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131.
The purpose of this study was to determine what role lakeshore homeowner associations might play in environmental management. Lakeshore homeowner associations are formally organized groups of individuals owning property on or in the vicinity of a lake. Lakeshore homeowner associations in the Adirondack Park region of New York State were investigated by both a questionnaire mailed to all presidents and an informal field survey of some permanent lakeshore residents. The study showed that many of these organizations have become highly involved in an array of environmental management activities during their relatively long history. These activities include monitoring septic tank seepage, regulating the use of motorboats, restricting shoreline development, and assisting state and local planning agencies in detecting zoning violations. Some lakeshore homeowner associations are not highly involved in activities designed to maintain or improve quality of the lake environment. These associations are concerned instead primarily with organizing social events and performing other miscellaneous activities, such as access road maintenance. These associations, however, report lower overall water quality in their lakes than those associations with a high degree of involvement in environmental management. The study uncovered two important factors that tend to undermine the ability of lakeshore homeowner associations to undertake environmental management activities. One is the extent of cooperation that can be expected from nonmember residents of the lakeshore, such as seasonal vacationers. The second is an environmental problem that does not originate locally and therefore cannot be controlled by a local organization. Acid precipitation, rated by association presidents as their foremost water quality concern, is one such problem in the Adirondack Park Region.  相似文献   
132.
133.
BOD5 dates back to 1912 when the Royal Commission decided to use the mean residence time of water in the rivers of England, 5 days, as a standard to measure the biochemical oxygen demand. Initially designed to protect the quality of river waters from extensive sewage discharge, the use of BOD5 has been quickly extended to waste water treatment plants (WWTPs) to monitor their efficiency on a daily basis. The measurement has been automatized but remains a tedious, time- and resource-consuming analysis. We have cross-validated a surrogate BOD5 method on two sites in France and in the USA with a total of 109 samples. This method uses a fluorescent redox indicator on a 96-well microplate to measure microbial catabolic activity for a large number of samples simultaneously. Three statistical tests were used to compare surrogate and reference methods and showed robust equivalence.  相似文献   
134.
There is increasing interest among scholars in producing information that is useful and usable to land and natural resource managers in a changing climate. This interest has prompted transitions from scientist- to stakeholder-driven or collaborative approaches to climate science. A common indicator of successful collaboration is whether stakeholders use the information resulting from the projects in which they are engaged. However, detailed examples of how stakeholders use climate information are relatively scarce in the literature, leading to a challenge in understanding what researchers can and should expect and plan for in terms of stakeholder use of research findings. Drawing on theoretical, typological, and evaluation insights from the field of information use, we examine stakeholder use of climate information emerging from 13 collaborative climate science projects conducted in the western United States between 2012 and 2016. Three primary types of use emerge from our findings—conceptual, instrumental, and justification—reflecting common typologization of information use. Conceptual use was the most predominant. We suggest that researcher awareness of this typology can enable more systematic understanding of what project outputs stakeholders use and impacts of those outputs, giving way to new areas of inquiry and aiding in the conceptualization and design of climate information products for land and natural resource managers.  相似文献   
135.
ABSTRACT

The recorded exceedances of the 24-hr PM10 National Ambient Air Quality Standard (NAAQS) in Treasure Valley, Idaho, have been associated with prolonged stagnation periods during the winter. A comprehensive modeling study of PM10 impact in Treasure Valley was performed to support the State Implementation Plan (SIP). The study included base-year and short-term episodic conditions. The ISCST3 (Industrial Source Complex Short Term 3) model, using the base-year meteorology and gridded emissions of mobile sources, point sources, and wood burning as input, generally agreed well with measurements in both temporal patterns and annual averages. The WYNDvalley model was evaluated using monitoring data and was used to simulate the PM10 impact for episodic exceedances during stagnant winter conditions. An emission inventory was prepared for a base year (1995) and then extrapolated to the years 2000, 2005, 2010, and 2015 in order to determine air quality planning requirements. According to the simulations using base-year emissions and meteorology, exceedances are not expected. However, exceedances at some stations could be expected using projected emissions and episodic meteorology. Results from emission control strategies we developed indicate that mobile-source emissions have the most significant impact; reduction of 25% would be needed to eliminate the simulated exceedances in all projected years.  相似文献   
136.
