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'Manureshed' management guides the sustainable use of manure resources by matching areas of crop demand (nutrient sinks) with areas generating livestock manure (nutrient sources). A better understanding of the impacts of manureshed management on water quality within sensitive watersheds is needed. We quantified the potential water quality benefits of manureshed-oriented management through scenario-based analyses in the Susquehanna River Basin (SRB) using the Soil and Water Assessment Tool (SWAT). Five manureshed management scenarios were developed and compared with a baseline "business-as-usual" scenario. The baseline assumes manure is less transportable, which means some locations have manure application in excess of crop demand. The "watershed nutrient balance" scenarios assume excess manure from surplus locations are transportable, and manure is applied around the SRB based on crop nutrient demand. The "watershed nutrient balance avoiding runoff prone areas" scenarios assume manure is transportable but not applied in vulnerable landscapes of the SRB. Each scenario was evaluated under two application rates considering crop nitrogen demand (N-based) and phosphorus demand (P-based). P-based manureshed management was more effective in water quality improvements than N-based. P-based nutrient balance scenarios simulated 3% and 25% reduction in TN and TP from the baseline scenario at the watershed outlet. The N- and P-based scenarios avoiding runoff prone areas simulated 3% and 6% reduction in TN loss, and 4% and 25.2% reduction in TP loss respectively from the baseline. Overall, the manureshed management scenarios were more effective in improving the quality of local streams in livestock-intensive regions than at the watershed outlet. This article is protected by copyright. All rights reserved.Water quality outcomes of manureshed management were modeled using SWAT Redistributing manure based upon cropland nutrient requirements improved water quality N-based manuresheds allowed better targeting and placement of manure due to availability of receiving land P-based manuresheds prevented nutrient buildup in the soil and reduced nutrient loss.

Accurate and reliable forecasts of quickflow, including interflow and overland flow, are essential for predicting rainfall–runoff events that can wash off recently applied agricultural nutrients. In this study, we examined whether a gridded version of the Sacramento Soil Moisture Accounting model with Heat Transfer (SAC-HT) could simulate and forecast quickflow in two agricultural watersheds in east-central Pennsylvania. Specifically, we used the Hydrology Laboratory–Research Distributed Hydrologic Model (HL-RDHM) software, which incorporates SAC-HT, to conduct a 15-yr (2003–17) simulation of quickflow in the 420-km2 Mahantango Creek watershed and in WE-38, a 7.3-km2 headwater interior basin. We directly calibrated HL-RDHM using hydrologic observations at the Mahantango Creek outlet, while all grid cells within Mahantango Creek, including WE-38, were calibrated indirectly using scalar multipliers derived from the basin outlet calibration. Using the calibrated model, we then assessed the quality of short-range (24–72 h) deterministic forecasts of daily quickflow in both watersheds over a 2-yr period (July 2017–October 2019). At the basin outlet, HL-RDHM quickflow simulations showed low biases (PBIAS = 10.5%) and strong agreement (KGE″ = 0.81) with observations. At the headwater scale, HL-RDHM overestimated quickflow (PBIAS = 69.0%) to a greater degree, but quickflow simulations remained satisfactory (KGE″ = 0.65). When applied to quickflow forecasting, HL-RDHM produced skillful forecasts (>90% of Peirce and Gerrity skill scores above 0.5) at all lead times and significantly outperformed persistence forecasts, although skill gains in Mahantango Creek were slightly lower. Accordingly, short-range quickflow forecasts by HL-RDHM show promise for informing operational decision-making in agriculture. Significance Statement Daily runoff forecasts can alert farmers to rainfall–runoff events that have the potential to wash off recently applied fertilizers and manures. To gauge whether daily runoff forecasts are accurate and reliable, we used runoff monitoring data from a large agricultural watershed and one of its headwater tributaries to evaluate the quality of short-term runoff forecasts (1–3 days ahead) that were generated by a National Weather Service watershed model. Results showed that the accuracy and reliability of daily runoff forecasts generally improved in both watersheds as lead times increased from 1 to 3 days. Study findings highlight the potential for National Weather Service models to provide useful short-term runoff forecasts that can inform operational decision-making in agriculture.

BACKGROUND Water is critical to the production of crops, especially when faced with seasonal drought or freshwater scarcity. We compared the effect of negative pressure irrigation (NPI) on water use efficiency (WUE), nutrient uptake, yield and quality of Brassica chinensis L. using a greenhouse plot experiment. Three different water supply pressures (-5, -10 and -15 kPa), and a conventional irrigation (CK) treatment, were arranged in a randomized design with three replications. RESULTS Our results suggest that plant height, leaf area, number of leaves and ratio of root to shoot were significantly correlated with water supply pressure. Specifically, our results show that B. chinensis L. yield was increased 50% with NPI versus CK. Water supply pressure had a significant effect on N and P nutrient uptake and no significant effect on K. The average concentration of vitamin C was greatest with -5 kPa treatment and consecutively declined. According to our results, NPI can save up to 36.8% of water used and improve WUE by 61.3% during growth of B. chinensis L. Our results suggest that the optimum irrigation management strategy is -5 kPa treatment. CONCLUSION NPI versus CK can provide more stable irrigation water and retain soil moisture during plant growth, resulting in an increased WUE and yield with suitable water supply pressure. While our results suggest that NPI can enhance B. chinensis L. yield and perhaps also quality, future research should explore the mechanism of NPI in relation to yield and water use efficiency. © 2021 Society of Chemical Industry.

Temporal variation of soil moisture is one of the influencing factors affecting crop water use efficiency (WUE). Compared with fluctuating soil moisture (FSM), stable soil moisture (SSM) with weaker temporal variance has the potential to improve the WUE of crops. However, response of crop rhizosphere microbiome to soil moisture temporal variation remains unclear. In this study, we performed pot experiments on romaine lettuce (Lactuca sativa L. var. longifolia) to compare the effects of different soil moisture temporal variation on plant growth, yield, water use efficiency (WUE), and rhizosphere bacterial and fungal community structures, via manual irrigation and negative pressure irrigation to create FSM and SSM conditions, respectively. The results indicate that SSM improved the growth and WUE of romaine lettuce. Moreover, the rhizosphere microbial community composition of romaine lettuce differed under SSM and FSM conditions. Under SSM, bacterial Bacillus, fungal Aspergillus and Chaetomium were enriched in the romaine lettuce rhizosphere, whereas some taxa such as bacterial Devosia, Lysobacter, Blastococus and Bacillus, fungal Alternaria were reduced; these taxa could therefore be biomarkers in future research. Partial least squares path model (PLS-PM) analysis revealed that rhizosphere microbial communities were indirectly affected by the soil moisture temporal variation, as evidenced by the improvement in plant growth. Our results suggest that the rhizosphere microbial communities of romaine lettuce primarily respond to changes in the soil moisture temporal variation through the plant-microbiome interaction but are not directly affected by soil moisture.

