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USGS2002

Ground-cover vegetation in wetland forests of the lower Suwannee River floodplain, Florida, and potential impacts of flow reductions

Ground-cover vegetation was surveyed in wetland forests in the lower Suwannee River floodplain, Florida, in a study conducted by the U.S. Geological Survey in cooperation with the Suwannee River Water Management District from 1996 to 1999. Increased water use in the basin, supplied primarily from ground water, could reduce ground-water discharge to the river and flows in the lower Suwannee River. Many of the 282 ground-cover species found in wetland forests of the floodplain have distributions that are related to flow-dependent hydrologic characteristics of forest types, and their distributions would change if flows were reduced. Overall species diversity in the floodplain might decrease, and the composition of ground-cover vegetation in all forest types might change with flow reductions. The study area included forests within the 10-year floodplain of the lower Suwannee River from its confluence with the Santa Fe River to the lower limit of forests near the Gulf of Mexico. The floodplain is divided into three reaches (riverine, upper tidal, and lower tidal) due to variations in hydrology, vegetation, and soils with proximity to the coast. The riverine (non-tidal) reach had the greatest number of total species (203) and species unique to that reach (81). Mitchella repens, Toxicodendron radicans, and Axonopus furcatus were the most frequently dominant species in riverine bottomland hardwoods. Free-floating aquatic species, such as Spirodela punctata and Lemna valdiviana, were the dominant species in the wettest riverine swamps. The upper tidal reach had the lowest number of total species (116), only two species unique to that reach, and the lowest density of ground cover (26 percent). Panicum commutatum and Crinum americanum were frequent dominant species in upper tidal forests. The lower tidal reach had the highest ground-cover density (43 percent) and the second highest number of total species (183) and number of species unique to that reach (55). Saururus cernuus and species of Carex were frequently dominant in lower tidal swamps. Lower tidal hammocks, the most elevated lower tidal forests, were dominated by Osmunda cinnamomea and Chasmanthium laxum. Flow reductions in the lower Suwannee River could change the flow-dependent hydrologic characteristics of wetland forests. Decreases in inundation and saturation in riverine forests could result in a decrease in the number and extent of semi-permanently inundated ponds. As a result, several species of free-floating, aquatic plants that grow only in riverine floodplain ponds might decrease in abundance or disappear if flows were reduced. Decreases in inundation and saturation could also result in a shift to more upland species in all riverine forests and upper tidal bottomland hardwoods. Upland species and some exotic species might increase in abundance in the floodplain, invading forests where hydrologic conditions have been altered by flow reductions. Depth and duration of inundation due to river flooding could decrease in all riverine and upper tidal forests, probably resulting in a shift of species to those that are typically found in forests with shallower, shorter-duration floods. Salinity in the lower tidal reach and adjacent areas of the upper tidal reach might increase with flow reductions, and the distribution of species might change due to varying tolerances of salinity among species. Species with low salt-tolerance unique to the lower tidal reach might disappear from the floodplain, and species with high salinity tolerance could increase in abundance, replacing less salt-tolerant species.

Water-Resources Investigations Report↗

USGS2004

A method for simulating transient ground-water recharge in deep water-table settings in central Florida by using a simple water-balance/transfer-function model

A relatively simple method is needed that provides estimates of transient ground-water recharge in deep water-table settings that can be incorporated into other hydrologic models. Deep water-table settings are areas where the water table is below the reach of plant roots and virtually all water that is not lost to surface runoff, evaporation at land surface, or evapotranspiration in the root zone eventually becomes ground-water recharge. Areas in central Florida with a deep water table generally are high recharge areas; consequently, simulation of recharge in these areas is of particular interest to water-resource managers. Yet the complexities of meteorological variations and unsaturated flow processes make it difficult to estimate short-term recharge rates, thereby confounding calibration and predictive use of transient hydrologic models. A simple water-balance/transfer-function (WBTF) model was developed for simulating transient ground-water recharge in deep water-table settings. The WBTF model represents a one-dimensional column from the top of the vegetative canopy to the water table and consists of two components: (1) a water-balance module that simulates the water storage capacity of the vegetative canopy and root zone; and (2) a transfer-function module that simulates the traveltime of water as it percolates from the bottom of the root zone to the water table. Data requirements include two time series for the period of interest?precipitation (or precipitation minus surface runoff, if surface runoff is not negligible) and evapotranspiration?and values for five parameters that represent water storage capacity or soil-drainage characteristics. A limiting assumption of the WBTF model is that the percolation of water below the root zone is a linear process. That is, percolating water is assumed to have the same traveltime characteristics, experiencing the same delay and attenuation, as it moves through the unsaturated zone. This assumption is more accurate if the moisture content, and consequently the unsaturated hydraulic conductivity, below the root zone does not vary substantially with time. Results of the WBTF model were compared to those of the U.S. Geological Survey variably saturated flow model, VS2DT, and to field-based estimates of recharge to demonstrate the applicability of the WBTF model for a range of conditions relevant to deep water-table settings in central Florida. The WBTF model reproduced independently obtained estimates of recharge reasonably well for different soil types and water-table depths.

Scientific Investigations Report↗

USGS2017

Phenology, growth, and fecundity as determinants of distribution in closely related nonnative taxa

Invasive species researchers often ask: Why do some species invade certain habitats while others do not? Ecological theories predict that taxonomically related species may invade similar habitats, but some related species exhibit contrasting invasion patterns. Brassica nigra , Brassica tournefortii , and Hirschfeldia incana are dominant, closely related nonnative species that have overlapping, but dissimilar, distributions. Brassica tournefortii is rapidly spreading in warm deserts of the southwestern United States, whereas B. nigra and H. incana are primarily limited to semiarid and mesic regions. We compared traits of B. tournefortii that might confer invasiveness in deserts with those of related species that have not invaded desert ecosystems. Brassica tournefortii , B. nigra and H. incana were compared in controlled experiments conducted outdoors in a mesic site (Riverside, CA) and a desert site (Blue Diamond, NV), and in greenhouses, over 3 yr. Desert and mesic B. tournefortii populations were also compared to determine whether locally adapted ecotypes contribute to desert invasion. Experimental variables included common garden sites and soil water availability. Response variables included emergence, growth, phenology, and reproduction. There was no evidence for B. tournefortii ecotypes, but B. tournefortii had a more rapid phenology than B. nigra or H. incana . Brassica tournefortii was less affected by site and water availability than B. nigra and H. incana , but was smaller and less fecund regardless of experimental conditions. Rapid phenology allows B. tournefortii to reproduce consistently under variable, stressful conditions such as those found in Southwestern deserts. Although more successful in milder, mesic ecosystems, B. nigra and H. incana may be limited by their ability to reproduce under desert conditions. Rapid phenology and drought response partition invasion patterns of nonnative mustards along a gradient of aridity in the southwestern United States, and may serve as a predictive trait for other potential invaders of arid and highly variable ecosystems.

