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At least 577 records · Page 32Linked to original sources

USGS2016

Deriving habitat models for northern long-eared bats from historical detection data: A case study using the Fernow Experimental Forest

The listing of the northern long-eared bat ( Myotis septentrionalis ) as federally threatened under the Endangered Species Act following severe population declines from white-nose syndrome presents considerable challenges to natural resource managers. Because the northern long-eared bat is a forest habitat generalist, development of effective conservation measures will depend on appropriate understanding of its habitat relationships at individual locations. However, severely reduced population sizes make gathering data for such models difficult. As a result, historical data may be essential in development of habitat models. To date, there has been little evaluation of how effective historical bat presence data, such as data derived from mist-net captures, acoustic detection, and day-roost locations, may be in developing habitat models, nor is it clear how models created using different data sources may differ. We explored this issue by creating presence probability models for the northern long-eared bat on the Fernow Experimental Forest in the central Appalachian Mountains of West Virginia using a historical, presence-only data set. Each presence data type produced outputs that were dissimilar but that still corresponded with known traits of the northern long-eared bat or are easily explained in the context of the particular data collection protocol. However, our results also highlight potential limitations of individual data types. For example, models from mist-net capture data only showed high probability of presence along the dendritic network of riparian areas, an obvious artifact of sampling methodology. Development of ecological niche and presence models for northern long-eared bat populations could be highly valuable for resource managers going forward with this species. We caution, however, that efforts to create such models should consider the substantial limitations of models derived from historical data, and address model assumptions.

West Virginia↗

USGS1990

Applicability of ambient toxicity testing to national or regional water-quality assessment

Comprehensive assessment of the quality of natural waters requires a multifaceted approach. Descriptions of existing conditions may be achieved by various kinds of chemical and hydrologic analyses, whereas information about the effects of such conditions on living organisms depends on biological monitoring. Toxicity testing is one type of biological monitoring that can be used to identify possible effects of toxic contaminants. Based on experimentation designed to monitor responses of organisms to environmental stresses, toxicity testing may have diverse purposes in water-quality assessments. These purposes may include identification of areas that warrant further study because of poor water quality or unusual ecological features, verification of other types of monitoring, or assessment of contaminant effects on aquatic communities. Toxicity-test results are most effective when used as a complement to chemical analyses, hydrologic measurements, and other biological monitoring. However, all toxicity-testing procedures have certain limitations that must be considered in developing the methodology and applications of toxicity testing in any large-scale water-quality-assessment program. A wide variety of toxicity-test methods have been developed to fulfill the needs of diverse applications. The methods differ primarily in the selections made relative to four characteristics: (1) test species, (2) endpoint (acute or chronic), (3) test-enclosure type, and (4) test substance (toxicant) that functions as the environmental stress. Toxicity-test approaches vary in their capacity to meet the needs of large-scale assessments of existing water quality. Ambient testing, whereby the test organism is exposed to naturally occurring substances that contain toxicant mixtures in an organic or inorganic matrix, is more likely to meet these needs than are procedures that call for exposure of the test organisms to known concentrations of a single toxicant. However, meaningful interpretation of ambient test results depends on the existence of accompanying chemical analysis of the ambient media. The ambient test substance may be water or sediments. Sediment tests have had limited application, but they are useful because most toxicants tend to accumulate in sediments and many test species either inhabit the sediments or are in frequent contact with them. Biochemical testing methods, which have been developing rapidly in recent years, are likely to be among the most useful procedures for large-scale water-quality assessments. They are relatively rapid and simple, and more. importantly, they focus on biochemical changes that are the initial responses of virtually all organisms to environmental stimuli. Most species are sensitive to relatively few toxicants, and their sensitivities vary as conditions change. Therefore, each test method has particular uses and limitations, and no single test has universal applicability. One of the most informative approaches to toxicity testing is to combine biochemical tests with other test methods in a 'battery of tests' that is diversified enough to characterize different types of toxicants and different trophic levels. However, such an approach can be costly, and if not carefully designed, it may not yield enough additional information to warrant the additional cost. The application of toxicity tests to large-scale water-quality assessments is hampered by a number of difficulties. Toxicity tests often are not sensitive enough to enable detection of most contaminant problems in the natural environment. Furthermore, because sensitivities among different species and test conditions can be highly variable, conclusions about the toxicant problems of an ecosystem are strongly dependent on the test procedure used. In addition, the experimental systems used in toxicity tests cannot replicate the complexity or variability of natural conditions, and positive test results cannot identify the source or nature of

