Quantifying population declines based on presence‐only records for red‐list assessments

Accurate trend estimates are necessary for understanding which species are declining and which are most in need of conservation action. Imperfect species detection may result in unreliable trend estimates because this may lead to the overestimation of declines. Because many management decisions are based on population trend estimates, such biases could have severe consequences for conservation policy. We used an occupancy‐modeling framework to estimate detectability and calculate nationwide population trends for 14 Swiss amphibian species both accounting for and ignoring imperfect detection. Through the application of International Union for Conservation of Nature Red List criteria to the different trend estimates, we assessed whether ignoring imperfect detection could affect conservation policy. Imperfect detection occurred for all species and detection varied substantially among species, which led to the overestimation of population declines when detectability was ignored. Consequently, accounting for imperfect detection lowered the red‐list risk category for 5 of the 14 species assessed. We demonstrate that failing to consider species detectability can have serious consequences for species management and that occupancy modeling provides a flexible framework to account for observation bias and improve assessments of conservation status. A problem inherent to most historical records is that they contain presence‐only data from which only relative declines can be estimated. A move toward the routine recording of nonobservation and absence data is essential if conservation practitioners are to move beyond this toward accurate population trend estimation.     

Project house water: a novel interdisciplinary framework to assess the environmental and socioeconomic consequences of flood-related impacts

Protecting our water resources in terms of quality and quantity is considered one of the big challenges of the twenty-first century, which requires global and multidisciplinary solutions. A specific threat to water resources, in particular, is the increased occurrence and frequency of flood events due to climate change which has significant environmental and socioeconomic impacts. In addition to climate change, flooding (or subsequent erosion and run-off) may be exacerbated by, or result from, land use activities, obstruction of waterways, or urbanization of floodplains, as well as mining and other anthropogenic activities that alter natural flow regimes. Climate change and other anthropogenic induced flood events threaten the quantity of water as well as the quality of ecosystems and associated aquatic life. The quality of water can be significantly reduced through the unintentional distribution of pollutants, damage of infrastructure, and distribution of sediments and suspended materials during flood events. To understand and predict how flood events and associated distribution of pollutants may impact ecosystem and human health, as well as infrastructure, large-scale interdisciplinary collaborative efforts are required, which involve ecotoxicologists, hydrologists, chemists, geoscientists, water engineers, and socioeconomists. The research network “project house water” consists of a number of experts from a wide range of disciplines and was established to improve our current understanding of flood events and associated societal and environmental impacts. The concept of project house and similar seed fund and boost fund projects was established by the RWTH Aachen University within the framework of the German excellence initiative with support of the German research foundation (DFG) to promote and fund interdisciplinary research projects and provide a platform for scientists to collaborate on innovative, challenging research. Project house water consists of six proof-of-concept studies in very diverse and interdisciplinary areas of research (ecotoxicology, water, and chemical process engineering, geography, sociology, economy). The goal is to promote and foster high-quality research in the areas of water research and flood-risk assessments that combine and build off-laboratory experiments with modeling, monitoring, and surveys, as well as the use of applied methods and techniques across a variety of disciplines.     

Spectroscopic study of organic coatings on fine particles,exposed to ozone and simulated sunlight

This work intends to quantify the variation in optical properties of aerosol by in-situ spectroscopic monitoring the ozonolysis of a mixture of typical biomass burning compounds. The reaction occurs on silica and glass particles in the presence of simulated sunlight.Fused silica particles (Aerosil) were coated with a thin film of a 1:1 mixure of 4-phenoxyphenol with 4-carboxyphenone as a photosensitizer. UV–VIS spectra of dichloromethane extracts from the particles recorded before and after treatment, show development of a new band after prolonged ozone and light exposure.Changes in optical properties are reported, and variations of spectroscopic features are discussed. We show that the ozone-induced heterogeneous photochemical reaction does produce species absorbing light in the solar spectral range. Further, we demonstrate that the heterogeneous photosensitized reactions at 200 ppb ozone (strongly ozone polluted regions) for a time period of 7 h aging process, can increase light absorption of atmospheric aerosols in the tropospheric actinic window (>290 nm) by 0.4 absorption units ng-C^?1 O₃ ppm^?1 in the region 290–358 nm and by 1.0 absorption units ng-C^?1 O₃ ppm^?1 in the region 360–448 nm.Chemical changes of such surface films were identified by diffuse reflectance infrared Fourier transform spectroscopy of coated glass spheres, and we suggest formation of humic-like substances comparable to those reported in continental aerosol.     

Limitations for heavy metal release during thermo-chemical treatment of sewage sludge ash

Phosphate recycling from sewage sludge can be achieved by heavy metal removal from sewage sludge ash (SSA) producing a fertilizer product: mixing SSA with chloride and treating this mixture (eventually after granulation) in a rotary kiln at 1000 ± 100 °C leads to the formation of volatile heavy metal compounds that evaporate and to P-phases with high bio-availability. Due to economical and ecological reasons, it is necessary to reduce the energy consumption of this technology. Generally, fluidized bed reactors are characterized by high heat and mass transfer and thus promise the saving of energy. Therefore, a rotary reactor and a fluidized bed reactor (both laboratory-scale and operated in batch mode) are used for the treatment of granulates containing SSA and CaCl₂. Treatment temperature, residence time and - in case of the fluidized bed reactor - superficial velocity are varied between 800 and 900 °C, 10 and 30 min and 3.4 and 4.6 m s⁻¹. Cd and Pb can be removed well (>95 %) in all experiments. Cu removal ranges from 25% to 84%, for Zn 75-90% are realized. The amount of heavy metals removed increases with increasing temperature and residence time which is most pronounced for Cu.In the pellet, three major reactions occur: formation of HCl and Cl₂ from CaCl₂; diffusion and reaction of these gases with heavy metal compounds; side reactions from heavy metal compounds with matrix material. Although, heat and mass transfer are higher in the fluidized bed reactor, Pb and Zn removal is slightly better in the rotary reactor. This is due the accelerated migration of formed HCl and Cl₂ out of the pellets into the reactor atmosphere. Cu is apparently limited by the diffusion of its chloride thus the removal is higher in the fluidized bed unit.     

Quantitative recommendations for amphibian terrestrial habitat conservation derived from habitat selection behavior

Conservation scientists have noted that conservation managers rarely use scientific information when making decisions. One of the reasons why managers rarely use scientific information may be that conservation scientists rarely provide their knowledge in a way that can directly be used by conservation practitioners. Here we show how quantitative recommendations for conservation can be derived. Previous research on terrestrial habitat selection behavior of toads (Bufo bufo and Bufo viridis) showed that wood deposits are a key resource in the terrestrial habitat. We used habitat-dependence analysis to estimate the amount of this key resource, wood deposits, that individual toads require. Based on these estimates we then quantify the requirements for wood deposits for a population. Additionally, we quantified the area that a population requires. Although wood deposits vary strongly in size, we found little evidence for size preferences: only one species preferred smallest sizes of wood deposits. We report all the estimates in a way that can be directly used by conservation managers. Habitat-dependence analysis is a simple and useful tool to quantify habitat requirements. Provisioning of wood deposits may improve the quality of terrestrial habitat for amphibians. Thereby, managers may increase the carrying capacity of terrestrial habitats and support elevated population densities.