Soil moisture and temperature are incorporated into Soil Taxonomy through the broad classes of moisture and temperature regimes. Although both are important variables in soil formation and land use, soil temperature regime (STR) is typically applied at the family level, whereas soil moisture regime (SMR) is applied at the suborder level. In this paper, we are questioning whether moving SMR to the family level will create a classification system that is more efficient and provide more information to the user at higher categories. The pros and cons of moving ustic, xeric, and udic SMRs from suborder to family category are discussed. To explore this potential change, we used Shannon diversity (Delta H) as an index of the information gain moving from order to suborder when classifying a soil. The analysis indicated a relatively small Delta H for most of the country considering current suborder classes. The proposed group of suborders, characterized by diagnostic horizons instead of SMR, conveyed a considerably larger Delta H supporting a substantial gain in information if the change was incorporated into Soil Taxonomy. The proposed change also has the potential to reduce the number of subgroup taxa by nearly 50%, without losing any of the current information within each taxa. Counterarguments for the change are that SMRs have soil genesis connotations and provide a way to group similar soils on broad-scale maps. A change in the hierarchy of SMRs within Soil Taxonomy could deemphasize the relevance of soil moisture to soil genesis, morphology, and ecology. Published version Public domain – authored by a U.S. government employee

China has become the largest carbon-emitting country in the world since 2007. To achieve national environmental goals by 2030, the carbon emissions per unit of gross domestic product (GDP) will need to fall to 60-65% of 2005 levels. Such a dramatic decrease presents a challenge for a nation in adjusting its energy source and usage, but via monitoring of reductions, greater understanding can be gained of how carbon emitters are responding to national goals. We analyzed the change in carbon emissions from China's fossil energy consumption from population, per capita GDP, energy efficiency improvements and energy structure using a Kaya identity model and Logarithmic Mean Divisia Index (LMDI) factor decomposition method from 2006 to 2018. Results suggest that trends in carbon emissions from 2006 to 2018 can be broken down into four periods: a rapid increase period during 2006-2011, a slowdown increase period during 2011-2014, a consecutive decline period during 2014-2016 and a rebound during 2017-2018. Trends in carbon emissions were greatly affected by per capita GDP and energy efficiency. While per capita GDP increased carbon emissions, energy efficiency had a countering effect on carbon emissions. Our results suggests that China's measures in the past decade to reduce carbon emissions (i.e. carrying out carbon emissions trading on a fixed basis, readjusting the economic structure, optimizing the energy structure, improving energy efficiency and increasing forest carbon sinks) have helped to reduce carbon emissions. However, China should continue to actively respond to climate change while striving to achieve of economic sustainable development and social progress.

Nutrition is fundamental to white-tailed deer (Odocoileus virginianus) management given its relationship to habitat carrying capacity and population productivity. Ecological Sites (ESs) are a United States federal landscape management unit of specific land potential due to unique soils, topography, climate, parent material, and perhaps deer forage nutritional value. We present results of a study that extends the use of ESs to inform white-tailed deer management by evaluating indicator plant chemistry in two spring forb species, Indian cucumber root (Medeola virginiana) and Canada mayflower (Maianthemum canadense), across the northcentral Appalachians. We sampled spring forbs and underlying soils across two ESs: Dry, upland, oak-maple-hemlock hardwood forest (OMH) and Deep soil, high slope, northern hardwood forests (NHF). Plant elemental content, soil pH, and site aspect, slope and elevation were measured. Our results show that forb chemistry differs between species and within a species geographically. Indian cucumber root, as compared to Canada mayflower, has significantly higher Mg, Na, Cu, Fe, and Zn, and lower Mn. Canada mayflower in the NHF ES, versus OMH ES, was found to have significantly higher K, Mn, and B. Indian cucumber root in the NHF ES, versus the OMH ES, was found to have significantly higher Mg, Al, Fe, and Ca:P ratio but lower K. Linear discriminant analysis shows that plant tissue Mn was the best discriminator between species, and between ESs, Canada mayflower plant tissue Mn and Indian cucumber plant tissue P, K, Ca, Mg and Mn were best discriminators. Given that nutrition determines habitat carrying capacity, differences in forage nutrition between ESs may have different potentials to support deer. Forage nutrition is an important aspect of deer habitat conditions and carrying capacity, thus ESs are likely to support deer populations with different growth potential, which means that even if the same plant species occur in different ESs their nutritional value to deer may differ.

Iron-coated indicator of reduction in soils (IRIS) devices have been used for nearly two decades to help assess and document reducing conditions in soils, and official guidance has been approved for interpreting these data. Interest in manganese (Mn)-coated IRIS devices has increased because Mn oxides are reduced under more moderately reducing conditions than iron (Fe) oxides (which require strongly reducing conditions), such that they are expected to be better proxies for some important ecosystem services like denitrification. However, only recently has the necessary technology become available to produce Mn-coated IRIS, and the need is now emerging for guidance in interpreting data derived from Mn IRIS. Ninety-six data sets collected over a 2-yr period from 40 plots at 18 study sites among eight states were used to compare the performance of Mn-coated IRIS with Fe-coated IRIS and to assess the effect of duration of saturation and soil temperature as environmental drivers on the reduction and removal of the oxide coating. It appears that the current threshold prescribed by the National Technical Committee for Hydric Soils for Fe-coated IRIS is appropriate for periods when soil temperatures are warmer (>11 °C), but is unnecessarily conservative when soil temperatures are cooler (5–11 °C). In contrast, Mn-coated devices are particularly useful early in the growing season when soil temperatures are cool. Our data show that when using a threshold of 30% removal of Mn oxide coatings there is essentially 100% confidence of the presence of reducing soil conditions under cool (

Background Identifying the behavioral state for wild animals that can’t be directly observed is of growing interest to the ecological community. Advances in telemetry technology and statistical methodologies allow researchers to use space-use and movement metrics to infer the underlying, latent, behavioral state of an animal without direct observations. For example, researchers studying ungulate ecology have started using these methods to quantify behaviors related to mating strategies. However, little work has been done to determine if assumed behaviors inferred from movement and space-use patterns correspond to actual behaviors of individuals. Methods Using a dataset with male and female white-tailed deer location data, we evaluated the ability of these two methods to correctly identify male-female interaction events (MFIEs). We identified MFIEs using the proximity of their locations in space as indicators of when mating could have occurred. We then tested the ability of utilization distributions (UDs) and hidden Markov models (HMMs) rendered with single sex location data to identify these events. Results For white-tailed deer, male and female space-use and movement behavior did not vary consistently when with a potential mate. There was no evidence that a probability contour threshold based on UD volume applied to an individual’s UD could be used to identify MFIEs. Additionally, HMMs were unable to identify MFIEs, as single MFIEs were often split across multiple states and the primary state of each MFIE was not consistent across events. Conclusions Caution is warranted when interpreting behavioral insights rendered from statistical models applied to location data, particularly when there is no form of validation data. For these models to detect latent behaviors, the individual needs to exhibit a consistently different type of space-use and movement when engaged in the behavior. Unvalidated assumptions about that relationship may lead to incorrect inference about mating strategies or other behaviors.