Circular↗

USGS2021

Effect of temperature, nitrate concentration, pH and bicarbonate addition on biomass and lipid accumulation in the sporulating green alga PW95

The mixed effects of temperature (20 °C, 25 °C and 30 °C), nitrate concentration (0.5 mM and 2.0 mM), pH buffer, and bicarbonate addition (trigger) on biomass growth and lipid accumulation were investigated in the environmental alga PW95 during batch experiments in standardized growth medium. PW95 was isolated from coal-bed methane production water and classified as a Chlamydomonas -like species by morphological characterization and phylogenetic analysis (18S, ITS, rbc L). A factorial experimental design tested the mixed effects on PW95 before and after nitrate depletion to determine a low cost, high efficiency combination of treatments for biomass growth and lipid accumulation. Results showed buffer addition affected growth for most of the treatments and bicarbonate trigger had no statistically significant effect on growth and lipid accumulation. PW95 displayed the highest growth rate and chlorophyll content at 30 °C and 2.0 mM nitrate and there was an inverse relation between biomass accumulation and lipid accumulation at the extremes of nitrate concentration and temperature. The combination of higher temperature (30 °C) and lower nitrate level (0.5 mM) without the use of a buffer or bicarbonate addition resulted in maximal daily biomass accumulation (5.30 × 10 6 cells/mL), high biofuel potential before and after nitrate depletion (27% and 20%), higher biofuel productivity (16 and 15 mg/L/d, respectively), and desirable fatty acid profiles (saturated and unsaturated C16 and C18 chains). Our results indicate an important interaction between low nitrate levels, temperature, and elevated pH for trade-offs between biomass and lipid production in PW95. This work serves as a model to approach and advance the study of physiological responses of novel microalgae to diverse culture conditions that mimic environmental changes for outdoor biofuel production. The most promising conditions for growth and biofuel production were identified for PW95 and this approach can be implemented for other microalgal production systems.

Algal Research↗

USGS2008

Experimental measurements of vapor-liquid equilibria of the H2O + CO2 + CH4 ternary system

Reported are the experimental measurements on vapor-liquid equilibria in the H2O + CO2 + CH4 ternary system at temperatures from (324 to 375) K and pressures from (10 to 50) MPa. The results indicate that the CH4 solubility in the ternary mixture is about 10 % to 40 % more than that calculated by interpolation from the Henry's law constants of the binary system, H2O + CH4, and the solubility of CO2 is 6 % to 20 % more than what is calculated by the interpolation from the Henry's law constants of the binary mixture, H 2O + CO2. ?? 2008 American Chemical Society.

Journal of Chemical and Engineering Data↗

USGS2012

Nematomorph parasites indirectly alter the food web and ecosystem function of streams through behavioural manipulation of their cricket hosts.

Nematomorph parasites manipulate crickets to enter streams where the parasites reproduce. These manipulated crickets become a substantial food subsidy for stream fishes. We used a field experiment to investigate how this subsidy affects the stream community and ecosystem function. When crickets were available, predatory fish ate fewer benthic invertebrates. The resulting release of the benthic invertebrate community from fish predation indirectly decreased the biomass of benthic algae and slightly increased leaf break-down rate. This is the first experimental demonstration that host manipulation by a parasite can reorganise a community and alter ecosystem function. Nematomorphs are common, and many other parasites have dramatic effects on host phenotypes, suggesting that similar effects of parasites on ecosystems might be widespread.

