74 research outputs found

    Contrasting tree-cover loss and subsequent land cover in two neotropical forest regions: sample-based assessment of the Mexican Yucatán and Argentine Chaco

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    The neotropical-forest’s northern and southern extremes, covering the Mexican Yucatán and the Argentine Chaco, have among the highest rates of recent tree-cover loss in the biome. This study contrasts the character of loss in these regions, estimating proportions of types of loss and subsequent land cover. It is based on two-stage probability sampling design and field and satellite-image surveys. All estimates include uncertainties, which could be further reduced via model-assisted estimation or additional sampling. This approach can be replicated in other regions to estimate types of loss and associated land cover from a definitive, in-situ perspective. The character of loss in the two areas differed greatly. That in the Yucatán was 54% temporary, mostly under fallow or selectively logged, while that in the Chaco was 85% permanent, split nearly equally between crops and pasture. These data contribute to a quantitative basis for studies of socio-economic drivers of neotropical deforestation.Fil: Krylov, Alexander. University of Maryland; Estados UnidosFil: Steininger, Marc K.. University of Maryland; Estados UnidosFil: Hansen, Matthew C.. University of Maryland; Estados UnidosFil: Potapov, Peter V.. University of Maryland; Estados UnidosFil: Stehman, Stephen V.. State University of New York; Estados UnidosFil: Gost, Allison. University of Maryland; Estados UnidosFil: Noel, Jacob. University of Maryland; Estados UnidosFil: Talero Ramirez, Yamile. University of Maryland; Estados UnidosFil: Tyukavina, Alexandra. University of Maryland; Estados UnidosFil: Di Bella, Carlos Marcelo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ellis, Edward A.. Universidad Veracruzana; MéxicoFil: Ellis, Peter. The Nature Conservancy. Global Lands; Estados Unido

    Natural climate solutions

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    Our thanks for inputs by L. Almond, A. Baccini, A. Bowman, S. CookPatton, J. Evans, K. Holl, R. Lalasz, A. Nassikas, M. Spalding, M. Wolosin, and expert elicitation respondents. Our thanks for datasets developed by the Hansen lab and the NESCent grasslands working group (C. Lehmann, D. Griffith, T. M. Anderson, D. J. Beerling, W. Bond, E. Denton, E. Edwards, E. Forrestel, D. Fox, W. Hoffmann, R. Hyde, T. Kluyver, L. Mucina, B. Passey, S. Pau, J. Ratnam, N. Salamin, B. Santini, K. Simpson, M. Smith, B. Spriggs, C. Still, C. Strömberg, and C. P. Osborne). This study was made possible by funding from the Doris Duke Charitable Foundation. Woodbury was supported in part by USDA-NIFA Project 2011-67003-30205 Data deposition: A global spatial dataset of reforestation opportunities has been deposited on Zenodo (https://zenodo.org/record/883444). This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1710465114/-/DCSupplemental.Peer reviewedPublisher PD

    Global Trends of Forest Loss Due to Fire From 2001 to 2019

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    Forest fires contribute to global greenhouse gas emissions and can negatively affect public health, economic activity, and provision of ecosystem services. In boreal forests, fires are a part of the ecosystem dynamics, while in the humid tropics, fires are largely human-induced and lead to forest degradation. Studies have shown changing fire dynamics across the globe due to both climate and land use change. However, global trends in fire-related forest loss remain uncertain due to the lack of a globally consistent methodology applied to high spatial resolution data. Here, we create the first global 30-m resolution satellite-based map of annual forest loss due to fire. When producing this map, we match the mapped area of forest loss due to fire to the reference area obtained using a sample-based unbiased estimator, thus enabling map-based area reporting and trend analysis. We find an increasing global trend in forest loss due to fire from 2001 to 2019, driven by near-uniform increases across the tropics, subtropical, and temperate Australia, and boreal Eurasia. The results quantify the increasing threat of fires to remaining forests globally and may improve modeling of future forest fire loss rates under various climate change and development scenarios

    Оценка влияния однонуклеотидного полиморфизма val158met гена катехол-О-метилтрансферазы (СОМТ) на эффективность спинальной аналгезии в 1 сутки после лапароскопических операций по поводу колоректального рака (пилотное исследование)