California;Nevada↗

USGS2020

Mangrove blue carbon in the face of deforestation, climate change, and restoration

Coastal wetlands have disproportionately high carbon densities, known as blue carbon, compared to most terrestrial ecosystems. Mangroves and their blue carbon stocks are at risk globally from land‐use and land‐cover change (LULCC) activities such as aquaculture, alongside biophysical disturbances such as sea‐level rise and cyclones. Global estimates of carbon emissions from mangrove loss have been previously unable to differentiate between the variable impacts of different drivers of loss. This article discusses the impacts that different LULCC activities and biophysical disturbances have on carbon stocks (biomass and soil) and greenhouse gas fluxes (CO 2 and CH 4 ). The dynamics of carbon stocks and fluxes depends on the type of LULCC; aquaculture often results in biomass and soil carbon removal, and some forms of agriculture can substantially increase methane emissions. Natural disturbances have mixed impacts on mangrove carbon; sea‐level rise will drown some mangroves and their carbon stocks but provide opportunities for new carbon accumulation, while cyclones can have immediate negative impacts on stocks but positive impacts on sequestration during recovery. Mangrove rehabilitation practices can actively restore carbon stocks and reduce greenhouse gas emissions from previous land uses. It is critical to consider the type of LULCC when estimating carbon emissions due to mangrove loss or rehabilitation. Mangrove blue carbon is now high on the international conservation policy agenda, and a better understanding of how carbon stocks and fluxes respond to anthropogenic and biophysical disturbance may provide better incentives for mangrove conservation and sustainable management.

Annual Plant Reviews↗

USGS2001

Restoration of biogeochemical function in mangrove forests

Forest structure of mangrove restoration sites (6 and 14 years old) at two locations (Henderson Creek [HC] and Windstar [WS]) in southwest Florida differed from that of mixed-basin forests (>50 years old) with which they were once contiguous. However, the younger site (HC) was typical of natural, developing forests, whereas the older site (WS) was less well developed with low structural complexity. More stressful physicochemical conditions resulting from incomplete tidal flushing (elevated salinity) and variable topography (waterlogging) apparently affected plant survival and growth at the WS restoration site. Lower leaf fall and root production rates at the WS restoration site, compared with that at HC were partly attributable to differences in hydroedaphic conditions and structural development. However, leaf and root inputs at each restoration site were not significantly different from that in reference forests within the same physiographic setting. Macrofaunal consumption of tethered leaves also did not differ with site history, but was dramatically higher at HC compared with WS, reflecting local variation in leaf litter processing rates, primarily by snails (Melampus coffeus). Degradation of leaves and roots in mesh bags was slow overall at restoration sites, however, particularly at WS where aerobic decomposition may have been more limited. These findings indicate that local or regional factors such as salinity regime act together with site history to control primary production and turnover rates of organic matter in restoration sites. Species differences in senescent leaf nitrogen content and degradation rates further suggest that restoration sites dominated by Laguncularia racemosa and Rhizophora mangle should exhibit slower recycling of nutrients compared with natural basin forests where Avicennia germinans is more abundant. Structural development and biogeochemical functioning of restored mangrove forests thus depend on a number of factors, but site-specific as well as regional or local differences in hydrology and concomitant factors such as salinity and soil waterlogging will have a strong influence over the outcome of restoration projects.

Restoration Ecology↗

USGS2010

Can we improve the salinity tolerance of genotypes of Taxodium by using varietal and hybrid crosses?

Taxodium distichum (L.) Rich. var. distichum [baldcypress (BC)], Taxodium distichum var. mexicanum Gordon [Montezuma cypress (MC)], and a Taxodium hybrid (\'Nanjing Beauty\': BC x MC cross, T302) were evaluated for salt tolerance in 2006 at Nacogdoches, TX. Plants were irrigated weekly with four levels of salinity [0, 1, 3.5, and 6 ppt (0, 17, 60, and 102 mol*m -3 )] for 13 weeks and then 0, 2, 7, and 12 ppt (0, 34, 120, and 204 mol*m -3 ) for another 12 weeks. Salinity treatments did not have a significant effect on growth rate; however, there were significant differences in growth rate among the three genotypes. Genotype T302 produced the greatest wet weight, whereas MC had stronger apical dominance and exhibited the greatest increase in height over the course of study. As expected, sodium (Na) concentration in Taxodium leaves increased as sea salt concentrations increased but did not tilt Na/potassium (K) ratios to stressful disproportions. Of the three genotypes, BC exhibited the highest leaf content of Na, calcium (Ca), sulfur (S), and iron (Fe); MC had the lowest leaf content of Na, Ca, S, and Fe; and T302 was intermediate. The benefits of using a hybrid cross (T302) that maintains greater biomass than BC or MC across a range of salinities must be weighed against the potential additional pruning and training necessary for cutting-grown clones relative to BC and MC propagated from seed and flood tolerance relative to BC. Still, combining the best characteristics of different varieties of T. distichum should facilitate the production of favorable genotypes tolerant to a number of soil physical and chemical property fluctuations for arboricultural operations.

