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461.
Henriette?I.?JagerEmail author Mark?S.?Bevelhimer Roy?L.?King Katy?A.?Smith 《Environmental management》2011,48(4):795-807
Military landscapes represent a mixture of undisturbed natural ecosystems, developed areas, and lands that support different
types and intensities of military training. Research to understand water-quality influences of military landscapes usually
involves intensive sampling in a few watersheds. In this study, we developed a survey design of accessible headwater watersheds
intended to improve our ability to distinguish land–water relationships in general, and training influences, in particular,
on Fort Stewart, GA. We sampled and analyzed water from watershed outlets. We successfully developed correlative models for
total suspended solids (TSS), total nitrogen (TN), organic carbon (OC), and organic nitrogen (ON), which dominated in this
blackwater ecosystem. TSS tended to be greater in samples after rainfall and during the growing season, and models that included
%Wetland suggested a “build-and-flush” relationship. We also detected a positive association between TSS and tank-training, which
suggests a need to intercept sediment-laden runoff from training areas. Models for OC showed a negative association with %Grassland. TN and ON both showed negative associations with %Grassland, %Wetland, and %Forest. Unexpected positive associations were observed between OC and equipment-training activity and between ON and %Bare ground + Roads. Future studies that combine our survey-based approach with more intensive monitoring of the timing and intensity of training
would be needed to better understand the mechanisms for these empirical relationships involving military training. Looking
beyond local effects on Fort Stewart streams, we explore questions about how exports of OC and nitrogen from coastal military
installations ultimately influence estuaries downstream. 相似文献
462.
After nearly a century of height suppression, willows (Salix spp.) in the northern range of Yellowstone National Park, U.S.A., are increasing in height growth as a possible consequence of wolf (Canis lupus) restoration, climate change, or other factors. Regardless of the drivers, the recent release of this rare but important habitat type could have significant implications for associated songbirds that are exhibiting declines in the region. Our objective was to evaluate bird response to releasing willows by comparing willow structure and bird community composition across three willow growth conditions: height suppressed, recently released, and previously tall (i.e., tall prior to the height increase of released willows). Released and previously tall willows exhibited high and similar vertical structure, but released willows were significantly lower in horizontal structure. Suppressed willows were significantly shorter and lower in horizontal cover than released or previously tall willows. Bird richness increased along a gradient from lowest in suppressed to highest in previously tall willows, but abundance and diversity were similar between released and previously tall willows, despite lower horizontal cover in the released condition. Common Yellowthroat (Geothlypis trichas) and Lincoln's Sparrow (Melospiza lincolnii) were found in all three growth conditions; however, Yellow Warbler (Dendroica petechia), Warbling Vireo (Vireo gilvus), Willow Flycatcher (Empidonax traillii), and Song Sparrow (Melospiza melodii) were present in released and previously tall willows only. Wilson's Warbler (Wilsonia pusilla) was found in previously tall willows only, appearing to specialize on tall, dense willows. The results of our a priori habitat models indicated that foliage height diversity was the primary driver of bird richness, abundance, and diversity. These results indicate that vertical structure was a more important driver of bird community variables than horizontal structure and that riparian and willow-dependent bird species have responded positively to increased willow growth in the region. 相似文献
463.
Roy Debashis Neogi Sudarsan De Sirshendu 《Environmental science and pollution research international》2021,28(32):43483-43506
Environmental Science and Pollution Research - Novel functionalized polymeric beads have been prepared by a simple phase inversion technique and its potential as an effective sorbent for reactive... 相似文献
464.
Karnatak Gunjan Das Basanta Kumar Sarkar Uttam Kumar Borah Simanku Roy Aparna Parida Pranay Lianthuamluaia Lianthuamluaia Das Archan Kanti Behera Bijay Kumar Pandit Arun Sahoo Amiya Kumar Bhattacharjya Birendra Kumar Chakraborty Sangeeta Mondal Kausik Chandra Purna 《Environmental science and pollution research international》2022,29(50):75431-75440
Environmental Science and Pollution Research - The rapid degradation, overexploitation, and encroachment of floodplain wetlands have led to considerable decline in fish diversity and production... 相似文献
465.
Li H Chen Y Crittenden J Hand D Taylor R 《Journal of the Air & Waste Management Association (1995)》2006,56(8):1155-1166
A high-efficiency particulate air (HEPA)-carbon filtration system was developed by the Access Business Group, LLC, to reduce the indoor levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). The HEPA filter removes the particle-bound PCDD/Fs, and the carbon filter removes the gaseous fraction. Because of the toxicity of PCDD/Fs, it is very difficult to handle them in the laboratory. In this study, mathematical modeling was performed to evaluate the performance of the HEPA-carbon filtration system for PCDD/Fs removal and to optimize its design and operation. The model was calibrated with experimental data conducted with toluene in a sealed room. Model simulations with four selected congeners demonstrated that it takes approximately 1 hr for the indoor air treatment system to reach the maximum removal efficiency and that the carbon air filter has a life time of 10(7) yr for dioxin removal. Given a zero emission from the HEPA filter, the overall removal efficiency is 78.7% for 2,3,7,8-tetrachloro dibenzo-p-dioxins, 89.8% for octa-chlorodibenzodioxin, 78% for tetra-chlorodibenzofuran, and 89.8% for octa-chlorodibenzofuran. The larger the mass emission from the HEPA filter, the lower the overall removal efficiency, and the larger the ratio of the filter flow rate (Q(f)) to the room flow rate (Q), the higher the overall removal efficiency. When the ratio of Q(f)/Q is 15, an overall removal efficiency of 90% can be reached for all four of the selected compounds. The removal of the four selected compounds does not change as the relative humidity increases < or = 90%. 相似文献
466.
Pearl Weinberger Dan Sher Roy Greenhalgh 《Journal of environmental science and health. Part. B》2013,48(2):269-281
Abstract Fresh and estuarine water algae maintained in laboratory microcosms simulating river‐lake/estuary‐bay systems were exposed to 14C‐fenitrothion formulated with Atlox and tank mixed with Aerotex or Dowanol (11.5:1.5:1.5 w/v/v). Generally, the tank mix co‐solvents determined the amount of uptake and the array of derivatives formed by the algae. Typically, exposed to an Aerotex mix the ratio of ethyl acetate extractable (NP) fraction : ethyl acetate unextractable (P) fraction was as 3.5:1.0, exposed to a Dowanol mix the ratio was as 1.5:1.0. Within any comparable time period, fresh water algae turned over more of the C‐ring of fenitrothion than the estuarine genera. Turn‐over was enhanced when Aerotex was the tank mix co‐solvent. 相似文献