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We analysed the responses of 11 ecosystem models to elevated atmospheric [CO2] (eCO2) at two temperate forest ecosystems (Duke and Oak Ridge National Laboratory (ORNL) Free-Air CO2 Enrichment (FACE) experiments) to test alternative representations of carbon (C)–nitrogen (N) cycle processes. * We decomposed the model responses into component processes affecting the response to eCO2 and confronted these with observations from the FACE experiments. * Most of the models reproduced the observed initial enhancement of net primary production (NPP) at both sites, but none was able to simulate both the sustained 10-yr enhancement at Duke and the declining response at ORNL: models generally showed signs of progressive N limitation as a result of lower than observed plant N uptake. Nonetheless, many models showed qualitative agreement with observed component processes. The results suggest that improved representation of above-ground–below-ground interactions and better constraints on plant stoichiometry are important for a predictive understanding of eCO2 effects. Improved accuracy of soil organic matter inventories is pivotal to reduce uncertainty in the observed C–N budgets. * The two FACE experiments are insufficient to fully constrain terrestrial responses to eCO2, given the complexity of factors leading to the observed diverging trends, and the consequential inability of the models to explain these trends. Nevertheless, the ecosystem models were able to capture important features of the experiments, lending some support to their projections.

Previous paleolimnological studies demonstrated that the sediments of Garba Guracha, situated at 3950 m asl in the afro-alpine zone of the Bale Mountains of Ethiopia, provide a complete Late Glacial and Holocene paleoclimate and environmental archive. We revisited Garba Guracha in order to retrieve new sediment cores and to apply new environmental proxies, e.g. charcoal, diatoms, biomarkers, and stable isotopes. Our chronology is established using 210Pb dating and radiocarbon dating of bulk sedimentary organic matter, bulk n-alkanes, and charcoal. Although bedrock was not reached during coring, basal ages confirm that sedimentation started at the earliest ~ 16 cal kyr BP. The absence of a systematic age offset for the n-alkanes suggests that “pre-aging” is not a prominent issue in this lake, which is characterised by a very small afro-alpine catchment. X-ray fluorescence scans and total organic carbon contents show a prominent transition from minerogenic to organic-rich sediments around 11 cal kyr BP coinciding with the Holocene onset. While an unambiguous terrestrial versus aquatic source identification seems challenging, the n-alkane-based Paq proxy, TOC/N ratios, δ13C values, and the sugar biomarker patterns suggest a predominantly autochthonous organic matter source. Supraregional climate events, such as the African Humid Period, the Younger Dryas (YD), a 6.5 cal kyr BP short drying event, and the 4.2 cal kyr BP transition to overall drier climate are recorded in our archive. The Garba Guracha record suggests that northern hemisphere forcings played a role in the Eastern African highland paleoclimate.

To resolve the various types of biological ice nuclei (IN) with atmospheric models, an extension of the empirical parameterization (EP) (Phillips et al. 2008; 2013) is proposed to predict the active IN from multiple groups of primary biological aerosol particles (PBAPs). Our approach is to utilize coincident observations of PBAP sizes, concentrations, biological composition, and ice-nucleating ability. The parameterization organizes the PBAPs into five basic groups: fungal spores, bacteria, pollen, viral particles, plant/animal detritus, algae, and their respective fragments. This new biological component of the EP was constructed by fitting predicted concentrations of PBAP IN to those observed at the Amazon Tall Tower Observatory (ATTO) site located in the central Amazon. The fitting parameters for pollen and viral particles, plant/animal detritus, which are much less active as IN than fungal and bacterial groups, are constrained based on their ice nucleation activity from the literature. The parameterization has empirically derived dependencies on the surface area of each group (except algae), and the effects of variability in their mean sizes and number concentrations are represented via their influences on the surface area. The concentration of active algal IN is estimated from literature-based measurements.Predictions of this new biological component of the EP are consistent with previous laboratory and field observations not used in its construction. The EP scheme was implemented in a 0D parcel model. It confirms that biological IN account for most of the total IN activation at temperatures warmer than −20°C and at colder temperatures dust and soot become increasingly more important to ice nucleation.