Ecology Letters↗

USGS1993

Complex interactions of multiple aquatic consumers: an experimental mesocosm manipulation

In 7-m 3 outdoor tanks filled with lake water, the presence/absence of omnivorous young-of-the- year Micropterus salmoides), zooplanktivorous Menidia beryllina , and herbivorous larval Hyla chrysocelis was experimentally manipulated. A cross-classified design was used to assess the interactive effects of these vertebrate consumers on the experimental food webs. The primary effects of the experimental manipulations on food web components were two- and three-way interactions in which the effect of a given treatment was dependent on the presence of another treatment. Results suggest that the addition or removal of consumers may not cause linear, additive changes in food webs.

Canadian Journal of Fisheries and Aquatic Sciences↗

USGS2024

Measurement of illite particle thickness using a direct Fourier transform of small-angle X-ray scattering data

It has been suggested that interstratified illite-smectite (I-S) minerals are composed of aggregates of fundamental particles. Many attempts have been made to measure the thickness of such fundamental particles, but each of the methods used suffers from its own limitations and uncertainties. Small-angle X-ray scattering (SAXS) can be used to measure the thickness of particles that scatter X-rays coherently. We used SAXS to study suspensions of Na-rectorite and other illites with varying proportions of smectite. The scattering intensity ( I ) was recorded as a function of the scattering vector, q = (4 /) sin(/2), where  is the X-ray wavelength and  is the scattering angle. The experimental data were treated with a direct Fourier transform to obtain the pair distance distribution function (PDDF) that was then used to determine the thickness of illite particles. The Guinier and Porod extrapolations were used to obtain the scattering intensity beyond the experimental q , and the effects of such extrapolations on the PDDF were examined. The thickness of independent rectorite particles (used as a reference mineral) is 18.3 Å. The SAXS results are compared with those obtained by X-ray diffraction peak broadening methods. It was found that the power-law exponent (α) obtained by fitting the data in the region of q = 0.1-0.6 nm -1 to the power law ( I = I 0 q -α ) is a linear function of illite particle thickness. Therefore, illite particle thickness could be predicted by the linear relationship as long as the thickness is within the limit where α <4.0.

Clays and Clay Minerals↗

USGS2011

Movements and survival of black-footed ferrets associated with an experimental translocation in South Dakota

Black-footed ferrets ( Mustela nigripes ) apparently were extirpated from all native habitats by 1987, and their repatriation requires a combination of captive breeding, reintroductions, and translocations among sites. Improvements in survival rates of released ferrets have resulted from experience in quasi-natural environments during their rearing. Reestablishment of a self-sustaining wild population by 1999 provided the 1st opportunity to initiate new populations by translocating wild-born individuals. Using radiotelemetry, we compared behaviors and survival of 18 translocated wild-born ferrets and 18 pen-experienced captive-born ferrets after their release into a prairie dog colony not occupied previously by ferrets. Translocated wild-born ferrets moved significantly less and had significantly higher short-term survival rates than their captive-born counterparts. Using mark–recapture methods, we also assessed potential impacts to the established donor population of removing 37% of its estimated annual production of kits. Annual survival rates for 30 ferret kits remaining at the donor subcomplex were higher than rates for 54 ferret kits at the control subcomplex (unmanipulated) for males (+82%) and females (+32%). Minimum survival of translocated kits did not differ significantly from survival of those at the control subcomplex. Direct translocation of young, wild-born ferrets from site to site appears to be an efficient method to establish new populations.