HortScience↗

USGS2025

Characterizing pyrethroid and fipronil concentrations in biosolids

Pesticides are prevalent in wastewater, yet few studies have measured pesticides in biosolids and aqueous media from samples collected concurrently. Seventeen California wastewater treatment plants (WWTPs) were sampled in May 2020. Biosolids samples were analyzed for 27 analytes, and paired aqueous samples (influent and effluent) were analyzed for 23 analytes. Analytes included fipronil and its transformation products (fiproles), pyrethroids, novaluron, and several other pesticides with down-the-drain transport potential. Of the 27 compounds analyzed in biosolids samples, 16 were detected in at least one sample, and 10 had a detection frequency (DF) of at least 25 %. Fipronil sulfone, fipronil sulfide, and fipronil were the most frequently detected fiproles (DF = 100 %, 94 %, and 67 %, respectively); permethrin was the most frequently detected pyrethroid (DF = 100 %), followed by bifenthrin (DF = 94 %), cyhalothrin (DF = 89 %), and etofenprox (DF = 78 %). To elucidate fipronil transformation pathways within the treatment system, data from the three sample types were compared; findings were generally consistent with transformation pathways reported previously (e.g., some fiproles were rarely detected in influent or biosolids, but frequently detected in effluent, indicating their formation during the treatment process). No correlations were found between WWTP characteristics and pesticide concentrations in biosolids. The fraction of organic carbon ( f OC ) of each biosolids sample was measured, and a statistically significant negative correlation was observed between f OC and some fiproles, but not fipronil; possible explanations are discussed. Additional analysis for two major agricultural pesticides (bifenthrin and permethrin) indicated that estimated mass loads of these pesticides in biosolids applied to land as a soil amendment are minimal (approximately 2 to 3 orders of magnitude lower) compared to inputs from agricultural applications. This study provides insight on the magnitude of pesticides entering the environment via land-applied biosolids; existing regulations surrounding agricultural pesticide applications are expected to also be protective of the relatively low inputs from biosolids.

Science of the Total Environment↗

USGS1996

Evaluating evapotranspiration for six sites in Benton, Spokane, and Yakima counties, Washington, May 1990 to September 1992

This report evaluates evapotranspiration for six sites in Benton, Spokane, and Yakima Counties, Washington. Three sites were located on the Arid Lands Ecology Reserve in Benton County: one at a full-canopy grassland in Snively Basin (Snively Basin site), one at a sparse-canopy grassland adjacent to two weighing lysimeters (grass lysimeter site), and one at a sagebrush grassland adjacent to two weighing lysimeters (sage lysimeter site). Two sites were located on the Turnbull National Wildlife Refuge in Spokane County: one at a full-canopy grassland in a meadow (Turnbull meadow site), the other a full-canopy grassland near a marsh (Turnbull marsh site). The last site was located in a sagebrush grassland in the Black Rock Valley in Yakima County (Black Rock Valley site). The periods of study at the six sites varied, ranging from 5 months at the Black Rock Valley site to more than 2 years at the Snively Basin, grass lysimeter, and sage lysimeter sites. The periods of study were May 1990 to September 1992 for the Snively Basin, grass lysimeter, and sage lysimeter sites; May 1991 to September 1992 for the Turnbull meadow site; May 1991 to April 1992 for the Turnbull marsh site; and March to September 1992 for the Black Rock Valley site. Evapotranspiration and energy-budget fluxes were estimated for the Snively Basin site, the Turnbull meadow site, and the Black Rock Valley site using the Bowen-ratio and Penman-Monteith methods. Daily evapotranspiration for the Snively Basin site was also estimated using a deep-percolation model for the Columbia Basin. The Bowen-ratio method and weighing lysimeters were used at the grass and sage lysimeter sites. The Penman-Monteith method was used at the Turnbull marsh site. Daily evapotranspiration at the sites ranged from under 0.2 millimeter during very dry or cold periods to over 4\x11millimeters after heavy rainfall or during periods of peak transpiration. At all sites, peak evapotranspiration occurred in spring, coinciding with plant growth, and the lowest evapotranspiration occurred in late summer and winter, coinciding with plant dormancy and extremely hot or cold temperatures. Water budgets for the Snively Basin, grass lysimeter, and sage lysimeter sites were based on estimates of precipitation, evapotranspiration, and surface runoff. Surface runoff was estimated at zero for all sites. For the Snively Basin site, 1991 and 1992 water budgets using Penman-Monteith evapotranspiration estimates agreed within 1 percent of the annual budgets computed using deep-percolation model estimates; daily estimates of evapotranspiration by the two methods varied considerably, however. For the Snively Basin site, 100 percent of the precipitation became ET in 1991, and in 1992, about 91 percent of the precipitation became evapotranspiration. Water budgets based on weighing lysimeter data at the grass and sage lysimeter sites agreed within 1 percent of each other for 1991 and within 5 percent of each other for 1992. For 1991, 10 percent of the precipitation became ET at both lysimeter sites. For 1992, 94 to 98 percent of the precipitation became ET at the grass lysimeter site while 98 to 9 percent of the precipitation became ET at the sage lysimeter site. Though there were uncertainties in the methods used, recharge estimates for the Snively Basin and grass and sage lysimeter sites were of the same order of magnitude. The Penman-Monteith method (which incorporated Bowen-ratio measurements), deep- percolation model, and weighing lysimeters indicated that no recharge to subsurface systems (soil profile, unsaturated zone, and ground water) occurred in 1991 and that, in 1992, recharge to subsurface systems was probably less than 10 percent of the annual precipitation at the Snively Basin and grass and sage lysimeter sites.

Washington↗

USGS2018

An introduction and practical guide to use of the Soil-Vegetation Inventory Method (SVIM) data

Long-term vegetation dynamics across public rangelands in the western United States are not well understood because of the lack of large-scale, readily available historic datasets. The Bureau of Land Management’s Soil-Vegetation Inventory Method (SVIM) program was implemented between 1977 and 1983 across 14 western states, but the data have not been easily accessible. We introduce the SVIM vegetation cover dataset in a georeferenced, digital format; summarize how the data were collected; and discuss potential limitations and biases. We demonstrate how SVIM data can be compared with contemporary monitoring datasets to quantify changes in vegetation associated with wildfire and the abundance of exotic invasive species. Specifically, we compare SVIM vegetation cover data with cover data collected by BLM’s Assessment, Inventory, and Monitoring (AIM) program (2011–2016) in a focal area in the northern Great Basin. We address issues associated with analyzing and interpreting data from these distinct programs, including differences in survey methods and potential biases introduced by spatial and temporal variation in sampling. We compared SVIM and AIM survey methods at 44 plots and found that percent cover estimates had high correspondence for all measured functional groups. Comparisons between historic SVIM data and recent AIM data documented significant declines in the occupancy and cover of native shrubs and native perennial forbs , and a significant increase in exotic annual forbs. Wildfire was a driver of change for some functional groups, with greater change occurring in AIM plots that burned between the two time periods compared with those that did not. Our results are consistent with previous studies showing that many native shrub-dominated plant communities in the Great Basin have been replaced by exotic annuals. Our study demonstrates that SVIM data will be an important resource for researchers interested in quantifying vegetation change through time across public rangelands in the western United States.

