64 research outputs found

    Individual tree and stand-level carbon and nutrient contents across one rotation of loblolly pine plantations on a reclaimed surface mine

    Get PDF
    While reclaimed loblolly pine (Pinus taeda L.) plantations in east Texas, USA have demonstrated similar aboveground productivity levels relative to unmined forests, there is interest in assessing carbon (C) and nutrients in aboveground components of reclaimed trees. Numerous studies have previously documented aboveground biomass, C, and nutrient contents in loblolly pine plantations; however, similar data have not been collected on mined lands. We investigated C, N, P, K, Ca, and Mg aboveground contents for first-rotation loblolly pine growing on reclaimed mined lands in the Gulf Coastal Plain over a 32-year chronosequence and correlated elemental rates to stand age, stem growth, and similar data for unmined lands. At the individual tree level, we evaluated elemental contents in aboveground biomass components using tree size, age, and site index as predictor variables. At the stand-level, we then scaled individual tree C and nutrients and fit a model to determine the sensitivity of aboveground elemental contents to stand age and site index. Our data suggest that aboveground C and nutrients in loblolly pine on mined lands exceed or follow similar trends to data for unmined pine plantations derived from the literature. Diameter and height were the best predictors of individual tree stem C and nutrient contents (R ≥ 0.9473 and 0.9280, respectively) followed by stand age (R ≥ 0.8660). Foliage produced weaker relationships across all predictor variables compared to stem, though still significant (P ≤ 0.05). The model for estimating stand-level C and nutrients using stand age provided a good fit, indicating that contents aggrade over time predictably. Results of this study show successful modelling of reclaimed loblolly pine aboveground C and nutrients, and suggest elemental cycling is comparable to unmined lands, thus providing applicability of our model to related systems

    Yield-scaled mitigation of ammonia emission from N fertilization: the Spanish case

    Get PDF
    Online supplementary data available from stacks.iop.org/ERL/9/125005/mmedia[EN] Synthetic nitrogen (N) fertilizer and field application of livestock manure are the major sources of ammonia (NH3) volatilization. This N loss may decrease crop productivity and subsequent deposition promotes environmental problems associated with soil acidification and eutrophication. Mitigation measures may have associated side effects such as decreased crop productivity (e.g. if N fertilizer application is reduced), or the release of other reactive N compounds (e.g. N2O emissions if manure is incorporated). Here, we present a novel methodology to provide an integrated assessment of the best strategies to abate NH3 from N applications to crops. Using scenario analyses, we assessed the potential of 11 mitigation measures to reduce NH3 volatilization while accounting for their side effects on crop productivity, N use efficiency (NUE) and N surplus (used as an indicator of potential N losses by denitrification/nitrification and NO3 − leaching/run-off). Spain, including its 48 provinces, was selected as a case study as it is the third major producer of agricultural goods in Europe, and also the European country with the highest increase in NH3 emissions from 1990 to 2011. Mitigation scenarios comprised of individual measures and combinations of strategies were evaluated at a country- and regional level. Compared to the reference situation of standard practices for the year 2008, implementation of the most effective region-specific mitigation strategy led to 63% NH3 mitigation at the country level. Implementation of a single strategy for all regions reduced NH3 by 57% at the highest. Strategies that involved combining mitigation measures produced the largest NH3 abatement in all cases, with an 80% reduction in some regions. Among the strategies analyzed, only suppression of urea application combined with manure incorporation and incorporation of N synthetic fertilizers other than urea showed a fully beneficial situation: yieldscaled NH3 emissions were reduced by 82%, N surplus was reduced by 9%, NUE was increased by 19% and yield was around 98% that of the reference situation. This study shows that the adoption of viable measures may provide an opportunity for countries like Spain to meet the international agreements on NH3 mitigation, while maintaining crop yields and increasing NUEThe authors are grateful to the Spanish Ministry of Science and Innovation and the Autonomous Community of Madrid for their economic support through the NEREA project (AGL2012-37815- C05-01, AGL2012-37815-C05-04) and GASPORC (AGL2011-30023-C03) projects. We wish to thank the FIRE (Federation Ile de France de Recherche en Environment, CNRS and UPMC) as well as the Agrisost Project (S2009/AGR-1630). Eduardo Aguilera gratefully acknowledges funding by the 895-2011-1020 project (Canadian Social Sciences and Humanities Research Council). This paper has been produced within the context of the REMEDIA network (http://redremedia.wordpress.com).Sanz-Cobeña, A.; Lassaletta, L.; Estellés, F.; Del Prado, A.; Guardia Guardia, G.; Abalos, D.; Aguilera, E.... (2014). Yield-scaled mitigation of ammonia emission from N fertilization: the Spanish case. Environmental Research Letters. 9(12):1-12. https://doi.org/10.1088/1748-9326/9/12/125005S11291

    Kaposi's sarcoma of the lung: a case report.

    No full text
    Pulmonary Kaposi's sarcoma is a rare condition. Its diagnosis may be tricky due to its similarities in clinical and radiological features with pulmonary opportunistic infections as well as other lung lesions. Treatment for Kaposi's sarcoma include radiotherapy, chemotherapy and/or immunotherapy whereby lung Kaposi's sarcoma respond well to chemotherapy. An immunocompetent 68-year-old man was admitted with clinical, radiological and bronchoscopic features of bronchogenic carcinoma. However, the histological result revealed Kaposi's sarcoma of the lung. The patient was treated with radiotherapy and recovered well from his symptoms. Six months later the patient remain asymptomatic with essentially a normal chest x-ray
    • …
    corecore