The use of remote sensing in natural resource management is an easily accessible input for obtaining detailed information on the ground and landscape. There is a wide range of procedures to analyze the forest canopy through satellite images. The purpose of this work is to obtain a map of forest opening with remote sensing by relating several vegetation indices, Kauth-Thomas transformation and texture filters, to a Landsat 8OLI image. A factor analysis was made to evaluate the contribution of these variable to identify the opening of the forest cover, yielding a σ2 = 76%. The results show that the Modified Soil Adjusted Vegetation Index (MSAVI), Soil Adjusted Vegetation Index (SAVI), and brightness factor have the best correlation (0.225-0.216 component coefficient). The resulting model was reclassified into five categories of forest opening and associated with land use data from the National Institute of Statistics and Geography (INEGI-México). Thus, 95% of human settlements have a canopy opening between medium and very high, the crops areas 72%, and the low deciduous forest with secondary shrub vegetation 100% of the opening. Coniferous and mixed forests have a low to very low canopy opening 46% and 55%, respectively of their surface. The forests with secondary vegetation, both shrub and arboreal, present greater openness than the same forests in the primary state. Verification of the spatial representation data of canopy opening was made by comparing 94 hemispheric photographs with 94 sites located in open areas obtaining an r = 0.57. This work offers a simple and straightforward methodology, easily replicable in different types of vegetation using free satellite imagery. Hence, it is a helpful tool for decision-makers when considering the general status of conservation of forest systems and their spatial distribution.

Abstract During the Last Glacial Maximum (LGM), valley glaciers in the Bavarian/Bohemian Forest mountains (Central Europe) reached their maximum extent, forming prominent terminal moraines. In this study, we provide the timing for the terminal moraine complex in the south-facing Großer Schwarzbach Valley using in situ produced cosmogenic 10 Be dating. The moraine complex was deposited during the onset of the LGM, as indicated by the weighted mean exposure age of 25.7 ± 1.1 ka. This age represents the oldest cosmogenic data obtained for terminal moraine ridges in the Bavarian/Bohemian Forest. It is also older than the dated LGM moraines in other Central European Variscan ranges. In the Bavarian/Bohemian Forest, the age suggests an asynchronous stabilization of LGM moraines across the mountain range, which we attribute to differences in insolation of north- and south-facing sites. Additionally, the youngest preserved moraine, located at the mouth of the cirque, was deposited around 16.2 ± 0.6 ka.

The article presents the results of the analysis of the surface water quality changes in selected rural catchments in the Czech Republic. Three river basins are used as examples - the Blšanka, Loučka and Olšava river basins. These river basins have been facing long-term problems with surface water quality and, as in many similar rural areas there has been lack of information on water quality changes. The areas are located in regions with different physiogeographical characteristics as well as the varying scope and intensity of socio-economic activities. Individual catchments show a range of similar aspects associated with the distribution of pollution load and trends of the surface water quality. However, at the same time, many differences in the dynamics of trends of changes in water quality development exist. In spite of the fact that the crucial problems concerning the surface water pollution are similar, they differ in the characteristics of time changes in water quality as well as in the spatial distribution of load within the water basin. Due to the low average discharges of all recipients, both local municipal and industrial point sources of pollution play significant roles there however they are scarce. Considering the majority of basic indicators, long-term negative trends concerning the water quality development are observed in all assessed river basins. This trend, typical for many rural areas is opposite to the water quality development at the main river courses. Moreover, because of continuing intensive load from the non-point sources no significant improvement in water quality can be expected in the near future. The adoption of effective measures is currently hindered in part by the deferral of the application of the European legislation in the area of the construction of waste water treatment plants at middle-sized and small-sized settlements.

Aim Many species are currently expanding their ranges in response to climate change, but the mechanisms underlying these range expansions are in many cases poorly understood. In this paper we explore potential climatic factors governing the recent establishment of new palm populations far to the north of any other viable palm population in the world.Location Southern Switzerland, Europe, Asia and the world.Methods We identified ecological threshold values for the target species, Trachycarpus fortunei, based on gridded climate data, altitude and distributional records from the native range and applied them to the introduced range using local field monitoring and measured meteorological data as well as a bioclimatic model.Results We identified a strong relationship between minimum winter temperatures, influenced by growing season length and the distribution of the palm in its native range. Recent climate change strongly coincides with the palm's recent spread into southern Switzerland, which is in concert with the expansion of the global range of palms across various continents.Main conclusions Our results strongly suggest that the expansion of palms into (semi‐)natural forests is driven by changes in winter temperature and growing season length and not by delayed population expansion. This implies that this rapid expansion is likely to continue in the future under a warming climate. Palms in general, and T. fortunei in particular, are significant bioindicators across continents for present‐day climate change and reflect a global signal towards warmer conditions.