Abrupt changes in a forest ecosystem, whether natural or anthropogenic, are changes that occur over short time periods; such disturbance has the potential to drive state changes and alter forest resilience. Understanding how present-day abrupt forest change may alter ecosystem services is becoming more important due to ever-growing anthropogenic stresses. Forest managers trying the adapt to anthropogenic stress can benefit from the study and quantification of past abrupt changes in forests, especially when the legacy of past disturbance is still evident. Across the United Kingdom, Europe, and recently the northeastern United States, the examination of historic forest change due to charcoal manufacturing for the firing of iron or lime furnaces is yielding new insights relative to landscape stability, anthropogenic vs natural soil genesis, and forest evolution. We present results of a study that strives to evaluate how historic land clearing for the charcoal industry (supporting iron furnaces) affected local soils and may drive surrounding present day forest composition. We incorporate field sampling of hearth soils and modeled hydrologic parameters (in hearth and non-hearth areas), to quantify the uniqueness of relict charcoal hearth (RCH) systems. We identified 1,239 hearths using a LiDAR terrain analysis; approximately 10% of these were visited to quantify hearth morphology and soil moisture differences on and off hearth. Nine hearths from this 10% were intensively sampled and were associated with a northern Appalachian, USA furnace that was in operation from 1867 to 1904. Three profiles were excavated across each hearth and compared to an adjacent soil profile on the same contour. Soil descriptions were made of hearths and soil samples analyzed for total, trace and rare earth element content (Aqua Regia digestion). Soil pH (water) and fertility (Mehlich III extraction) were also determined. Results indicate that hearths have a unique geochemistry with higher bases and some concentrated metals and higher organic carbon. Coupled with a higher hearth soil water content, hypothesized to be due to an observed restrictive subsurface morphology and higher organic carbon, hearths are potentially unique locations of refugia for forest flora and fauna. Future research should more closely investigate whether hearths support unique species assemblages and how they may play a role in enhancing today’s forest biodiversity.

Across much of the Mid-Atlantic United States and Europe, relict charcoal hearths (RCHs) are a common landscape feature once used as a primary fuel source for iron smelting and quick-lime production. We investigated a landscape surrounding the Monroe Furnace in central Pennsylvania, which was in operation for around 17 years until 1846. This preliminary investigation explores landscape patterns of hearth placement in relation to the furnace and landscape position and resulting potential effect on soil moisture. We mapped RCHs using LiDAR derived hillshade models of varying aspects, elevation, and slope. We classified the different shapes of RCHs in relation to their geomorphic positions and modeled both a topographic and soil wetness index for selected hearths and off-hearth locations nearby. Two hearths were sampled in the field and their morphology and soil properties investigated.Hearths that were constructed on flatter slope gradients are seemingly more circular in shape and have more equal axes whereas steep slopes have a more oval shape elongated in one axis with the slope direction. More circular hearths are on or near flatter hillslope positions (such as on summits or shoulders) whereas eye-like shaped hearths are on steeper hillslope positions (like backslopes). Based on initial topographic wetness index data, hearths are not acting as sinks for flow but instead often cause water to flow around them leading to drier conditions within RCHs.Trenches alongside the slope orthogonal direction of the two sampled RCHs show a single layered stratigraphy, i.e. both sides had only one continuous technogenic, charcoal rich layer. The downslope half of both sites had generally higher contents of macroscopic charcoal pieces as well as buried colluvial- and buried fossilized A-horizons underlying the charcoal rich layer. Both sites are not perfectly levelled, but slightly sloped. Buried B- and colluvial horizons show signs of heat induced reddening of iron oxides on the top few centimeters. Preliminary results suggest significant differences in soil chemical and physical properties of the technogenic layer in comparison to the adjacent forest soils.

Throughout the northeastern United States and Europe, relic charcoal hearths (RCHs) are more regularly being discovered in proximity to furnaces used for iron or quick-lime production; charcoal was used as a primary fuel source in the furnaces. RCHs have been found across parts of Europe and Connecticut, USA in different hillslope positions, on vary degrees of slope and aspect, all of which can be a factor affecting the shape of the RCH. Their usage for charcoal production varied with the time period, furnaces were in operation with some hearths being used once and older ones (such as in Europe) being used multiple times. RCHs across the northcentral Appalachians, USA have been minimally investigated, thus determining where they occur on the landscape, their shape, and their morphologic positions will be useful in discerning their effect on surface hydrology and soil development. Our study focuses on developing a repeatable process for: finding RCHs and quantifying how RCHs may alter surface hydrology. We used a combination of processed LiDAR data to create hillshades, and slope gradients to visualize RCHs. A total of 6,758 hearths have been digitized across three study areas that reflect different historical time periods of construction and environments. We hypothesize that the construction of RCHs can alter the surface hydrology of their surrounding environments. To fully quantify the landscape-level effects of RCHs, a subset of the total was created to fully digitize the RCHs’ area. The RCH was broken into their rim and platform components. A topographic wetness index (TWI), and SAGA wetness index (SWI) was created for two study areas in order to quantify surface hydrology effects. We found that RCH platforms have a significantly higher TWI and SWI than the rim counterparts indicating that the platform is wetter than the RCH outer rims. Geomorphic position was found to not effect wetness. Using field measured volumetric water content, we found that as distance from the center of the hearth increases, the drier the soil becomes. Using a combination of GIS flow path analysis, and RCH geometry, standardized ellipses using the axis of local RCHs and the mean area of the total RCHs were created to understand the upslope (control) and downslope (experiment) effects of hearths on the surface hydrology. Preliminary analysis indicates that downslope positions from RCHs are drier than upslope positions and that there is a significant difference in the relationship between slope position and distance from an RCH and the corresponding TWI and SWI values. Future research will address the effect of slope position and distance to quantify the effect of RHCs on surface hydrology. Furthermore, the soil chemical changes from RCH creation and the increase moisture may increase the habitat for rare species of both plants and animals that otherwise would not be present. Understanding the extent of the impact human activity can have on various ecosystems can help forest managers, conservationists, pedologists, and climatologists better adapt their management or research pursuits within a specific environment to prepare for future changes, natural or anthropogenic.

