67 research outputs found

    White Blood, Black Gold: The Commodification of Wild Rubber in the Bolivian Amazon, 1870-1920

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    The Bolivian rubber boom thrived during the 1880 and 1920 decades throughout the Amazonian fluvial network (Madre de Dios, Beni, Purús, Madeira and Beni rivers). The economic potential of rubber quickly became a decisive phenomenon in the social history of Eastern Bolivia, linked with the definitive ocupation of marginal territories, new interethnic relations, national and international migration, taxation, property entitlement, the foundation of cities, the rise of nationalism, the struggle to settle republican frontiers and a novel regional opening to global economy. The boom also encouraged substantial developments in cartography, hidrography, botanics and ethnology. Our goal is to describe the singularities of the rubber-tapping industry in Bolivia and to analyse the representations of “nature” held by rubber tappers of the period: there was indeed a modernist discourse based on the usual ideas of "progress" and "civilization" of the industry opposed to the "wildness", "savagery" and "barbarism" massively attributed to Amazonia, and also a generalized notion of the jungle as a "desert land" open to opportunities for the self-made man. In retrospect, these discourses can certainly reveal a lack of “ecological awareness”. However, a closer analysis of historical sources also shows the existence of voices that were more nuanced and reflexive, and in some cases even dared to point out the limits of extractivism –not only in "ecological" terms but also in reference to the life of the indigenous and creole populations involved in the rubber boom

    Elevated CO\u3csub\u3e2\u3c/sub\u3e further lengthens growing season under warming conditions

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    Observations of a longer growing season through earlier plant growth in temperate to polar regions have been thought to be a response to climate warming. However, data from experimental warming studies indicate that many species that initiate leaf growth and flowering earlier also reach seed maturation and senesce earlier, shortening their active and reproductive periods. A conceptual model to explain this apparent contradiction, and an analysis of the effect of elevated CO2—which can delay annual life cycle events—on changing season length, have not been tested. Here we show that experimental warming in a temperate grassland led to a longer growing season through earlier leaf emergence by the first species to leaf, often a grass, and constant or delayed senescence by other species that were the last to senesce, supporting the conceptual model. Elevated CO2 further extended growing, but not reproductive, season length in the warmed grassland by conserving water, which enabled most species to remain active longer. Our results suggest that a longer growing season, especially in years or biomes where water is a limiting factor, is not due to warming alone, but also to higher atmospheric CO2 concentrations that extend the active period of plant annual life cycles

    Elevated CO\u3csub\u3e2\u3c/sub\u3e further lengthens growing season under warming conditions

    Get PDF
    Observations of a longer growing season through earlier plant growth in temperate to polar regions have been thought to be a response to climate warming. However, data from experimental warming studies indicate that many species that initiate leaf growth and flowering earlier also reach seed maturation and senesce earlier, shortening their active and reproductive periods. A conceptual model to explain this apparent contradiction, and an analysis of the effect of elevated CO2—which can delay annual life cycle events—on changing season length, have not been tested. Here we show that experimental warming in a temperate grassland led to a longer growing season through earlier leaf emergence by the first species to leaf, often a grass, and constant or delayed senescence by other species that were the last to senesce, supporting the conceptual model. Elevated CO2 further extended growing, but not reproductive, season length in the warmed grassland by conserving water, which enabled most species to remain active longer. Our results suggest that a longer growing season, especially in years or biomes where water is a limiting factor, is not due to warming alone, but also to higher atmospheric CO2 concentrations that extend the active period of plant annual life cycles

    PHACEphenology_database_final_forSD

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    Weekly phenology observations exposed to CO2 enrichment and warming over course of the growing season years 2007-2011 in a mixed-grass prairie, Cheyenne WY

    Data from: Five years of phenology observations from a mixed-grass prairie exposed to warming and elevated CO2

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    Atmospheric CO2 concentrations have been steadily increasing since the Industrial Era and contribute to concurrent increases in global temperatures. Many observational studies suggest climate warming alone contributes to a longer growing season. To determine the relative effect of warming on plant phenology, we investigated the individual and joint effects of warming and CO2 enrichment on a mixed-grass prairie plant community by following the development of six common grassland species and recording four major life history events. Our data support that, in a semi-arid system, while warming advances leaf emergence and flower production, it also expedites seed maturation and senescence at the species level. However, the additive effect can be an overall lengthening of the growing and reproductive seasons since CO2 enrichment, particularly when combined with warming, contributed to a longer growing season by delaying plant maturation and senescence. Fostering synthesis across multiple phenology datasets and identifying key factors affecting plant phenology will be vital for understanding regional plant community responses to climate change

    Desflurane consumption with the Zeus during automated closed circuit versus low flow anesthesia.

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    During automated closed-circuit anesthesia (CCA), the Zeus (Dräger, Lübeck, Germany) uses a high initial fresh gas flow (FGF) to rapidly attain the desired agent and carrier gas concentrations, resulting in a desflurane consumption well above patient uptake. Because both FGF and carrier gas composition can affect consumption, we determined the Zeus' agent consumption with automated CCA and with automated low flow anesthesia (LFA) (= maintenance FGF of 0.7 L min(-1)) with 3 different carrier gases.Clinical TrialComparative StudyJournal ArticleSCOPUS: ar.jinfo:eu-repo/semantics/publishe

    PHACEphenology_summary_final_forSD

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    Mean timing of life cycle events (in DOY) for all species in all treatments in all years. Treatment designation are as follows: ct are the ambient CO2, ambient temperature treatments (i.e. control); cT are the ambient CO2, warmed treatments; Ct are the CO2 enriched, ambient temperature treatments; and CT are the CO2 enriched, warmed treatments. Marked (*) cells designate those species that initiated leaf emergence and flower production earliest, and seed maturation and senescence latest in the season within a treatment within a year. Standard errors (SE) are included in parenthesis where applicable. Where SE is blank, there was no variation in induction dates for that particular species or the sample size was not more than one individual per treatment per year. Number of plots (n) where species did occur per treatment is also included (maximum possible n is 5)
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