STREAM ASSESSMENTS USING BIOTIC INDICES: RESPONSES TO PHYSICOCHEMICAL VARIABLES1

ABSTRACT: Responses of the Wyoming Stream Integrity Index (WSII), a regionally calibrated multimetric index, were investigated in relation to background elevational changes in water quality and habitat conditions versus accelerated anthropogenic degradation at the watershed scale. Assessments were conducted for three rivers in southeast Wyoming: the Little Medicine Bow River, the Medicine Bow River, and Rock Creek. Pearson correlation coefficients and regression models related “core metrics” and index scores to elevational gradients of physicochemical variables. Velocity, substrate, and weighted habitat values were positively correlated to index scores, while suspended solids was negatively correlated. The exclusive dependence of index scores on physical variables specifies the type of environmental gradients the WSII is most robust in detecting. The individual “core metrics” Plecoptera taxa, Trichoptera taxa, percent Trichoptera without Hydropsychidae, and percent noninsects appeared most sensitive to physical changes and were thus driving associations between index scores and physical variables. Despite strong correlations with physical variables, anomalies existed where habitat conditions were good, unknown stressors existed, or gradients were naturally occurring despite “Poor” index scores (i.e., degraded stream conditions). Such findings illustrate the influence of regional variability on biotic indices and the importance of identifying sufficient reference and impaired stream reaches used to develop and calibrate multimetric indices relying on reference conditions.     

FOREST‐RIVER INTERACTIONS: INFLUENCE ON HYPORHEIC DISSOLVED ORGANIC CARBON CONCENTRATIONS IN A FLOODPLAIN TERRACE1

ABSTRACT: In large floodplain rivers, hyporheic (subsurface) flow‐paths transfer nutrients from productive riparian terraces to oligotrophic off‐channel habitats. Because dissolved organic carbon (DOC) fuels microbial processes and hyporheic microorganisms represent the first stage of retention and transformation of these nutrients, understanding DOC flux can provide information on the constraints of microbial metabolism in the hyporheic zone of rivers. We monitored hydrology, physicochemical indicators, and dissolved organic carbon (DOC) dynamics during low and high discharge periods in the hyporheic zone of a riparian terrace on the Queets River, Washington, to understand what processes control the supply of carbon to subsurface microbial communities. As discharge increased, terrace hyporheic flowpaths changed from parallel to focused, and the location of surface water inputs to the terrace shifted from the terrace edge to head. Overall, DOC concentrations decreased along hyporheic flowpaths; however, concentrations at points along the flowpaths varied with position along the head gradient and age of the overlying vegetation. We estimated that there is insufficient DOC in adverting surface water to support hyporheic microbial metabolism in this riparian terrace. These trends indicate that there are additional carbon sources to the subsurface water, and we conclude that DOC is leaching from overlying riparian soils within the forest patches. Thus, subsurface DOC concentrations reflect a balance between surface water inputs, metabolic uptake, and allochthonous inputs from forest soils.     

DEVELOPMENT AND EVALUATION OF MULTIPLE‐OBJECTIVE DECISION‐MAKING METHODS FOR WATERSHED MANAGEMENT PLANNING1

ABSTRACT: Making decisions for environmental management is a complex task due to the multiplicity and diversity of technological choices. Furthermore, the exploitation of natural resources and the preservation of the natural environment imply objectives that are often in conflict within a sustainable development paradigm. Managers and other decision makers require techniques to assist them in understanding strategic decision making. This paper illustrates the use of a multiple‐objective decision‐making methodology and an integrative geographical information system‐based decision‐making tool developed to help watershed councils prioritize and evaluate restoration activities at the watershed level. Both were developed through a multidisciplinary approach. The decision‐making tool is being applied in two watersheds of Oregon's Willamette River Basin. The results suggest that multiple‐objective methods can provide a valuable tool in analyzing complex watershed management issues.     