The use of phytoextraction plant species to accumulate soil metals into harvestable plant parts is a method used for managing soils with high cadmium (Cd). We evaluated three Cd accumulating species recently recommended for such use in cacao farms where Cd removal is needed to maintain markets: Helianthus annuus (sunflower), Brassica napus (rapeseed), and Chyrsopogon zizanioides (vetiver). Plants were grown in two greenhouse pot experiments with different Cd-spiked growth media: (sand plus perlite) and a natural soil. Plant total Cd and Cd uptake in shoot biomass of all species, across both experiments, increased linearly with increasing amounts of added Cd. Rapeseed had the highest plant total Cd and sunflower had the highest Cd uptake in shoot biomass. The highest application of Cd corresponded to the highest plant total Cd and shoot biomass Cd uptake, regardless of species. The bioconcentration factor (BCF) for each species increased in a curvilinear manner with added Cd, with maximum BCF values for plants grown in the sand and perlite matrix at 2.5 mg kg−1 added Cd and in the natural soil at 5.0 mg kg−1 added Cd. We conclude that the Cd uptake (shoot biomass only) capability of the three species examined is greatest for sunflower given its increased uptake with Cd additions, its BCF value > 1, and lack of observed visual Cd toxicity symptoms, fungus and insect damage. Although these species had BCF >1, the potential annual removal of Cd would have been too small to support a meaningful phytoextraction practice.

Efforts to reduce insecticide inputs against plum curculio, Conotrachelus nenuphar, a key pest of apples in eastern North America, include perimeter-row insecticide sprays applied after the whole-orchard petal fall spray to manage dispersing adults and, more recently, insecticide sprays confined to odor-baited trap trees. Entomopathogenic nematodes (EPNs) are virulent to ground-dwelling stages of C. nenuphar, and may be applied to the ground underneath trap-tree canopies. Here, we (1) compared the efficacy of the odor-baited trap tree approach with grower-prescribed (=grower standard) sprays to manage C. nenuphar populations over a six-year period in seven commercial apple orchards in New England, and (2) assessed the performance of the EPN Steinernema riobrave at suppressing ground-dwelling stages of C. nenuphar. In addition, the performance of S. riobrave was compared against that of S. carpocapsae and S. feltiae in one year. Across the six years, percent fruit injury on trap tree plots averaged 11.3% on odor-baited trap trees and 1.4% on unbaited trees in grower standard plots, highlighting the ability of trap trees to aggregate C. nenuphar activity and subsequent injury. Mean percentage injury on fruit sampled from interior trees, the strongest measure of treatment performance, in trap tree plots did not differ significantly from that recorded on interior trees in grower standard spray plots (0.95 vs. 0.68%, respectively). Steinernema riobrave consistently reduced C. nenuphar populations as indicated by the significantly lower number of adult C. nenuphar that emerged from the soil, when compared to water control. Steinernema carpocapsae and S. riobrave performed similarly well, and both EPN species outperformed S. feltiae. Our combined findings indicate that an IPM approach that targets multiple life stages of C. nenuphar has the potential to manage this pest more sustainably in a reduced-spray environment.

Eastern United States loess mapped by the U.S. Department of Agriculture, National Resources Conservation Service (USDA-NRCS) mostly occurs near major river systems like the Delaware and Susquehanna Rivers. The proximity of loess along major river valleys suggests late-Quaternary glacial meltwater sediments were dominant sediment sources for loess. Based on differing lithologies of meltwater deposits in these systems, we hypothesize that loess in each river system has a unique geochemical and mineralogical signature. To test this hypothesis, we examined pedons developed in loess parent materials, and adjacent to either the Delaware or West-Branch of the Susquehanna River, both of which carried large amounts of Wisconsinan outwash. Soils were analyzed for particle size distribution, clay mineralogy, and coarse and fine silt particle density, mineralogy, and geochemistry. Results show that while the pedons are similar in morphology, substantial differences exist in the pedons' textures, mineralogies, and geochemical compositions. We attribute the differences to parent material differences that stem from lithologically distinct sediment sources for loess from the two river systems. Susquehanna River loess has a higher particle density, and lower abundance of minerals such as Zr, base oxides (such as CaO), and rare earth elements. Discriminant analysis results suggest that developing a “loess fingerprint” for each river system based on major, minor and rare earth elements is possible, and likely to be useful in differentiating sources; however coarse silts may be a more effective fraction (than fine silts) for sediment sourcing, especially if rare earth elements are used.

Throughout the northeastern United States and Europe, relic charcoal hearths (RCHs) are more regularly being discovered in proximity to furnaces used for iron or quick-lime production; charcoal was used as a primary fuel source in the furnaces. RCHs have been found across parts of Europe and Connecticut, USA in different hillslope positions, on vary degrees of slope and aspect, all of which can be a factor affecting the shape of the RCH. Their usage for charcoal production varied with time period furnaces were in operation with some hearths being used once and older ones (such as in Europe) being used multiple times. RCHs across the northcentral Appalachians, USA have been minimally investigated, thus determining where they occur on the landscape, their shape, and their morphologic positions will be useful in discerning their effect on surface hydrology and soil development. Our study focuses on developing a repeatable process for: finding RCHs, classifying the different shapes or styles of the hearths in relation to their geomorphic positions and quantifying how RCHs may alter surface hydrology. We used a combination of processed LiDAR to create hillshades of varying light angles and altitude, and slope gradient maps derived from the same LiDAR, to visually digitize > 6,100 hearths. A subset of the mapped hearths was ground-truthed for accuracy of the methodology. For our study, three areas in the mid-Appalachian region of Pennsylvania were chosen for study in order to reflect different historical time periods of construction and environments. A goal of our study is to determine the age of hearths. We hypothesize that using a calculated 3D distance to nearby furnaces, hearths closer to furnaces will be the oldest and have a higher likelihood of being used multiple times resulting in multiple layers of charcoal-enriched substrate. An initial analysis of RCHs indicates a relationship between slope gradient and hearth shape. Hearths constructed on flatter slope gradients are seemingly more circular in shape and have more equal axes whereas steep slopes have a more oval shape being elongated in one axis and shortened on the other. Likewise, there may be a relationship between hillslope position and the shape of the RCHs such as more circular hearths are on or near flatter hillslope positions (such as on summits or shoulders) whereas oval shaped hearths are on steeper hillslope positions (like backslopes). We also modeled the effect of RCHs on hydrology. Based on a combination of topographic wetness index data and geomorphology, hearths are not acting as sinks for surface flow but instead often cause water to flow around them leading to slightly drier conditions within RCHs. Future work will address site-specific monitoring of hearth temperature and moisture, and hearth carbon decomposition dynamics in relation to temp and moisture conditions.

