Connectivity of wood thrush breeding,wintering, and migration sites based on range‐wide tracking

Many migratory animals are experiencing rapid population declines, but migration data with the geographic scope and resolution to quantify the complex network of movements between breeding and nonbreeding regions are often lacking. Determining the most frequently used migration routes and nonbreeding regions for a species is critical for understanding population dynamics and making effective conservation decisions. We tracked the migration of individual Wood Thrushes (Hylocichla mustelina) (n = 102) from across their range with light‐level geolocators and, for the first time, quantified migration routes and wintering regions for distinct breeding populations. We identified regional and species‐level migratory connectivity networks for this declining songbird by combining our tracking results with range‐wide breeding abundance estimates and forest cover data. More than 50% of the species occupied the eastern wintering range (Honduras to Costa Rica), a region that includes only one‐third of all wintering habitat and that is undergoing intensive deforestation. We estimated that half of all Wood Thrushes in North America migrate south through Florida in fall, whereas in spring approximately 73% funnel northward through a narrow span along the central U.S. Gulf Coast (88–93°W). Identifying migratory networks is a critical step for conservation of songbirds and we demonstrated with Wood Thrushes how it can highlight conservation hotspots for regional populations and species as a whole. Conectividad de Sitios de Reproducción, Invierno y Migración del Zorzal con Base en Rastreo de Cobertura Amplia     

GEOMORPHIC ANALOGIES FOR ASSESSING PROBABLE CHANNEL RESPONSE TO DAM REMOVAL1

ABSTRACT: There is a pressing need for tools to predict the rates, magnitudes, and mechanisms by which sediment is removed from a reservoir following dam removal, as well as for tools to predict where this sediment will be deposited downstream and how it will impact downstream channel morphology. In the absence of adequate empirical data, a good initial approach is to examine the impacts of dam removal within the context of the geomorphic analogies of channel evolution models and sediment waves. Channel changes at two dam breaching sites in Wisconsin involved a succession of channel forms and processes consistent with an existing channel evolution model. Sediment transported downstream after removal of other dams suggests that reservoir sediment may be translated downstream either as a distinct wave or gradually eroded away. More extensive data collection on existing dam removals is warranted before undertaking the removal of a large number of dams. However, if removal is to proceed based on current knowledge, then geomorphic analogies can be used as the foundation for sediment management and stabilization schemes.     

Light at night reduces digestive efficiency of developing birds: an experiment with king quail

The Science of Nature - Gravity is very important for many organisms, including web-building spiders. Probably the best approach to study the relevance of gravity on organisms is to bring them to...     

The Value of Validated Vulnerability Data for Conservation Planning in Rapidly Changing Landscapes

Data needed for informed conservation prioritization are generally greater than the data available, and surrogates are often used. Although the need to anticipate threats is recognized, the effectiveness of surrogates for predicting habitat loss (or vulnerability) to land-use change is seldom tested. Here, we compared properties of two different vulnerability surrogates to validated vulnerability—validated prediction of habitat conversion based on a recent assessment of land-use change. We found that neither surrogate was a particularly effective predictor of vulnerability. Importantly, both surrogates performed poorly in places most imminently threatened with habitat conversion. We also show that the majority of areas protected over the last two decades have low vulnerability to the most active threatening process in this biome (habitat conversion). The contrary patterns of vulnerability and protection suggest that use of validated vulnerability would help to clarify protection needs, which might lead to the improvement of conservation decisions. Our study suggests the integration of validated vulnerability into conservation planning tools may be an important requirement for effective conservation planning in rapidly changing landscapes. We apply our results to discuss the practical considerations and potential value of incorporating validated vulnerability into conservation planning tools both generally and in the context of New Zealand’s indigenous grasslands.     

Could a public ecology approach help resolve the mountaintop mining controversy?

In recent years, controversy has grown around decisions related to mountaintop removal mining of coal in Central Appalachia, USA. While this mining method can be particularly efficient, it necessitates removal and relocation of huge volumes of earth—permanently altering the natural landform and potentially impacting local environments and communities. Current decision-making systems and regulatory frameworks have been largely ineffective at incorporating the values and concerns of stakeholders. This is due, in part, to contradicting policies, a legacy of distrust, and problems related to scale. Further, the lack of good civic science related to mountaintop mining and meaningful routes for public involvement have also hampered effective decision-making. We propose that the fundamental concepts of public ecology may provide a progressive approach to resolving these complex issues, and examine the challenges that must be met along the way.     

