Integration of Wireless Sensor Networks into Cyberinfrastructure for Monitoring Hawaiian “Mountain-to-Sea” Environments

Monitoring the complex environmental relationships and feedbacks of ecosystems on catchment (or mountain)-to-sea scales is essential for social systems to effectively deal with the escalating impacts of expanding human populations globally on watersheds. However, synthesis of emerging technologies into a robust observing platform for the monitoring of coupled human-natural environments on extended spatial scales has been slow to develop. For this purpose, the authors produced a new cyberinfrastructure for environmental monitoring which successfully merged the use of wireless sensor technologies, grid computing with three-dimensional (3D) geospatial data visualization/exploration, and a secured internet portal user interface, into a working prototype for monitoring mountain-to-sea environments in the high Hawaiian Islands. A use-case example is described in which native Hawaiian residents of Waipa Valley (Kauai) utilized the technology to monitor the effects of regional weather variation on surface water quality/quantity response, to better understand their local hydrologic cycle, monitor agricultural water use, and mitigate the effects of lowland flooding.     

Grazed Riparian Management and Stream Channel Response in Southeastern Minnesota (USA) Streams

The U.S. Department of Agriculture-Natural Resources Conservation Service has recommended domestic cattle grazing exclusion from riparian corridors for decades. This recommendation was based on a belief that domestic cattle grazing would typically destroy stream bank vegetation and in-channel habitat. Continuous grazing (CG) has caused adverse environmental damage, but along cohesive-sediment stream banks of disturbed catchments in southeastern Minnesota, short-duration grazing (SDG), a rotational grazing system, may offer a better riparian management practice than CG. Over 30 physical and biological metrics were gathered at 26 sites to evaluate differences between SDG, CG, and nongrazed sites (NG). Ordinations produced with nonmetric multidimensional scaling (NMS) indicated a gradient with a benthic macroinvertebrate index of biotic integrity (IBI) and riparian site management; low IBI scores associated with CG sites and higher IBI scores associated with NG sites. Nongrazed sites were associated with reduced soil compaction and higher bank stability, as measured by the Pfankuch stability index; whereas CG sites were associated with increased soil compaction and lower bank stability, SDG sites were intermediate. Bedrock geology influenced NMS results: sites with carbonate derived cobble were associated with more stable channels and higher IBI scores. Though current riparian grazing practices in southeastern Minnesota present pollution problems, short duration grazing could reduce sediment pollution if managed in an environmentally sustainable fashion that considers stream channel response.     

Perceptions of Wood in Rivers and Challenges for Stream Restoration in the United States

This article reports a study of the public perception of large wood in rivers and streams in the United States. Large wood is an element of freshwater aquatic ecosystems that has attracted much scientific interest in recent years because of its value in biological and geomorphological processes. At the heart of the issue is the nature of the relationship between scientific recognition of the ecological and geomorphological benefits of wood in rivers, management practices utilizing wood for river remediation progress, and public perceptions of in-channel wood. Surveys of students’ perceptions of riverscapes with and without large wood in the states of Colorado, Connecticut, Georgia, Illinois, Iowa, Missouri, Oregon, and Texas suggest that many individuals in the United States adhere to traditionally negative views of wood. Except for students in Oregon, most respondents considered photographs of riverscapes with wood to be less aesthetically pleasing and needing more improvement than rivers without wood. Analysis of reasons given for improvement needs suggest that Oregon students are concerned with improving channels without wood for fauna habitat, whereas respondents elsewhere focused on the need for cleaning wood-rich channels for flood risk management. These results underscore the importance of public education to increase awareness of the geomorphological and ecological significance of wood in stream systems. This awareness should foster more positive attitudes toward wood. An integrated program of research, education, and policy is advocated to bridge the gap between scientific knowledge and public perception for effective management and restoration of river systems with wood.     

