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Full-Text Articles in Physical Sciences and Mathematics

Phytoplankton Development Within Tidal Freshwater Regions Of Two Virginia Rivers, Harold G. Marshall, Lubomira Burchardt Jul 2005

Phytoplankton Development Within Tidal Freshwater Regions Of Two Virginia Rivers, Harold G. Marshall, Lubomira Burchardt

Virginia Journal of Science

Phytoplankton composition and the range of seasonal patterns of abundance are presented for the tidal freshwater regions in two Virginia rivers based on data accumulated monthly from 1986 through 1999. Diatoms dominated the flora during spring, summer, and fall, whereas, other taxonomic categories were more representative when the river flow rates decreased, allowing for a more stable water system and increased residency time within this tidal region during summer and early fall. This summer/fall period was associated with increased water temperatures, higher productivity rates and chlorophyll levels, increased total phytoplankton abundance and species diversity. The major components of the summer …


Climate Change In Metropolitan Boston, Paul Kirshen, Matthias Ruth, William Anderson Mar 2005

Climate Change In Metropolitan Boston, Paul Kirshen, Matthias Ruth, William Anderson

New England Journal of Public Policy

Even though urban infrastructure systems are important and are designed according to socioeconomic and environmental conditions that are very sensitive to climate, there have been few major integrated assessments of the impacts of climate change on metropolitan infrastructure systems and services and possible adaptations. An analysis of the Boston metro area found that adaptation actions taken before full climate-change impacts occur will result in fewer expected negative impacts to the region than waiting for major impacts to occur. Adaptation of infrastructure to climate change must also consider land use management, environmental and socioeconomic impacts, equity, and adaptation actors and institutions. …


Quantification And Prediction Of Stream Dryness In The Interior Highlands, Justin M. Homan, Nicholas M. Girondo, Charles J. Gagen Jan 2005

Quantification And Prediction Of Stream Dryness In The Interior Highlands, Justin M. Homan, Nicholas M. Girondo, Charles J. Gagen

Journal of the Arkansas Academy of Science

Although ecological studies have noted streams drying in the Interior Highlands, published measurements of streambed dryness are lacking. Clearly, stream drying has the potential to affect benthic macroinvertebrate and fish communities. In 2003, we initiated an assessment of streambed dryness for three streams in the Ouachita Mountains representative of the Central Hills, Ridges, and Valleys. In the following summer, we applied the approach to 15 similar size watersheds in three distinct ecoregions of the Interior Highlands: Ouachita Mountains-Athens Plateau, Ozark Highlands-Springfield Plateau, and Lower Boston Mountains. Repeated dryness measurements were recorded in each stream and correlated to nearby USGS stream …


Sediment Loading And Water Quality Of Field Run-Off Water, J. S. Mcconnell, J. D. Mattice, B. W. Skulman, C. K. Bryant, M. Mozaffari Jan 2005

Sediment Loading And Water Quality Of Field Run-Off Water, J. S. Mcconnell, J. D. Mattice, B. W. Skulman, C. K. Bryant, M. Mozaffari

Journal of the Arkansas Academy of Science

Intensive tillage is commonly employed in many agronomic production systems in the United States. Tillage operations may include disking the field, re-smoothing the soil, seedbed formation, reducing the seedbeds, and shallow cultivation for weed control. Tillage practices in conjunction with rainfall have been linked to soil erosion, which may adversely affect the environment. The soil erosion dynamics of two large-scale production cotton fields that utilized both modern-conventional and conservation-tillage technology were examined. Studies were conducted in the cotton-producing region of southeast Arkansas in the Bayou Bartholomew watershed. Bayou Bartholomew is currently listed by the United States Environmental Protection Agency as …