Pleistocene dynamics are usually associated with the formation of characteristic landforms such as moraines, dunes, or kettle holes. However, cold climate processes can also shape the landscape but not result in such prominent relief features. This is especially true for slope deposits that have been formed in periglacial regions through geli-solifluction and/or cryoturbation. While the terms used to refer to such slope deposits may differ with the disciplines of soil science and/or geomorphology, such features are often still recognized by practicing scientists. In the US, geli-solifluction and/or cryoturbation features are subsumed with a very general term ‘colluvium’ whereas in Europe a more sophisticated number of terms is used separating sediments which formed under cold climate processes from sediments which formed due to anthropogenic induced soil erosion. Our study focuses on the stratigraphy of late Quaternary deposits and the soil formation in the northern Appalachians. The study area wasn’t glaciated during the Wisconsin glaciation; hence no MIS 5 or younger glacial deposits are reported.To advance a common terminology between geoscientist, we examined pedons representative of Holocene and periglacial dynamics that reflect the strong role that solifluction played in pre and MIS 5landscape dynamics. Especially on foot slopes and toe slopes pedon stratigraphy is characterized by a several meter-thick par-autochthonous deposits that are rich in clasts. Clasts in deposits are aligned with the slope direction and are imbricated; on back slopes par-autochthonous deposits are also present but more shallow. Stratigraphy and OSL chronology strongly suggests that during the late Pleistocene several phases of morphodynamics shaped the landscape via solifluction followed by an eolian input of silt to the soils/sediments. Geochemistry reflects the multi-layer character of the soil profiles showing clear differences between the bedrock and deposits above. Elevated values of manganese in the surface soil indicate the importance of plant litter biocylcing during the Holocene. Hence on a landscape scale, the distribution of soils and the pedogenesis is strongly related to the par-autochthonous character of the substrate rather than the bedrock.

Although many agricultural watersheds rely heavily on riparian buffer adoption to meet water quality goals, design and management constraints in current policies create adoption barriers. Based on focus group feedback, we developed a flexible buffer design paradigm that varies buffer width, vegetation, and harvesting. Sixteen years of daily-scale nutrient and sediment loads simulated with the Soil and Water Assessment Tool (SWAT) were coupled to the three-zone Riparian Ecosystem Management Model (REMM) to compare the effectiveness of traditional, policy-based buffer designs with designs that are more flexible and integrate features important to local farmers. Buffer designs included (i) 10 m grass, (ii) 15 m grass, (iii) 15 m deciduous trees, (iv) 30 m grass and trees, (v) 30 m grass and trees with trees harvested every 3 yr, and (vi) 30 m grass and trees with grass harvested every year. Allowing harvesting in one zone of the buffer vegetation (either trees or grasses) minimally affected water quality, with annual average percent reductions differing by 5% (p .05; 76-78% for total nitrogen [TN], 51-55% for total phosphorus [TP], and 68% for sediment). Under the highest input loading conditions, buffers with lower removal efficiencies removed more total mass than did buffers with high removal efficiencies. Thus, by focusing on mass reduction in addition to percent reduction, watershed-wide buffer implementation may be better targeted to TN, TP, and sediment reduced. These findings have important implications for informing flexible buffer design policies and enhanced placement of buffers in watersheds impaired by nutrient and sediment.

To avoid competition with food crops, biofuel feedstocks may need to be produced on economically marginal lands where yields are limited and replacement of existing vegetation will reduce soil C, foregoing some CO2 emission savings. Therefore, our first goal was to determine whether biochar application to marginal lands could improve switchgrass yield while sequestering sufficient soil C to eliminate the negative impact of cultivation. Because it may be difficult to obtain large quantities of biochar, our second goal was to compare small, incremental and large, all-at-once biochar applications. Our third goal was to determine whether biochar had any negative effects on earthworms, mycorrhizal fungi, soil bacteria, soil fungi, and soil enzyme activity. We grew switchgrass at two sites with poorly drained soils and two sites with excessively drained soils. Irrespective of site, biochar significantly increased yield when we rototilled in the entire amount before planting but not when we applied it incrementally between crop rows using a chisel plow. Biochar increased soil C stocks, in some cases increasing it beyond that found in soils of intact marginal land vegetation. Nevertheless, mixing biochar with soil had little or no impact on earthworm activity, mycorrhizal colonization, soil bacterial and fungal communities, and soil enzyme activities. We conclude that biochar may be part of an effective strategy for producing switchgrass on marginal lands, but the choice of application method depends on the relative importance of several considerations including biochar availability, switchgrass yield, C sequestration, soil erosion, and ease of application.

Soil magnetic parameters are increasingly being linked to climatic and environmental variation, and thus provide an useful information for tracking perturbations in terrestrial environments. Climat...

Mercury methylation, where inorganic mercury (Hg) is converted to methylmercury (MeHg), can increase in soils when flooded. While effects of the initial flooding of soils on MeHg production have been well studied, less is known about impacts of re-flooding on MeHg production. Lake Perez, an impounded recreational reservoir in the Appalachian Highlands, was completely drained then re-filled 7 years later. We use a combination of chemical, soil physical, and microbial data to quantify changes in MeHg before and after re-flooding of the lakebed. Portions that were transiently saturated due to pluvial flooding had the highest pre-flooded MeHg concentrations. When the lake was re-flooded, concentrations of MeHg in subaqueous soils increased by a factor of 2.74 (+174%) on average. Substantial variability was observed among the sampling sites, with smaller increases in MeHg at sites subjected to seasonal flooding during periods when the reservoir was drained. The increase of soil MeHg after re-flooding was lower in this study compared to studies that evaluated soil MeHg after initial flooding, indicating that re-flooding of a former lake bed caused a smaller response in MeHg production compared to initial flooding of terrestrial land. This study advances understanding of the environmental impact of impounded reservoirs.

The advent of real-time, short-term farm management tools is motivated by the need to protect water quality above and beyond the general guidance offered by existing nutrient management plans. Advances in high-performance computing and hydrologic or climate modeling have enabled rapid dissemination of real-time information that can assist landowners and conservation personnel with short-term management planning. This paper reviews short-term decision support tools for agriculture that are under various stages of development and implementation in the United States: (i) Wisconsin's Runoff Risk Advisory Forecast (RRAF) System, (ii) New York's Hydrologically Sensitive Area Prediction Tool, (iii) Virginia's Saturated Area Forecast Model, (iv) Pennsylvania's Fertilizer Forecaster, (v) Washington's Application Risk Management (ARM) System, and (vi) Missouri's Design Storm Notification System. Although these decision support tools differ in their underlying model structure, the resolution at which they are applied, and the hydroclimates to which they are relevant, all provide forecasts (range 24-120 h) of runoff risk or soil moisture saturation derived from National Weather Service Forecast models. Although this review highlights the need for further development of robust and well-supported short-term nutrient management tools, their potential for adoption and ultimate utility requires an understanding of the appropriate context of application, the strategic and operational needs of managers, access to weather forecasts, scales of application (e.g., regional vs. field level), data requirements, and outreach communication structure. USDA-NRCS Conservation Innovation Grants This review was supported, in part, by USDA-NRCS Conservation Innovation Grants to improve P indexing and modeling and to improve short-term forecasting tools for nutrient management planning.

