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USGS2020

High-throughput sequencing reveals distinct regional genetic structure among remaining populations of an endangered salt marsh plant in California

Conservation of rare species requires careful consideration to both preserve locally adapted traits and maintain genetic diversity, as species’ ranges fluctuate in response to a changing climate and habitat loss. Salt marsh systems in California have been highly modified and many salt marsh obligate species have undergone range reductions and habitat loss with concomitant losses of genetic diversity and connectivity. Remaining salt marshes are threatened by rising sea levels, and so these habitats will likely require active restoration and re-establishment efforts. This study aims to provide a reference point for the current status of genetic diversity and range-wide population structure of a federally and state listed endangered plant, Salt Marsh Bird’s Beak (Chloropyron maritimum subsp. maritimum) that can inform future preservation and restoration efforts. We used historical data and current monitoring information to locate and sample all known occurrences throughout the species range in Southern California, and three additional occurrences from Baja California, Mexico. We used flow cytometry and single nucleotide polymorphic markers (SNPs), generated by double-digest restriction-site associated DNA sequencing (ddRAD), to assess relative ploidy, and estimate genetic diversity and population structure across the region. Overall, we found four to five distinct genetic clusters that coincide with geographic regions. Genetic diversity was greatest in the southern part of the range including Baja California and San Diego. These findings can bolster management and restoration efforts by identifying potentially isolated occurrences and areas that are rich sources of allelic diversity, and by providing insight into the amount of genetic differentiation across the species range.

California↗

USGS2006

Modeling wetland plant community response to assess water-level regulation scenarios in the Lake Ontario-St. Lawrence River basin

The International Joint Commission has recently completed a five-year study (2000-2005) to review the operation of structures controlling the flows and levels of the Lake Ontario - St. Lawrence River system. In addition to addressing the multitude of stakeholder interests, the regulation plan review also considers environmental sustainability and integrity of wetlands and various ecosystem components. The present paper outlines the general approach, scientific methodology and applied management considerations of studies quantifying the relationships between hydrology and wetland plant assemblages (% occurrence, surface area) in Lake Ontario and the Upper and Lower St. Lawrence River. Although similar study designs were used across the study region, different methodologies were required that were specifically adapted to suit the important regional differences between the lake and river systems, range in water-level variations, and confounding factors (geomorphic types, exposure, sediment characteristics, downstream gradient of water quality, origin of water masses in the Lower River). Performance indicators (metrics), such as total area of wetland in meadow marsh vegetation type, that link wetland response to water levels will be used to assess the effects of different regulation plans under current and future (climate change) water-supply scenarios.

Environmental Monitoring and Assessment↗

USGS2015

Presence and abundance of non-native plant species associated with recent energy development in the Williston Basin

The Williston Basin, located in the Northern Great Plains, is experiencing rapid energy development with North Dakota and Montana being the epicenter of current and projected development in the USA. The average single-bore well pad is 5 acres with an estimated 58,485 wells in North Dakota alone. This landscape-level disturbance may provide a pathway for the establishment of non-native plants. To evaluate potential influences of energy development on the presence and abundance of non-native species, vegetation surveys were conducted at 30 oil well sites (14 ten-year-old and 16 five-year-old wells) and 14 control sites in native prairie environments across the Williston Basin. Non-native species richness and cover were recorded in four quadrats, located at equal distances, along four transects for a total of 16 quadrats per site. Non-natives were recorded at all 44 sites and ranged from 5 to 13 species, 7 to 15 species, and 2 to 8 species at the 10-year, 5-year, and control sites, respectively. Respective non-native cover ranged from 1 to 69, 16 to 76, and 2 to 82 %. Total, forb, and graminoid non-native species richness and non-native forb cover were significantly greater at oil well sites compared to control sites. At oil well sites, non-native species richness and forb cover were significantly greater adjacent to the well pads and decreased with distance to values similar to control sites. Finally, non-native species whose presence and/or abundance were significantly greater at oil well sites relative to control sites were identified to aid management efforts.