EVAPOTRANSPIRATION MEASUREMENT AND ESTIMATION OF THREE WETLAND ENVIRONMENTS IN THE UPPER ST. JOHNS RIVER BASIN,FLORIDA1

ABSTRACT: Accurate estimates of evapotranspiration from areas dominated by wetland vegetation are needed in the water budget of the Upper St. Johns River Basin. However, local data on evapotranspiration rates, especially in wetland environments, were lacking in the project area. In response to this need, the St. Johns River Water Management District collected evapotranspiration field data in Fort Drum Marsh Conservation Area over the period 1996 through 1999. Three large lysimeters were installed to measure the evapotranspiration from different wetland environments: sawgrass (Cladium jamaicense), cattail (Typha domingensis), and open water. In addition, pan evaporation was measured with a standard class “A” pan. Concurrently, meteorological data including rainfall, solar radiation, wind speed, relative humidity, air temperature, and atmospheric pressure were collected. By comparing computed evapotranspiration rates with those measured in the lysimeters, parameters in the Penman‐Monteith, the Priestley‐Taylor, and Reference‐ET methods, and evaporation pan coefficients were estimated for monthly and seasonal cycles. The results from the data collected in this study show that mean monthly evapotranspiration rates, computed by the different methods, are relatively close. From a practical point of view, results indicate that the evaporation pan can be used equally well as the more complex and data‐intensive methods. This paper presents the measured evapotranspiration rates, evaporation pan coefficients, and the estimated parameter values for three different methods to compute evapotranspiration in the project area. Since local data on evaporation are often scarce or lacking, this information may be useful to watershed hydrologists for practical application in other project regions.     

INTERACTIVE DISTRIBUTED CONSERVATION PLANNING1

ABSTRACT: In the environmental and agricultural conservation planning process, more efficient and effective tools are needed for planners to assist private landowners with making wiser land use decisions. Current methods are slow, inefficient, and costly. Scientific techniques have not been fully implemented within the planning process, yet such plans are increasingly needed to meet water quality and Total Maximum Daily Load (TMDL) requirements. The objectives of this study are to (a) utilize the web for accessing an integrated science‐based land use decision support system; (b) link decision tools, models, and databases to the user via the web; (c) link distributed models and databases for enhanced planning efficiency; and (d) integrate the above into an easily usable and readily accessible system. The procedures resulting in the initial design involved planning expertise and focus groups' input. The system was developed in partnership with the Natural Resources Conservation Service of the U.S. Department of Agriculture and several state agencies. A survey of 150 certified conservation planners, the end users, was conducted to identify the data sets and planning tools needed. Data, tools, and models then were selected and integrated into a web accessible system. Specifically, the first generation used a web interactive Geographic Information System (GIS) that overlaid onto digital orthoquads and/or soils polygons field boundaries, transportation, hydrologic features (such as drains, rivers, lakes, etc.), and high pesticide risk runoff or infiltration areas. Conservation planners found they could save time with the system. Clients could access the system quickly to help them prepare for meeting with their planner. Previously acquiring GIS maps in some cases had been a lengthy process that limited use of the information in land use decisions.     

A DECISION SUPPORT TOOL FOR THE MANAGEMENT OF MULTI‐RESERVOIR SYSTEMS1

ABSTRACT: A decision support tool is developed for the management of water resources, focusing on multipurpose reservoir systems. This software tool has been designed in such a way that it can be suitable to hydrosystems with multiple water uses and operating goals, calculating complex multi‐reservoir systems as a whole. The mathematical framework is based on the parameterization‐simulation‐optimization scheme. The main idea consists of a parametric formulation of the operating rules for reservoirs and other projects (i.e., hydropower plants). This methodology enables the radical decrease of the number of decision variables, making feasible the location of the optimal management policy, which maximizes the system yield and the overall operational benefit and minimizes the risk for the management decisions. The program was developed using advanced software engineering techniques. It is adaptable in a wide range of water resources systems, and its purpose is to support water and power supply companies and related authorities. It already has been applied to two of the most complicated hydrosystems of Greece, the first time as a planning tool and the second time as a management tool.     