Introduction Land use intensification and urbanisation processes are degrading hydrological ecosystem services in the Guapi-Macacu watershed of Rio de Janeiro. A proposal to pay farmers to restore natural watershed services might be an alternative to securing the water supply in the long-term for the around 2.5 million urban water users in the study region. This study quantifies the costs of changing current land use patterns to enhance watershed services and compares these costs to the avoided costs associated with water treatment for public supply. Methods We use farm-household data to estimate the opportunity costs of abandoning current land uses for the recovery of natural vegetation; a process that is very likely to improve water quality in terms of turbidity due to reduced inputs from erosion. Opportunity cost estimates are extrapolated to the watershed scale based on remote sensing land use classifications and vulnerability analysis to identify priority zones for watershed management interventions. To assess the potential demand for watershed services, we analyse water quality and treatment cost data from the main local water treatment plant. Results Changing agricultural land uses for watershed services provision generally comes at high opportunity costs in our study area near to the metropolis of Rio de Janeiro. Alternative low cost watershed conservation options do exist in the livestock production sector. These options have the potential to directly reduce the amount of sediments and nutrients reaching the water bodies, and in turn decrease the costs of treatment needed for drinking water. Land cover changes at the scale needed to improve water quality will, nonetheless, likely exceed the cost of additional investments in water treatment. Conclusions The state water utility company's willingness to pay for watershed services alone will not be enough to induce provision of additional watershed services. We conclude that monetary incentives conditioned on specific adjustments to existing production systems could still have a complementary role to play in improving watershed services. However, we note that our willingness to pay analysis focusses on only one of the potentially wide range of ecosystem services provided by natural vegetation in the Guapi-Macacu watershed. Factoring these ecosystem services into the willingness to pay equation is likely to change our assessment in favour of additional conservation action, be it through PES or other policy instruments.

Monitoring of permafrost has been ongoing since 1978 in the Abisko area, northernmost Sweden, when measurements of active layer thickness started. In 1980, boreholes were drilled in three mires in the area to record permafrost temperatures. Recordings were made twice per year, and the last data were obtained in 2002. During the International Polar Year (2007–2008), new boreholes were drilled within the ‘Back to the Future’ (BTF) and ‘Thermal State of Permafrost’ (TSP) projects that enabled year-round temperature monitoring. Mean annual ground temperatures (MAGT) in the mires are close to 0°C, ranging from -0.16 to -0.47°C at 5 m depth. Data from the boreholes show increasing ground temperatures in the upper and lower part by 0.4 to 1°C between 1980 and 2002. At one mire, permafrost thickness has decreased from 15 m in 1980 to ca. 9 m in 2009, with an accelerating thawing trend during the last decade.

The authors wish to express their sincere appreciation to Prof. Konrad Rydzyński from the Nofer Institute of Occupational Medicine in Lodz, Prof. Richard Robarts from the UNEP Global Environment Monitoring System (GEMS)/Water Programme, Prof. Paul DuBowy from the U.S. Army Corps of Engineers, and Prof. David Harper from the Department of Biology, the University of Leicester for their constructive comments on an earlier version of this paper. The authors also wish to acknowledge the research team of the Nofer Institute of Occupational Medicine in Lodz: Dr Danuta Ligocka and Dr Wiktor Wesołowski for their assistance during the laboratory processes. The research was supported by the following projects of the Polish Ministry of Science and Higher Education: – N N305 365738 “Analysis of point sources pollution of nutrients, dioxins and dioxin-like compounds in the Pilica River catchment and draw up of reclamation methods”; – 2PO4 G08830 “Accumulation of dioxins and dioxin-like pollutants in the food chain of the Sulejowski and Włocławski Reservoirs: chemometric analysis and toxicological estimation”.