USGS Science⌕ Search

SEARCH · USGS Science

Results for “Experimental Results”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 361 records · Page 20Linked to original sources
USGS2022

Climate change weakens the impact of disturbance interval on the growth rate of natural populations of Venus flytrap

Disturbances elicit both positive and negative effects on organisms; these effects vary in their strength and their timing. Effects of disturbance interval (i.e., the length of time between disturbances) on population growth will depend on both the timing and strength of positive and negative effects of disturbances. Climate change can modify the relative strengths of these positive and negative effects, leading to altered optimal disturbance intervals (the disturbance interval at which population growth rate is highest) and changes in the sensitivity of population growth rate to disturbance interval. While we know that climate may alter impacts of disturbance in some systems, we have a poor understanding of which effects of disturbance and which vital rates might drive an altered response to disturbance interval in a changing climate. We use demographic monitoring of natural populations of Dionaea muscipula , the Venus flytrap, that have experienced natural and managed fires, combined with realistic past and future climate projections, to construct climate- and fire-driven integral projection models (IPMs). We use these IPMs to compare the effect of fire return interval (FRI) on population growth rate in past and future climates. To dissect the mechanisms driving FRI response, we then construct IPMs with demographic data from an experimental manipulation of fire effects (ash addition, neighbor removal) and an accidental fire. Our results show that an FRI of 10 years is optimal for D. muscipula in past climate conditions, but a longer FRI (12 years) is optimal in future climate conditions. Further, deviations from optimal FRI reduce population growth rate dramatically in the past climate, but this reduction is muted in a future climate (future minus past sensitivity = 0.006, 95% CI [0.002, 0.011]). Finally, our experimental work suggests that fire effects are driven in part by positive, additive effects of competitor removal and ash addition immediately following a fire; for one population, both these treatments significantly increased population growth rate. Our work suggests that climate change can alter the response of populations to disturbance, highlighting the need to consider the interacting effects of multiple abiotic drivers when projecting future population growth and geographical distributions.

North Carolina↗
USGS2011

Experimental and simulation studies of iron oxides for geochemical fixation of CO2-SO2 gas mixtures

Iron-bearing minerals are reactive phases of the subsurface environment and could potentially trap CO 2 –SO 2 gas mixtures derived from fossil fuel combustion processes by their conversion to siderite (FeCO 3 ) and dissolved sulfate. Changes in fluid and mineral compositions resulting from reactions, involving the co-injection of SO 2 with CO 2 were observed both theoretically and experimentally. Experiments were conducted with a natural hematite (α-Fe 2 O 3 ) sample. A high pressure-high temperature apparatus was used to simulate conditions in geologic formations deeper than 800 m, where CO 2 is in the supercritical state. Solid samples were allowed to react with a NaCl–NaOH brine and SO 2 -bearing CO 2 -dominated gas mixtures. The predicted equilibrium mineral assemblage at 100 °C and 250 bar became hematite, dawsonite (NaAl(OH) 2 CO 3 ), siderite (FeCO 3 ) and quartz (SiO 2 ). Experimentally, siderite and dawsonite, derived from the presence of kaolinite (Al 2 Si 2 O 5 (OH) 4 ) in the parent material, were present in residual solids at longer reaction time intervals, which agreed well with results from the modelling work.

Energy Procedia↗
USGS2000

Preliminary study of gill NA+,K+-ATPase activity in juvenile spring chinook salmon following electroshock or handling stress

We compared gill Na+,K+-ATPase in subyearling and yearling spring chinook salmon Oncorhynchus tshawytscha 3 h, 24 h, and 7 d after exposure to either a short pulsed DC electroshock (300 V, 50 Hz, 8-ms pulse duration) or an acute handling stress. Mean gill Na+,K+-ATPase values ranged from 7.5 to 11.8 ??mol inorganic phosphate (Pi) ?? (mg protein)-1 ?? h-1. No significant differences were detected, with the exception of electroshocked subyearlings 7 d after treatment. Increased activity was attributed to the presence of two influential values. No significant differences were detected after removal of these observations, so the increase was not considered biologically significant. Inclusion of the outliers did not alter our interpretation of the results given that the observed increase was slight compared with the magnitude of changes reported under experimental conditions and in migrating juvenile salmonids. The treatment groups underwent a typical stress response and had significantly elevated cortisol and glucose levels 3 h after treatment. Recovery to control levels occurred within 24 h for cortisol and from 24 h to 7 d for glucose. Our results lead to the conclusion that neither acute electroshock nor acute handling stress alters Na+,K+-ATPase activity in juvenile spring chinook salmon.