Montana, North Dakota↗

USGS2018

Compositional data analysis of coal combustion products with an application to a Wyoming power plant

A mathematically sound approach for summarizing chemical analyses of feed coal and all its combustion products (bottom ash, economizer fly ash, and fly ash) is presented. The nature of the data requires the application of compositional techniques when conducting statistical analysis, techniques that have not been applied before to the study of partitioning of elements between the coal that enters the boiler and the associated coal combustion products. A collection of descriptive and inferential compositional techniques was used to analyze the coal combustion products from a Wyoming power plant burning Paleocene Wyodak–Anderson coal. The significance of the fluctuation in ash composition is determined by using a Hotelling’s T -squared test and bootstrapping. Tree displays allow for visualization of the progressive effect of filters in removal of chemical species based on their geochemical composition. Results indicate that, in general, as the suspended combustion products entrained in the flue gases move closer to the stack, chemical species are removed from the combustion gas, starting with minerals associated with elements having the lowest volatility.

Mathematical Geosciences↗

USGS2023

Phragmites management in high water: Cutting plants under water limits biomass production, carbohydrate storage, and rhizome viability

Invasion of Phragmites australis (common reed) in wetlands throughout North America, and particularly the Laurentian Great Lakes Basin, poses significant ecological problems. The extended period of low Great Lakes water levels from 2000 to 2013 created conditions for large expansions of Phragmites in the Great Lakes coastal zone. The following extended period of high water in the Great Lakes during late 2010’s, culminating in record high lake levels in 2020 allowed managers to take advantage of high water by using a cut-to-drown management strategy (i.e., cutting plants below the water surface to stop the flow of atmospheric gases) to control Phragmites populations. To examine the efficacy of a cut-to-drown control strategy, we conducted a controlled-greenhouse study that tested the effect of submergence and timing of cutting (early or late in growing season) on Phragmites growth and viability post treatment. To evaluate Phragmites growth and viability, we measured belowground biomass, rhizome non-structural carbohydrate content (NSC), and rhizome viability following a cut-to-drown treatment. Applying a cut-to-drown treatment reduced average belowground biomass production up to 99%, limited rhizome NSC content up to 83%, and inhibited rhizome viability, regardless of timing of cutting treatments. These results suggest that under high-water conditions, utilizing a cut-to-drown strategy has potential for being a useful control mechanism for Phragmites . However, further research is needed to determine to what extent these results will lead to sustained reductions in growth and viability under field conditions, where rhizome belowground biomass and storage capacity are much larger.

Wetlands Ecology and Management↗

USGS2010

Measuring bulrush culm relationships to estimate plant biomass within a southern California treatment wetland

Assessment of emergent vegetation biomass can be time consuming and labor intensive. To establish a less onerous, yet accurate method, for determining emergent plant biomass than by direct measurements we collected vegetation data over a six-year period and modeled biomass using easily obtained variables: culm (stem) diameter, culm height and culm density. From 1998 through 2005, we collected emergent vegetation samples ( Schoenoplectus californicus and Schoenoplectus acutus ) at a constructed treatment wetland in San Jacinto, California during spring and fall. Various statistical models were run on the data to determine the strongest relationships. We found that the nonlinear relationship: C B = β 0 D H β 1 10 ε , where CB was dry culm biomass (g m −2 ), DH was density of culms × average height of culms in a plot, and β 0 and β 1 were parameters to estimate, proved to be the best fit for predicting dried-live above-ground biomass of the two Schoenoplectus species. The random error distribution, ε, was either assumed to be normally distributed for mean regression estimates or assumed to be an unspecified continuous distribution for quantile regression estimates.

Wetlands↗

USGS2013

Thresholds in the response of free-floating plant abundance to variation in hydraulic connectivity, nutrients, and macrophyte abundance in a large floodplain river

Duckweed and other free-floating plants (FFP) can form dense surface mats that affect ecosystem condition and processes, and can impair public use of aquatic resources. FFP obtain their nutrients from the water column, and the formation of dense FFP mats can be a consequence and indicator of river eutrophication. We conducted two complementary surveys of diverse aquatic areas of the Upper Mississippi River as an in situ approach for estimating thresholds in the response of FFP abundance to nutrient concentration and physical conditions in a large, floodplain river. Local regression analysis was used to estimate thresholds in the relations between FFP abundance and phosphorus (P) concentration (0.167 mg l −1 L), nitrogen (N) concentration (0.808 mg l −1 ), water velocity (0.095 m s −1 ), and aquatic macrophyte abundance (65 % cover). FFP tissue concentrations suggested P limitation was more likely in spring, N limitation was more likely in late summer, and N limitation was most likely in backwaters with minimal hydraulic connection to the channel. The thresholds estimated here, along with observed patterns in nutrient limitation, provide river scientists and managers with criteria to consider when attempting to modify FFP abundance in off-channel areas of large river systems.