South Dakota↗

USGS2012

Experimental investigation of false positive errors in auditory species occurrence surveys

False positive errors are a significant component of many ecological data sets, which in combination with false negative errors, can lead to severe biases in conclusions about ecological systems. We present results of a field experiment where observers recorded observations for known combinations of electronically broadcast calling anurans under conditions mimicking field surveys to determine species occurrence. Our objectives were to characterize false positive error probabilities for auditory methods based on a large number of observers, to determine if targeted instruction could be used to reduce false positive error rates, and to establish useful predictors of among-observer and among-species differences in error rates. We recruited 31 observers, ranging in abilities from novice to expert, that recorded detections for 12 species during 180 calling trials (66,960 total observations). All observers made multiple false positive errors and on average 8.1% of recorded detections in the experiment were false positive errors. Additional instruction had only minor effects on error rates. After instruction, false positive error probabilities decreased by 16% for treatment individuals compared to controls with broad confidence interval overlap of 0 (95% CI: -46 to 30%). This coincided with an increase in false negative errors due to the treatment (26%; -3 to 61%). Differences among observers in false positive and in false negative error rates were best predicted by scores from an online test and a self-assessment of observer ability completed prior to the field experiment. In contrast, years of experience conducting call surveys was a weak predictor of error rates. False positive errors were also more common for species that were played more frequently, but were not related to the dominant spectral frequency of the call. Our results corroborate other work that demonstrates false positives are a significant component of species occurrence data collected by auditory methods. Instructing observers to only report detections they are completely certain are correct is not sufficient to eliminate errors. As a result, analytical methods that account for false positive errors will be needed, and independent testing of observer ability is a useful predictor for among-observer variation in observation error rates.

Ecological Applications↗

USGS2008

Experimental and field observations of breach dynamics accompanying erosion of Marmot Cofferdam, Sandy River, Oregon

A key issue faced in dam removal is the rate and timing of remobilization and discharge of stored reservoir sediments following the removal. Different removal strategies can result in different trajectories of upstream sediment transport and knickpoint migration. We examine this issue of for the Marmot Dam removal in Sandy River, Oregon, USA using both physical experiments and field studies accompanying removal of the dam in October 2007. The physical experiment was designed to provide insights on how and if the position of a cofferdam notch will affect how reservoir sediments are remobilized, with the goal of minimizing the volume of sediment stranded in terraces. Data and observations indicate that at lower failure discharges, notch position impacts the location of cofferdam failure as well as the location of the first major knickpoint and its trajectory. In particular, notch positions that force the river to migrate laterally in order to adjust to natural valley orientation and morphology were most effective in removing larger volumes of sediment and reducing terrace heights. Actual cofferdam notching to maximize erosion produced extremely rapid and significant erosion of reservoir sediments. Comparison of model results with field observations suggests that the physical experiments provided solid predictions of rates of erosion and overall knickpoint trajectory.

Conference Paper↗

USGS2009

Impacts of experimentally increased foraging effort on the family: offspring sex matters

We examined how short-term impacts of experimentally increased foraging effort by one parent reverberate around the family in a monomorphic seabird (little auk, Alle alle), and whether these effects depend on offspring sex. In many species, more effort is required to rear sons successfully than daughters. However, undernourishment may have stronger adverse consequences for male offspring, which could result in a lower fitness benefit of additional parental effort when rearing a son. We tested two alternative hypotheses concerning the responses of partners to handicapping parents via feather clipping: partners rearing a son are (1) more willing or able to compensate for the reduced contribution of their mate, or (2) less willing or able to compensate, compared to those rearing a daughter. Hypothesis 1 predicts that sons will be no more adversely affected than daughters, and the impact on parents will be greater when rearing a son. Hypothesis 2 predicts that sons will be more adversely affected than daughters, and parents raising a son less affected. Although experimental chicks of both sexes fledged in poorer condition than controls, sons attained higher mass and more rapid growth than daughters in both groups. Clipped parents lost a similar proportion of their initial mass regardless of chick sex, whereas partners of clipped birds lost more mass when rearing a son. These results support hypothesis 1: impacts of increased foraging effort by one parent were felt by offspring, regardless of their sex, and by the partners of manipulated birds, particularly when the offspring was male. ?? 2009 The Association for the Study of Animal Behaviour.

