Field performance of a fan‐driven spray evaporator

An emerging evaporation technology uses a powerful axial fan and high‐pressure spray nozzles to propel a fine mist into the atmosphere at high air and water flow rates. Commercial units have been deployed at several locations in North America and worldwide since the mid‐1990s, typically in arid or semiarid climates. A commercial spray evaporator was field tested at the U.S. Department of Energy's Savannah River Site in South Carolina to develop quantitative performance data under relatively humid conditions. A semiempirical correlation was developed from eight tests from March through August 2003. For a spray rate of 250 L/min (66 gpm) and continuous year‐round operation at the Savannah River Site, the predicted average evaporation rate is 48 L/min (13 gpm). © 2006 Washington Savannah River Company     

CERES — A model of forest stand biomass dynamics for predicting trace contaminant,nutrient, and water effects. I. Model description

CERES is a forest stand growth model which incorporates sugar transport in order to predict both short-term effects and long-term accumulation of trace contaminants and/or nutrients when coupled with the soil chemistry model (SCHEM), and models of solute uptake (DIFMAS and DRYADS) of the Unified Transport Model, UTM. An important feature of CERES is its ability to interface with the soil-plant-atmosphere water model (PROSPER) as a means of both predicting and studying the effects of plant water status on growth and solute transport.CERES considers the biomass dynamics of plants, standing dead and litter with plants divided into leaves, stems, roots, and fruits. The plant parts are divided further into sugar substrate, storage, and in the case of stems and roots, heartwood components.Each ecosystem component is described by a mass balance equation written as a first-order ordinary differential equation.     

Modelling solute uptake and incorporation into vegetation and litter

The concepts and algorithms of the Baldwin, Nye and Tinker model describing solute movement from bulk soil solution to roots (DIFMAS) and a model of solute dynamics and accumulation in plant tissues and litter (DRYADS) are presented. Foliar uptake of solutes and gases are included in the DRYADS code. These models form components in a coupled system of models having hourly resolution of carbon, water, and solute dynamics in terrestrial ecosystems. Applications showing successive hourly, monthly, and annual results illustrate the utility of the models. The DRYADS model sensitivity to both leaf solute conductivity and root solute conductivity parameters suggest the importance of careful experimental determination of these plant properties. The tissues of solute entry (leaves, roots) initially accumulate solutes in a fixed form in preference to the more remote tissues (stems, fruits). Model application results show that root sapwood is the first major site of trace contaminant accumulation from soil-borne pollutants. The algorithms describing solute movement along a concentration gradient in phloem and as mass flow in the xylem transpiration stream result in high mobility of solutes in vegetation. The simulated diurnal pattern of root solute uptake showed that more than 85% of solutes were taken up during the daylight hours. The simulations further showed that contaminants had the greatest effect on the litter system. Toxic effects of contaminants on decomposition resulted in lower mineralization losses and accumulation of contaminant in litter with continuing deposition.     

Foraging behavior and echolocation of wild horseshoe bats Rhinolophus ferrumequinum and R. hipposideros (Chiroptera,Rhinolophidae)

Summary 1. Echolocation and foraging behavior of the horseshoe bats Rhinolophus ferrumequinum and R. hipposideros feeding under natural conditions are described. 2. The calls of both species consisted predominantly of a long CF segment, often initiated and terminated by brief FM sweeps of substantial bandwidth. 3. R. hipposideros typically flew close to vegetation, and fed by aerial hawking, gleaning and by pouncing on prey close to the ground. R. hipposideros called with a CF segment close to 112 kHz which is the second harmonic of the vocalization; its calls included low intensity primary harmonics, and had prominent initial and terminal FM sweeps of considerable bandwidth. When searching for prey on the wing it had longer interpulse intervals than R. ferrumequinum, but emitted shorter pulses at a higher repetition rate; overall it had a similar duty cycle to R. ferrumequinum. 4. R. ferrumequinum, calling with a CF segment close to 83 kHz, also used harmonics other than the dominant secondary in its calls, and modified its echolocation according to ecological conditions. This species showed certain parallels with R. rouxi of Asia. It was observed feeding by aerial hawking and by flycatching. When scanning for prey from a perch (perch hunting), calls were of shorter duration, and interpulse intervals were on average longer, than when bats were flying. Mean duty cycle was longer in flight, and the bandwidths and frequency sweep rates of the FM segments in the calls increased in comparison with perched bats. 5. FM information may facilitate determination of target range and the location and nature of obstacles; it may also be involved in the interpretation of echoes and the detection of moving targets among clutter. The rising FM sweep initiating the call in both species when flying (and to a lesser extent perch hunting) in the wild must have a significant adaptive role, and should be considered an essential component of the call; rhinolophids should be termed FM/CF/FM bats.Abbreviations CF constant frequency - FM frequency modulated - FM₁ initial rising frequency sweep - FM₂ terminal falling frequency sweep - PRR pulse repetition rate - SD standard deviation - SNR signal-to-noise ratio     