Rangeland Ecology and Management↗

USGS2001

Sediment quality in Burlington Harbor, Lake Champlain, U.S.A.

Surface samples and cores were collected in 1993 from the Burlington Harbor region of Lake Champlain. Sediment samples were analyzed for trace metals (cadmium, copper, lead, nickel, silver and zinc), simultaneously extracted metal/acid volatile sulfide (SEM-AVS), grain size, nutrients (carbon and nitrogen) and organic contaminants (polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs)). The concentrations of cadmium, copper, silver and zinc from the partial sediment digestion of the surface samples correlated well with each other (r2 > 0.60) indicating that either a common process, or group of processes determined the sediment concentrations of these metals. In an analysis of the spatial distribution of the trace metals and PAHs, high surficial concentrations were present in the southern portion of the Harbor. The trace metal trend was strengthened when the concentrations were normalized by grain size. A sewage treatment plant outfall discharge was present in the southeastern portion of the Harbor at the time of this study and is the major source of trace metal and PAH contamination. Evaluation of sediment cores provides a proxy record of historical trace metal and organic inputs. The peak accumulation rate for copper, cadmium, lead, and zinc was in the late 1960s and the peak silver accumulation rate was later. The greatest accumulation of trace metals occurred in the late 1960s after discharges from the STP began. Subsequent declines in trace metal concentrations may be attributed to increased water and air regulations. The potential toxicity of trace metals and organic contaminants was predicted by comparing contaminant concentrations to benchmark concentrations and potential trace metal bioavailability was predicted with SEM-AVS results. Surface sample results indicate lead, silver, ???PAHs and ???PCBs are potentially toxic and/or bioavailable. These predictions were supported by studies of biota in the Burlington Harbor watershed. There is a clear trend of decreasing PAH and trace metal contaminant concentrations with distance from the STP outfall.Surface samples and cores were collected in 1993 from the Burlington Harbor region of Lake Champlain. Sediment samples were analyzed for trace metals (cadmium, copper, lead, nickel, silver and zinc), simultaneously extracted metal/acid volatile sulfide (SEM-AVS), grain size, nutrients (carbon and nitrogen) and organic contaminants (polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs)). The concentrations of cadmium, copper, silver and zinc from the partial sediment digestion of the surface samples correlated well with each other (r2>0.60) indicating that either a common process, or group of processes determined the sediment concentrations of these metals. In an analysis of the spatial distribution of the trace metals and PAHs, high surficial concentrations were present in the southern portion of the Harbor. The trace metal trend was strengthened when the concentrations were normalized by grain size. A sewage treatment plant outfall discharge was present in the southeastern portion of the Harbor at the time of this study and is the major source of trace metal and PAH contamination. Evaluation of sediment cores provides a proxy record of historical trace metal and organic inputs. The peak accumulation rate for copper, cadmium, lead, and zinc was in the late 1960s and the peak silver accumulation rate was later. The greatest accumulation of trace metals occurred in the late 1960s after discharges from the STP began. Subsequent declines in trace metal concentrations may be attributed to increased water and air regulations. The potential toxicity of trace metals and organic contaminants was predicted by comparing contaminant concentrations to benchmark concentrations and potential trace metal bioavailability was predicted with SEM-AVS results. Surface sample results indicate lead, silver, ??PAHs and ??PCBs are potentially toxic and/or bi

Water, Air, & Soil Pollution↗

USGS2011

Liquefaction and other ground failures in Imperial County, California, from the April 4, 2010, El Mayor-Cucapah earthquake

The Colorado River Delta region of southern Imperial Valley, California, and Mexicali Valley, Baja California, is a tectonically dynamic area characterized by numerous active faults and frequent large seismic events. Significant earthquakes that have been accompanied by surface fault rupture and/or soil liquefaction occurred in this region in 1892 (M7.1), 1915 (M6.3; M7.1), 1930 (M5.7), 1940 (M6.9), 1950 (M5.4), 1957 (M5.2), 1968 (6.5), 1979 (6.4), 1980 (M6.1), 1981 (M5.8), and 1987 (M6.2; M6.8). Following this trend, the M7.2 El Mayor-Cucapah earthquake of April 4, 2010, ruptured approximately 120 kilometers along several known faults in Baja California. Liquefaction caused by the M7.2 El Mayor-Cucapah earthquake was widespread throughout the southern Imperial Valley but concentrated in the southwest corner of the valley, southwest of the city centers of Calexico and El Centro where ground motions were highest. Although there are few strong motion recordings in the very western part of the area, the recordings that do exist indicate that ground motions were on the order of 0.3 to 0.6g where the majority of liquefaction occurrences were found. More distant liquefaction occurrences, at Fites Road southwest of Brawley and along Rosita Canal northwest of Holtville were triggered where ground motions were about 0.2 g. Damage to roads was associated mainly with liquefaction of sandy river deposits beneath bridge approach fills, and in some cases liquefaction within the fills. Liquefaction damage to canal and drain levees was not always accompanied by vented sand, but the nature of the damage leads the authors to infer that liquefaction was involved in the majority of observed cases. Liquefaction-related damage to several public facilities - Calexico Waste Water Treatment Plant, Fig Lagoon levee system, and Sunbeam Lake Dam in particular - appears to be extensive. The cost to repair these facilities to prevent future liquefaction damage will likely be prohibitive. As such, it is likely that liquefaction will recur at these facilities during the next large earthquake in this area.