North American Journal of Fisheries Management↗
USGS2000

Microbial populations in contaminant plumes

Efficient biodegradation of subsurface contaminants requires two elements: (1) microbial populations with the necessary degradative capabilities, and (2) favorable subsurface geochemical and hydrological conditions. Practical constraints on experimental design and interpretation in both the hydrogeological and microbiological sciences have resulted in limited knowledge of the interaction between hydrogeological and microbiological features of subsurface environments. These practical constraints include: (1) inconsistencies between the scales of investigation in the hydrogeological and microbiological sciences, and (2) practical limitations on the ability to accurately define microbial populations in environmental samples. However, advances in application of small-scale sampling methods and interdisciplinary approaches to site investigations are beginning to significantly improve understanding of hydrogeological and microbiological interactions. Likewise, culture-based and molecular analyses of microbial populations in subsurface contaminant plumes have revealed significant adaptation of microbial populations to plume environmental conditions. Results of recent studies suggest that variability in subsurface geochemical and hydrological conditions significantly influences subsurface microbial-community structure. Combined investigations of site conditions and microbial-community structure provide the knowledge needed to understand interactions between subsurface microbial populations, plume geochemistry, and contaminant biodegradation.

Hydrogeology Journal↗
USGS2024

Transglobal spread of an ecologically relevant sea urchin parasite

Mass mortality of the dominant coral reef herbivore Diadema antillarum in the Caribbean in the early 1980s contributed to a persistent phase shift from coral- to algal-dominated reefs. In 2022, a scuticociliate most closely related to Philaster apodigitiformis caused further mass mortality of D. antillarum across the Caribbean, leading to >95% mortality at affected sites. Mortality was also reported in the related species Diadema setosum in the Mediterranean in 2022, though the causative agent of the Mediterranean outbreak has not yet been determined. In April 2023, mass mortality of Diadema setosum occurred along the Sultanate of Oman's coastline. Urchins displayed signs compatible with scuticociliatosis including abnormal behavior, drooping and loss of spines, followed by tissue necrosis and death. Here we report the detection of an 18S rRNA gene sequence in abnormal urchins from Muscat, Oman, that is identical to the Philaster strain responsible for D. antillarum mass mortality in the Caribbean. We also show that scuticociliatosis signs can be elicited in Diadema setosum by experimental challenge with the cultivated Philaster strain associated with Caribbean scuticociliatosis. These results demonstrate the Philaster sp. associated with D. antillarum mass mortality has rapidly spread to geographically distant coral reefs, compelling global-scale awareness and monitoring for this devastating condition through field surveys, microscopy, and molecular microbiological approaches, and prompting investigation of long-range transmission mechanisms.

ISME Journal↗
USGS1996

Vertical spatial coherence model for a transient signal forward-scattered from the sea surface

The treatment of acoustic energy forward scattered from the sea surface, which is modeled as a random communications scatter channel, is the basis for developing an expression for the time-dependent coherence function across a vertical receiving array. The derivation of this model uses linear filter theory applied to the Fresnel-corrected Kirchhoff approximation in obtaining an equation for the covariance function for the forward-scattered problem. The resulting formulation is used to study the dependence of the covariance on experimental and environmental factors. The modeled coherence functions are then formed for various geometrical and environmental parameters and compared to experimental data.