Upper Mississippi River↗

USGS1985

Correlations among hydrocarbon microseepage, soil chemistry, and uptake of micronutrients by plants, Bell Creek oil field, Montana

Chelate-extractable iron and manganese concentrations in soils over and around the Bell Creek oil field suggest that compared to low average background values, there are moderate amounts of these elements directly over the production area and higher concentrations distributed in an aureole pattern around the periphery of the field. Adsorbed and organically bound iron and manganese appear to be readily taken up by plants resulting in anomalously high levels of these elements in leaves and needles over the oil field and suggesting correlation with corresponding low concentrations in soils. Iron and manganese appear to have bypassed the soil formation process where, under normal oxidizing conditions, they would have ultimately precipitated as insoluble oxides and hydroxides.

Journal of Geochemical Exploration↗

USGS1986

A tubular-coring device for use in biogeochemical sampling of succulent and pulpy plants

A hand-operated, tubular-coring device developed for use in biogeochemical sampling of succulent and pulpy plants is described. The sampler weighs about 500 g (1.1 lb); and if 25 × 175 mm (1 × 7 in) screw-top test tubes are used as sample containers, the complete sampling equipment kit is easily portable, having both moderate bulk and weight.

Journal of Geochemical Exploration↗

USGS2019

Invasive plant species

Invasive species may be one of the worts environmental problems facing the conservation of natural areas, because of their role in changing ecosystem function. At the same time, invasive species cause much human suffering and economic loss. The approach to eliminating invasive species can be improved by a better understanding of the various types of invasive species, and the scientific hypotheses surrounding their ability to invade novel environments. Despite the billions of dollars spent each year, invasive species are difficult if not impossible to eliminate after they have established. Various methods of eliminating plant species from natural communities are described in this review. An increased understanding of the nature of invasive species including their genetic relationship to their progenitors, hypotheses regarding their invasive qualities, and effective approaches for their removal from ecosystems are all sorely needed. Volunteers can help in the invasive species effort by working on local plant/animal removal projects, reporting invasive species sightings to appropriate officials, or working with scientists to collect basic data for ecological research.

Book chapter↗

USGS2015

Responses to water depth and clipping of twenty−three plant species in an Indian monsoonal wetland

Responses of species to disturbances give insights into how species might respond to future wetland changes. In this study, species of monsoonal wetlands belonging to various functional types (graminoid and non−graminoid emergents, submersed aquatic, floating−leaved aquatic) varied in their growth responses to water depth and harvesting. We tested the effects of water depth (moist soil, flooded) and clipping (unclipped, and clipped) on the biomass and longevity of twenty−three dominant plant species of monsoonal wetlands in the Keoladeo National Park, India in a controlled experiment. With respect to total biomass and survival, six species responded positively to flooding and twelve species responded negatively to clipping. Responses to flooding and clipping, however, sometimes interacted. Individualistic responses of species to water levels and clipping regimes were apparent; species within a functional group did not always respond similarly. Therefore, detailed information on the individualistic responses of species may be needed to predict the vegetation composition of post−disturbance wetlands. In particular, as demands for fresh water increase around the world, studies of life history constraints and responses to hydrological changes will aid wetland managers in developing strategies to conserve biodiversity.

Keoladeo National Park↗

USGS2007

Reproductive responses of male fathead minnows exposed to wastewater treatment plant effluent, effluent treated with XAD8 resin, and an environmentally relevant mixture of alkylphenol compounds