Rights and Conflicts in the Management of Fisheries in the Lower Songkhram River Basin,Northeast Thailand

A complex, pre-existing local property rights system, characterized by overlap and conflict, comprises the local basis for managing inland fisheries in communities of the Lower Songkhram River Basin (LSRB) of Northeastern Thailand. The components, conflicts and changes of the system are analyzed for fourteen communities, focusing on the auction system for barrages, an illegal and destructive, yet tolerated, fishery. These rights, adapted to gear type, seasonality, and habitat of the LSRB fisheries, are a critical social resource and proven management system that should be legitimized. Recommendations are made for both improving general inland fisheries policy and reforming the barrage fishery.     

Flood Effects on an Alaskan Stream Restoration Project: The Value of Long‐Term Monitoring1

Densmore, Roseann V. and Kenneth F. Karle, 2009. Flood Effects on an Alaskan Stream Restoration Project: The Value of Long‐Term Monitoring. Journal of the American Water Resources Association (JAWRA) 45(6):1424‐1433. Abstract: On a nationwide basis, few stream restoration projects have long‐term programs in place to monitor the effects of floods on channel and floodplain configuration and floodplain vegetation, but long‐term and event‐based monitoring is required to measure the effects of these stochastic events and to use the knowledge for adaptive management and the design of future projects. This paper describes a long‐term monitoring effort (15 years) on a stream restoration project in Glen Creek in Denali National Park and Preserve in Alaska. The stream channel and floodplain of Glen Creek had been severely degraded over a period of 80 years by placer mining for gold, which left many reaches with unstable and incised streambeds without functioning vegetated floodplains. The objectives of the original project, initiated in 1991, were to develop and test methods for the hydraulic design of channel and floodplain morphology and for floodplain stabilization and riparian habitat recovery, and to conduct research and monitoring to provide information for future projects in similar degraded watersheds. Monitoring methods included surveyed stream cross‐sections, vegetation plots, and aerial, ground, and satellite photos. In this paper we address the immediate and outlying effects of a 25‐year flood on the stream and floodplain geometry and riparian vegetation. The long‐term monitoring revealed that significant channel widening occurred following the flood, likely caused by excessive upstream sediment loading and the fairly slow development of floodplain vegetation in this climate. Our results illustrated design flaws, particularly in regard to identification and analysis of sediment sources and the dominant processes of channel adjustment.     

Effects of agronomic practices on phytoremediation of an aged PAH-contaminated soil

Phytoremediation offers an ecologically and economically attractive remediation technique for soils contaminated with polycyclic aromatic hydrocarbons (PAHs). In addition to the choice of plant species, agronomic practices may affect the efficiency of PAH phytoremediation. Inorganic nutrient amendments may stimulate plant and microbial growth, and clipping aboveground biomass might stimulate root turnover, which has been associated with increases in soil microbial populations. To assess the influence of fertilization and clipping on PAH dissipation in a nutrient-poor, aged PAH-contaminated soil, a 14-mo phytoremediation study was conducted using perennial ryegrass (Lolium perenne) as a model species. Six soil treatments were performed in replicate: unplanted; unplanted and fertilized; planted; planted and fertilized; planted and clipped; and planted, clipped, and fertilized. Plant growth, soil PAH concentrations, and the concentrations of total and PAH-degrading microorganisms were measured after 7 and 14 mo. Overall, planting (with nearly 80% reduction in total PAHs) and planting + clipping (76% reduction in total PAHs) were the most effective treatments for increased PAH dissipation after 14 mo. Fertilization greatly stimulated plant and total microbial growth, but negatively affected PAH dissipation (29% reduction in total PAHs). Furthermore, unplanted and fertilized soils revealed a similar negative impact (25% reduction) on PAH dissipation after 14 mo. Clipping did not directly affect PAH dissipation, but when combined with fertilization (61% reduction in total PAHs), appeared to mitigate the negative impact of fertilization on PAH dissipation. Therefore, fertilization and clipping may be included in phytoremediation design strategies, as their combined effect stimulates plant growth while not affecting PAH dissipation.     

