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At least 1,153 records · Page 64Linked to original sources
USGS2016

Critical elements in sediment-hosted deposits (clastic-dominated Zn-Pb-Ag, Mississippi Valley-type Zn-Pb, sedimentary rock-hosted Stratiform Cu, and carbonate-hosted Polymetallic Deposits): A review: Chapter 12

Some sediment-hosted base metal deposits, specifically the clastic-dominated (CD) Zn-Pb deposits, carbonate-hosted Mississippi Valley-type (MVT) deposits, sedimentary-rock hosted stratiform copper deposits, and carbonate-hosted polymetallic (“Kipushi type”) deposits, are or have been important sources of critical elements including Co, Ga, Ge, and Re. The generally poor data concerning trace element concentrations in these types of sediment-hosted ores suggest that there may be economically important concentrations of critical elements yet to be recognized.

Book chapter↗
USGS1963

Quantitation of microorganic compounds in waters of the Great Lakes by adsorption on activated carbon

Microorganic compounds in waters of Lakes Michigan and Huron have been sampled by adsorption on activated carbon in filters installed aboard the M/V Cisco and at the Hammond Bay Laboratory of the U.S. Bureau of Commercial Fisheries. The organic compounds were eluted from the carbon according to techniques developed at the U.S. Public Health Service. On the assumption that chloroform eluates represent less polar compounds from industrial sources and alcohol eluates the more polar varieties of natural origin, plots of chloroform eluates against alcohol eluates appear to be useful in judging water qualities. Based upon these criteria, the data in this paper indicate that both the waters of northern Lake Michigan and of Lake Huron, in the vicinity of Hammond Bay, Michigan, are relatively free from pollution. The limnetic waters of Lake Michigan showed a particularly high ratio of alcohol to chloroform eluates. Data for monthly samples indicated that this ratio fluctuated seasonally. The periodicity of the fluctuations was similar to those of lake levels and water temperatures.

Conference Paper↗
USGS1986

Hydrology of carbonate aquifers in southwestern Linn County and adjacent parts of Benton, Iowa, and Johnson Counties, Iowa

Groundwater is the major source of water in Linn County and the surrounding area. Approximately 90 percent of the groundwater production is from Silurian, Devonian, and Quaternary aquifers. The Silurian and Devonian aquifers consist of limestone and dolomite with minor shale beds, which have a regional dip to the southwest of approximately 20 feet per mile. The Silurian aquifer in east-central Iowa is confined from below by Upper Ordovician, Maquoketa Formation shales, and from above by the Kenwood Member of the Wapsipinicon Formation and the Otis and Bertram formations. The Quaternary aquifer consists of unconsolidated sand and gravel beds in the glacial drift, and in the alluvium which is associated with modern streams. The alluvium consists of lenticular beds of poorly-to well-sorted silt, sand, and gravel. The sand and gravel beds are interlayered with relatively-impermeable beds of till, silt, and clay. Water moves through the Silurian aquifer in part due to a complex distribution of porous and dense carbonate facies. Horizons containing skeletal molds in the Silurian dolomite have porosities as much as 39 percent, and are laterally equivalent to dolomites with porosities as little as less than one percent. Because of subsequent fracturing and solutional enlargement of these porous horizons, hydrologic correlation of the primary water-yielding zones is not always possible. One horizon, however, does occur approximately 70 to 105 feet above the base of the Silurian, and is the most consistently productive water-yielding unit in the area. This horizon is Informally referred to as the Farmers Creek aquifer. The potentiometric surface of the Silurian aquifer has a gradient towards the Cedar River, indicating discharge from the aquifer through the alluvium into the river. By comparison, the potentiometric surface of the overlying Devonian aquifer is equal to that of the Silurian and may range to more than 40 feet higher. Yields to individual wells completed in the Silurian and Devonian carbonate aquifers vary from less than 10 to about 500 gallons per minute. Individual wells completed in the Quaternary aquifer yield as much as 2,000 gallons per minute. Water analyses from the Devonian and Silurian aquifers indicate that they are of similar chemical quality at most locations in the study area. However, they may commonly contain concentrations of sulfate that exceed 1,000 mil grams per liter. Dissolved-solids concentrations as much as 2,350 milligrams per liter occur in the Silurian aquifer in the western and southwestern part of the study area. Water from the Quaternary aquifer generally is suitable for most uses and dissolved-solids concentrations generally are less than 750 milligrams per liter.