IEEE Journal of Oceanic Engineering↗
USGS2005

Establishing native grasses in a big sagebrush-dominated site: An intermediate restoration step

Many semiarid rangelands in the Great Basin, U.S.A., are shifting dominance to woody species as a consequence of land degradation including intense livestock grazing and fire suppression. Whereas past rehabilitation efforts in Big sagebrush ( Artemisia tridentata ) steppes removed the shrub and added introduced forage grasses to successfully shift communities from shrublands to grasslands, current consensus is that native species should be included in restoration projects and that retention of some woody plants is desirable. We examined the potential for interseeding grasses into dense shrub communities as a precursor to thinning shrubs and releasing grasses from shrub interference. We compared seedling establishment of the native grass, Bluebunch wheatgrass ( Pseudoroegneria spicata ), with that of the Eurasia grass, Crested wheatgrass ( Agropyron desertorum ), in dense Ar. tridentata stands. Shrubs may play an important role as nurse plants for seedling establishment (reduced solar radiation, “island of fertility” effect) but result in highly contrasting light environments and root interference for seedlings. In experimental plots, we examined effects of Ar. tridentata shade levels (0, 40, 70, and 90% reduction of solar radiation) and initial root exclusion (present/absent) on the establishment and growth of P. spicata and Ag. desertorum seedlings. With this design we evaluated the interference effects of Ar. tridentata on the two grasses and identified the most beneficial microsites for grass restoration in Ar. tridentata –dominated communities. We predicted seedling survival and growth to be greater under moderate shade (40% reduction) and limited root competition than under no or strong shade conditions (0 and 90%) and unrestricted root interactions. Fifty to 85% of the P. spicata and Ag. desertorum seedlings survived the dry summer months of 1995 and 1996 and the intervening winter. Neither shading nor root exclusion from Ar. tridentata affected final seedling survival of either species. Seedling biomass of both grass species was negatively affected by initial root interactions with Ar. tridentata. However, the analysis of seedling biomass variability (coefficient of variation) indicated that in all shade and root-exclusion treatments, some seedlings of both species developed to large individuals to survive in Ar. tridentata –dominated rangelands. Thus, the use of interseeding techniques shows promise for restoring herbaceous species in dense Ar. tridentata stands and should be given further consideration when shrub retention is an important consideration.

Utah↗
USGS2018

A laboratory-calibrated model of coho salmon growth with utility for ecological analyses

We conducted a meta-analysis of laboratory- and hatchery-based growth data to estimate broadly applicable parameters of mass- and temperature-dependent growth of juvenile coho salmon ( Oncorhynchus kisutch ). Following studies of other salmonid species, we incorporated the Ratkowsky growth model into an allometric model and fit this model to growth observations from eight studies spanning ten different populations. To account for changes in growth patterns with food availability, we reparameterized the Ratkowsky model to scale several of its parameters relative to ration. The resulting model was robust across a wide range of ration allocations and experimental conditions, accounting for 99% of the variation in final body mass. We fit this model to growth data from coho salmon inhabiting tributaries and constructed ponds in the Klamath Basin by estimating habitat-specific indices of food availability. The model produced evidence that constructed ponds provided higher food availability than natural tributaries. Because of their simplicity (only mass and temperature are required as inputs) and robustness, ration-varying Ratkowsky models have utility as an ecological tool for capturing growth in freshwater fish populations.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2007

The R3/R5 impoundment study: A large-scale management experiment

Managed wetlands provide a broad spectrum of resources to migratory waterbirds (shorebirds, wading birds, and waterfowl) throughout the annual cycle. Successful conservation and management of waterbirds depends on integrated approaches that (1) incorporate larger spatial and temporal scales than traditional approaches to wetland management, and (2) use experimental designs to reduce uncertainty about the response of the systems to management. In a previous experiment on USFWS National Wildlife Refuges in the Northeast, we explored the effects of water-level management on migratory shorebirds in spring. We documented regional patterns of shorebird use of Refuge wetlands and showed that across the region, a slow drawdown was superior to 2 alternatives. USGS and USFWS have now cooperatively undertaken an expanded study focusing on 3 waterbird guilds in the context of the complete annual cycle and over a larger spatial extent. For this 3-yr study, now in its first year, 2 impoundments were selected at each of 23 NWRs across the Northeast and Upper Midwest Regions. Two experimental treatments (annual water regimes focused on early-season or late-season drawdowns) are being applied each year in a cross-over design. This experimental design will increase our understanding of cross-seasonal interactions which result from specific hydrologic regimes aimed at a particular waterbird guild. Monitoring will allow waterbird responses to be linked with direct effects of water management on plant and invertebrate populations. Results of this large-scale experiment will be used to motivate formal adaptive management of wetlands and waterbirds at refuges following completion of this experiment.

