763 research outputs found

    Forests and climate change: adaptation and mitigation

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    ETFRN news No. 50: Forests and Climate Change: adaptation and mitigation. This newsletter contains interesting materials for those who think about the question how to proceed with forests and climate change after Copenhagen, with or without an agreement. Here below are presented some observations from this newsletter: • Adaptation and mitigation are separate issues in the climate discussions, but in forest practice they are two sides of the same coin. • We need forest management directed at the realization of different objectives at the same time, we do not need pure ‘carbon forests’. Not addressing ‘people’ and ‘planet’ considerations is increasingly seen – by both the public and private sector – as a business risk. • Not all countries will be able to comply with REDD rules in the short term. The voluntary carbon market will remain important. • REDD is an opportunity and a risk for local communities. Risks should be made transparent, and open and equal participation by communities in design and decision-making should be promoted • REDD and other forest-based climate change mitigation measures are likely to be low-cost and effective in the short to medium term. Some stakeholders fear that forests may become a too-cheap mitigation option and corrupt the overall climate agreement. In most calculations, however, the costs of developing, operating and managing the institutional system required to produce credible and sustainable forest carbon credits are not internalized in forest carbon prices. If they were, forest carbon prices would become much higher and more realistic. • The role of forests must be clarified and articulated in National Adaptation Programs of Action (NAPAs). At present most political attention and financing is focused on REDD, and, in general, on climate mitigation. Only recently has the concern for the role of forests in adaptation gained ground; this emanates from the growing recognition that climate change will happen anyway. Moreover, climate change will affect the most vulnerable ecosystems and poorer regions. • There is a clear need for harmonization and coherence in the certification market (SFM, and carbon, fair trade etc.). Certification is not necessarily the only credible basis for payment. As illustrated in this issue, mutual trust can be an alternative, particularly for small-scale initiatives that cannot afford the high transaction costs of certification

    Partitioning the impact of environmental drivers and species interactions in dynamic aquatic communities

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    © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Musters, C. J. M., Ieromina, O., Barmentlo, S. H., Hunting, E. R., Schrama, M., Cieraad, E., Vijver, M. G., & van Bodegom, P. M. Partitioning the impact of environmental drivers and species interactions in dynamic aquatic communities. Ecosphere, 10(11), (2019): e02910, doi:10.1002/ecs2.2910.Temperate aquatic communities are highly diverse and seasonally variable, due to internal biotic processes and environmental drivers, including human‐induced stressors. The impact of drivers on species abundance is supposed to differ fundamentally depending on whether populations are experiencing limitations, which may shift over the season. However, an integrated understanding of how drivers structure communities seasonally is currently lacking. In order to partition the effect of drivers, we used random forests to quantify interactions between all taxa and environmental factors using macrofaunal data from 18 agricultural ditches sampled over two years. We found that, over the agricultural season, taxon abundance became increasingly better predicted by the abundances of co‐occurring taxa and nutrients compared to other abiotic factors, including pesticides. Our approach provides fundamental insights in community dynamics and highlights the need to consider changes in species interactions to understand the effects of anthropogenic stressors.The authors are grateful to B. Schaub of Water Board Rijnland for his help, E. Gertenaar for assistance in the fieldwork, M. Wouterse for DOC measurements, and B. Koese for help with taxonomic identification of macrofaunal samples. CM designed the study, did the statistical modeling and analyses, and wrote the draft paper; OI did field sampling and taxonomic identification and constructed the datasets; OI and HB structured the data; EH, MS, ES, MV, and PvB contributed to the study design and the conceptual improvement of the manuscript; all authors substantially revised the subsequent drafts

    Local ecosystem feedbacks and critical transitions in the climate

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    Global and regional climate models, such as those used in IPCC assessments, are the best tools available for climate predictions. Such models typically account for large-scale land-atmosphere feedbacks. However, these models omit local vegetationenvironment 5 feedbacks that are crucial for critical transitions in ecosystems. Here, we reveal the hypothesis that, if the balance of feedbacks is positive at all scales, local vegetation-environment feedbacks may trigger a cascade of amplifying effects, propagating from local to large scale, possibly leading to critical transitions in the largescale climate. We call for linking local ecosystem feedbacks with large-scale land10 atmosphere feedbacks in global and regional climate models in order to yield climate predictions that we are more confident about

