizons have been accessioned into the Hubbard Brook physical sample archive; the archived mass of each is included in the horizon table. In addition to these pedons sampled in detail, a number of reconnaissance observations, made at a lower level of detail, and without sampling, were made in 2023 in order to validate a hydropedologic soil model created at Hubbard Brook. These data are included in a separate table. 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. 

This dataset documents all pedons (soil profiles) that have been located with GPS (2 meter horizontal accuracy) and have been described by genetic horizon for the Hubbard Brook Experimental Forest, within the White Mountain National Forest, NH. Soil profiles were observed between 1995 and 2022 and have been described and sampled at two levels of detail. Soil profiles in the pedon table were dug to bedrock or into the C horizon except where high boulder content limited excavation. The depth of all major soil horizons was measured and most pedons had descriptions written and physical samples collected. The horizon table contains physical observations and chemical analyses for the horizons sampled in the pedon table. Over 2500 of these horizons have had physical samples accessioned into the Hubbard Brook sample archive; the archived mass is included in the horizon table. The reconnaissance table includes pedons observed at a lower level of detail. Small pits were generally dug to a depth of 40 cm or greater, and minimal observations, as needed, were recorded to classify the soil profile by soil map unit (hpu). These data were collected to supplement the detailed observations in the previous two data tables in support of development of a spatial model of soil distribution for the entire Hubbard Brook Experimental Forest. No samples were collected from reconnaissance pits. 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. 

This dataset consists of raster files predicting spatial patterns in soils for the entire Hubbard Brook Experimental Forest. Eight soil units are used, following a hydropedologic approach, based on relationships between soil genetic horizon presence and thickness, and the frequency and depth of groundwater fluctuations. Nine raster files on a five-meter grid are presented, including one raster each showing the probability of presence of each of the eight soil units; the ninth raster represents the soil unit most likely to be present at each grid cell. The methods section of the metadata includes descriptions of the eight soil units and guidance for users of the model outputs. 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. 

This dataset consists of groundwater levels measured within wells distributed across Watershed 3 at Hubbard Brook Experimental Forest from 2007-2020. Water levels are expressed as a depth (cm) from the soil surface. This dataset is a part of a larger project aimed at explaining the spatial and temporal variation in stream water chemistry at the headwater catchment scale using a framework based on the combined study of hydrology and soil development – hydropedology. The project will demonstrate how hydrology strongly influences soil development and soil chemistry, and in turn, controls stream water quality in headwater catchments. Understanding the linkages between hydrology and soil development can provide valuable information for managing forests and stream water quality. Feedbacks between soils and hydrology that lead to predictable landscape patterns of soil chemistry have implications for understanding spatial gradients in site productivity and suitability for species with differing habitat requirements or chemical sensitivity. Tools are needed that identify and predict these gradients that can ultimately provide guidance for land management and silvicultural decision making. Better integration between soil science, hydrology, and biogeochemistry will provide the conceptual leap needed by the hydrologic community to be able to better predict and explain temporal and spatial variability of stream water quality and understand water sources contributing to streamflow. 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. 

Mineral weathering is an important soil-forming process driven by the interplay of water, organisms, solution chemistry, and mineralogy. The influence of hillslope-scale patterns of water flux on mineral weathering in soils is still not well understood, particularly in humid postglacial soils, which commonly harbor abundant weath- erable primary minerals. Previous work in these settings showed the importance of lateral hydrologic patterns to hillslope-scale pedogenesis. In this study, we hypothesized that there is a corresponding relationship between hydrologically driven pedogenesis and chemical weathering in podzols in the White Mountains of New Hamp- shire, USA. We tested this hypothesis by quantifying the depletion of plagioclase in the fine fraction (≤2 mm) of closely spaced, similar-age podzols along a gradient in topography and depth to bedrock that controls lateral water flow. Along this gradient, laterally developed podzols formed through frequent, episodic flushing by up- slope groundwater, and vertically developed podzols formed through characteristic vertical infiltration. We estimated the depletion of plagioclase-bound elements within the upper mineral horizons of podzols using mass transfer coefficients (τ) and quantified plagioclase losses directly through electron microscopy and microprobe analysis. Elemental depletion was significantly more pronounced in the upslope lateral eluvial (E horizon- dominant) podzols relative to lateral illuvial (B horizon-dominant) and vertical (containing both E and B hori- zons) podzols downslope, with median Na losses of ~74 %, ~56 %, and ~40 %, respectively. When comparing genetic E horizons, Na and Al were significantly more depleted in laterally developed podzols relative to vertically developed podzols. Microprobe analysis revealed that ~74 % of the plagioclase was weathered from the mineral pool of lateral eluvial podzols, compared to ~39 % and ~23 % for lateral illuvial podzols and vertically developed podzols, respectively. Despite this intense weathering, plagioclase remains the second most abundant mineral in soil thin sections. These findings confirm that the concept of soil development as occurring vertically does not accurately characterize soils in topographically complex regions. Our work improves the current understanding of pedogenesis by identifying distinct, short-scale gradients in mineral weathering shaped by local patterns of hydrology and topography. 

Hbr363: WS3 One year of resin-extracted solutes from variably saturated soils The Lateral Weathering Study looks at spatial patterns of mineral weathering processes at Hubbard Brook Experimental Forest. This project is characterizing mineral and elemental depletion/enrichment, soil morphology and chemistry, solute transport, and groundwater chemistry along hydropedological gradients. This dataset provides the total elemental mass of inorganic solutes (Ca, Na, Mg, Al, Fe, Mn, P, and S) as well as dissolved organic carbon (DOC) that were extracted off resins installed into shallow groundwater wells (~30-100cm) in Watershed 3. Resin packs were deployed for a total of one year (August 2019-2020) with four consecutive deployment periods, to avoid overloading resin ion capacity. Total mass for each solute was accounted for an entire resin pack, which was 5cm in height and 5cm in diameter, containing approximately 90 g of resin. Resin packs were installed in three different topographic positions along three transects (sites = 9), to characterize solute mass fluxes through different hydropedological units. 

Soil pits and horizons were described and sampled as part of the Lateral Weathering project within Watershed 3, Hubbard Brook Experimental Forest, Woodstock, NH, USA from 2018-2020. Soil pits were dug and described using NRCS methods. When possible, physical samples were archived in the Hubbard Brook Sample Archive. 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. 

This dataset consists of chemical analyses of subsurface water samples collected from Watershed 3, Hubbard Brook Experimental Forest, Woodstock, NH, USA from 2009-2020. Samples include groundwater samples pumped from monitoring wells, grab samples of natural groundwater seeps, and soil water samples pumped from Prenart lysimeters. For samples from wells where water table was monitored, depth to water table is given. 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.