Forest–savanna–<i>morichal</i> dynamics in relation to fire and human occupation in the southern Gran Sabana (SE Venezuela) during the last millennia

Montoya, Encarni; Rull, Valentı́; Stansell, Nathan D.; Abbott, Mark B.; Nogué, Sandra; Bird, Broxton W.; Díaz, Wilmer

doi:10.1016/j.yqres.2011.06.014

Cited by 47 publications

(45 citation statements)

References 46 publications

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“…Fig. 3;Montoya et al 2011). Similarly, recent data (Veraverbeke et al 2017) and modelling (Romps et al 2014) also suggest that lightning frequency and lightning-caused wildfires are associated with current global warming.…”

Section: Do Lightning-caused Wildfires Vary With Climate?supporting

confidence: 55%

Were Western European Neandertals Able to Make Fire?

et al. 2018

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Significant variability has been observed in the frequency of fire use over the course of the Late Pleistocene at several Middle Paleolithic sites in southwest France. In particular, Neandertals appear to have used fire more frequently during warm climatic periods and very infrequently during cold periods. After reviewing several lines of evidence and alternative explanations for this variability, the null hypothesis that these Neandertals were not able to make fire still stands.

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Section: Do Lightning-caused Wildfires Vary With Climate?supporting

confidence: 55%

Were Western European Neandertals Able to Make Fire?

et al. 2018

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“…the increase in edible plants at LC is driven primarily by Mauritia/Mauritiella, along with Agavaceae, Caryocar, Byrsonima, Lecythidaceae, and Theobroma among others (Figure 6). The increase in Mauritia/Mauritiella follows a similar pattern to sites across seasonally flooded savannas in lowland South America during this period (Kahn and de Granville, 1992;Behling and Hooghiemstra, 1998Burbridge et al, 2004;Montoya and Rull, 2011;Montoya et al, 2011b;Balee, 2013;Rull et al, 2013;Rull and Montoya, 2014;Maezumi et al, 2015;Junqueira et al, 2017). This regional phenomenon has been attributed to both natural and anthropogenic drivers (Montoya and Rull, 2011;Montoya et al, 2011a,c;Rull and Montoya, 2014;Maezumi et al, 2015).…”

Section: Pre-columbian Impact On Forest Compositionmentioning

confidence: 62%

New Insights From Pre-Columbian Land Use and Fire Management in Amazonian Dark Earth Forests

et al. 2018

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Anthropogenic climate change driven by increased carbon emissions is leading to more severe fire seasons and increasing the frequency of mega-fires in the Amazon. This has the potential to convert Amazon forests from net carbon sinks to net carbon sources. Although modern human influence over the Earth is substantial, debate remains over when humans began to dominate Earth's natural systems. To date, little is known about the history of human land use in key regions like the Amazon. Here, we examine the history of human occupation from a ∼8,500 year-old sediment core record from Lake Caranã (LC) in the eastern Amazon. The onset of pre-Columbian activity at LC (∼4,500 cal yr B.P.) is associated with the beginning of fire management and crop cultivation, later followed by the formation of Amazonian Dark Earth soils (ADEs) ∼2,000 cal yr B.P. Selective forest enrichment of edible plants and low-severity fire activity altered the composition and structure of forests growing on ADEs (ADE forests) making them more drought susceptible and fire-prone. Following European colonization (1661 A.D.), the Amazon rubber boom (mid-1800s to 1920 A.D.) is associated with record-low fire activity despite drier regional climate, indicating fire exclusion. The formation of FLONA Reserve in 1974 A.D. is accompanied by the relocation of traditional populations and a fire suppression policy. Despite suppression efforts, biomass burning and fire severity in the past decade is higher than any other period in the record. This is attributed to combined climate and human factors which create optimal conditions for mega-fires in ADE forests and threatens to transform the Amazon from a net carbon sink to a net carbon source. To help mitigate the occurrence of mega-fires, a fire management policy reducing fire-use and careful fire management for farming may help to reduce fuel loads and the occurrence of mega-fires in fire-prone ADE forests. As both natural and anthropogenic pressures are projected to increase in the Amazon, this study provides valuable insights into the legacy of past human land use on modern ADE forest composition, structure, and flammability that can inform ecological benchmarks and future management efforts in the eastern Amazon.

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“…The development of M. flexuosa swamps and increases in charcoal influx have been seen in numerous paleoecological records from savanna ecosystems in Colombia (Behling andHooghiemstra, 1998, 1999;Berrio et al, 2002a, b), Venezuela (Montoya et al, 2011b;Rull and Montoya, 2014;Rull, 1999, 2009), and Brazil (DaSilva Meneses et al, 2013. Previously two hypotheses have been proposed to account for the late Holocene development of these M. flexuosa palm swamps.…”

Section: Mauritia Flexuosamentioning

confidence: 94%

Effects of past climate variability on fire and vegetation in the cerrãdo savanna of the Huanchaca Mesetta, NE Bolivia

et al. 2015

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Abstract. Cerrãdo savannas have the greatest fire activity of all major global land-cover types and play a significant role in the global carbon cycle. During the 21st century, temperatures are projected to increase by ∼ 3 • C coupled with a precipitation decrease of ∼ 20 %. Although these conditions could potentially intensify drought stress, it is unknown how that might alter vegetation composition and fire regimes. To assess how Neotropical savannas responded to past climate changes, a 14 500-year, high-resolution, sedimentary record from Huanchaca Mesetta, a palm swamp located in the cerrãdo savanna in northeastern Bolivia, was analyzed with phytoliths, stable isotopes, and charcoal. A nonanalogue, cold-adapted vegetation community dominated the Lateglacial-early Holocene period (14 500-9000 cal yr BP, which included trees and C 3 Pooideae and C 4 Panicoideae grasses. The Lateglacial vegetation was fire-sensitive and fire activity during this period was low, likely responding to fuel availability and limitation. Although similar vegetation characterized the early Holocene, the warming conditions associated with the onset of the Holocene led to an initial increase in fire activity. Huanchaca Mesetta became increasingly firedependent during the middle Holocene with the expansion of C 4 fire-adapted grasses. However, as warm, dry conditions, characterized by increased length and severity of the dry season, continued, fuel availability decreased. The establishment of the modern palm swamp vegetation occurred at 5000 cal yr BP. Edaphic factors are the first-order control on vegetation on the rocky quartzite mesetta. Where soils are sufficiently thick, climate is the second-order control of vegetation on the mesetta. The presence of the modern palm swamp is attributed to two factors: (1) increased precipitation that increased water table levels and (2) decreased frequency and duration of surazos (cold wind incursions from Patagonia) leading to increased temperature minima. Natural (soil, climate, fire) drivers rather than anthropogenic drivers control the vegetation and fire activity at Huanchaca Mesetta. Thus the cerrãdo savanna ecosystem of the Huanchaca Plateau has exhibited ecosystem resilience to major climatic changes in both temperature and precipitation since the Lateglacial period.

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Forest–savanna–morichal dynamics in relation to fire and human occupation in the southern Gran Sabana (SE Venezuela) during the last millennia

Cited by 47 publications

References 46 publications

Were Western European Neandertals Able to Make Fire?

Were Western European Neandertals Able to Make Fire?

New Insights From Pre-Columbian Land Use and Fire Management in Amazonian Dark Earth Forests

Effects of past climate variability on fire and vegetation in the cerrãdo savanna of the Huanchaca Mesetta, NE Bolivia

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