Animal Behaviour↗

USGS1987

Concentrations of metals in mink and other mammals from Washington and Idaho

From 1981 to 1983, concentrations dfof metals were determined in mink Mustela vison , muskrats Ondatra zibethica , and small mammals at one contaminated site in Idaho and at two less contaminated sites in Idaho and Washington. The highest concentrations of Pb and Cd occurred in samples from the Coeur d'Alene River system near or downstream from an extensive mining—smelting complex in northern Idaho. Maximum concentrations of Pb in the liver of a mink (22 μg g −1 ) and in pooled liver samples of both voles ( Microtus spp. , 5·8 μg g −1 ) and deer mice ( Peromyscus maniculatus , 10·5 μg g −1 ) were higher than those inducing serious problems, including mortality, in experimental mammals on Pb-contaminated diets. Concentrations of Cd, Cu, Hg, and Zn were generally low. Declines in certain mammal populations have probably occurred in northern Idah as a result of direct toxicity of metals and associated secondary effects on cover and food supply.

Idaho, Washington↗

USGS2002

Status and opportunities for genomics research with rainbow trout

The rainbow trout (Oncorhynchus mykiss) is one of the most widely studied of model fish species. Extensive basic biological information has been collected for this species, which because of their large size relative to other model fish species are particularly suitable for studies requiring ample quantities of specific cells and tissue types. Rainbow trout have been widely utilized for research in carcinogenesis, toxicology, comparative immunology, disease ecology, physiology and nutrition. They are distinctive in having evolved from a relatively recent tetraploid event, resulting in a high incidence of duplicated genes. Natural populations are available and have been well characterized for chromosomal, protein, molecular and quantitative genetic variation. Their ease of culture, and experimental and aquacultural significance has led to the development of clonal lines and the widespread application of transgenic technology to this species. Numerous microsatellites have been isolated and two relatively detailed genetic maps have been developed. Extensive sequencing of expressed sequence tags has begun and four BAC libraries have been developed. The development and analysis of additional genomic sequence data will provide distinctive opportunities to address problems in areas such as evolution of the immune system and duplicate genes. ?? 2002 Elsevier Science Inc. All rights reserved.

Conference Paper↗

USGS1989

Graphical method for determining the coefficient of consolidation c from a flow-pump permeability test

A graphical method has been developed for determining the coefficient of consolidation from the transient phases of a flow-pump permeability test. The flow pump can be used to infuse fluid into or withdraw fluid from a laboratory sediment specimen at a constant volumetric rate in order to obtain data that can be used to calculate permeability using Darcy's law. When the initial transient-response curve (hydraulic head as a function of time) generated by this test is examined analytically in terms of a one-dimensional consolidation process, representative type-curve solutions to the associated forced-flow and pressure-decay models are derived. These curves provide the basis for graphically evaluating the permeability k , the coefficient of consolidation c v , and the coefficient of volume change m v . The curve-matching technique is easy and rapid, and it can be applied to results of forced-flow tests, both infusion and withdrawal, as well as to subsequent pressure-decay records. Values of k, c v , and m v for a laterally confined kaolinite specimen were determined by this graphical method and appear to be in reasonably good agreement with numerically derived estimates (within 20%). Discrepancies between the two sets of results seem to be largely a function of data quality rather than of method of analysis. Where responses of hydraulic head as a function of time are apparently unaffected by experimental sources of error, agreement is excellent (within 4%). Application of this graphical method to triaxial testing has inherent uncertainties, because the solution curves that describe one-dimensional deformation are used to analyze a three-dimensional process.

Geotechnical Testing Journal↗

USGS2009

Experimental infection of Hawai'i 'Amakihi (hemignathus virens) with West Nile virus and competence of a co-occurring vector, culex quinquefasciatus: potential impacts on endemic Hawaiian avifauna.