    Methane emissions from floodplains in the Amazon Basin: challenges in developing a process-based model for global applications

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    Tropical wetlands are estimated to represent about 50% of the natural wetland methane (CH<sub>4</sub>) emissions and explain a large fraction of the observed CH<sub>4</sub> variability on timescales ranging from glacial–interglacial cycles to the currently observed year-to-year variability. Despite their importance, however, tropical wetlands are poorly represented in global models aiming to predict global CH<sub>4</sub> emissions. This publication documents a first step in the development of a process-based model of CH<sub>4</sub> emissions from tropical floodplains for global applications. For this purpose, the LPX-Bern Dynamic Global Vegetation Model (LPX hereafter) was slightly modified to represent floodplain hydrology, vegetation and associated CH<sub>4</sub> emissions. The extent of tropical floodplains was prescribed using output from the spatially explicit hydrology model PCR-GLOBWB. We introduced new plant functional types (PFTs) that explicitly represent floodplain vegetation. The PFT parameterizations were evaluated against available remote-sensing data sets (GLC2000 land cover and MODIS Net Primary Productivity). Simulated CH<sub>4</sub> flux densities were evaluated against field observations and regional flux inventories. Simulated CH<sub>4</sub> emissions at Amazon Basin scale were compared to model simulations performed in the WETCHIMP intercomparison project. We found that LPX reproduces the average magnitude of observed net CH<sub>4</sub> flux densities for the Amazon Basin. However, the model does not reproduce the variability between sites or between years within a site. Unfortunately, site information is too limited to attest or disprove some model features. At the Amazon Basin scale, our results underline the large uncertainty in the magnitude of wetland CH<sub>4</sub> emissions. Sensitivity analyses gave insights into the main drivers of floodplain CH<sub>4</sub> emission and their associated uncertainties. In particular, uncertainties in floodplain extent (i.e., difference between GLC2000 and PCR-GLOBWB output) modulate the simulated emissions by a factor of about 2. Our best estimates, using PCR-GLOBWB in combination with GLC2000, lead to simulated Amazon-integrated emissions of 44.4 ± 4.8 Tg yr<sup>−1</sup>. Additionally, the LPX emissions are highly sensitive to vegetation distribution. Two simulations with the same mean PFT cover, but different spatial distributions of grasslands within the basin, modulated emissions by about 20%. Correcting the LPX-simulated NPP using MODIS reduces the Amazon emissions by 11.3%. Finally, due to an intrinsic limitation of LPX to account for seasonality in floodplain extent, the model failed to reproduce the full dynamics in CH<sub>4</sub> emissions but we proposed solutions to this issue. The interannual variability (IAV) of the emissions increases by 90% if the IAV in floodplain extent is accounted for, but still remains lower than in most of the WETCHIMP models. While our model includes more mechanisms specific to tropical floodplains, we were unable to reduce the uncertainty in the magnitude of wetland CH<sub>4</sub> emissions of the Amazon Basin. Our results helped identify and prioritize directions towards more accurate estimates of tropical CH<sub>4</sub> emissions, and they stress the need for more research to constrain floodplain CH<sub>4</sub> emissions and their temporal variability, even before including other fundamental mechanisms such as floating macrophytes or lateral water fluxes

    The influence of exposure and physiology on microplastic ingestion by the freshwater fish Rutilus rutilus (roach) in the River Thames, UK

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    Microplastics are widespread throughout aquatic environments. However, there is currently insufficient understanding of the factors influencing ingestion of microplastics by organisms, especially higher predators such as fish. In this study we link ingestion of microplastics by the roach Rutilus rutilus, within the non-tidal part of the River Thames, to exposure and physiological factors. Microplastics were found within the gut contents of roach from six out of seven sampling sites. Of sampled fish, 33% contained at least one microplastic particle. The majority of particles were fibres (75%), with fragments and films also seen (22.7% and 2.3% respectively). Polymers identified were polyethylene, polypropylene and polyester, in addition to a synthetic dye. The maximum number of ingested microplastic particles for individual fish was strongly correlated to exposure (based on distance from the source of the river). Additionally, at a given exposure, the size of fish correlated with the actual quantity of microplastics in the gut. Larger (mainly female) fish were more likely to ingest the maximum possible number of particles than smaller (mainly male) fish. This study is the first to show microplastic ingestion within freshwater fish in the UK and provides valuable new evidence of the factors influencing ingestion that can be used to inform future studies on exposure and hazard of microplastics to fish

