Detection of endangered species is invaluable for conservation efforts, yet many traditional sampling techniques are ineffective at low population abundances or during certain periods of the year. Here, we compared results from a newly developed eDNA approach and the traditional observational method for the endangered pool frog (Pelophylax lessonae). Analysis using an occupancy-modeling framework indicated that the probability of pools being occupied using eDNA (0.93) was higher than for the traditional method of counting calling males and silent observed individuals (0.72). Detailed analysis revealed complementarity among the methods. That is, the traditional method gave a high rate of observation in June, whereas eDNA gave at least as many or more observations during other parts of the year. Discrepancies among the methods depended on the dominant lifecycle stage, and eDNA concentrations were higher when juveniles were present than at times when spawning occurred. eDNA concentrations were also positively related to P. lessonae observations. Our study demonstrates that an eDNA protocol for monitoring of endangered amphibian species can be particularly valuable during periods when individuals are hard to detect by observational methods, and provides guidance to sampling efforts for research and monitoring programs in other regions and systems.
Understanding how long-term abiotic and biotic processes are linked at a landscape level is of major interest for analyzing future impact on humans and the environment from present-day societal planning. This article uses results derived from multidisciplinary work at a coastal site in Sweden, with the aim of describing future landscape development. First, based on current and historical data, we identified climate change, shoreline displacement, and accumulation/erosion processes as the main drivers of landscape development. Second, site-specific information was combined with data from the Scandinavian region to build models that describe how the identified processes may affect the site development through time. Finally, the process models were combined to describe a whole interglacial period. With this article, we show how the landscape and ecosystem boundaries are affected by changing permafrost conditions, peat formation, sedimentation, human land use, and shoreline displacement.Electronic supplementary materialThe online version of this article (doi:10.1007/s13280-013-0407-5) contains supplementary material, which is available to authorized users.
Abstract. Global warming is expected to be most pronounced in the Arctic where permafrost thaw and release of old carbon may provide an important feedback mechanism to the climate system. To better understand and predict climate effects and feedbacks on the cycling of elements within and between ecosystems in northern latitude landscapes, a thorough understanding of the processes related to transport and cycling of elements is required. A fundamental requirement to reach a better process understanding is to have access to high-quality empirical data on chemical concentrations and biotic properties for a wide range of ecosystem domains and functional units (abiotic and biotic pools). The aim of this study is therefore to make one of the most extensive field data sets from a periglacial catchment readily available that can be used both to describe present-day periglacial processes and to improve predictions of the future. Here we present the sampling and analytical methods, field and laboratory equipment and the resulting biogeochemical data from a state-of-the-art whole-ecosystem investigation of the terrestrial and aquatic parts of a lake catchment in the Kangerlussuaq region, West Greenland. This data set allows for the calculation of whole-ecosystem mass balance budgets for a long list of elements, including carbon, nutrients and major and trace metals. The data set is freely available and can be downloaded from PANGAEA:
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