Conference Paper↗
USGS1951

Effects of DDT on saltmarsh wildlife: 1949

Briefly describes DDT experimental spraying program, wildlife species studied, the marsh, and tidal movements. Discusses resulting effects of DDT on vertebrates and invertebrates.

Special Scientific Report - Wildlife↗
USGS2011

Soil warming alters seed-bank responses across the geographic range of freshwater Taxodium distichum (Cupressaceae) swamps

Premise of the Study: Climate warming is predicted to have far‐reaching effects on the distribution of species, but those effects may depend on the flexibility of regenerating species in responding to climate gradients. We conducted a study to determine whether the variation in the response of seed banks to temperature varied across the latitudinal range of Taxodium distichum swamps in North America. • Methods: The soil was collected in a long‐term research network and heated experimentally to three current‐day spring normal soil temperatures (average maximum daily spring normal soil temperatures during May in Illinois, Arkansas, and Louisiana, USA, respectively: 22°, 25°, and 29°C). A “normal” is the mean temperature calculated over a 30‐yr interval (1971–2000). Seed‐bank density and biomass responses were examined in relation to latitude and difference in the soil temperature of the experiment and the spring normal. • Key Results: Using first‐ and second‐order regression analysis, we determined that the variation in total germination density was lowest mid‐range and in experimental soil temperatures similar to the spring normal. For some dominant species, the variance in germination density was higher in the northern ( Cephalanthus occidentalis ) or the southern part of the network ( Saururus cernuus and Polygonum pensylvanicum ). Overall, the variance of total biomass (root, shoot, whole plant) was higher if the experimental soil temperature was warmer than the spring normal. • Conclusions: Our results suggest that the regeneration of some populations of swamp species may have more flexibility to respond to climate warming than others.

Alabama, Arkansas, Florida, Georgia, Illinois, Ken↗
USGS2001

Effect of scale on the behavior of atrazine in surface waters

Field runoff is an important transport mechanism by which agricultural pesticides, including atrazine, move into the hydrologic environment. Atrazine is chosen because it is widely used, is transported in runoff relatively easily, is widely observed in surface waters, and has relatively little loss in the stream network. Data on runoff of atrazine from experimental plot and field studies is combined with annual estimates of load in numerous streams and rivers, resulting in a data set with 408 observations that span 14 orders of magnitude in area. The load as a percent of use (LAPU) on an annual basis is the parameter that is compared among the studies. There is no difference in the mean or range of LAPU values for areas from the size of experimental field plots (???0.000023 ha) and small watersheds (<100 000 ha). The relatively invariant LAPU value observed across a large range of watershed areas implies that the characteristics of atrazine itself (application method and chemical properties) are important in determining the extent of runoff. The variable influences on the extent of runoff from individual watershed characteristics and weather events are superimposed on the relatively invariant LAPU value observed across the range of watershed areas. The results from this study establish the direct relevance for agricultural field plot studies to watershed studies across the full range of scale.

Environmental Science & Technology↗
USGS2001

Toward linking maize chemistry to archaeological agricultural sites in the North American Southwest

Maize (Zea mays L.) was the staple domestic food crop for Ancestral Pueblo people throughout the northern American Southwest. It is thought to have been the basic food of the inhabitants of Chaco Canyon. New Mexico, a location that was a major centre of Ancestral Pueblo building and population during the 11th and early 12th centuries AD. Modern heirloom varieties of Native American corn have been difficult to grow in experimental fields in Chaco Canyon. Given an abundance of apparent storage structures in Chacoan buildings, it is possible that some corn recovered from archaeological contexts, was imported from surrounding areas. The ultimate goal of this research is to determine whether the corn in Chaco Canyon was grown locally or imported. This paper establishes the feasibility of a method to accomplish this goal. This study reports the results of using inductively coupled plasma-mass spectrometric (ICP-MS) instrumentation to determine chemical constituents of experimental fields and modern heirloom varieties of Native American corn. Analysis of 19 elements is adequate to differentiate soil and corn from three field areas. These results are promising: however, a number of problems, including post-depositional alterations in maize, remain to be solved. ?? 2001 Academic Press.