Many areas in the world are characterized by shallow soils underlain by weathered bedrock, but root-rock interactions and their implications for regolith weathering are poorly understood. To test the role of tree roots in weathering bedrock, we excavated four pits along a catena in a shale-dominated catchment at the Susquehanna Shale Hills Critical Zone Observatory (SSHCZO) in central Pennsylvania. We measured a variety of biological, physical, and chemical properties including: 1) root density, distribution, and respiration, 2) soil gas, and 3) elemental compositions, mineralogy, and morphology of soil, rock, and rock fracture fill at ridge top, mid-slope, toe-slope, and valley floor sites. As expected, root density declined rapidly with depth; nevertheless, fine roots were present in rock fractures even in the deepest, least weathered shale sampled (~ 180 cm below the land surface). Root densities in shale fractures were comparable between the ridge top and mid-slope pits. However, they were significantly lower in the toe-slope, despite increasing rock fracture densities, which is likely due to a shallower water table depth at the downslope site. Average root respiration (per mass of dry root tissue) in rock fractures was comparable to rates in the soil. Thus, the total flux of CO2 from root respiration tracked root densities, decreasing with depth. Potential microbial respiration, estimated as the laboratory C mineralization potential, was about an order of magnitude lower than measured root respiration in both the soil and shale fractures. Roots were only observed in large aperture (> 50 μm) shale fractures that were filled with particulate material. The fill in these fractures was mineralogically and geochemically similar to the lowest soil horizons with respect to clay composition, element mobility, extractable dissolved organic C (DOC), inorganic N-species, and potentially mineralizable C and N, while total C and total N values for the fracture fill were similar to the shale bedrock. In the bulk soil, depletion profiles (Al, Fe, K, Mg, and Si) relative to unweathered shale reflected characteristic weathering of illite and vermiculized chlorite to kaolinite and are similar between soils and fracture fill. Such similarities indicate that the fracture coatings are likely the result of pedogenic processes that occur at depth in the fractures rather than translocation of soil particles downward into the fractures. Overall, our data suggest that roots and fill in shale fractures down to ~ 180 cm are qualitatively similar to those in surface soil horizons. Thus, the deepest manifestation of the chemical depletion profiles observed in the pits consists of the rock fracture fill, and this fill is present at low concentrations with similarly low concentrations of fine roots.

Large, continuous forest provides critical habitat for some species of forest dependent wildlife. The rapid expansion of shale gas development within the northern Appalachians results in direct loss of such habitat at well sites, pipelines, and access roads; however the resulting habitat fragmentation surrounding such areas may be of greater importance. Previous research has suggested that infrastructure supporting gas development is the driver for habitat loss, but knowledge of what specific infrastructure affects habitat is limited by a lack of spatial tracking of infrastructure development in different land uses. We used high-resolution aerial imagery, land cover data, and well point data to quantify shale gas development across four time periods (2010, 2012, 2014, 2016), including: the number of wells permitted, drilled, and producing gas (a measure of pipeline development); land use change; and forest fragmentation on both private and public land. As of April 2016, the majority of shale gas development was located on private land (74% of constructed well pads); however, the number of wells drilled per pad was lower on private compared to public land (3.5 and 5.4, respectively). Loss of core forest was more than double on private than public land (4.3 and 2.0%, respectively), which likely results from better management practices implemented on public land. Pipelines were by far the largest contributor to the fragmentation of core forest due to shale gas development. Forecasting future land use change resulting from gas development suggests that the greatest loss of core forest will occur with pads constructed farthest from pre-existing pipelines (new pipelines must be built to connect pads) and in areas with greater amounts of core forest. To reduce future fragmentation, our results suggest new pads should be placed near pre-existing pipelines and methods to consolidate pipelines with other infrastructure should be used. Without these mitigation practices, we will continue to lose core forest as a result of new pipelines and infrastructure particularly on private land.

Most empirical studies of field management effects on runoff water quality rely on edge-of-field monitoring, which is generally unreplicated and prone to high variances, or small plots, which constrain the use of conventional farm equipment and can hinder insight into landscape processes that drive hydrology. We sought to develop field-scale lysimeters that were sufficiently large to support assessment of landscape processes but also replicated to allow quantitative comparisons of hydrologic processes. A hillslope underlain by limestone bedrock with a recent history of hydrologic observation was selected in central Pennsylvania. Twelve 15 m x 27 m plots were established and defined by earthen berms on all sides to isolate and collect overland flow, along with tile drains to collect shallow lateral flow. Over three years, considerable variability in site hydrology was observed between lysimeters, highlighting differences in the extent of hydrologic isolation of some lysimeters as well as in flows that potentially bypassed our collection infrastructure. Even so, clear patterns were observed in surface and subsurface flow that enabled grouping of plots based on hydrologic similarities. Results illustrate the experimental opportunities and limitations of developing field-scale lysimeters for agronomic inference.

Browsing ungulates alter forest productivity and vegetation succession through selective foraging on species that often dominate early succession. However, the long-term and large-scale effects of browsing on forest succession are not possible to project without the use of simulation models. To explore the effects of ungulates on succession in a spatially explicit manner, we developed a Browse Extension that simulates the effects of browsing ungulates on the growth and survival of plant species cohorts within the LANDIS-II spatially dynamic forest landscape simulation model framework. We demonstrate the capabilities of the new extension and explore the spatial effects of ungulates on forest composition and dynamics using two case studies. The first case study examined the long-term effects of persistently high white-tailed deer browsing rates in the northern hardwood forests of the Allegheny National Forest, USA. In the second case study, we incorporated a dynamic ungulate population model to simulate interactions between the moose population and boreal forest landscape of Isle Royale National Park, USA. In both model applications, browsing reduced total aboveground live biomass and caused shifts in forest composition. Simulations that included effects of browsing resulted in successional patterns that were more similar to those observed in the study regions compared to simulations that did not incorporate browsing effects. Further, model estimates of moose population density and available forage biomass were similar to previously published field estimates at Isle Royale and in other moose-boreal forest systems. Our simulations suggest that neglecting effects of browsing when modeling forest succession in ecosystems known to be influenced by ungulates may result in flawed predictions of aboveground biomass and tree species composition.