    Prevalence and factors associated with musculoskeletal complaints and disability in individuals with brachial plexus injury:a cross-sectional study

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    Purpose (1) To determine the prevalence of musculoskeletal complaints (MSCs) in the non-affected bodily structures in individuals with brachial plexus injury (BPI) and (2) to analyse factors associated with MSCs and disability. Methods Survey among individuals with BPI and a control group. Multivariable logistic and linear regression analyses were used to identify factors associated with MSCs or disability. Results Forty-nine percent of individuals (34/70) with BPI experienced MSC, which was not significantly different from controls (35%, n = 40/113). Complaints were most often located in high back (OR = 3.6) or non-affected limb (OR = 2.2) or neck (OR = 2.1). Greater disability was associated with the presence of MSC in individuals with BPI (OR = 1.1, 95% confidence interval (95% CI) = 1.0; 1.1). Those with no or a low level of education (B = -10.2, 95% CI = -19.6; -1.4), a history of nerve surgery (B = 11.1, 95% CI = -0.2; 20.9), and moderately affected active range of motion (AROM) of the affected limb (B = 20.7, 95% CI = 8.8; 31.0) experienced most disability. Individuals with severely affected AROM showed a wide range of experienced disability. Conclusions Clinicians should be aware that almost half of individuals with BPI have MSCs in the non-affected bodily structures, which was associated with increased disability.</p

    Антибіотикопрофілактика в хірургії

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    Наук. кер.: М.Г. КононенкоГнійно-запальні післяопераційні ускладнення за останні десятиріччя набувають все більшої актуальності. Це вже стає проблемою. Такі ускладнення необхідно попереджувати. Для забезпечення тканин операційного поля антибіотиком у ефективній (бактерицидній) концентрації на весь період хірургічного втручання проводять антибіотикопрофілактику (АБП). Вона є складовою частиною комплексної профілактики гнійно-запальних ускладнень. При цитуванні документа, використовуйте посилання http://essuir.sumdu.edu.ua/handle/123456789/2734

    N deposition and elevated CO2 on methane emissions: Differential responses of indirect effects compared to direct effects through litter chemistry feedbacks

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    Increases in atmospheric CO2 concentration and N deposition are expected to affect methane (CH4) production in soils and emission to the atmosphere, directly through increased plant litter production and indirectly through changes in substrate quality. We examined how CH4 emission responded to changes in litter quality under increased N and CO2, beyond differences in CH4 resulting from changes in litter production. We used senesced leaves from 13C-labeled plants of Molinia caerulea grown at elevated and ambient CO2 and affected by N fertilization to carry out two experiments: a laboratory litter incubation and a pot experiment. N fertilization increased N and decreased C concentrations in litter whereas elevated CO2 decreased litter quality as reflected in litter C and N concentrations and in the composition of lignin and saturated fatty acids within the litter. In contrast to our expectations, CH4 production in the laboratory incubation decreased when using litter from N-fertilized plants as substrate, whereas litter from elevated CO2 had no effect, compared to controls without N and at ambient CO2. Owing to high within-treatment variability in CH4 emissions, none of the treatment effects were reflected in the pot experiment. C mineralization rates were not affected by any of the treatments. The decrease in CH4 emissions due to indirect effects of N availability through litter quality changes (described here for the first time) contrast direct effects of N fertilization on CH4 production. The complex interaction of direct effects with indirect effects of increased N on litter quality may potentially result in a net decrease in CH4 emissions from wetlands in the long term.Fil: Pancotto, Veronica Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Bodegom, P. M. van. University Of Amsterdam; Países BajosFil: Hal, J. van. University Of Amsterdam; Países BajosFil: Logtestijn, R. S. P. van. University Of Amsterdam; Países BajosFil: Blokker, P.. University Of Amsterdam; Países BajosFil: Toet, S.. University Of Amsterdam; Países Bajos. University Of York; Reino UnidoFil: Aerts, R.. University Of Amsterdam; Países Bajo
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