Polycyclic aromatic hydrocarbons and their hydroxylated metabolites in fish bile and sediments from coastal waters of Colombia

Sediments and fish bile collected from the Atlantic coastal waters of Colombia were analyzed for 16 parent polycyclic aromatic hydrocarbons (PAHs), and 23 hydroxylated PAHs (OH-PAHs), respectively. Sediments contained overall mean SigmaPAH concentrations of 2090, 234 and 170 ng/g, dry wt, for Cartagena Bay, Caimanera Marsh, and Totumo Marsh, respectively. The mean concentration of the summed OH-PAHs in fish bile was 1250, 180 and 64.1 ng/g bile wt for Cartagena Bay, Caimanera Marsh, and Totumo Marsh, respectively. The results suggest that Cartagena Bay is heavily polluted by PAHs, and that exposure to high concentrations of PAHs together with other factors could contribute to the decreased health of fish living in this ecosystem. This is one of the first studies to describe the analysis of 23 individual OH-PAHs in fish bile, using authentic standards.     

Phase partitioning modeling of ethanol, isopropanol, and methanol with BTEX compounds in water

This study investigates the equilibrium phase partitioning behavior of ethanol, isopropanol, and methanol in a two-phase liquid-liquid system consisting of water and an individual BTEX (Benzene, Toluene, Ethylbenzene, and Xylenes) compound. A previously developed computer program is enhanced to generate ternary phase diagrams for analysis of each three-component cosolvent-nonaqueous phase liquid (NAPL)-water mixture combination. The required activity coefficients are estimated using the UNIFAC (Universal Quasichemical Functional group Activity Coefficient) model. The UNIFAC-derived ternary phase diagrams generally show good agreement against published experimental data, and similar phase partitioning behavior is observed for every BTEX compound in the presence of the same cosolvent. Furthermore, a set of laboratory experiments is conducted to determine the maximum single-phase water content for every mixture combination considered in this study where the volume composition of the cosolvent and the NAPL components is a blend of 85% alcohol and 15% BTEX compound. Comparison of experimentally-derived maximum single-phase water contents against UNIFAC-derived results shows good agreement for mixtures containing ethanol and methanol, but relatively poor agreement for mixtures containing isopropanol.     

Composition and yields of secondary organic aerosol formed from OH radical-initiated reactions of linear alkenes in the presence of NOx: Modeling and measurements

The products and mechanism of secondary organic aerosol (SOA) formation from the OH radical-initiated reactions of linear alkenes in the presence of NO_x were investigated in an environmental chamber. The SOA consisted primarily of products formed through reactions initiated by OH radical addition to the CC double bond, including β-hydroxynitrates and dihydroxynitrates, as well as cyclic hemiacetals, dihydrofurans, and dimers formed from particle-phase reactions of dihydroxycarbonyls. 1,4-Hydroxynitrates formed through reactions initiated by H-atom abstraction also appeared to contribute. Product yields and OH radical and alkoxy radical rate constants taken from the literature or calculated using structure–reactivity methods were used to develop a quantitative chemical mechanism for these reactions. SOA yields were then calculated using this mechanism with gas-particle partitioning theory and estimated product vapor pressures for comparison with measured values. Calculated and measured SOA yields agreed very well at high carbon numbers when semi-volatile products were primarily in the particle phase, but diverged with decreasing carbon number to a degree that depended on the model treatment of dihydroxycarbonyls, which appeared to undergo reversible reactions in the particle phase. The results indicate that the chemical mechanism developed here provides an accurate representation of the gas-phase chemistry, but the utility of the SOA model depends on the partitioning regime. The results also demonstrate some of the advantages of studying simple aerosol-forming reactions in which the majority of products can be identified and quantified, in this case leading to insights into both gas- and particle-phase chemistry.