Journal of Archaeological Science↗
USGS1992

Speciation in experimental C-O-H fluids produced by the thermal dissociation of oxalic acid dihydrate

Fluid speciations and their related reaction pathways were studied in C-O-H-system fluids produced by the thermal dissociation of oxalic acid dihydrate (OAD: H 2 C 2 O 4 · 2H 2 O) sealed in silica glass capsules. Experiments were conducted in the temperature range 230–750°C, with bulk fluid densities in the range 0.01–0.53 g/cm 3 . Pressure was controlled by temperature and density in the isochoric systems. The quenched products of dissociation experiments were an aqueous liquid and one (supercritical fluid) or, rarely, two (vapor plus liquid) carbonic phase (s). In-situ Raman microanalyses were performed on the quenched carbonic phases at room temperature, at which fluid pressures ranged from about 50 to 340 bars. Bulk fluid speciations were reconstructed from the Raman analyses via mass balance constraints, and appear to monitor the true fluid speciations at run conditions. In experiments from the lowtemperature range (230–350°C), fluid speciations record the dissociation of OAD according to the reaction OAD = CO 2 + CO + 3 H 2 O . A process of the form CO + H 2 O = CO 2 + H 2 is driven to the right with increasing temperature. The hydrogen gas produced tends to escape from the sample systems via diffusion into/through the silica glass capsules, shifting bulk compositions toward equimolar binary H 2 O-CO 2 mixtures. The speciations of fluids in experiments with minimal hydrogen loss show poor agreement with speciations calculated for equilibrium fluids by the corresponding-states model of Saxena and Fei (1988). Such disagreement suggests that the formations of CH 4 and graphite are metastably inhibited in the current experiments, which correlates with their absence or trivial abundances in experimental products. Moreover, calculations in which the stabilities of methane and graphite are suppressed suggest that such metastable equilibrium is approached only in experiments at temperatures greater than about 600–650°C. These results have applications to fluid processes in geological environments, in addition to considerations of using oxalate compounds as volatile sources in experimental studies. It is possible that disequilibrium or metastable fluids may be entrapped as inclusions; re-speciation (toward metastable or stable equilibrium) during P-T evolution of a given terrain would place the fluid inclusion on a new isochore that would not project through the original conditions of entrapment. Moreover, the disequilibrium to metastable nature of dissociation reactions, coupled with the diffusional mobility of hydrogen gas observed in the current experiments, suggests that the predominance of binary H 2 O-CO 2 fluid mixtures in natural inclusions from medium- to high-grade metamorphic terrains may be more than a coincidence of similar initial bulk compositions.

Geochimica et Cosmochimica Acta↗
USGS2015

Effects of harvesting forest biomass on water and climate regulation services: A synthesis of long-term ecosystem experiments in eastern North America

Demand for woody biomass fuels is increasing amidst concerns about global energy security and climate change, but there may be negative implications of increased harvesting for forest ecosystem functions and their benefits to society (ecosystem services). Using new methods for assessing ecosystem services based on long-term experimental research, post-harvest changes in ten potential benefits were assessed for ten first-order northern hardwood forest watersheds at three long-term experimental research sites in northeastern North America. As expected, we observed near-term tradeoffs between biomass provision and greenhouse gas regulation, as well as tradeoffs between intensive harvest and the capacity of the forest to remediate nutrient pollution. In both cases, service provision began to recover along with the regeneration of forest vegetation; in the case of pollution remediation, the service recovered to pre-harvest levels within 10 years. By contrast to these two services, biomass harvesting had relatively nominal and transient impacts on other ecosystem services. Our results are sensitive to empirical definitions of societal demand, including methods for scaling societal demand to ecosystem units, which are often poorly resolved. Reducing uncertainty around these parameters can improve confidence in our results and increase their relevance for decision-making. Our synthesis of long-term experimental studies provides insights on the social-ecological resilience of managed forest ecosystems to multiple drivers of change.