California↗

USGS2011

Monitoring habitat restoration projects: U.S. Fish and Wildlife Service Pacific Region Partners for Fish and Wildlife Program and Coastal Program Protocol

The U.S. Fish and Wildlife Service's (FWS) Pacific Region (Region 1) includes more than 158 million acres (almost 247,000 square miles) of land base in Idaho, Oregon, Washington, Hawai`i, the Commonwealth of the Northern Mariana Islands, American Samoa, Guam, the Republic of Palau, the Federated States of Micronesia, and the Republic of the Marshall Islands. Region 1 is ecologically diverse with landscapes that range from coral reefs, broadleaf tropical forests, and tropical savannahs in the Pacific Islands, to glacial streams and lakes, lush old-growth rainforests, inland fjords, and coastal shoreline in the Pacific Northwest, to the forested mountains, shrub-steppe desert, and native grasslands in the Inland Northwest. Similarly, the people of the different landscapes perceive, value, and manage their natural resources in ways unique to their respective regions and cultures. The Partners for Fish and Wildlife Program (Partners Program) and Coastal Program work with a variety of partners in Region 1 including individual landowners, watershed councils, land trusts, Soil and Water Conservation Districts, non-governmental organizations, Tribal governments, Native Hawaiian organizations, and local, State, and Federal agencies. The Partners Program is the FWS's vanguard for working with private landowners to voluntarily restore and conserve fish and wildlife habitat. Using non-regulatory incentives, the Partners Program engages willing partners to conserve and protect valuable fish and wildlife habitat on their property and in their communities. This is accomplished by providing the funding support and technical and planning tools needed to make on-the-ground conservation affordable, feasible, and effective. The primary goals of the Pacific Region Partners Program are to: Promote citizen and community-based stewardship efforts for fish and wildlife conservation Contribute to the recovery of at-risk species, Protect the environmental integrity of the National Wildlife Refuges, Contribute to the implementation of the State Comprehensive Wildlife Conservation Strategies, and Help achieve the objectives of the National Fish Habitat Partnerships and regionally based bird conservation plans (for example, North American Waterfowl Management Plan, U.S. Pacific Island Shorebird Conservation Plans, Intermountain West Regional Shorebird Plan, etc.). The Partners Program accomplishes these priorities by: Developing and maintaining strong partnerships, and delivering on-the-ground habitat restoration projects designed to reestablish habitat function and restore natural processes; Addressing key habitat limiting factors for declining species; Providing corridors for wildlife and decrease impediments to native fish and wildlife migration; and Enhancing native plant communities by reducing invasive species and improving native species composition. The Coastal Program is a voluntary fish and wildlife conservation program that focuses on watershed-scale, long-term collaborative resource planning and on-the-ground restoration projects in high-priority coastal areas. The Coastal Program conducts planning and restoration work on private, State, and Federal lands, and partnerships with other agencies-Native American Tribes, citizens, and organizations are emphasized. Coastal Program goals include restoring and protecting coastal habitat, providing technical and cost-sharing assistance where appropriate, supporting community-based restoration, collecting and developing information on the status of and threats to fish and wildlife, and using outreach to promote stewardship of coastal resources. The diversity of habitats and partners in Region 1 present many opportunities for conducting restoration projects. Faced with this abundance of opportunity, the Partners Program and Coastal Program must ensure that limited staffing and project dollars are allocated to benefit the highest priority resources and achieve the highest quality results for Federal trust species. In 2007, the Partners Program and Coastal Program developed a Strategic Plan to guide program operations and more efficiently conserve habitat by focusing partnership building and habitat improvement actions within 35 Partners Program Focus Areas and 9 Coastal Program Focus Areas (U.S. Fish and Wildlife Service, 2010). The Strategic Plan also contains four other goals: broaden and strengthen partnerships; improve information sharing and communications; enhance workforce; and increase accountability to ensure that program resources are used efficiently and effectively. This protocol will help achieve all goals of the Strategic Plan.

Techniques and Methods↗

USGS2008

Where temperate meets tropical: Multi-factorial effects of elevated CO2, nitrogen enrichment, and competition on a mangrove-salt marsh community

Our understanding of how elevated CO 2 and interactions with other factors will affect coastal plant communities is limited. Such information is particularly needed for transitional communities where major vegetation types converge. Tropical mangroves ( Avicennia germinans ) intergrade with temperate salt marshes ( Spartina alterniflora ) in the northern Gulf of Mexico, and this transitional community represents an important experimental system to test hypotheses about global change impacts on critical ecosystems. We examined the responses of A. germinans (C 3 ) and S. alterniflora (C 4 ), grown in monoculture and mixture in mesocosms for 18 months, to interactive effects of atmospheric CO 2 and pore water nitrogen (N) concentrations typical of these marshes. A. germinans , grown without competition from S. alterniflora , increased final biomass (35%) under elevated CO 2 treatment and higher N availability. Growth of A. germinans was severely curtailed, however, when grown in mixture with S. alterniflora , and enrichment with CO 2 and N could not reverse this growth suppression. A field experiment using mangrove seedlings produced by CO 2 ‐ and N‐enriched trees confirmed that competition from S. alterniflora suppressed growth under natural conditions and further showed that herbivory greatly reduced survival of all seedlings. Thus, mangroves will not supplant marsh vegetation due to elevated CO 2 alone, but instead will require changes in climate, environmental stress, or disturbance to alter the competitive balance between these species. However, where competition and herbivory are low, elevated CO 2 may accelerate mangrove transition from the seedling to sapling stage and also increase above‐ and belowground production of existing mangrove stands, particularly in combination with higher soil N.