Leadership,followers' mental health and job performance in organizations: A comprehensive meta‐analysis from an occupational health perspective

The present meta‐analysis investigates the associations between leadership, followers' mental health, and job performance by taking into account different groups of leadership constructs including transformational leadership, relations‐oriented leadership, task‐oriented leadership, destructive leadership, and leader–member exchange. Six categories of mental health‐related outcomes are considered representing both negative and positive mental health states of followers, namely, affective symptoms, burnout, stress, well‐being, psychological functioning, and health complaints. Meta‐analytic models are used to estimate the association between these categories of leadership and mental health. Our results reveal that transformational leadership, a high quality of relations‐oriented and task‐oriented leadership behavior, as well as a high quality of leader–follower interaction are positively associated with mental health. In contrast, destructive leadership is strongly negatively associated with mental health. In addition, the mediation effects of leadership on job performance via mental health are estimated. Results partially support the mediating role of mental health concerning the relationship between leadership and job performance. Our results emphasize the importance of leadership as an occupational health factor, and they may serve as basis for the planning and designing of occupational health policies and interventions despite existing research limitations. Copyright © 2016 John Wiley & Sons, Ltd.     

Under what conditions does job control moderate the relationship between time pressure and employee well‐being? Investigating the role of match and personal control beliefs

Drawing upon the concept of match, this two‐wave study of 206 employees investigated job control (facets of autonomy) and personal control beliefs (locus of control, LOC) as moderators of time pressure–work engagement (WE) and the time pressure–general subjective well‐being (SWB) relationships. It was hypothesized that autonomy would accentuate the positive relationship of time pressure with WE and attenuate the negative relationship with SWB and that these moderations would occur only for employees with an internal LOC. Additionally, it was expected that a facet of job control (timing autonomy) that matched the specific demand (time pressure) would be more likely to act as a moderator than “less‐matching” facets (decision making or method autonomy). The results revealed that the interaction between time pressure, autonomy, and LOC for WE was strongest and for SWB only significant when the timing facet of autonomy served as the moderator (thus, when the autonomy facet matched the demand). However, the pattern of moderation was contrary to that expected. When time pressure increased, high autonomy became beneficial for the WE of employees with an external LOC but detrimental for the WE and SWB of employees with an internal LOC. Explanations for the unexpected findings are provided. Copyright © 2016 John Wiley & Sons, Ltd.     

Human resource management systems and work attitudes: The mediating role of future time perspective

This paper examines the role of employees' future time perspective (FTP) in the association between human resource management (HRM) systems and work‐related attitudes. Drawing on social exchange theory, signaling theory, and affective events theory, we hypothesize HRM systems' indirect effects on individual‐level job satisfaction and affective organizational commitment as mediated by FTP. The results of this multilevel study, comprising 913 employees of 76 business units, provide evidence that HRM systems have (i) direct effects on employees' FTP and (ii) indirect effects on job satisfaction and organizational commitment via FTP. In addition, three HRM bundles' (i.e., knowledge, skills, and abilities enhancing; motivation enhancing; and opportunity enhancing) corresponding indirect effects are explored. We discuss the results, theoretical contributions, and practical implications of the study, as well as future research directions. Copyright © 2016 John Wiley & Sons, Ltd.     

Getting away from them all: Managing exhaustion from social interaction with telework

Drawing on the conservation of resources and recovery literatures, we examine how social job characteristics—interpersonal interaction, job interdependence, and external interaction—relate to work exhaustion. We then explore the efficacy of a part‐time telework (PTT) practice in alleviating work exhaustion associated with social interaction. Study 1 is a within‐subject assessment of work exhaustion before and after a PTT practice; participants are 51 information technology professionals in a financial services firm. Study 2 is a between‐subject assessment of work exhaustion among part‐time teleworkers and non‐teleworkers; participants are 258 U.S. workers spanning a variety of industries. Study 2 replicated the model tested in Study 1, and we extended the conceptualization of interpersonal interaction to examine both quantity and quality of interaction. In both studies, PTT provided a recovery opportunity, attenuating the relationship between interpersonal interaction and work exhaustion; however, after PTT but not before, work exhaustion increased as external interaction increased. In Study 2, work exhaustion decreased as interaction quality increased; in contrast, work exhaustion increased as interaction quantity increased and PTT attenuated this relationship. Our recommendations aim to help balance telework practices in light of social job characteristics and their opposing effects on work exhaustion. Copyright © 2017 John Wiley & Sons, Ltd.