Avian responses to an emergent,wetland weed

African boxthorn (Lycium ferocissimum Solanaceae) is a Weed of National Significance in Australia. It is particularly problematic in Victoria and is thought to not only threaten native wildlife but also provide important habitat, particularly to birds, when there is no native alternative. In a wetland ecosystem such as a saltmarsh, boxthorn has the potential to increase structural complexity because it can stand as an emergent above surrounding vegetation. We compared bird assemblages and behaviour in saltmarsh vegetation with and without boxthorn in a coastal wetland in south‐east Australia. Species assemblage, but not richness, changed with the presence of boxthorn. The presence of singing honeyeaters (Lichenostomus virescens) and white‐fronted chats (Epthianura albifrons), the two most common native bird species (based on numerical and spatial dominance), appeared to drive these differences; singing honeyeaters preferred boxthorn while white‐fronted chats avoided it. The presence of boxthorn increased the seasonal availability of fruit and flowers, which was reflected by a high frequency of foraging for fruit and nectar where boxthorn was present. In saltmarshes without boxthorn, there was a higher frequency of foraging for insects. Some, but not all, species responded to increased structural complexity and fruit/floral resources provided by boxthorn. Consequently, management by reducing boxthorn is likely to alter bird communities and the usage of sites by some native species, thus management success should consider fine‐scale biodiversity objectives, such as managing for particular types or species of birds.     

Management of ecosystem services in mountain forests: Review of indicators and value functions for model based multi-criteria decision analysis

The main ecosystem services (ES) central European mountain forests provide are: protection against gravitational hazards, timber production, recreation, biodiversity conservation and carbon storage, which are all in high demand. These demands make managing mountain forests a challenging task, involving manifold synergies and conflicts between the different ES. There is therefore an urgent need for appropriate concepts and tools for support decisions in forest management and planning (FMP) to take into consideration all ES and to manage the wide variety of information types, parameters and uncertainties involved in assessing the sustainability of ES. Multi-criteria decision analysis (MCDA) provides a suitable set of methods for sustainability evaluations. In this study sustainability means the persistent fulfilment of the required ES. To address all the phases of the FMP process, MCDA and forest models should be applied together, with indicators providing the main interfaces to combine them. This paper aims to: i) review assessment approaches in order to select appropriate and widely accepted indicators for measuring and assessing the effects of different silvicultural management alternatives on forest ES, and ii) present additional standardisation approaches (value functions) for each indicator. Standardisations are necessary to make the different ES comparable and to study synergies and trade-offs between different management objectives in MCDA. The main ES in central European mountain regions are considered, with a clear focus on those indicators that are directly derivable from forest model outputs and that can refer to sustainable forest management practices. The scales considered are that of the single forest stand and of the larger forest management unit. A holistic indicator-based analysis framework for FMP in mountain forests can be built using the indicators and value functions described. The influence of different management alternatives on ES can then be evaluated, taking into consideration the instruments and information on forest management (forest models, inventory) available. All indicators are selected according to existing and approved approaches that only require data that is normally available in operational forest management. The framework can thus be an important element in developing a decision support system for FMP in mountain forests.     

Livestock-driven land use change to model species distributions: Egyptian vulture as a case study

Species distribution models (SDMs) are increasingly used to predict species ranges and their shifts under future scenarios of global environmental change (GEC). SDMs are thus incorporating key drivers of GEC (e.g. climate, land use) to improve predictions of species’ habitat suitability (i.e. as an indicator of species occurrence). Yet, most SDMs incorporating land use only consider dominant land cover types, largely ignoring other key aspects of land use such as land management intensity and livestock. We developed SDMs including main land use components (i.e. land cover, livestock and its management intensity) to assess their relative importance in shaping habitat suitability for the Egyptian vulture, an endangered raptor linked to livestock presence. We modelled current and future (2020 and 2050) habitat suitability for this vulture using an organism-centred approach. This allowed us to account for basic species’ habitat needs (i.e. nesting cliff) while gaining insight into our variables of interest (i.e. livestock and land cover). Once nest-site requirements were fulfilled, land use variables (i.e. openland and sheep and goat density) were the main factors determining species’ habitat suitability. Current suitable area could decrease by up to 6.81% by 2050 under scenarios with rapid economic growth but no focus on environmental conservation and rural development. Local solutions to environmental sustainability and rural development could double current habitat suitability by 2050. Land use is expected to play a key role in determining Egyptian vulture's distribution through land cover change but also through changes in livestock management (i.e. species and stocking density). Change in stocking densities (sheep and goats/km²) becomes thus an indicator of habitat suitability for this vulture in our study area. Abandonment of agro-pastoral practises (i.e. below ∼15–20 sheep and goats/km²) will negatively influence the species distribution. Nonetheless, livestock densities above these values will not further increase habitat suitability. Given the widespread impacts of livestock on ecosystems, the role of livestock and its management intensity in SDMs for other (non-livestock-related) species should be further explored.     