Iowa↗
USGS2024

Methodology for inclusion of produced and stored carbon dioxide in the U.S. Geological Survey Federal lands greenhouse gas inventory

The U.S. Geological Survey (USGS) has developed two new carbon dioxide (CO2) emissions and sequestration accounting methods for use in future reports. The first method is a Federal lease-produced CO2 emissions calculation for an update of the report, “Federal Lands Greenhouse Gas Emissions and Sequestration in the United States.” The methodology to incorporate Federal lease CO2 production emissions into the updated report relies on CO2 sales royalty data from the Office of Natural Resources Revenue (ONRR). The end usage points for the gas include enhanced oil recovery with CO2 (CO2-EOR), food and beverage, and chemical production. CO2-EOR is the main end point for natural CO2 production in the United States; it accounted for 94% of usage in 2022 [1]. Federal lands emissions from this sector are estimated at 460 metric tons of CO2 in 2022, a very small amount relative to most other Federal lands emissions sector estimates. The second new method, planned for a separate report, is a calculation of the geologic storage of CO2 on Federal lands. The second method estimates the CO2 stored under Federal surface lands and documents Federal climate change mitigation efforts. Currently, there is no storage of CO2 at an industrial level on Federal lands, however multiple proposals and projects are planned. This method was developed on non-Federal lands datasets in an effort to prepare for when these activities on Federal lands will require accounting. National estimates for CO2 geologic storage using this method, but without a Federal lands filtering step, totaled 8.0 million metric tons (Mt) in 2022. The two methods described here are new benchmark methods in a collection of accounting procedures to document the current state of greenhouse gas emissions and their storage on Federal lands. These benchmarks can then be used to measure any subsequent changes in emissions from or carbon storage beneath Federal lands. While the magnitude of the values is currently non-existent to small, emissions mitigation goals established by decision makers indicate that these values will grow, and their documentation will take on greater value and use.

continental United States↗
USGS2026

In-situ geochronology using LA-ICP-MS/MS: Application of the Lu-Hf system in carbonate, apatite and fluorite

Geochronology is a fundamental tool for reconstructing earth history and constraining the timing of ore deposit formation. Traditionally, U-rich minerals like zircon, titanite, monazite and apatite have been analysed to determine the timing of mineralization and alteration events. However, not all deposits or alteration assemblages contain these minerals, and the U-Pb system can be disturbed due to open system behaviour. We present a methodology for obtaining in-situ Lu-Hf dates from various minerals to demonstrate the potential for dating ore deposits that lack U-rich minerals. Carbonate, apatite and fluorite minerals from different tectonic settings and geological environments were analysed. We acquired Lu-Hf and REE (rare earth element) data from carbonate minerals from a carbonatite orebody and dike samples from the Mountain Pass REE carbonatite deposit in California, USA. We also tested a ‘double-dating’ method, where U-Th-Pb dates and Lu-Hf dates were obtained from the same analysis of apatite from rocks in the Michigan’s Great Lakes Tectonic Zone. Preliminary results for Lu-Hf dating of fluorite from carbonatite rocks in the Lemitar Mountains of New Mexico are also included. The analytical methodology shows promising results in each of these cases where there is sufficient parent Lu and U and measurable daughter Hf and Pb respectively.

Conference Paper↗
USGS2001

Adsorption of sulfur dioxide on ammonia-treated activated carbon fibers

A series of activated carbon fibers (ACFs) and ammonia-treated ACFs prepared from phenolic fiber precursors have been studied to elucidate the role of pore size, pore volume, and pore surface chemistry on adsorption of sulfur dioxide and its catalytic conversion to sulfuric acid. As expected, the incorporation of basic functional groups into the ACFs was shown as an effective method for increasing adsorption of sulfur dioxide. The adsorption capacity for dry SO2 did not follow specific trends; however the adsorption energies calculated from the DR equation were found to increase linearly with nitrogen content for each series of ACFs. Much higher adsorption capacities were achieved for SO2 in the presence of oxygen and water due to its catalytic conversion to H2SO4. The dominant factor for increasing adsorption of SO2 from simulated flue gas for each series of fibers studied was the weight percent of basic nitrogen groups present. In addition, the adsorption energies calculated for dry SO2 were shown to be linearly related to the adsorption capacity of H2SO4 from this flue gas for all fibers. It was shown that optimization of this parameter along with the pore volume results in higher adsorption capacities for removal of SO2 from flue gases. ?? 2001 Elsevier Science Ltd. All rights reserved.