瑞典中部梅拉伦湖早期富营养化的沉积物证据及重金属污染

梅拉伦湖是瑞典中部100多万居民的供水源和娱乐区,有重大的环境影响.为了建立评估目前的营养水平和重金属污染水平的背景资料,分析了取自湖泊的沉积岩心.从硅藻推断的湖水磷浓度表明,20世纪前南比约克盆地(梅拉伦湖东部的一个盆地)中的营养物水平比以前假定的(约6ugTP/L)要高(10～20μgTP/L).从3个盆地(南比约克盆地、伊斯塞尔盆地以及艾斯雪盆地)获得的稳定性同位素和铅浓度分析结果表明,19世纪以及早些时候由于汇水盆地广泛开展的金属生产和加工,特别是在贝里斯拉根地区,使得该湖泊受到污染.在20世纪关闭了采矿和金属工厂之后该湖泊的铅污染形势有了相当大的好转过去的采矿业所造成的铅污染比20世纪末汽车尾气排放、矿石然料燃烧以及现代生产所造成的污染要严重.     

The effect of thermodynamic data on computer model predictions of uranium speciation in natural water systems

Computer models have found widespread application in order to help elucidate and predict changes in environmental systems. One such application is the prediction of trace metal speciation in aqueous systems. This is achieved by solving a set of non-linear equations involving equilibrium constants for all the components in the system, within mass and charge balance constraints. In this study a comparison of the predicted uranium speciation from two computer programs, WHAM and PHREEQCI, is used to illustrate the effect variations in thermodynamic data can have on the models produced. Using the original thermodynamic data provided with the models, WHAM predicted the UO2(2+) ion as the major species (84%) while PHREEQCI predicted UO2(HPO4)2(2-) as the major species (86%). Substituting uranium data from the Nuclear Energy Agency Thermochemical Database project (NEA-TDB) into both programs produced similar results from each program, with UO2F+ predicted to dominate (68%) in a groundwater sample. Natural water samples often contain humic substances. The possible interaction of such substances with uranium was also modelled. The WHAM program includes a discreet site electrostatic humic substance model, however in order to use the PHREEQCI program to model humic substance interactions, a 'model fulvic acid' dataset was added to the program. These models predicted 85 to 98% uranium-humic substance species at neutral pH. This indicates that humic substances do need to be taken into account when modelling uranium speciation in natural water samples.     

Uranium speciation in moorland river water samples: a comparison of experimental results and computer model predictions

An on-line method has been developed for separating inorganic and organic bound uranium species present in river water samples. The method utilised a small chelating resin (Hyphan) column incorporated into the sample introduction manifold of an ICP-MS instrument. The method was evaluated for samples from rivers on Dartmoor (Devon, UK), an area of granite overlain with peat bogs. The results indicate that organic-uranium species form a major proportion (80%) of the total dissolved uranium present. Further work with synthetic water samples indicated that the level of dissolved organic carbon played a greater role in determining the level of organic-uranium species than did sample pH. Computer models for the water samples were constructed using the WHAM program (incorporating uranium data from the Nuclear Energy Agency Thermochemical Database project) in order to predict the levels of organic-uranium species that would form. By varying the proportion of humic and fulvic acids used in the humic component, predictions within 10% of the experimental results were obtained. The program did exhibit a low bias at higher pH values (7.5) and low organic carbon concentrations (0.5 microg ml(-1)), but under the natural conditions prevalent in the Dartmoor water samples, the model predictions were successful.     

The US freshwater supply shortage: Experiences with desalination as part of the solution

Parts of the USA are facing impending shortages of freshwater. One proposed solution is the construction of desalination plants to turn seawater into freshwater. Although seawater desalination plants are widely used in the Middle East, especially Saudi Arabia, there are few desalination plants in the USA. In 2003, Tampa Bay Water built the largest desalination plant in North America. Persistent operating problems and escalating costs have caused the utility to re-evaluate its reliance on the seawater desalination plant as part of a long-term regional water supply strategy. In addition, environmental effects of the plant are uncertain. Advances in reverse osmosis technology have significantly reduced desalination costs. However, desalination of seawater is still more expensive than other freshwater supply sources and demand management measures. With time and research, seawater desalination may prove to be a sustainable, cost-effective source of new freshwater supplies, especially if plants are coupled with renewable energy sources. Until then, the development of small-scale groundwater desalination plants, the re-use of water, water conservation, and a more efficient allocation of water through higher prices and rising block rates will be important strategies in meeting growing water demand. Moreover, it is important to improve the coordination between water supply planning and land use planning as populations continue to increase.