Earl Davey - Academia.edu (original) (raw)

Papers by Earl Davey

Ecological Applications, 1991

Three different sizes of marine microcosms were used to study the influence of two features of sp... more Three different sizes of marine microcosms were used to study the influence of two features of spatial scale on the chemical fate and ecological effects of the pesticide Kepone. Increasing the size of microcosms reduced the ratio of wall surface area to volume of ...

Limnology and Oceanography, 1975

... The analytical methods were modified from Riley and Taylor (1968a) and Davey et al. (1970) as... more ... The analytical methods were modified from Riley and Taylor (1968a) and Davey et al. (1970) as follows. ... The ammonium form was chosen because ammonia is easily purified by iso-thermal diffusion. The volume of resin is reduced to 5 ml for a 4-liter seawater sam-ple. ...

Limnology and Oceanography, 1970

Page 1. 486 NOTES AND COMMENT REMOVAL OF TRACE METALS FROM MARINE CULTURE MEDIA ABSTRACr The sodi... more Page 1. 486 NOTES AND COMMENT REMOVAL OF TRACE METALS FROM MARINE CULTURE MEDIA ABSTRACr The sodium form of purified Chelex-100 can be used to remove trace metals from arti-ficial and natural seawater ...

Limnology and Oceanography, 1973

JARNEFELT, H. 1955. Uber die Sedimentation des Sestons. Int. Ver. Theor. Angew. Limnol. Verh. 12:... more JARNEFELT, H. 1955. Uber die Sedimentation des Sestons. Int. Ver. Theor. Angew. Limnol. Verh. 12: 144-148. OHLE, W. 1962. Der Stoffhaushalt der Seen als Grundlage einer allgemeinen Stoffwechseldy-namik der Gewasser. Kiel. Meeresforsch. 18: 107-120. SCOTT, W., AND ...

Limnology and Oceanography, 1967

... This paper includes results to be presented in a thesis by Mr. Earl Davey in partial fulfillm... more ... This paper includes results to be presented in a thesis by Mr. Earl Davey in partial fulfillment of the requirements for a Ph.D. degree at Oregon State University. ... (1962) apparatus by substituting a model L-208-6 Loenco six-port gas-sam-pling valve for the Perkin Elmer valve (Fig. ...

American Journal of Botany, 2015

Ecological Indicators, 2008

Estuaries and Coasts, 2015

Ecological Applications, 2011

Computed tomography (CT) imaging has been used to describe and quantify subtidal, benthic animals... more Computed tomography (CT) imaging has been used to describe and quantify subtidal, benthic animals such as polychaetes, amphipods, and shrimp. Here, for the first time, CT imaging is used to quantify wet mass of coarse roots, rhizomes, and peat in cores collected from organic-rich (Jamaica Bay, New York) and mineral (North Inlet, South Carolina) Spartina alterniflora soils. Image analysis software was coupled with the CT images to measure abundance and diameter of the coarse roots and rhizomes in marsh soils. Previously, examination of marsh roots and rhizomes was limited to various hand-sieving methods that were often time-consuming, tedious, and error prone. CT imaging can discern the coarse roots, rhizomes, and peat based on their varying particle densities. Calibration rods composed of materials with standard densities (i.e., air, water, colloidal silica, and glass) were used to operationally define the specific x-ray attenuations of the coarse roots, rhizomes, and peat in the marsh cores. Significant regression relationships were found between the CT-determined wet mass of the coarse roots and rhizomes and the hand-sieved dry mass of the coarse roots and rhizomes in both the organic-rich and mineral marsh soils. There was also a significant relationship between the soil percentage organic matter and the CT-determined peat particle density among organic-rich and mineral soils. In only the mineral soils, there was a significant relationship between the soil percentage organic matter and the CT-determined peat wet mass. Using CT imaging, significant positive nitrogen fertilization effects on the wet masses of the coarse roots, rhizomes, and peat, and the abundance and diameter of rhizomes were measured in the mineral soils. In contrast, a deteriorating salt marsh island in Jamaica Bay had significantly less mass of coarse roots and rhizomes at depth (10-20 cm), and a significantly lower abundance of roots and rhizomes compared with a stable marsh. However, the diameters of the rhizomes in the deteriorating marsh were significantly greater than in the stable marsh. CT imaging is a rapid approach to quantify coarse roots, rhizomes, peat, and soil particle densities in coastal wetlands, but the method is unable at this time to quantify fine roots.

Ecological Applications, 1999

Sediment cores were imaged using a Computer-Aided Tomography (CT) scanner at Massachusetts Genera... more Sediment cores were imaged using a Computer-Aided Tomography (CT) scanner at Massachusetts General Hospital, Boston, Massachusetts, United States. Procedures were developed, using the attenuation of X-rays, to differentiate between sediment and the ...

Ecological Applications, 2013

Marshes in the urban Jamaica Bay Estuary, New York, USA are disappearing at an average rate of 13... more Marshes in the urban Jamaica Bay Estuary, New York, USA are disappearing at an average rate of 13 ha/yr, and multiple stressors (e.g., wastewater inputs, dredging activities, groundwater removal, and global warming) may be contributing to marsh losses. Among these stressors, wastewater nutrients are suspected to be an important contributing cause of marsh deterioration. We used census data, radiometric dating, stable nitrogen isotopes, and soil surveys to examine the temporal relationships between human population growth and soil nitrogen; and we evaluated soil structure with computer-aided tomography, surface elevation and sediment accretion trends, carbon dioxide emissions, and soil shear strength to examine differences among disappearing (Black Bank and Big Egg) and stable marshes (JoCo). Radiometric dating and nitrogen isotope analyses suggested a rapid increase in human wastewater nutrients beginning in the late 1840s, and a tapering off beginning in the 1930s when wastewater treatment plants (WWTPs) were first installed. Current WWTPs nutrient loads to Jamaica Bay are approximately 13 995 kg N/d and 2767 kg P/d. At Black Bank, the biomass and abundance of roots and rhizomes and percentage of organic matter on soil were significantly lower, rhizomes larger in diameter, carbon dioxide emission rates and peat particle density significantly greater, and soil strength significantly lower compared to the stable JoCo Marsh, suggesting Black Bank has elevated decomposition rates, more decomposed peat, and highly waterlogged peat. Despite these differences, the rates of accretion and surface elevation change were similar for both marshes, and the rates of elevation change approximated the long term relative rate of sea level rise estimated from tide gauge data at nearby Sandy Hook, New Jersey. We hypothesize that Black Bank marsh kept pace with sea level rise by the accretion of material on the marsh surface, and the maintenance of soil volume through production of larger diameter rhizomes and swelling (dilation) of waterlogged peat. JoCo Marsh kept pace with sea-level rise through surface accretion and soil organic matter accumulation. Understanding the effects of multiple stressors, including nutrient enrichment, on soil structure, organic matter accumulation, and elevation change will better inform management decisions aimed at maintaining and restoring coastal marshes.