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    The aim: To assess the effect of COMT G1947A genetic polymorphism (val158met) on the efficacy of spinal analgesia on day 1 after laparoscopic surgery for colorectal cancer.Material and methods. In a pilot study involving 100 patients with colorectal cancer, operated through laparoscopic access, using spinal analgesia (10.0–12.5 mg of bupivacaine + 200 mcg of morphine), the frequency of COMT gene G1947A (val158met) polymorphism, the intensity of pain on day 1 after surgery, the frequency and severity of nausea, vomiting, skin itching, the need for additional analgesia have been assessed.Results. The frequency distribution of alleles val/val (25%), val/met (45%) and met/met (30%) was consisted with Hardy-Weinberg equilibrium (χ2=0.96; P>0.05) and was not significantly different from the healthy donor group. In the groups of patients with various COMT alleles of val158met polymorphism, the studied parameters also did not differ significantly.Conclusion. Study did not find significant link between spinal analgesia efficacy on day 1 after laparoscopic surgery for colorectal cancer and COMT rs4680 G1947A (val158met) polymorphism. Further research to enhance the power of the study is warranted to reach the final conclusions.Цель: оценка влияния SNP val158met гена COMT на эффективность спинальной аналгезии в 1 сутки после лапароскопических операций по поводу колоректального рака.Материал и методы. В пилотном исследовании, включавшем 100 пациентов c колоректальным раком, оперированных лапароскопическим доступом, с использованием в комплексе анестезиологического пособия спинальной аналгезии (10–12,5 мг бупивакаина + 200 мкг морфина), оценили частоту полиморфизма val158met гена COMT, интенсивность боли в 1 сутки после операции, частоту и выраженность тошноты, рвоты, кожного зуда, потребность в дополнительном обезболивании.Результаты. Распределение частот аллелей val/val (25%), val/met (45%) и met/met (30%) подчинялось закону Харди-Вайнберга (χ2=0,96; р>0,05) и статистически значимо не отличалось от группы здоровых доноров. В группах носителей различных аллелей SNP val158met исследуемые показатели статистически значимо не отличались.Заключение. Зависимости эффективности спинальной аналгезии в 1 сутки после лапароскопических операций по поводу колоректального рака от SNP val158met гена СОМТ не выявили. Для получения окончательных выводов необходимо проведение дальнейших исследований

    Global fine-resolution data on springtail abundance and community structure

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    Springtails (Collembola) inhabit soils from the Arctic to the Antarctic and comprise an estimated ~32% of all terrestrial arthropods on Earth. Here, we present a global, spatially-explicit database on springtail communities that includes 249,912 occurrences from 44,999 samples and 2,990 sites. These data are mainly raw sample-level records at the species level collected predominantly from private archives of the authors that were quality-controlled and taxonomically-standardised. Despite covering all continents, most of the sample-level data come from the European continent (82.5% of all samples) and represent four habitats: woodlands (57.4%), grasslands (14.0%), agrosystems (13.7%) and scrublands (9.0%). We included sampling by soil layers, and across seasons and years, representing temporal and spatial within-site variation in springtail communities. We also provided data use and sharing guidelines and R code to facilitate the use of the database by other researchers. This data paper describes a static version of the database at the publication date, but the database will be further expanded to include underrepresented regions and linked with trait data.</p

    Globally invariant metabolism but density-diversity mismatch in springtails.

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    Soil life supports the functioning and biodiversity of terrestrial ecosystems. Springtails (Collembola) are among the most abundant soil arthropods regulating soil fertility and flow of energy through above- and belowground food webs. However, the global distribution of springtail diversity and density, and how these relate to energy fluxes remains unknown. Here, using a global dataset representing 2470 sites, we estimate the total soil springtail biomass at 27.5 megatons carbon, which is threefold higher than wild terrestrial vertebrates, and record peak densities up to 2 million individuals per square meter in the tundra. Despite a 20-fold biomass difference between the tundra and the tropics, springtail energy use (community metabolism) remains similar across the latitudinal gradient, owing to the changes in temperature with latitude. Neither springtail density nor community metabolism is predicted by local species richness, which is high in the tropics, but comparably high in some temperate forests and even tundra. Changes in springtail activity may emerge from latitudinal gradients in temperature, predation and resource limitation in soil communities. Contrasting relationships of biomass, diversity and activity of springtail communities with temperature suggest that climate warming will alter fundamental soil biodiversity metrics in different directions, potentially restructuring terrestrial food webs and affecting soil functioning

    Magnetohydrodynamic Oscillations in the Solar Corona and Earth’s Magnetosphere: Towards Consolidated Understanding

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