Carbon↗
USGS1997

Adsorption of SO 2 onto oxidized and heat-treated activated carbon fibers (ACFs)

A series of activated carbon fibers (ACFs) and heat-treated oxidized ACFs prepared from phenolic fiber precursors have been studied to elucidate the role of pore size, pore surface chemistry and pore volume for the adsorption of SO 2 and its catalytic conversion to H 2 SO 4 . For untreated ACFs, the initial rate of SO 2 adsorption from flue gas was shown to be inversely related to pore size. At longer times, the amount of SO 2 adsorbed from flue gas was dependent on both the pore size and pore volume. Oxidation of the ACFs, using an aqueous oxidant, decreased their adsorption capacity for SO 2 from flue gas due to a decrease in pore volume and repulsion of the SO 2 from acidic surface groups. If these samples were heat-treated to desorb the oxygen containing function groups, the amount of SO 2 adsorption increased. This increase in adsorption capacity was directly correlated to the amount of CO 2 evolved during heat-treatment of the oxidized ACFs. The amount of SO 2 adsorbed for these samples was related to the pore size, pore surface chemistry and pore volume. This analysis is explained in more detail in this paper.

Carbon↗
USGS2007

An estimate of carbon emissions from 2004 wildfires across Alaskan Yukon River Basin

Background Wildfires are an increasingly important component of the forces that drive the global carbon (C) cycle and climate change as progressive warming is expected in boreal areas. This study estimated C emissions from the wildfires across the Alaskan Yukon River Basin in 2004. We spatially related the firescars to land cover types and defined the C fractions of aboveground biomass and the ground layer (referring to the top 15 cm organic soil layer only in this paper) consumed in association with land cover types, soil drainage classes, and the C stocks in the ground layer. Results The fires led to a burned area of 26,500 km 2 and resulted in the total C emission of 81.1 ± 13.6 Tg (Tg, Teragram; 1 Tg = 10 12 g) or 3.1 ± 0.7 kg C m -2 burned. Of the total C emission, about 73% and 27% could be attributed to the consumption of the ground layer and aboveground biomass, respectively. Conclusion The predominant contribution of the ground layer to the total C emission implies the importance of ground fuel management to the control of wildfires and mitigation of C emissions. The magnitude of the total C emission depends on fire extent, while the C loss in kg C m -2 burned is affected strongly by the ground layer and soil drainage condition. The significant reduction in the ground layer by large fires may result in profound impacts on boreal ecosystem services with an increase in feedbacks between wildfires and climate change.

Carbon Balance and Management↗
USGS2013

National assessment of geologic carbon dioxide storage resources: Results

In 2012, the U.S. Geological Survey (USGS) completed an assessment of the technically accessible storage resources ( TA SR ) for carbon dioxide (CO 2 ) in geologic formations underlying the onshore and State waters area of the United States. The formations assessed are at least 3,000 feet (914 meters) below the ground surface. The TA SR is an estimate of the CO 2 storage resource that may be available for CO 2 injection and storage that is based on present-day geologic and hydrologic knowledge of the subsurface and current engineering practices. Individual storage assessment units (SAUs) for 36 basins were defined on the basis of geologic and hydrologic characteristics outlined in the assessment methodology of Brennan and others (2010, USGS Open-File Report 2010–1127) and the subsequent methodology modification and implementation documentation of Blondes, Brennan, and others (2013, USGS Open-File Report 2013–1055). The mean national TA SR is approximately 3,000 metric gigatons (Gt). The estimate of the TA SR includes buoyant trapping storage resources ( B SR ), where CO 2 can be trapped in structural or stratigraphic closures, and residual trapping storage resources, where CO 2 can be held in place by capillary pore pressures in areas outside of buoyant traps. The mean total national B SR is 44 Gt. The residual storage resource consists of three injectivity classes based on reservoir permeability: residual trapping class 1 storage resource ( R1 SR ) represents storage in rocks with permeability greater than 1 darcy (D); residual trapping class 2 storage resource ( R2 SR ) represents storage in rocks with moderate permeability, defined as permeability between 1 millidarcy (mD) and 1 D; and residual trapping class 3 storage resource ( R3 SR ) represents storage in rocks with low permeability, defined as permeability less than 1 mD. The mean national storage resources for rocks in residual trapping classes 1, 2, and 3 are 140 Gt, 2,700 Gt, and 130 Gt, respectively. The known recovery replacement storage resource ( KRR SR ) is a conservative estimate that represents only the amount of CO 2 at subsurface conditions that could replace the volume of known hydrocarbon production. The mean national KRR SR , determined from production volumes rather than the geologic model of buoyant and residual traps that make up TA SR , is 13 Gt. The estimated storage resources are dominated by residual trapping class 2, which accounts for 89 percent of the total resources. The Coastal Plains Region of the United States contains the largest storage resource of any region. Within the Coastal Plains Region, the resources from the U.S. Gulf Coast area represent 59 percent of the national CO 2 storage capacity.