Louisiana↗

USGS2024

Factors contributing to pesticide contamination in riverine systems: The role of wastewater and landscape sources

Wastewater treatment plant (WWTP) discharges can be a source of organic contaminants, including pesticides, to rivers. An integrated model was developed for the Potomac River watershed (PRW) to determine the amount of accumulated wastewater percentage of streamflow (ACCWW) and calculate predicted environmental concentrations (PECs) for 14 pesticides in non-tidal National Hydrography Dataset Plus Version 2.1 stream segments. Predicted environmental concentrations were compared to measured environmental concentrations (MECs) from 32 stream sites that represented a range of ACCWW and land use to evaluate model performance and to assess possible non-WWTP loading sources. Statistical agreement between PECs and MECs was strongest for insecticides, followed by fungicides and herbicides. Principal component analysis utilizing optical fluorescence and ancillary water quality data identified wastewater and urban runoff sources. Pesticides that indicated relatively larger sources from WWTPs included dinotefuran, fipronil, carbendazim, thiabendazole, and prometon whereas imidacloprid, azoxystrobin, propiconazole, tebuconazole, and diuron were more related to urban runoff. In addition, PECs generally comprised a low proportion of MECs, which indicates possible dominant loading sources beyond WWTP discharges. Cumulative potential toxicity was higher for sites with greater ACCWW and/or located in developed areas. Imidacloprid, fipronil, and carbendazim accounted for the largest portion of predicted potential toxicity across sites. The chronic aquatic life toxicity benchmarks for freshwater invertebrates were exceeded for 82 % of the imidacloprid detections ( n = 28) and 47 % of the fipronil detections ( n = 19). These results highlight the ecological implications of pesticide contamination from WWTP discharges and also the potential legacy effects from accumulated soil and groundwater sources. Pesticide management strategies that mitigate both current and historical impacts may improve the health of aquatic ecosystems.

Potomac River watershed↗

USGS2007

Construction and testing of a simple and economical soil greenhouse gas automatic sampler

Quantification of soil greenhouse gas emissions requires considerable sampling to account for spatial and/or temporal variation. With manual sampling, additional personnel are often not available to sample multiple sites within a narrow time interval. The objectives were to construct an automatic gas sampler and to compare the accuracy and precision of automatic versus manual sampling. The automatic sampler was tested with carbon dioxide (CO2) fluxes that mimicked the range of CO2 fluxes during a typical corn-growing season in eastern Nebraska. Gas samples were drawn from the chamber at 0, 5, and 10 min manually and with the automatic sampler. The three samples drawn with the automatic sampler were transferred to pre-vacuumed vials after 1 h; thus the samples in syringe barrels stayed connected with the increasing CO2 concentration in the chamber. The automatic sampler sustains accuracy and precision in greenhouse gas sampling while improving time efficiency and reducing labor stress. Copyright ?? Taylor & Francis Group, LLC.

Journal of Plant Nutrition↗

USGS2016

Hydrogeological framework, numerical simulation of groundwater flow, and effects of projected water use and drought for the Beaver-North Canadian River alluvial aquifer, northwestern Oklahoma