Phosphorus speciation in manure-amended alkaline soils

Two common manure storage practices are stockpiles and lagoons. The manure from stockpiles is applied to soils in solid form, while lagoon manure is applied as a liquid. Soil amendment with manure in any form introduces a significant amount of phosphorus (P) that exists in both organic and inorganic forms. However, little is known about P speciation in manure stored under different conditions, or the subsequent forms when applied to soils. We used solution (31)P nuclear magnetic resonance (NMR) spectroscopy and conventional P fractionation and speciation methods to investigate P forms in dairy manure and liquid lagoon manure, and to study how long-term amendment with these manures influenced surface and subsurface soil P speciation. Our results show that the P forms in solid and lagoon manure are similar. About 30% of the total P was organic, mostly as orthophosphate monoesters. On a dry weight basis, total P was much higher in the solid manure. In the manure-amended soils the total P concentrations of the surface soils were similar, regardless of manure type. Total P in the subsurface soil was greater in the lagoon-manure-amended soil than the solid-manure-amended subsurface soil. However, the fraction of organic P was greater in the subsurface of the solid-manure-amended soil. The NMR results indicate that the majority of organic P in the soils is phytic acid, which is enriched in the surface soils compared with the subsurface soils. These results provide insight into P speciation and dynamics in manure-amended soils that will further increase our understanding on how best to manage manure disposal on soils.     

Cofoundress relatedness and group productivity in colonies of social <Emphasis Type="Italic">Dunatothrips</Emphasis> (Insecta: Thysanoptera) on Australian <Emphasis Type="Italic">Acacia</Emphasis>

Facultative joint colony founding by social insects provides opportunities to analyze the roles of genetic and ecological factors in the evolution of cooperation. Although cooperative nesting is observed in range of social insect taxa, the most detailed studies of this behavior have been conducted with Hymenoptera (ants, bees, and wasps). Here, we show that foundress associations in the haplodiploid social thrips Dunatothrips aneurae (Insecta: Thysanoptera) are most often comprised of close relatives (sisters), though groups with unrelated foundresses are also found. Associations among relatives appear to be facilitated by limited female dispersal, which results in viscous population structure. In addition, we found that per capita productivity declined with increasing group size, sex ratios were female-biased, and some female offspring apparently remained in their natal domicile for some time following eclosion. D. aneurae thus exhibits a suite of similarities with eusocial Hymenoptera, providing evidence for the convergent evolution of associated social and life-history traits in Hymenoptera and Thysanoptera.     

Facilitating climate‐change‐induced range shifts across continental land‐use barriers

Climate changes impose requirements for many species to shift their ranges to remain within environmentally tolerable areas, but near‐continuous regions of intense human land use stretching across continental extents diminish dispersal prospects for many species. We reviewed the impact of habitat loss and fragmentation on species’ abilities to track changing climates and existing plans to facilitate species dispersal in response to climate change through regions of intensive land uses, drawing on examples from North America and elsewhere. We identified an emerging analytical framework that accounts for variation in species' dispersal capacities relative to both the pace of climate change and habitat availability. Habitat loss and fragmentation hinder climate change tracking, particularly for specialists, by impeding both propagule dispersal and population growth. This framework can be used to identify prospective modern‐era climatic refugia, where the pace of climate change has been slower than surrounding areas, that are defined relative to individual species' needs. The framework also underscores the importance of identifying and managing dispersal pathways or corridors through semi‐continental land use barriers that can benefit many species simultaneously. These emerging strategies to facilitate range shifts must account for uncertainties around population adaptation to local environmental conditions. Accounting for uncertainties in climate change and dispersal capabilities among species and expanding biological monitoring programs within an adaptive management paradigm are vital strategies that will improve species' capacities to track rapidly shifting climatic conditions across landscapes dominated by intensive human land use.     