Circular↗
USGS2000

Effects of asynchronous snowmelt on flushing of dissolved organic carbon: A mixing model approach

In many snowmelt-dominated catchments, stream dissolved organic carbon (DOC) levels typically increase rapidly as spring melt commences, peak before maximum discharge, and decrease quickly as melting continues. We present data from Deer Creek (Summit County, CO) that shows this distinctive flushing response of DOC during snowmelt runoff, with DOC stored in landscape soils flushed to the stream in response to infiltrating melt waters. Our prior studies show that asynchronous melting of the snowpack across the landscape causes the spring DOC flush to be initiated at different times throughout the catchment. In this study we quantify characteristics of the asynchronous melt and its effect on DOC flushing. We investigated whether a simple mixing model can be used to capture the essentials of the asynchronous melting of a seasonal snowpack and its controls on DOC transport. We divided the catchment into zones of aspect and elevation, which largely determine spatial and temporal variations in the distribution of snow. TOPMODEL was used to simulate the hydrology in each zone, and the simulated flow paths were routed through a simple DOC mixing model to predict contributions of DOC to the stream. The zonal responses were aggregated to give a predicted response of hydrology and DOC fluxes for the entire catchment. Our results indicate that asynchronous melting-which determines the timing of contributions of discharge and DOC to streamflow from different areas of the landscape-can be quantified using a simple modeling approach.

Hydrological Processes↗
USGS2015

Soil greenhouse gas emissions and carbon budgeting in a short-hydroperiod floodplain wetland

Understanding the controls on floodplain carbon (C) cycling is important for assessing greenhouse gas emissions and the potential for C sequestration in river-floodplain ecosystems. We hypothesized that greater hydrologic connectivity would increase C inputs to floodplains that would not only stimulate soil C gas emissions but also sequester more C in soils. In an urban Piedmont river (151 km 2 watershed) with a floodplain that is dry most of the year, we quantified soil CO 2 , CH 4 , and N 2 O net emissions along gradients of floodplain hydrologic connectivity, identified controls on soil aerobic and anaerobic respiration, and developed a floodplain soil C budget. Sites were chosen along a longitudinal river gradient and across lateral floodplain geomorphic units (levee, backswamp, and toe slope). CO 2 emissions decreased downstream in backswamps and toe slopes and were high on the levees. CH 4 and N 2 O fluxes were near zero; however, CH 4 emissions were highest in the backswamp. Annual CO 2 emissions correlated negatively with soil water-filled pore space and positively with variables related to drier, coarser soil. Conversely, annual CH 4 emissions had the opposite pattern of CO 2 . Spatial variation in aerobic and anaerobic respiration was thus controlled by oxygen availability but was not related to C inputs from sedimentation or vegetation. The annual mean soil CO 2 emission rate was 1091 g C m −2  yr −1 , the net sedimentation rate was 111 g C m −2  yr −1 , and the vegetation production rate was 240 g C m −2  yr −1 , with a soil C balance (loss) of −338 g C m −2  yr −1 . This floodplain is losing C likely due to long-term drying from watershed urbanization.