On-site, continuous-flow experiments were conducted during August and October 2002 at a major metropolitan wastewater treatment plant (WWTP) to determine if effluent exposure induced endocrine disruption as manifested in the reproductive competence of sexually mature male fathead minnows ( Pimephales promelas ). The fathead minnows were exposed in parallel experiments to WWTP effluent and WWTP effluent treated with XAD8 macroreticular resin to remove the hydrophobic-neutral fraction which contained steroidal hormones, alkylphenolethoxylates (APEs), and other potential endocrine disrupting compounds (EDCs). The effluent composition varied on a temporal scale and the continuous-flow experiments captured the range of chemical variability that occurred during normal WWTP operations. Exposure to WWTP effluent resulted in vitellogenin induction in male fathead minnows, with greater response in October than in August. Concentrations of ammonia, APEs, 17β-estradiol, and other EDCs also were greater in October than in August, reflecting a change in effluent composition. In the October experiment, XAD8 treatment significantly reduced vitellogenin induction in the male fathead minnows relative to the untreated effluent, whereas in August, XAD8 treatment had little effect. During both experiments, XAD8 treatment removed greater than 90% of the APEs. Exposure of fish to a mixture of APEs similar in composition and concentration to the WWTP effluent, but prepared in groundwater and conducted at a separate facility, elicited vitellogenin induction during both experiments. There was a positive relation between vitellogenin induction and hepatosomatic index (HSI), but not gonadosomatic index (GSI), secondary sexual characteristics index (SSCI), or reproductive competency. In contrast to expectations, the GSI and SSCI increased in males exposed to WWTP effluent compared to groundwater controls. The GSI, SSCI, and reproductive competency were positively affected by XAD8 treatment of the WWTP effluent.

Aquatic Toxicology↗

USGS2011

Demasculinization of male fish by wastewater treatment plant effluent

Adult male fathead minnows ( Pimephales promelas ) were exposed to effluent from the City of Boulder, Colorado wastewater treatment plant (WWTP) under controlled conditions in the field to determine if the effluent induced reproductive disruption in fish. Gonadal intersex and other evidence of reproductive disruption were previously identified in white suckers ( Catostomus commersoni ) in Boulder Creek downstream from this WWTP effluent outfall. Fish were exposed within a mobile flow-through exposure laboratory in July 2005 and August 2006 to WWTP effluent (EFF), Boulder Creek water (REF), or mixtures of EFF and REF for up to 28 days. Primary (sperm abundance) and secondary (nuptial tubercles and dorsal fat pads) sex characteristics were demasculinized within 14 days of exposure to 50% and 100% EFF. Vitellogenin was maximally elevated in both 50% and 100% EFF treatments within 7 days and significantly elevated by 25% EFF within 14 days. The steroidal estrogens 17β-estradiol, estrone, estriol, and 17α-ethynylestradiol, as well as estrogenic alkylphenols and bisphenol A were identified within the EFF treatments and not in the REF treatment. These results support the hypothesis that the reproductive disruption observed in this watershed is due to endocrine-active chemicals in the WWTP effluent.

Colorado↗

USGS2011

Contamination of nonylphenolic compounds in creek water, wastewater treatment plant effluents, and sediments from Lake Shihwa and vicinity, Korea: Comparison with fecal pollution

Nonylphenolic compounds (NPs), coprostanol (COP), and cholestanol, major contaminants in industrial and domestic wastewaters, were analyzed in creek water, wastewater treatment plant (WWTP) effluent, and sediment samples from artificial Lake Shihwa and its vicinity, one of the most industrialized regions in Korea. We also determined mass discharge of NPs and COP, a fecal sterol, into the lake, to understand the linkage between discharge and sediment contamination. Total NP (the sum of nonylphenol, and nonylphenol mono- and di-ethoxylates) were 0.32–875 μg L -1 in creeks, 0.61–87.0 μg L -1 in WWTP effluents, and 29.3–230 μg g -1 TOC in sediments. Concentrations of COP were 0.09–19.0 μg L -1 in creeks, 0.11–44.0 μg L -1 in WWTP effluents, and 2.51–438 μg g -1 TOC in sediments. The spatial distributions of NPs in creeks and sediments from the inshore region were different from those of COP, suggesting that Lake Shihwa contamination patterns from industrial effluents differ from those from domestic effluents. The mass discharge from the combined outfall of the WWTPs, located in the offshore region, was 2.27 kg d -1 for NPs and 1.00 kg d -1 for COP, accounting for 91% and 95% of the total discharge into Lake Shihwa, respectively. The highest concentrations of NPs and COP in sediments were found in samples at sites near the submarine outfall of the WWTPs, indicating that the submarine outfall is an important point source of wastewater pollution in Lake Shihwa.