Introduced mosquito-borne avian disease is a major limiting factor in the recovery and restoration of native Hawaiian forest birds. Annual epizootics of avian pox (Avipoxvirus) and avian malaria (Plasmodium relictum) likely led to the extinction of some species and continue to impact populations of susceptible Hawaiian honeycreepers (Drepanidinae). The introduction of a novel pathogen, such as West Nile virus (WNV), could result in further population declines and extinctions. During September and October 2004, we infected Hawai'i' Amakihi (Hemignathus virens) with a North American isolate of WNV by needle inoculation and mosquito bite to observe susceptibility, mortality, and illness in this endemic passerine, and to determine the vector competence of the co-occurring, introduced mosquito Culex quinquefasciatus. All experimentally infected Hawai'i ;Amakihi became viremic, with a mean titer >10(5) plaque-forming units (PFU)/ml, and they experienced clinical signs ranging from anorexia and lethargy to ataxia. The fatality rate among needle-inoculated Hawai'i' Amakihi (n=16) was 31.3%, but mortality in free-ranging birds is likely to increase due to predation, starvation, thermal stress, and concomitant infections of avian malaria and pox. Surviving Hawai'i' Amakihi seem to clear WNV from the peripheral blood by 7-10 days postinfection (DPI), and neutralizing antibodies were detected from 9 to 46 DPI. In transmission trials, Hawaiian Cx. quinquefasciatus proved to be a competent vector and Hawai'i Amakihi an adequate amplification host of WNV, suggesting that epizootic WNV could readily become an additional limiting factor of some native Hawaiian bird populations.

Hawai'i↗

USGS2019

Temperature-dependent variations in mineralogy, major element chemistry and the stable isotopes of boron, lithium and chlorine resulting from hydration of rhyolite glass: Constraints from hydrothermal experiments at 150 to 350°C and 25 MPa

Rhyolite-hosted hydrothermal systems in the continental crust contain valuable energy and mineral resources that make them of special interest across several scientific disciplines. Despite extensive research on these systems, the temperature-dependence of chemical reactions between host rocks and aqueous-rich fluids and the mineralogical transformations resulting from these reactions are not well quantified. To expand our understanding of the controlling processes operating in these systems, we carried out seven laboratory experiments in which rhyolite was reacted with deionized water at 150 °C to 350 °C and 25 MPa. An additional experiment at 200 °C was carried out to examine the effect of dissolved CO 2 on the reactions. The overarching goal of this experimental study was to provide new insights on the temperature-dependence of water-rock interaction in continental hydrothermal systems. We applied a wide range of chemical, isotopic and mineralogical methods to analyze the reacted rhyolite and waters, and the major observations are: (1) the rhyolite progressively hydrates with increasing temperature between 150 °C to a maximum of 8.2 wt% H 2 O at 275 °C; hydration then decreases until 350 °C in conjunction with the destruction of the rhyolite glass and crystallization of secondary mineral phases; (2) the ratio of molecular water (H 2 O m ) to hydroxyl (OH − ) of the water that is dissolved in the reacted rhyolite decreases from ∼7 at 150 °C to ∼4 at 250 °C; (3) the main secondary minerals formed are the zeolite ferrierite (T ≥ 275 °C); biotite, albite and cristobalite mainly form at higher experimental temperatures (T ≥ 300 °C); (4) the reacted waters are nearly saturated with respect to amorphous silica; (5) at temperatures ≥ 275 °C nearly all the chlorine is leached into solution; (6) fluorine leaching from the rhyolite gradually increases between 150 °C and 250 °C, but then gradually decreases at higher temperatures and is incorporated into a secondary mineral phase; (7) dissolved CO 2 in the water enhances alkali metal cation leaching from the rhyolite; and (8) calculated Na-K and silica geothermometer temperatures differ from the experimental temperatures by varying amounts. In addition, apart from some small lithium isotope fractionation at temperatures ≤ 250 °C, the stable isotopes of boron, lithium and chlorine do not fractionate during rhyolite-water reactions, and the stable isotope compositions of these species in the reacted water are similar to those in the reactant rhyolite. These results provide new insights for a broad range of applications, including quantifying processes involving rhyolite glass hydration (obsidian hydration dating, perlite formation and discriminating secondary from magmatic water in rhyolitic matrix-glass of volcanic pyroclasts), for geothermal energy and mineral deposit exploration and for monitoring volcanoes.