This report describes a study of the hydrology, hydrogeological framework, numerical groundwater-flow models, and results of simulations of the effects of water use and drought for the Beaver-North Canadian River alluvial aquifer, northwestern Oklahoma. The purpose of the study was to provide analyses, including estimating equal-proportionate-share (EPS) groundwater-pumping rates and the effects of projected water use and droughts, pertinent to water management of the Beaver-North Canadian River alluvial aquifer for the Oklahoma Water Resources Board. The Beaver-North Canadian River alluvial aquifer consists of unconsolidated sand, gravel, silt, and clay in varying proportions that underlies the Beaver and North Canadian River Valleys for approximately 175 miles (mi) from the Oklahoma Panhandle to the western edge of Oklahoma City in central Oklahoma. The aquifer as delineated for this study varies from 4 to 12 mi wide and is as thick as 308 feet (ft) in the northwest where the aquifer includes the Ogallala Formation. There are two distinct but in most areas hydraulically connected alluvial units that compose the Beaver-North Canadian River alluvial aquifer: a Quaternary-age topographically higher terrace deposit and a topographically lower, younger alluvium along the active river channel that includes active and Quaternary-age alluvium. The Beaver River composes the headwaters of the North Canadian River, which begins at the confluence of the Beaver River and Wolf Creek. The aquifer is divided for water management into two geographic areas: Reach I upstream from Canton Dam and Reach II downstream from Canton Dam. Reach I covers an area of approximately 874 square miles (mi 2 ), and Reach II covers an area of approximately 371 mi 2 . The Beaver-North Canadian River alluvial aquifer crosses several climatic zones, from semiarid in the west to continental subhumid in the east. Mean annual precipitation varies from 23.5 inches (in.) in the western part of this aquifer to 35.7 in. in the east. Surface-water demands were met through numerous temporary and permanent surface-water diversions from the Beaver and North Canadian Rivers during the period of study. During the study period, seven diversions removed a mean annual 2,000 acre-feet (acre-ft) of water from Reach I. There were 14 diversions from Reach II with a mean annual permitted volume of approximately 81,000 acre-ft, including diversion into the Lake Hefner Canal for the Oklahoma City public water supply. During the period of this study, 17 temporary surface-water diversion permits were active in Reach I, with total permitted volumes of 2,000 acre-ft, and 41 diversions were active in Reach II, with total permitted volumes of 38,000 acre-ft. The total water use for each temporary permit was assumed to be taken over the 3-month period allotted to temporary withdrawal permits. The groundwater-use analysis full period of record, 1967–2011, was divided into two sub-intervals because of varying water use, 1970–80 and 1981–2011. Groundwater use in Reach I and Reach II was substantially greater from 1970 to 1980 compared to the rest of the period, and the sub-period 1981–2011 was used because this period includes recent population growth and modern irrigation methods. The total mean annual groundwater use in Reach I was 15,309 acre-feet per year (acre-ft/yr) during 1967–2011; 20,724 acre-ft/yr during 1970–80, and 13,739 acre-ft/yr during 1981–2011. Total mean annual groundwater use in Reach II was similar but slightly less than in Reach I, with 14,098 acre-ft/yr during 1967–2011; 19,963 acre-ft/yr during 1970–80; and 12,285 acre-ft/yr during 1981–2011. Irrigation composed 72 percent of groundwater use in Reach I and 48 percent of groundwater use in Reach II during the 1967–2011 period. Public water supply was a much smaller proportion of total groundwater use in Reach I (15 percent) than in Reach II (39 percent). The proportion of groundwater use for power was 10 percent in Reach I and 5.2 percent in Reach II. All other water-use categories in Reach I only composed 2.2 percent of groundwater use in Reach I. In Reach II, industrial, mining, and commercial categories combined accounted for 4.4 percent of groundwater use; recreation, fish, and wildlife groundwater use accounted for 2.3 percent; and nonirrigated agriculture accounted for 1.5 percent of groundwater use. Permian-age bedrock underlies the Beaver-North Canadian River alluvial aquifer. In the east, the Dog Creek Shale, the Duncan Sandstone, and the Blaine and Chickasha Formations, none of which are notable sources of groundwater in the study area, underlie the Beaver-North Canadian River alluvial aquifer. In the northwestern part of Reach I, bedrock is composed of the Rush Springs and Marlow Formations, which are productive aquifers in some areas. The Cloud Chief Formation is not a source of groundwater. One hydrogeological unit was delineated in the Beaver-North Canadian River alluvial aquifer, composed of the terrace deposits and alluvium, with limited flow between this unit and bedrock units. Groundwater in this aquifer generally flows from northwest to southeast and across the aquifer toward the Beaver and North Canadian Rivers. Groundwater recharge from precipitation was estimated for the entire Beaver-North Canadian River alluvial aquifer and then itemized for both reaches by using a soil-water-balance (SWB) model. At two locations in Reach I, a water-table fluctuation method was used to estimate local recharge. Total mean annual groundwater recharge from the soil-water-balance method was estimated to be approximately 136,400 acre-ft in Reach I and 82,400 acre-ft in Reach II; the mean annual recharge for both reaches combined was approximately 218,800 acre-ft. Two sites in Reach I located at observation wells with continuous water-level measurements and nearby streamflow-gaging stations with precipitation gages were used to estimate the percentage of precipitation that becomes groundwater recharge. The Woodward site was located at observation well OW-4 near the Woodward, Okla. (07237500), streamflow-gaging station. Total precipitation and recharge for the Woodward and Seiling sites were calculated for the water year 2013. The Woodward site had a total of 14.18 in. of precipitation and 6.3 in. of recharge was calculated, equaling 44 percent of precipitation. The mean percentage of precipitation that was estimated to become recharge in the SWB model for the period 1980–2011 at that location was 9.2 percent, although adjacent SWB-model cells were as high as 20 percent of precipitation. The Seiling site had a total of 26.84 in. of precipitation during the water year 2013, and a total of 6.9 in. of recharge was estimated, equaling 25.9 percent of precipitation. At the Seiling site, the mean percentage of precipitation that became recharge in the SWB model for the period 1980–2011 was 23.0 percent. The principal inflow to the Beaver-North Canadian River alluvial aquifer was estimated to be surface recharge from precipitation, and plant evapotranspiration was estimated to be the greatest discharge, followed by stream and lake base flow, groundwater pumping, and flow to seeps and springs along the eastern margin of the aquifer. Reach I also included inflow from the High Plains aquifer as lateral inflow of groundwater, though this flow was estimated to be a very minor component of the total water budget. Most of the Beaver and North Canadian Rivers were determined to be gaining streamflow from groundwater, but several reaches in Reach I upstream from Wolf Creek were determined to be losing streamflow through infiltration to the aquifer. Aquifer hydrogeologic characteristics were estimated from borehole lithologic logs, well-construction information, and published aquifer tests and during numerical model calibration. The maximum saturated aquifer thickness in Reach I was estimated to be 308 ft, and the mean thickness was estimated to be 36 ft. The maximum saturated thickness in Reach II was estimated to be 86 ft, and the mean thickness was estimated to be 29 ft. Mean hydraulic conductivity of Reach I was estimated to be 70 feet per day (ft/d) with a range of 7–279 ft/d. Mean hydraulic conductivity in Reach II was estimated to be 92 ft/d with a range of 4–279 ft/d. Both reach models were calibrated manually by using trial-and-error adjustment of recharge, hydraulic conductivity, specific yield, and conductance of boundary conditions. The Reach I model used 28 head observations during the steady-state period of 1980 and 487 head observations during the transient period of 1981–2011. The root-mean-square error of head residuals (observed minus simulated head) was 3.86 ft, and 83 percent of head residuals were between -5 and 5 ft. The Reach II model was calibrated to 75 steady-state head observations and 134 head observations during the transient period. The root-mean-square error of head residuals for that reach was 3.58 ft, and similar to Reach I, 85 percent of residuals were between -5 and 5 ft. Several analyses were performed by using the numeric groundwater-flow models as predictive tools, including estimating the EPS pumping rate for both reaches. The EPS is defined by the Oklahoma Water Resources Board as an annual per-acre groundwater-pumping rate that will reduce saturated thickness in half of the aquifer to 5 ft or less over a period of 20 years; additional estimates were made for periods of 40 and 50 years. Other analyses included using models to estimate the effects of groundwater pumping and a prolonged drought on groundwater in storage and streamflow and lake storage of water. The EPS pumping rate was found to be approximately 0.57 acre-feet per acre per year ([acre-ft/acre]/yr) in Reach I and 0.73 (acre-ft/acre)/yr in Reach II for a 20-year period. For a 40-year period, the annual EPS pumping rate was determined to be 0.54 (acre-ft/acre)/yr in Reach I and 0.61 (acre-ft/acre)/yr in Reach II. For a 50-year period, the EPS pumping rate was determined to be 0.53 (acre-ft/acre)/yr in Reach I and 0.61 (acre-ft/acre)/yr in Reach II. Groundwater pumping at the 2011 rate for 50 years resulted in a 3.6-percent decrease in the amount of water in groundwater storage in Reach I and a decrease of 2.5 percent in the amount of groundwater in storage in Reach II. A cumulative 32-percent increase in pumping greater than the 2011 rate over a period of 50 years caused a decrease in groundwater storage of 4.0 percent in Reach I and 3.3 percent in Reach II. A hypothetical severe drought was simulated by using aquifer recharge flow rates during the drought year of 2011 for a period of 10 years. All other flows including evapotranspiration and groundwater pumping were set at estimated 2011 rates. The hypothetical drought caused a decrease in water in aquifer storage by about 7 percent in Reach I and 7 percent in Reach II. Another analysis of the effects of hypothetical drought estimated the effects of drought on streamflow and lake storage. The hypothetical drought was simulated by decreasing recharge by 75 percent for a selected 10-year period (1994–2004) during the 1980–2011 simulation. In Reach I, the amounts of water stored in Canton Lake and streamflow at the Seiling, Okla., streamflow-gaging station were analyzed. Streamflow at the Seiling station decreased by a mean of 75 percent and was still diminished by 10 percent after 2011. In Reach II, the effect of drought on the streamflow at the Yukon, Okla., streamflow-gaging station was examined. The greatest mean streamflow decrease was approximately 60 percent during the simulated drought, and after 2011, the mean decrease in streamflow was still about 5 percent. Canton Lake storage decreased by as much as 83 percent during the simulated drought and did not recover by 2011.