Virginia↗
USGS2014

Lattice Boltzmann methods applied to large-scale three-dimensional virtual cores constructed from digital optical borehole images of the karst carbonate Biscayne aquifer in southeastern Florida

Digital optical borehole images at approximately 2 mm vertical resolution and borehole caliper data were used to create three-dimensional renderings of the distribution of (1) matrix porosity and (2) vuggy megaporosity for the karst carbonate Biscayne aquifer in southeastern Florida. The renderings based on the borehole data were used as input into Lattice Boltzmann methods to obtain intrinsic permeability estimates for this extremely transmissive aquifer, where traditional aquifer test methods may fail due to very small drawdowns and non-Darcian flow that can reduce apparent hydraulic conductivity. Variogram analysis of the borehole data suggests a nearly isotropic rock structure at lag lengths up to the nominal borehole diameter. A strong correlation between the diameter of the borehole and the presence of vuggy megaporosity in the data set led to a bias in the variogram where the computed horizontal spatial autocorrelation is strong at lag distances greater than the nominal borehole size. Lattice Boltzmann simulation of flow across a 0.4 × 0.4 × 17 m (2.72 m 3 volume) parallel-walled column of rendered matrix and vuggy megaporosity indicates a high hydraulic conductivity of 53 m s −1 . This value is similar to previous Lattice Boltzmann calculations of hydraulic conductivity in smaller limestone samples of the Biscayne aquifer. The development of simulation methods that reproduce dual-porosity systems with higher resolution and fidelity and that consider flow through horizontally longer renderings could provide improved estimates of the hydraulic conductivity and help to address questions about the importance of scale.

Water Resources Research↗
USGS2016

Toward more realistic projections of soil carbon dynamics by Earth system models

Soil carbon (C) is a critical component of Earth system models (ESMs), and its diverse representations are a major source of the large spread across models in the terrestrial C sink from the third to fifth assessment reports of the Intergovernmental Panel on Climate Change (IPCC). Improving soil C projections is of a high priority for Earth system modeling in the future IPCC and other assessments. To achieve this goal, we suggest that (1) model structures should reflect real-world processes, (2) parameters should be calibrated to match model outputs with observations, and (3) external forcing variables should accurately prescribe the environmental conditions that soils experience. First, most soil C cycle models simulate C input from litter production and C release through decomposition. The latter process has traditionally been represented by first-order decay functions, regulated primarily by temperature, moisture, litter quality, and soil texture. While this formulation well captures macroscopic soil organic C (SOC) dynamics, better understanding is needed of their underlying mechanisms as related to microbial processes, depth-dependent environmental controls, and other processes that strongly affect soil C dynamics. Second, incomplete use of observations in model parameterization is a major cause of bias in soil C projections from ESMs. Optimal parameter calibration with both pool- and flux-based data sets through data assimilation is among the highest priorities for near-term research to reduce biases among ESMs. Third, external variables are represented inconsistently among ESMs, leading to differences in modeled soil C dynamics. We recommend the implementation of traceability analyses to identify how external variables and model parameterizations influence SOC dynamics in different ESMs. Overall, projections of the terrestrial C sink can be substantially improved when reliable data sets are available to select the most representative model structure, constrain parameters, and prescribe forcing fields.

Global Biogeochemical Cycles↗
USGS2016

Climate change and dissolved organic carbon export to the Gulf of Maine

Ongoing climate change is affecting the concentration, export (flux), and timing of dissolved organic carbon (DOC) exported to the Gulf of Maine (GoM) through changes in hydrologic regime. DOC export was calculated for water years 1950 through 2013 for 20 rivers and for water years 1930 through 2013 for 14 rivers draining to the GoM. DOC export was also estimated for the 21st century based on climate and hydrologic modeling in a previously published study. DOC export was calculated by using the regression model LOADEST to fit seasonally adjusted concentration discharge (C-Q) relations. Our results are an analysis of the sensitivity of DOC export to changes in hydrologic conditions over time since land cover and vegetation were held constant over time. Despite large interannual variability, all rivers had increasing DOC export during winter and these trends were significant ( p < 0.05) in 10 out of 20 rivers for 1950 to 2013 and in 13 out of 14 rivers for 1930 to 2013. All rivers also had increasing annual export of DOC although fewer trends were statistically significant than for winter export. Projections for DOC export during the 21st century were variable depending on the climate model and greenhouse gas emission scenario that affected future river discharge through effects on precipitation and evapotranspiration. The most consistent result was a significant increase in DOC export in winter in all model-by-emission scenarios. DOC export was projected to decrease during the summer in all model-by-emission scenarios, with statistically significant decreases in half of the scenarios.