The evolution of phosphorus (P) management decision support tools (DSTs) and systems (DSS), in support of food and environmental security has been most strongly affected in developed regions by national strategies (i) to optimize levels of plant available P in agricultural soils, and (ii) to mitigate P runoff to water bodies. In the United States, Western Europe, and New Zealand, combinations of regulatory and voluntary strategies, sometimes backed by economic incentives, have often been driven by reactive legislation to protect water bodies. Farmer-specific DSSs, either based on modeling of P transfer source and transport mechanisms, or when coupled with farm-specific information or local knowledge, have typically guided best practices, education, and implementation, yet applying DSSs in data poor catchments and/or where user adoption is poor hampers the effectiveness of these systems. Recent developments focused on integrated digital mapping of hydrologically sensitive areas and critical source areas, sometimes using real-time data and weather forecasting, have rapidly advanced runoff modeling and education. Advances in technology related to monitoring, imaging, sensors, remote sensing, and analytical instrumentation will facilitate the development of DSSs that can predict heterogeneity over wider geographical areas. However, significant challenges remain in developing DSSs that incorporate "big data" in a format that is acceptable to users, and that adequately accounts for catchment variability, farming systems, and farmer behavior. Future efforts will undoubtedly focus on improving efficiency and conserving phosphate rock reserves in the face of future scarcity or prohibitive cost. Most importantly, the principles reviewed here are critical for sustainable agriculture.

Meeting the growing food production needs of a society, while simultaneously maintaining or improving water quality, is a challenge facing many watersheds around the world. Across many nations, the agricultural norm is for farmers to dictate what, when and where to plant based on market demand and the most economically efficient use of land resources for the individual farm enterprise. As an alternative, the European Union (EU) has explored the potential of a soil-based, land use framework to achieve economic and environmental targets in agriculturally dominated watersheds; however, this framework has not been explored in the United States (US). We investigated the potential for an EU style soil-based, land use framework to improve water quality, while maintaining crop yields, in a sub-watershed of the Chesapeake Bay. The Soil and Water Assessment Tool (SWAT) was utilized to model crop growth, and losses of total nitrogen (TN), total phosphorus (TP) and sediment for an 8-year period (2010 - 2017). Based on SWAT model results, an algorithm was developed to spatially reallocate crop rotations within existing agricultural land to reduce TN, TP, and sediment losses based on soil properties while maintaining a similar production area of each rotation. Hay was reallocated onto landscapes most vulnerable to erosion and nutrient loss, whereas corn-soybean rotations were reallocated onto less vulnerable areas. In the reallocated scenario, 28% of agricultural lands retained the same crop rotation as the baseline scenario while 72% were reassigned. In a SWAT simulation of the reallocated scenario, TN, TP and sediment losses were reduced by 15%, 14% and 39%, respectively at an average annual scale. These results suggest that simply redistributing crop rotations within an impaired watershed can make significant water quality improvements even without additional structural best management practices. Although watershed-scale benefits were evaluated here, future research is needed to understand how this approach affects farm-level factors, as implementation may require some farmers to change the type of crops they grow.

Localized management of white-tailed deer (Odocoileus virginianus) involves the removal of matriarchal family units with the intent to create areas of reduced deer density. However, application of this approach has not always been successful, possibly because of female dispersal and high deer densities. We developed a spatially explicit, agent-based model to investigate the intensity of deer removal required to locally reduce deer density depending on the surrounding deer density, dispersal behavior, and size and shape of the area of localized reduction. Application of this model is illustrated using the example of abundant deer populations in Pennsylvania, USA. Most scenarios required at least 5 years before substantial deer density reductions occurred. Our model indicated that a localized reduction was successful for scenarios in which the surrounding deer density was lowest (30 deer/mi²), localized antlerless harvest rates were ≥ 30%, and the removal area was ≥ 5 mi² . When the size of the removal area was

On the Ground•The identification of unique areas of vegetative potential across the Northern Appalachians is complicated by a long land-use history of vegetation management.•We introduce provisional ecological sites and associated state-and-transition models for the region, which can be differentiated by latitudinal drivers of: precipitation and temperature; local parent material and resulting soil differences; and landscape position, slope, or aspect.•Identification of ecological sites and associated States or Phases in the Northern Appalachians provides land managers with quantifiable benchmarks for assessing forest compositional shifts due to natural or anthropogenic disturbance.

The recent availability of 1-m laser imaging, detection, and ranging (LiDAR) data in Pennsylvania provides a high resolution digital elevation model (DEM) which could improve on existing USDA-NRCS Order 2 soil survey mapping. The ability of LiDAR derived terrain indices to predict hydric soil presence was evaluated across the Northern Appalachians. We developed a logistic regression model to predict hydric soil presence using a dataset of 1153-field data points and several terrain indices derived from LiDAR DEMs. The best performing regression model included slope derived from a 1-m LiDAR DEM, depressions derived from a 5-m LiDAR DEM, and physiographic region. This model was able to successfully predict 67% of hydric soils and 73% of non-hydric soils from a validation dataset. The model performed better at predicting non-hydric soils compared with hydric soils and was not as effective in low slope areas. This suggests that the 1-m LiDAR hydrologic variables used in the study cannot completely account for soil hydric status.

Across the northcentral Appalachians, USA, high silt content soils are found as silty mantles or deep, high silt content pedons. The origin of such soils can be attributed to additions of wind-blown dust deposits (WBD) or local parent materials (i.e. shales or siltstone lithology). Previous research on silt soils originating specifically from WBD attributed to late marine isotope stage (MIS) 2 loess has often been isolated to drainageways receiving outwash from deglaciation. We hypothesize that thin (

Identifying areas of environmental exposure potential for humans due to contaminated soils is an ever growing concern for cities with extensive industrial histories. We applied a Potential Ecological Risk Index (RI) to evaluate the contamination degree of hazardous elements in soils from Linfen, northern China. The city has experienced extensive industrial pollution over time and is home to ～676,500 people. We analyzed in 0–10 and 10–20 cm soil depth the spatial distribution, sources and potential ecological risks of heavy metals (Cr, Ni, Cu, Zn, As and Pb) across Linfen in order to derive a human exposure risk map. Results indicate that the mean urban topsoil concentrations of Ni, Zn, As and Pb were 36.24 mg·kg−1, 91.41 mg·kg−1, 15.20 mg·kg−1 and 28.12 mg·kg−1, respectively, and exceeded corresponding background values. The coefficient of variation of Cu, Zn and Pb was greater than 50%, suggesting high variation in urban area. Contamination factor indices for Ni, Zn, As and Pb were higher than 1 and suggests urban soils in Linfen are moderately contaminated. The calculated 47.1% integrated pollution load index was higher than 1 and suggests that half of the city has an increasing pollution risk. The spatial variability of the Pollution Load Index and Risk Index suggest moderately to strongly contaminated areas in the east and center areas of the city. Our data suggest that Ni, As and Pb have the potential for posing the greatest ecological risk at most city sites and likely originated from numerous sources (vehicular traffic, exhaust, coal combustion, metal manufacturing and other anthropogenic activities) given the disparate spatial pattern and elevated concentrations relative to native soil background values.