Hubbard Brook Experimental Forest, Neversink River↗
USGS2017

Ecohydrological role of biological soil crusts across a gradient in levels of development

Though biological soil crusts (biocrusts) form abundant covers in arid and semiarid regions, their competing effects on soil hydrologic conditions are rarely accounted for in models. This study presents the modification of a soil water balance model to account for the presence of biocrusts at different levels of development (LOD) and their impact on one-dimensional hydrologic processes during warm and cold seasons. The model is developed, tested, and applied to study the hydrologic controls of biocrusts in context of a long-term manipulative experiment equipped with meteorological and soil moisture measurements in a Colorado Plateau ecosystem near Moab, Utah. The climate manipulation treatments resulted in distinct biocrust communities, and model performance with respect to soil moisture was assessed in experimental plots with varying LOD as quantified through a field-based roughness index ( RI ). Model calibration and testing yielded excellent comparisons to observations and smooth variations of biocrust parameters with RI approximated through simple regressions. The model was then used to quantify how LOD affects soil infiltration, evapotranspiration, and runoff under calibrated conditions and in simulation experiments with gradual modifications in biocrust porosity and hydraulic conductivity. Simulation results show that highly developed biocrusts modulate soil moisture nonlinearly with LOD by altering soil infiltration and buffering against evapotranspiration losses, with small impacts on runoff. The nonlinear and threshold variations of the soil water balance in the presence of biocrusts of varying LOD helps explain conflicting outcomes of various field studies and sheds light on the ecohydrological role of biocrusts in arid and semiarid ecosystems.

Utah↗
USGS2023

Review and development of best practices for toxicity tests with dreissenid mussels

Since their introduction to North America in the 1980s, research to develop effective control tools for invasive mussels ( Dreissena polymorpha and D. rostriformis bugensis ) has been ongoing across various research institutions using a range of testing methods. Inconsistencies in experimental methods and reporting present challenges for comparing data, repeating experiments, and applying results. The Invasive Mussel Collaborative established the Toxicity Testing Work Group (TTWG) in 2019 to identify “best practices” and guide development of a standard framework for dreissenid mussel toxicity testing protocols. We reviewed the literature related to laboratory-based dreissenid mussel toxicity tests and determined the degree to which standard guidelines have been used and their applicability to dreissenid mussel testing. We extracted detailed methodology from 99 studies from the peer-reviewed and gray literature and conducted a separate analysis for studies using presettlement and postsettlement mussels. We identified specific components of methods and approaches that could be refined or standardized for dreissenid mussels. These components included species identification, collection methods, size/age class distinction, maintenance practices, testing criteria, sample size, response measures, reporting parameters, exposure methods, and mortality criteria. We consulted experts in the field of aquatic toxicology and dreissenid mussel biology on our proposed. The final recommendations contained in the present review are based on published standard guidelines, methods reported in the published and gray literature, and the expertise of TTWG members and an external panel. In addition, our review identifies research needs for dreissenid mussel testing including improved methods for early–life stage testing, comparative data on life stages and between dreissenid mussel species, inclusion of a reference toxicant, and additional testing of nontarget species (i.e., other aquatic organisms). Environ Toxicol Chem 2023;42:1649–1666. © 2023 His Majesty the King in Right of Canada. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. Reproduced with the permission of the Minister of Environment and Climate Change Canada. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Environmental Toxicology and Chemistry↗
USGS2017

Maximizing establishment and survivorship of field-collected and greenhouse-cultivated biocrusts in a semi-cold desert

Aims Biological soil crusts (biocrusts) are soil-surface communities in drylands, dominated by cyanobacteria, mosses, and lichens. They provide key ecosystem functions by increasing soil stability and influencing soil hydrologic, nutrient, and carbon cycles. Because of this, methods to reestablish biocrusts in damaged drylands are needed. Here we test the reintroduction of field-collected vs. greenhouse-cultured biocrusts for rehabilitation. Methods We collected biocrusts for 1) direct reapplication, and 2) artificial cultivation under varying hydration regimes. We added field-collected and cultivated biocrusts (with and without hardening treatments) to bare field plots and monitored establishment. Results Both field-collected and cultivated cyanobacteria increased cover dramatically during the experimental period. Cultivated biocrusts established more rapidly than field-collected biocrusts, attaining ~82% cover in only one year, but addition of field-collected biocrusts led to higher species richness, biomass (as assessed by chlorophyll a) and level of development. Mosses and lichens did not establish well in either case, but late successional cover was affected by hardening and culture conditions. Conclusions This study provides further evidence that it is possible to culture biocrust components from later successional materials and reestablish cultured organisms in the field. However, more research is needed into effective reclamation techniques.

Plant and Soil↗