Monitoring the natural attenuation of a sewage sludge toxicity using the Allium cepa test

Appropriate final disposal of sewage sludge (SS) generated by wastewater treatment plants (WWTP) has been considered a serious environmental problem, but also a viable alternative to be applied in agriculture, once SS is rich in organic matter and nutrients. However, SS can be a source of contamination of several toxic agents. Therefore, its use in agriculture requires special care to avoid possible damage to the environment and exposed organisms. Detoxification of toxic wastes can be performed using the monitored natural attenuation, which involves biological, physical and chemical processes that frequently occur in the environment. This study aimed to assess the feasibility of decontaminating SS after different periods of monitored natural attenuation. To this end, samples of SS and associations of soil/SS with proportions of 10, 25 and 50% SS were buried for 0, 2, 6 and 12 months in holes prepared in a place free of contamination. Allium cepa was used as an indicator to assess the efficiency of the natural attenuation process. According to chemical analysis, the SS samples presented a high concentration of m- and p-cresol, especially for samples analyzed after 0 or 2 months of natural attenuation. The microorganisms present in the SS belonged to 17 different genera of bacteria, which varied in the microbial composition among samples. Both, raw SS and aqueous SS extracts induced DNA damage in A. cepa, even when associated with soil. However, this effect was observed to decline during the attenuation period, although significant effects were detected for the highest tested concentration (100% SS) even at the end of this process. These results thus indicated the necessity of applying a stabilization process associating SS and soil for a period of at least 12 months and showed that the studied raw SS is not a viable material for use as a soil reconditioner, even after natural attenuation. A. cepa test proved to be a useful tool to assess the efficiency of SS detoxification process. Therefore, we suggest that the application of SS in agriculture should be approached with caution and that the SS must be previously submitted to methodologies that evaluate its toxic potential.     

Long‐term temporal and spatial trends in eutrophication status of the Baltic Sea

Much of the Baltic Sea is currently classified as ‘affected by eutrophication’. The causes for this are twofold. First, current levels of nutrient inputs (nitrogen and phosphorus) from human activities exceed the natural processing capacity with an accumulation of nutrients in the Baltic Sea over the last 50–100 years. Secondly, the Baltic Sea is naturally susceptible to nutrient enrichment due to a combination of long retention times and stratification restricting ventilation of deep waters. Here, based on a unique data set collated from research activities and long‐term monitoring programs, we report on the temporal and spatial trends of eutrophication status for the open Baltic Sea over a 112‐year period using the HELCOM Eutrophication Assessment Tool (HEAT 3.0). Further, we analyse variation in the confidence of the eutrophication status assessment based on a systematic quantitative approach using coefficients of variation in the observations. The classifications in our assessment indicate that the first signs of eutrophication emerged in the mid‐1950s and the central parts of the Baltic Sea changed from being unaffected by eutrophication to being affected. We document improvements in eutrophication status that are direct consequences of long‐term efforts to reduce the inputs of nutrients. The reductions in both nitrogen and phosphorus loads have led to large‐scale alleviation of eutrophication and to a healthier Baltic Sea. Reduced confidence in our assessment is seen more recently due to reductions in the scope of monitoring programs. Our study sets a baseline for implementation of the ecosystem‐based management strategies and policies currently in place including the EU Marine Strategy Framework Directives and the HELCOM Baltic Sea Action Plan.     

