Manganese-coated IRIS to document reducing soil conditions

Iron-coated indicatorof 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 (\u3e11 °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 (\u3c11 °C) conditions

The recovery of European freshwater biodiversity has come to a halt

Owing to a long history of anthropogenic pressures, freshwater ecosystems are among the most vulnerable to biodiversity loss1. Mitigation measures, including wastewater treatment and hydromorphological restoration, have aimed to improve environmental quality and foster the recovery of freshwater biodiversity2. Here, using 1,816 time series of freshwater invertebrate communities collected across 22 European countries between 1968 and 2020, we quantified temporal trends in taxonomic and functional diversity and their responses to environmental pressures and gradients. We observed overall increases in taxon richness (0.73% per year), functional richness (2.4% per year) and abundance (1.17% per year). However, these increases primarily occurred before the 2010s, and have since plateaued. Freshwater communities downstream of dams, urban areas and cropland were less likely to experience recovery. Communities at sites with faster rates of warming had fewer gains in taxon richness, functional richness and abundance. Although biodiversity gains in the 1990s and 2000s probably reflect the effectiveness of water-quality improvements and restoration projects, the decelerating trajectory in the 2010s suggests that the current measures offer diminishing returns. Given new and persistent pressures on freshwater ecosystems, including emerging pollutants, climate change and the spread of invasive species, we call for additional mitigation to revive the recovery of freshwater biodiversity.N. Kaffenberger helped with initial data compilation. Funding for authors and data collection and processing was provided by the EU Horizon 2020 project eLTER PLUS (grant agreement no. 871128); the German Federal Ministry of Education and Research (BMBF; 033W034A); the German Research Foundation (DFG FZT 118, 202548816); Czech Republic project no. P505-20-17305S; the Leibniz Competition (J45/2018, P74/2018); the Spanish Ministerio de Economía, Industria y Competitividad—Agencia Estatal de Investigación and the European Regional Development Fund (MECODISPER project CTM 2017-89295-P); Ramón y Cajal contracts and the project funded by the Spanish Ministry of Science and Innovation (RYC2019-027446-I, RYC2020-029829-I, PID2020-115830GB-100); the Danish Environment Agency; the Norwegian Environment Agency; SOMINCOR—Lundin mining & FCT—Fundação para a Ciência e Tecnologia, Portugal; the Swedish University of Agricultural Sciences; the Swiss National Science Foundation (grant PP00P3_179089); the EU LIFE programme (DIVAQUA project, LIFE18 NAT/ES/000121); the UK Natural Environment Research Council (GLiTRS project NE/V006886/1 and NE/R016429/1 as part of the UK-SCAPE programme); the Autonomous Province of Bolzano (Italy); and the Estonian Research Council (grant no. PRG1266), Estonian National Program ‘Humanitarian and natural science collections’. The Environment Agency of England, the Scottish Environmental Protection Agency and Natural Resources Wales provided publicly available data. We acknowledge the members of the Flanders Environment Agency for providing data. This article is a contribution of the Alliance for Freshwater Life (www.allianceforfreshwaterlife.org).Peer reviewe

Case Study: Provisional, Forested Ecological Sites in the Northern Appalachians and Their State-and-Transition Models

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 Rangelands archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform March 202

Insights and approaches for mapping soil organic carbon as a dynamic soil property

Soil organic C (SOC) content is one of the most dynamic of soil properties. In this study, we examined the effects of land use change on SOC pools for a single soil series and developed a mapping approach to relate SOC dynamics to land use change. Six paired sites, consisting of adjacent agricultural field and forest within a single delineation, were sampled and the SOC pools determined. The average forest SOC pool (157 Mg ha-1) was significantly higher (P \u3c 0.05) than the field pool (103 Mg ha-1), supporting the importance of land use on SOC pools. We propose the development of a SOC phase based on land use to map such differences. Master O and A horizon data should be used to establish SOC phases. Data can be obtained from existing soil surveys, updates, or C accounting activities. Land use classes can be identified with digital imagery and SOC phases can be assigned to all mapping units. Mapping units sampled for C accounting can be resampled to detect patterns and rates of change. This approach provides a robust data set to effectively map and model SOC pools and change across the landscape. © Soil Science Society of America, 5585 Guilford Rd., Madison WI 53711 USA All rights reserved

The Use of LiDAR Terrain Data in Characterizing Surface Roughness and Microtopography

The availability of light detection and ranging data (LiDAR) has resulted in a new era of landscape analysis. For example, improvements in LiDAR data resolution may make it possible to accurately model microtopography over a large geographic area; however, data resolution and processing costs versus resulting accuracy may be too costly. We examined two LiDAR datasets of differing resolutions, a low point density (0.714 points/m2 spacing) 1 m DEM available statewide in Pennsylvania and a high point density (10.28 points/m2 spacing) 1 m DEM research-grade DEM, and compared the calculated roughness between both resulting DEMs using standard deviation of slope, standard deviation of curvature, a pit fill index, and the difference between a smoothed splined surface and the original DEM. These results were then compared to field-surveyed plots and transects of microterrain. Using both datasets, patterns of roughness were identified, which were associated with different landforms derived from hydrogeomorphic features such as stream channels, gullies, and depressions. Lowland areas tended to have the highest roughness values for all methods, with other areas showing distinctive patterns of roughness values across metrics. However, our results suggest that the high-resolution research-grade LiDAR did not improve roughness modeling in comparison to the coarser statewide LiDAR. We conclude that resolution and initial point density may not be as important as the algorithm and methodology used to generate a LiDAR-derived DEM for roughness modeling purposes

Mn-Coated IRIS to Document Reducing Soil Conditions

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 (\u3e11 °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 (\u3c11 °C) conditions

Data from: Soil chemistry, and not short-term (1-2 year) deer exclusion, explains understory plant occupancy in forests affected by acid deposition

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 northeastern United States. 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 modeled species was constant and high (p > 0.65), and occupancy probability of most taxa was best explained by at least 1 soil chemistry parameter. Specifically, ericaceous competing vegetation was more likely to occupy acidic (pH < 3.5), base cation poor (K < 0.20 cmolc/kg) sites, while deer-preferred plants were less likely to occur when soil manganese exceeded 0.1 cmolc/kg. 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 northcentral 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 unfavorable soil conditions. Future research should consider study designs that address the complexity of deer forest interactions, especially in areas with complex site-vegetation histories

Tree_Data_2014

Overstory tree measurements (>=5" dbh) at 24 sampling sites at Rothrock and Bald Eagle state forests in central Pennsylvania. See Vegetation_Metadata_2014.csv and Vegetation_Metadata_2014.csv for specific column descriptions and data formatting

Species_Code_List_2014

List of species names for abbreviation codes used in Tree_Data_2014.csv, Seedling_Data_2014.csv, and Cover_Data_204.cs