Via magnetic susceptibility and X-ray fluorescence spectrometry, we examined soil heavy metal contents across an abandoned steel and iron plant that has been in production for 50 years. Soil magnetic susceptibility and heavy metal contents similarly decreased with increasing distance from the plant's industrial, central area. Results indicate that the mean value of soil magnetic susceptibility was 2727 × 10−8 m3·kg−1 and the max peak was 100 m from the plant's center. Frequency dependent susceptibility values less than 2%, suggest the presence of coarse grains from industrial activities. A significant positive correlation occurs between magnetic susceptibility and Mn, Fe, Cu and Pb. Irregular-shaped and non-spherical aggregates are the main morphology of technogenic magnetic particles found in soil samples. Our results indicate that the North, Northeast and East sampling areas generally have the highest pollutants values and these directions correspond with prevailing wind directions at differing times of the year. Mapping the spatial distribution of metals could lead to high-resolution risk targeting areas for remediation and land use planning.

Riparian buffers are a widely adopted agricultural best management practice due to their ability to reduce sediment and nutrient loads to streams. Current efforts in the Commonwealth of Pennsylvania to incentivize widespread adoption of riparian buffers have fallen short as the state struggles to be in compliance with Chesapeake Bay restoration goals. Constrained buffer design in current policies has been identified as one of the barriers to adoption, and therefore this research explores the water quality tradeoffs that may result from a more flexible buffer design paradigm. The Spring Creek watershed in central Pennsylvania was selected as the case study watershed to test the effectiveness of four different buffer designs (variations in vegetation and width) and two alternative buffer management scenarios that involved harvesting of either grass or trees from the buffer. Three crop rotations were simulated in the Soil & Water Assessment Tool (SWAT), with nutrient and sediment loads coupled to the Riparian Ecosystem Management Model (REMM) to better understand how input loads affect the effectiveness of a specific buffer design and how the effectiveness of a buffer design changes as a function of input load. Simulations were run at a daily scale for 16 years, allowing annual-scale performance as well as event-specific performance to be investigated. The results revealed that knowing annual removal efficiency of a buffer is insufficient and that adoption recommendations should be made based on loads treated by the buffer, as higher nutrient and sediment masses may be reduced by buffers with lower removal efficiencies.

This study compared water-use efficiency (WUE) and nutrient absorption of Glebionis coronaria L. through emitters of ceramic tube (CT) and polyvinyl formal (PF) under negative pressure irrigation. Three (↓4 kPa, ↓8 kPa, ↓12 kPa) water-supply treatments and artificial watering (CK) with pot experiments were investigated. The results showed that soil water content ranged from 18.1 to 27.2% with CT and 18.5–27.6% with PF, respectively. A decrease of water supply pressure resulted in a gradual decrease of water supply, water consumption, and nitrogen content of Glebionis coronaria L., whereas the contents of phosphorus and potassium gradually increased. The soil water content, plant height, yield, nutrient uptake, and WUE of plants irrigated with the PF emitter were superior to those irrigated with the CT emitter. The best water supply model was a water supply pressure of ↓4 kPa during the early growth stage and ↓8 kPa in the middle and late stages. Thus, water supply pressure has significant effects on the growth and development, yield, WUE, and nutrient absorption of Crown Daisy.

The loss of species diversity and plant community structure throughout the temperate deciduous forests of North America have often been attributed to overbrowsing by white-tailed deer (Odocoileus virginanus). Slow species recovery following removal from browsing, or reduction in deer density, has been termed a legacy effect of past deer herbivory. However, vegetation legacy effects have also coincided with changes to soil chemistry throughout the north-eastern USA. In this paper, we assess the viability of soil chemistry (i.e. pH, extractable nutrients and extractable metals) and other factors (topography, light, overstory basal area and location) as alternative explanations for a lack of vegetation recovery. We compared the relative effects of soil chemistry, site conditions and short-term (1–2 year) deer exclusion on single-species occupancy probabilities of 10 plant taxa common to oak-hickory forests in central Pennsylvania. We found detection for all modelled species was constant and high (p^ > 0.65), and occupancy probability of most taxa was best explained by at least one soil chemistry parameter. Specifically, ericaceous competing vegetation was more likely to occupy acidic (pH < 3.5), base cation-poor (K < 0.20 cmolc kg−1) sites, while deer-preferred plants were less likely to occur when soil manganese exceeded 0.1 cmolc kg−1. Short-term deer exclusion did not explain occupancy of any plant taxon, and site conditions were of nominal importance. This study demonstrates the importance of soil chemistry in shaping plant community composition in the north-central Appalachians, and suggests soil as an alternative, or additional, explanation for deer vegetation legacy effects. We suggest that the reliance on phyto-indicators of deer browsing effects may overestimate the effects of browsing if those species are also limited by unfavourable soil conditions. Future research should consider study designs that address the complexity of deer forest interactions, especially in areas with complex site-vegetation histories.

Riparian wetlands are well known for providing the important ecosystem service of carbon storage. However, changes in land-use regimes surrounding riparian wetlands have been shown to result in alterations to the wetland plant community. These plant community changes have the potential to alter litter quality, decomposition rates, and ultimately the capacity of riparian wetlands to store carbon. To determine the effects of plant community shifts associated with disturbance on decomposition and carbon inputs, we performed a yearlong decomposition experiment using in situ herbaceous material, leaf litter, and control litter and examined biomass inputs in six headwater riparian wetlands in central Pennsylvania. Two sites were classified as Hemlock-Mixed Hardwood Palustrine Forest, two were classified as Broadleaf Palustrine Forest, and two were classified as Reed Canary Grass-Floodplain Grassland (Zimmerman et al. 2012). Plant matter with greater initial percent C, percent lignin, and lignin:N ratios decomposed more slowly while plant matter with greater initial cellulose decomposed more quickly. However, no significant differences were found between plant community types in decomposition rate or amount of carbon remaining at the end of the experiment, indicating that the differences in plant community type did not have a large impact on decomposition in riparian wetlands. This work has important implications for studies that examine the decomposition dynamics of a few select species, as they may not capture the decomposition dynamics of the plant community and thus extrapolating results from these studies to the larger ecosystem may be inappropriate.