Commercial harvest and export of snapping turtles (Chelydra serpentina) in the United States: trends and the efficacy of size limits at reducing harvest

As Asian turtle populations have crashed, China has increasingly turned to international import to meet domestic demand, which has increased pressure on global turtle populations. Snapping turtles (Chelydra serpentina) are being harvested in unprecedented numbers in the United States (US) to meet the needs of this international market. Here we report US snapping turtle live export from 1999 to 2013, and for the first time test the effectiveness of size limits in reducing commercial harvest numbers. Over three million live snapping turtles from farm and wild caught stock were exported from the US to Asia in 2012–14 alone. Increases in the export of wild caught snapping turtles to over 200,000 individuals in 2012 and 2014, compared to under 50,000 in other years, may indicate that farms are becoming unable to keep up with increasing demand. Annual harvest pressure at the state level increased linearly from 1998 to 2013, mirroring trends in federal export over the same time period. Our model estimates that size-limits were effective at reducing harvest by 30–87% in years with high harvest pressure. However, the majority of size limit regulations result in the removal of larger breeding adults, which has been shown to be detrimental to long term population viability. Regulatory approaches dedicated to the long term management of this iconic species will need to balance the short term gains, in the form of reduced harvest rates, with long term population viability.     

Assessment of Data Quality: Errors of Measurement and Errors of Process

As projects progress from pilot studies with few simple variables and small samples, the research process as a whole becomes qualitatively more complex and subject to an array of contamination by errors and mistakes. Data usually undergo a series of manipulations (e.g., recording, computer entry, transmission) prior to final statistical analysis. The process, then, consists of numerous operations only ending with eventual statistical analysis and write-up. We present a means of estimating the impact of process error in the same terms as psychometric reliability and discuss the implications for reducing the impact of errors on overall data quality.     

A structured decision making analysis to increase a Red-cockaded Woodpecker population and balance stakeholder objectives for a National Forest

Longleaf pine (Pinus palustris) savanna is a biodiverse ecosystem native to the southeastern United States. Due to fire suppression and timber harvest, longleaf pine has declined to 3% of its original range. The extant forest provides habitat for many threatened and endangered species, including the endangered Red-cockaded Woodpecker (Picoides borealis; RCW), a cavity-nesting bird that co-evolved with fire-maintained forest, resulting in savanna-like old-growth forest as the bird’s preferred habitat. Our study site, the Oakmulgee Ranger District of the Talladega National Forest, harbors the largest RCW population in Alabama and is managed with an emphasis on RCW conservation. The United States Forest Service (USFS) also manages the Oakmulgee for uses such as wildlife conservation, recreation, and timber harvest. Despite efforts to restore RCW habitat and install artificial cavities in the Oakmulgee, the number of RCW groups has not exceeded 123, although the Recovery Plan objective is 394 groups. Our project was motivated by the USFS expressing interest in determining why the RCW population has not exceeded 123 groups. We proposed using structured decision making (SDM) with the USFS and other stakeholders to address this problem. Our goals were to explicitly define management objectives, build a Bayesian belief network with a model of how decision alternatives are believed to affect management objectives, and use a sensitivity analysis to determine the part of the model to which RCW population growth was most sensitive. Therefore, results from the analysis were expected to give insights into 1) ecological factors limiting RCW population growth, 2) how management can overcome these limits, plus 3) the relative expected ability of different decision alternatives to satisfy multiple objectives in addition to increasing RCW group number. We held four SDM workshops with representatives from the USFS, the Animal and Plant Health Inspection Service, the Longleaf Alliance, the Birmingham Audubon Society, and local residents. Stakeholder objectives consisted of maximizing the following: RCW group number, forest health, recreational enjoyment, community economic health, and aesthetics. Cavity insert installation had the greatest probability of increasing the number of RCW groups. The number of RCW groups was most affected by cavity availability, adult survival, reproductive output, food availability, and herbaceous understory. Prescribed burning was most likely to meet the combination of stakeholder objectives, followed by midstory removal. Our findings suggest that cavity installation efforts may need to be increased in the Oakmulgee to increase RCW group number. Also it could be beneficial to investigate how RCWs select cavity tree locations with the goal of increasing the chance that RCWs use artificial cavities to form new groups. The Bayesian belief network provided insights into factors limiting RCW population growth and how management can overcome these limits. The Bayesian belief network also can be used to prioritize management methods in the Oakmulgee given stakeholder objectives and time constraints.