Palmer TM  Brody AK 《Ecology》2007,88(12):3004-3011
The foundation of many plant-ant mutualisms is ant protection of plants from herbivores in exchange for food and/or shelter. While the role of symbiotic ants in protecting plants from stem- and leaf-feeding herbivores has been intensively studied, the relationship between ant defense and measures of plant fitness has seldom been quantified. We studied ant aggression, damage by herbivores and seed predators, and fruit production among Acacia drepanolobium trees occupied by four different acacia-ant species in an East African savanna. Levels of ant aggression in response to experimental disturbance differed strongly among the four species. All four ant species recruited more strongly to new leaf growth on host plants following disturbance, while recruitment to developing fruits was on average an order of magnitude lower. Host plants occupied by more aggressive ant species suffered significantly less vegetative damage from leaf-feeding insects, stem-boring beetles, and vertebrate browsers than host plants occupied by less aggressive ant species. However, there were no differences among fruiting host plants occupied by different ant species in levels of seed predation by bruchid seed predators. Fruit production on host trees was significantly correlated with tree stem diameter but not with the identity of resident ants. Our results demonstrate that defense of host plants may differ substantially among ant species and between vegetative and reproductive structures and that fruit production is not necessarily correlated with high levels of aggression by resident ants.  相似文献   
137.
Previous research on employee willingness to accept mobility opportunities involving geographic relocation has generally not specified characteristics of potential destination communities. However, studies of employee adjustment following relocation suggest that community characteristics are critical to employee satisfaction. In order to better understand the factors that influence employees' acceptance of mobility opportunities, we investigated differences in both levels and antecedents of willingness to accept mobility opportunities involving relocation between similar communities and relocation between dissimilar communities. Results suggest that employees were particularly reluctant to accept moves between dissimilar communities, and that the role of career factors, community attachment, and location preferences as antecedents varied depending on the specific nature of the mobility opportunity. Implications for research and practice are discussed.  相似文献   
138.
The sea urchin cardinalfish, Siphamia tubifer (Perciformes: Apogonidae), is unusual among coral reef fishes for its use of bioluminescence, produced by symbiotic bacteria, while foraging at night. As a foundation for understanding the relationship between the symbiosis and the ecology of the fish, this study examined the diel behavior, host urchin preference, site fidelity, and homing of S. tubifer in June and July of 2012 and 2013 at reefs near Sesoko Island, Okinawa, Japan (26°38′N, 127°52′E). After foraging, S. tubifer aggregated in groups among the spines of the longspine sea urchin, Diadema setosum, and the banded sea urchin, Echinothrix calamaris. A preference for D. setosum was evident (P < 0.001), especially by larger individuals (>25 mm standard length, P < 0.01), and choice experiments demonstrated the ability of S. tubifer to recognize and orient to a host urchin and to conspecifics. Tagging studies revealed that S. tubifer exhibits daily fidelity to a host urchin; 43–50 and 26–37 % of tagged individuals were associated with the same urchin after 3 and 7 days. Tagged fish also returned to their site of origin after displacement; by day two, 23–43 and 27–33 % of tagged individuals returned from displacement distances of 1 and 2 km. These results suggest that S. tubifer uses various environmental cues for homing and site fidelity; similar behaviors and cues might be used by larvae for recruitment to settlement sites and for the acquisition of luminous symbiotic bacteria.  相似文献   
139.
Nitrogen (N) based secondary metabolite production is thought to be costly to plants because N is required for growth, as well as, the synthesis of these compounds. Therefore, variation in N availability may result in variation in N-based secondary metabolite production. Here, we determine the effect of N fertilization on caffeine (N-based alkaloid) production in coffee (Coffea arabica) seedlings. A growth chamber experiment was performed with three N treatments applied to seedlings. N fertilization increased plant growth, leaf biomass, and plant N. Caffeine concentration in phloem exudates was greater in high-N fertilized plants relative to intermediate- and low-N plants. However, leaf, stem, root, and total overall caffeine concentration and content did not differ across N treatments. These results suggest caffeine in coffee is strongly regulated by genetic factors, and environment is likely less important to caffeine phenotype. This is among the first studies to investigate the effect of N fertilization on caffeine within the phloem, which has important implications for herbivores that are sensitive to caffeine and plant N and feed from the phloem of coffee.  相似文献   
140.
Sludge generated in waste water treatment process can be a major sink for some pharmaceutical and personal care products (PPCPs). The land application of sewage sludge (in the form of biosolids in the United States) can therefore potentially introduce PPCPs into the environment. After treatment, biosolids are often subjected to a storage period before land application. However, little information is available with regard to the fate of PPCPs in biosolids during the storage. In this work, the persistence of seven pharmaceuticals and one antibacterial was evaluated using ultrasonic extraction and liquid-chromatography tandem mass spectrometry (LC-MS/MS). The impacts of aeration and sunlight exposure were investigated. During the experiment, no elimination was observed for carbamazepine, triclosan, and ciprofloxacin while elimination was found for tetracycline, doxycycline, clindamycin, erythromycin, and clarithromycin. Using an availability-adjusted kinetic model, the 50% dissipation time was 37 to >77d for tetracycline, 53 to >77d for doxycycline, 1.0-1.6d for clindamycin, 1.1-1.9d for clarithromycin, and 7.0-17d for erythromycin. Those compounds were found more persistent under anaerobic conditions than aerobic condition with a longer 50% dissipation time by a factor of 1.5-2. However, minor impact was observed from sunlight irradiation.  相似文献   
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