Chemosphere↗

USGS2004

From in-situ coal to fly ash: A study of coal mines and power plants from Indiana

This paper presents data on the properties of coal and fly ash from two coal mines and two power plants that burn single-source coal from two mines in Indiana. One mine is in the low-sulfur (<1%) Danville Coal Member of the Dugger Formation (Pennsylvanian) and the other mines the high-sulfur (>5%) Springfield Coal Member of the Petersburg Formation (Pennsylvanian). Both seams have comparable ash contents (???11%). Coals sampled at the mines (both raw and washed fractions) were analyzed for proximate/ultimate/sulfur forms/heating value, major oxides, trace elements and petrographic composition. The properties of fly ash from these coals reflect the properties of the feed coal, as well as local combustion and post-combustion conditions. Sulfur and spinel content, and As, Pb and Zn concentrations of the fly ash are the parameters that most closely reflect the properties of the source coal. ?? 2004 Elsevier B.V. All rights reserved.

International Journal of Coal Geology↗

USGS2018

Variation in plant defense suppresses herbivore performance

Defensive variability of crops and natural systems can alter herbivore communities and reduce herbivory . However, it is still unknown how defense variability translates into herbivore suppression. Nonlinear averaging and constraints in physiological tracking (also more generally called time-dependent effects) are the two mechanisms by which defense variability might impact herbivores . We conducted a set of experiments manipulating the mean and variability of a plant defense, showing that defense variability does suppress herbivore performance and that it does so through physiological tracking effects that cannot be explained by nonlinear averaging. While nonlinear averaging predicted higher or the same herbivore performance on a variable defense than on an invariable defense, we show that variability actually decreased herbivore performance and population growth rate. Defense variability reduces herbivore performance in a way that is more than the average of its parts. This is consistent with constraints in physiological matching of detoxification systems for herbivores experiencing variable toxin levels in their diet and represents a more generalizable way of understanding the impacts of variability on herbivory . Increasing defense variability in croplands at a scale encountered by individual herbivores can suppress herbivory, even if that is not anticipated by nonlinear averaging.

Current Biology↗

USGS2004

Estimating disturbance effects from military training using developmental instability and physiological measures of plant stress

We used developmental instability, water potential, and variable fluorescence to determine if populations of winged sumac (Rhus copallinum) were being negatively effected by military training disturbance. We established nine sites that represented a land-use disturbance gradient with three impact levels (low, medium, and high), the effects mostly due to mechanized infantry training maneuvers. Although mean values of developmental instability, water potential, and variable fluorescence differed significantly among sites, the patterns did not consistently differentiate sites relative to the disturbance gradient. At the population level, some measures of developmental instability and variable fluorescence were positively correlated. All nine sites consisted of habitat mosaics, with the abundance of higher quality habitat patches and canopy gaps closely related to habitat impacts. It may be that R. copallinum is selecting similar micro-environments at all sites and therefore minimizing inter-site variation in stress measures, despite large differences in overall habitat condition. Our results call for caution in developing ecological indicators using the response of physiological and morphological measures from a single plant species. ?? 2003 Elsevier Ltd. All rights reserved.

Ecological Indicators↗

USGS2023

Satellite-derived plant cover maps vary in performance depending on version and product

Understanding the accuracy and appropriate application scale of satellite-derived maps of vegetation cover is essential for effective management of the vast, remote rangelands of the world. However, the underlying models are updated frequently and may combine with rapidly changing vegetation conditions to cause variations in accuracy and precision over time. We sought to assess how model performance changed between different versions of satellite-derived cover products (Rangeland Analysis Platform, RAP, and Rangeland Condition Monitoring and Assessment Protocol, RCMAP) and how the performance of LandCart compared to RAP and RCMAP. Additionally, we asked how variability in agreement between LandCart and field-based models varied with scale. We utilized an intensive dataset of grid-point intercept functional group cover data collected between 2016 and 2020 across the ∼113 kHA 2015 Soda Wildfire to 1) evaluate r 2 agreement between versions of each satellite-derived product and plot-level field data and 2) assess relative standard error of agreement in cover between LandCart and continuous field-based Empirical Bayesian Kriging (EBK) regression models. Agreement between satellite- compared to field-plot values of cover (r 2 ) increased for RCMAP Version 5.0 compared to Version 2.0, but there were negligible changes between versions of RAP. Despite this, r 2 values of RCMAP and LandCart were nearly always less than RAP. Variability in agreement between EBK regression model cover and LandCart-derived cover decreased with the scale of consideration. Variability in agreement between satellite-derived cover products and field-based metrics is lowest at larger scale (mega-fire or regional) and varies from year to year and across versions, which could complicate detection of temporal changes in plant cover.

Idaho, Oregon↗