Global patterns and trends in human–wildlife conflict compensation

Human–wildlife conflict is a major conservation challenge, and compensation for wildlife damage is a widely used economic tool to mitigate this conflict. The effectiveness of this management tool is widely debated. The relative importance of factors associated with compensation success is unclear, and little is known about global geographic or taxonomic differences in the application of compensation programs. We reviewed research on wildlife‐damage compensation to determine geographic and taxonomic gaps, analyze patterns of positive and negative comments related to compensation, and assess the relative magnitude of global compensation payments. We analyzed 288 publications referencing wildlife compensation and identified 138 unique compensation programs. These publications reported US$222 million (adjusted for inflation) spent on compensation in 50 countries since 1980. Europeans published the most articles, and compensation funding was highest in Europe, where depredation by wolves and bears was the most frequently compensated damage. Authors of the publications we reviewed made twice as many negative comments as positive comments about compensation. Three‐quarters of the negative comments related to program administration. Conversely, three‐quarters of the positive comments related to program outcomes. The 3 most common suggestions to improve compensation programs included requiring claimants to employ damage‐prevention practices, such as improving livestock husbandry or fencing of crops to receive compensation (n = 25, 15%); modifying ex post compensation schemes to some form of outcome‐based performance payment (n = 21, 12%); and altering programs to make compensation payments more quickly (n = 14, 8%). We suggest that further understanding of the strengths and weaknesses of compensation as a conflict‐mitigation tool will require more systematic evaluation of the factors driving these opinions and that differentiating process and outcomes and understanding linkages between them will result in more fruitful analyses and ultimately more effective conflict mitigation.     

Social signals and sustainability: ambiguity about motivations can affect status perceptions of efficiency and curtailment behaviors

Perceived status can affect the diffusion of pro-environmental behaviors and sustainable consumption. However, the status of different forms of sustainable consumption has not been adequately explored. Previous studies suggest that curtailment behaviors are associated with low or neutral status, while efficiency behaviors are associated with high status. However, these studies have generally examined a small number of behaviors. Drawing from costly signaling theory, we developed a mixed methods study to explore whether and why pro-environmental behaviors are perceived to be associated with high or low status, the perceived motivation for those behaviors, and the relationship between motivation and status. We conducted structured, interactive interviews with 71 participants to explore perceptions of 19 behaviors. Using quantitative and qualitative analyses, we find that efficiency is rated higher status than curtailment largely due to monetary considerations. Efficiency is also perceived to be motivated by environmental concern to a greater degree than curtailment. Understanding the motivation for behaviors clarifies the social signal because it provides insights into whether one is incurring personal costs. Importantly, it is often unclear whether low-cost curtailment behaviors are adopted by choice rather than financial need. Ambiguity about the intentionality of behaviors results in such behaviors being perceived as lower status. Those who argue that curtailment will be necessary for long-term sustainability must address status perceptions because social stigmas could hinder their adoption. Overcoming such stigmas may require, indicating that curtailment behaviors are voluntary, but it may be more effective to use social or economic mechanisms to increase efficiency behaviors.     

Adaptive Capacity and Social-Environmental Change: Theoretical and Operational Modeling of Smallholder Coffee Systems Response in Mesoamerican Pacific Rim

Communities who rely directly on the natural environment for their survival typically have developed risk management strategies to enable them to avoid dangerous thresholds of change to their livelihoods. Development policy appropriate for natural resource-based communities requires an understanding of the primary drivers of social-ecological change, the ways in which affected households autonomously respond to such drivers, and the appropriate avenues for intervention to reduce vulnerability. Coffee has been, and still remains, one of the most important commodities of the Mesoamerican region, and hundreds of thousands of smallholder households in the region are dependent in some way on the coffee industry for their livelihood stability. We used the Analytical Network Process to synthesize expert knowledge on the primary drivers of livelihood change in the region as well as the most common household strategies and associated capacities necessary for effective response. The assessment identified both gradual systemic processes as well as specific environmental and market shocks as significant drivers of livelihood change across the region. Agronomic adjustments and new forms of social organization were among the more significant responses of farmers to these changes. The assessment indicates that public interventions in support of adaptation should focus on enhancing farmers’ access to market and technical information and finance, as well as on increasing the viability of farmers’ organizations and cooperatives.