Geochimica et Cosmochimica Acta↗

USGS2009

Fire treatment effects on vegetation structure, fuels, and potential fire severity in western U.S. forests

Abstract. Forest structure and species composition in many western U.S. coniferous forests have been altered through fire exclusion, past and ongoing harvesting practices, and livestock grazing over the 20th century. The effects of these activities have been most pronounced in seasonally dry, low and mid-elevation coniferous forests that once experienced frequent, low to moderate intensity, fire regimes. In this paper, we report the effects of Fire and Fire Surrogate (FFS) forest stand treatments on fuel load profiles, potential fire behavior, and fire severity under three weather scenarios from six western U.S. FFS sites. This replicated, multisite experiment provides a framework for drawing broad generalizations about the effectiveness of prescribed fire and mechanical treatments on surface fuel loads, forest structure, and potential fire severity. Mechanical treatments without fire resulted in combined 1-, 10-, and 100-hour surface fuel loads that were significantly greater than controls at three of five FFS sites. Canopy cover was significantly lower than controls at three of five FFS sites with mechanical-only treatments and at all five FFS sites with the mechanical plus burning treatment; fire-only treatments reduced canopy cover at only one site. For the combined treatment of mechanical plus fire, all five FFS sites with this treatment had a substantially lower likelihood of passive crown fire as indicated by the very high torching indices. FFS sites that experienced significant increases in 1-, 10-, and 100-hour combined surface fuel loads utilized harvest systems that left all activity fuels within experimental units. When mechanical treatments were followed by prescribed burning or pile burning, they were the most effective treatment for reducing crown fire potential and predicted tree mortality because of low surface fuel loads and increased vertical and horizontal canopy separation. Results indicate that mechanical plus fire, fire-only, and mechanical-only treatments using whole-tree harvest systems were all effective at reducing potential fire severity under severe fire weather conditions. Retaining the largest trees within stands also increased fire resistance. ?? 2009 by the Ecological Society of America.

Ecological Applications↗

USGS2001

Effects of forest-management activities on runoff components and ground-water recharge to Quabbin Reservoir, central Massachusetts

The effects of forest-management activities (timber cutting and herbicide application) on runoff components (total streamflow, direct runoff, and base flow) and on ground-water recharge per unit area were evaluated for two separate paired drainage basins of Quabbin Reservoir in central Massachusetts. The Cadwell Creek study area, studied from 1962-1973, included an experimental basin (Upper Cadwell Creek) and a control basin (Lower Cadwell Creek). In the experimental basin, herbicide was applied to mixed oaks, northern hardwoods, and understory vegetation in different riparian zones during the summers of 1967 and 1968, and some pine plantations were thinned or clear-cut during the winter of 1967-1968. These forest-management activities decreased the total basal area by about 34%. The decrease in total basal area resulted in an increase in total streamflow, direct runoff (total streamflow minus base flow), and ground-water recharge for six dormant seasons (October-April) and six growing seasons (May-September) during 1968-1973. Base flow increased for three dormant seasons and two growing seasons during 1968-1970 and the dormant seasons of 1971 and 1973. Base flow accounted for 34% and direct runoff accounted for 66% of the 94 mm (15%) increase in total streamflow during water years 1968-1973. Sixty-one percent of this increase in total streamflow occurred in the dormant seasons. The Dickey Brook study area, studied from 1985-1989, included an experimental basin (Dickey Brook) and a control basin (Dickey Brook Tributary). Some pine plantations were thinned or clear-cut in the headwaters of the experimental basin from October 1986 to March 1987 and October to December 1988. These forest-management activities decreased the total basal area by 24% during 1986-1987 and an additional 8% during 1988. The decrease in total basal area resulted in an increase in total streamflow, base flow, and ground-water recharge for only one dormant season and one growing season in 1987. Direct runoff only increased slightly during the 1987 dormant season. Base flow accounted for 91% and direct runoff accounted for 9% of the 92 mm (21%) increase in total streamflow during water year 1987. Seventy-seven percent of this increase in total streamflow occurred in the dormant season.

Conference Paper↗