Oklahoma↗

USGS2009

Water quality and evaluation of pesticides in lakes in the Ridge Citrus region of central Florida

Water chemistry, including major inorganic constituents, nutrients, and pesticide compounds, was compared between seven lakes surrounded by citrus agriculture and an undeveloped lake on the Lake Wales Ridge (herein referred to as the Ridge) in central Florida. The region has been recognized for its vulnerability to the leaching of agricultural chemicals into the subsurface due to factors including soils, climate, and land use. About 40 percent of Florida's citrus cultivation occurs in 'ridge citrus' areas characterized by sandy well drained soils, with the remainder in 'flatwoods citrus' characterized by high water tables and poorly drained soils. The lakes on the Ridge are typically flow-through lakes that exchange water with adjacent and underlying aquifer systems. This study is the first to evaluate the occurrence of pesticides in lakes on the Ridge, and also represents one of the first monitoring efforts nationally to focus on regional-scale assessment of current-use pesticides in small- to moderate-sized lakes (5 to 393 acres). The samples were collected between December 2003 and September 2005. The lakes in citrus areas contained elevated concentrations of major inorganic constituents (including alkalinity, total dissolved solids, calcium, magnesium, sodium, potassium, chloride, and sulfate), total nitrogen, pH, and pesticides compared to the undeveloped lake. Nitrate (as N) and total nitrogen concentrations were typically elevated in the citrus lakes, with maximum values of 4.70 and 5.19 mg/L (milligrams per liter), respectively. Elevated concentrations of potassium, nitrate, and other inorganic constituents in the citrus lakes likely reflect inputs from the surficial ground-water system that originated predominantly from agricultural fertilizers, soil amendments, and inorganic pesticides. A total of 20 pesticide compounds were detected in the lakes, of which 12 compounds exceeded the standardized reporting level of 0.06 ug/L (microgram per liter). Those most frequently detected above the 0.06-ug/L level were aldicarb sulfoxide, diuron, simazine degradates hydroxysimazine and didealkylatrazine (DDA), bromacil, norflurazon, and demethyl norflurazon which occurred at detection rates ranging from 25 to 86 percent of samples, respectively. Typically, pesticide concentrations in the lake samples were less than 1 microgram per liter. The number of targeted pesticide compounds detected per lake in the citrus areas ranged from 9 to 14 compared to 3 compounds detected at trace levels in the undeveloped lake. Consistent detections of parents and degradates in quarterly samples indicated the presence of pesticide compounds in the lakes many months or years (for example, bromacil) after their application, signaling the persistence of some pesticide compounds in the lakes and/or ground-water systems. Pesticide degradate concentrations frequently exceeded parent concentrations in the lakes. This study was the first in the Ridge citrus region to analyze for glyphosate - widely used in citrus - and its degradate aminomethylphosphonic acid (AMPA), neither of which were detected, as well as a number of triazine degradates, including hydroxysimazine, which were detected. The lake pesticide concentrations did not exceed current Federal aquatic-life benchmarks, available for 10 of the 20 detected pesticide compounds. Limited occurrences of bromacil, diuron, or norflurazon concentrations were within about 10 to 90 percent of benchmark guidelines for acute effects on nonvascular aquatic plants in one or two of the lakes. The lake pesticide concentrations for several targeted pesticides were relatively high compared to corresponding national stream-water percentiles, which is consistent with this region's vulnerability for pesticide leaching into water resources. Several factors were evaluated to gain insight into the processes controlling pesticide transport and fate, and to assess their utility for estimating th

Florida↗

USGS1995

Nutrient loading to Lewisville Lake, north-central Texas, 1984-87

Concentrations of nutrients in the streams of the 1,660-square-mile Lewisville Lake drainage basin have some association with the two types of physiographic regions in the basin prairie regions and cross timbers regions. Total nitrogen and phosphorus concentrations generally are larger in streams draining the prairie regions than in streams draining the cross timbers regions, a characteristic that might be accounted for in part by the fact that prairie regions tend to have more nutrient-rich, less-permeable soils than cross timbers regions. Most of the variability in nutrient loads is associated with variability in discharge. During a low-flow synoptic survey, the largest contributor of total nitrogen and total phosphorus (at the downstream-most site) was Isle du Bois Creek (815 pounds per day of total nitrogen and 146 pounds per day of total phosphorus). During a high-flow synoptic survey, the largest contributor of total nitrogen and total phosphorus (at the downstream-most site) was Elm Fork Trinity River (4,620 pounds per day of total nitrogen and 210 pounds per day of total phosphorus). On the basis of results of stormflow and periodic sampling, the total nitrite plus nitrate nitrogen that entered the reservoir on the average each day during 1986 was 5,640 pounds per day, and during 1987,4,480 pounds per day. During the same period, about one and one-half as much nitrogen in the form of total ammonia plus organic nitrogen entered the reservoir (8,530 pounds per day in 1986 and 7,020 pounds per day in 1987); and about one-fourth as much total phosphorus entered the reservoir during the period (1,310 pounds per day in 1986 and 1,080 pounds per day in 1987). Point sources accounted for small fractions (probably less than 10 percent) of the total nutrient load from Clear Creek, Little Elm Creek, Hickory Creek, and Elm Fork Trinity River. Most of the point-source load to Lewisville Lake could originate at a few sewage-treatment plants discharging to ungaged streams close to the reservoir. The estimated long-term (1974-89 water years) average annual total nitrogen load (excluding loads from sewage-treatment plants in ungaged areas) is 11,800 pounds per day. The estimated long-term (1974 89 water years) average annual total phosphorus load (excluding loads from sewage-treatment plants in ungaged areas) is 1,100 pounds per day.

Texas↗