Maine↗
USGS2017

Estimating belowground carbon stocks in isolated wetlands of the Northern Everglades Watershed, central Florida, using ground penetrating radar (GPR) and aerial imagery

Peat soils store a large fraction of the global soil carbon (C) pool and comprise 95% of wetland C stocks. While isolated freshwater wetlands in temperate and tropical biomes account for more than 20% of the global peatland C stock, most studies of wetland soil C have occurred in expansive peatlands in northern boreal and subarctic biomes. Furthermore, the contribution of small depressional wetlands in comparison to larger wetland systems in these environments is very uncertain. Given the fact that these wetlands are numerous and variable in terms of their internal geometry, innovative methods are needed for properly estimating belowground C stocks and their overall C contribution to the landscape. In this study, we use a combination of ground penetrating radar (GPR), aerial imagery, and direct measurements (coring) in conjunction with C core analysis to develop a relation between C stock and surface area, and estimate the contribution of subtropical depressional wetlands to the total C stock of pine flatwoods at the Disney Wilderness Preserve (DWP), Florida. Additionally, GPR surveys were able to image collapse structures underneath the peat basin of depressional wetlands, depicting lithological controls on the formation of depressional wetlands at the DWP. Results indicate the importance of depressional wetlands as critical contributors to the landscape C budget at the DWP and the potential of GPR-based approaches for (1) rapidly and noninvasively estimating the contribution of depressional wetlands to regional C stocks and (2) evaluating the formational processes of depressional wetlands.

Florida↗
USGS2017

The impact of late Holocene land-use change, climate variability, and sea-level rise on carbon storage in tidal freshwater wetlands on the southeastern United States Coastal Plain

This study examines Holocene impacts of changes in climate, land use, and sea-level rise (SLR) on sediment accretion, carbon accumulation rates (CAR), and vegetation along a transect of tidal freshwater forested wetlands (TFFW) to oligohaline marsh along the Waccamaw River, South Carolina (4 sites) and along the Savannah River, Georgia (4 sites). We use pollen, plant macrofossils, accretion, and CAR from cores, spanning the last 1500-6000 years to test the hypothesis that TFFW have remained stable throughout the late Holocene and that marshes transitioned from TFFW during elevated SLR during the Medieval Climate Anomaly, with further transformation resulting from colonial land-use change. Results show low and stable accretion and CAR through much of the Holocene, despite moderate changes associated with Holocene paleoclimate. In all records, the largest observed change occurred within the last ~400 years, driven by colonial land clearance, shifting terrigenous sediment into riparian wetlands, resulting in order-of-magnitude increases in accretion and C accumulation. The oligohaline marshes transitioned from TFFW ~300-500 years ago, coincident with colonial land clearance. Post-colonial decreases in CAR and accretion occur because of watershed reforestation over the last century. All sites show evidence of recent (decades to century) swamp forest decline due to increasing salinity and tidal inundation from SLR. This study suggests that allochthonous sediment input during colonialization helped maintain TFFW, but that current SLR rates are too high for TFFW to persist, although higher accretion rates in oligohaline marshes increases the resilience of tidal wetlands as they transition from TFFW to marsh.

Georgia, South Carolina↗
USGS2021

Land management strategies influence soil organic carbon stocks of prairie potholes of North America

Soil organic carbon (SOC) stocks of Prairie Pothole Region (PPR) wetlands in the central plains of Canada and the United States are highly variable due to natural variation in biota, soils, climate, hydrology, and topography. Land-use history (cropland, grassland) and land-management practices (drainage, restoration) also affect SOC stocks. We conducted a region-wide assessment of wetland SOC stocks using data from the Canadian and US portions of the PPR under various management types. Natural wetlands with no disturbance history in the wetland basin or surrounding catchment had considerably greater average SOC stocks in the upper (0–15 cm) soil profile than wetlands surrounded by cropland. Hydrologically restored wetlands did not show significantly greater SOC stocks than drained wetlands, but wetlands surrounded by restored grasslands did have greater SOC stocks in the upper soil profile than those surrounded by croplands. Similarities among cropped and restored wetlands likely were due to insufficient time since restoration, as well as high variability attributable to several environmental factors within the region. We conclude that avoided loss of natural wetlands from drainage and avoided loss of native grasslands from cropping have the most benefit for preserving wetland SOC stocks. Robust PPR SOC models that incorporate multiple abiotic, biotic, and land-use factors are required to determine where and when restoration is most effective for SOC sequestration.

Book chapter↗