Paleoecology as a guide to landscape conservation and restoration in the neotropical Gran Sabana

Rull, Valentı́; Vegas‐Vilarrúbia, Teresa; Montoya, Encarni

doi:10.22498/pages.25.2.82

Cited by 3 publications

(2 citation statements)

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“…The increase in the contribution of C 4 terrestrial plants before present-day forests is remarkable, particularly considering the forest onsets at various ages between 11,189 and 11,573 cal yr BP (Fig. However, there is a suggestion that the extensive savanna of the Gran Sabana in the Orinoco region of northern Amazonia occurred during this climatic event, followed by the amplification of the Holocene savanna due to anthropogenic fires (Rull et al 2017). Carlson 2013).…”

Section: Linkage To Past Climatementioning

confidence: 96%

“…The imprint of this event in South America remains to be investigated in greater depth. However, there is a suggestion that the extensive savanna of the Gran Sabana in the Orinoco region of northern Amazonia occurred during this climatic event, followed by the amplification of the Holocene savanna due to anthropogenic fires (Rull et al 2017). The record of C 4 terrestrial plants has been used to suggest dry periods in other Amazonian areas, not only in the YD, but also in the Last Glacial Maximum (LGM) and Oldest Dryas (OD; e.g., Absy et al 1991, van der Hammen and Absy 1994, Mayle et al 2000, Colinvaux et al 2000.…”

Section: Linkage To Past Climatementioning

confidence: 99%

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Unfolding long‐term Late Pleistocene–Holocene disturbances of forest communities in the southwestern Amazonian lowlands

et al. 2018

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Linking the distribution of plant species to geology has generally been biased by the oversimplification of landscape evolution and the lack of understanding of complex geological processes. The Amazonian lowlands have forests in different successional stages, and a growing perception is that such heterogeneity results from long-term environmental changes. This hypothesis is investigated by designing an analytical model based on past and present-day vegetation and successions of the plant communities, combined with an advanced understanding of geological history. An area of southwestern Amazonia was selected for floristic inventories, and we interpreted the paleovegetation based on C/N and d 13 C analyses of sedimentary organic matter. These data were examined in the context of the geological evolution on the basis of new sedimentological and chronological data. The topographically high Late Pleistocene deposits had continuous and highly diversified late-successional terra firme forests as well as local fluvial paleolandforms of younger ages with less diversified campinarana forests. Late Pleistocene-Holocene terrains in intermediate elevations had terra firme forests, but shorter trees with lower basal areas and ecotonal forests appeared near the confines of the forest-savanna, while Holocene deposits recorded only seasonally flooded varzea forests. Several deposits of Late Pleistocene and Late Pleistocene-Holocene age recorded an expansion of C 4 terrestrial plants before the establishment of the forest from~20,000 cal yr BP to 7578 cal yr BP, which is not related to past arid episodes. We recorded forests with onsets at 6130-3533 cal yr BP, 3402-2800 cal yr BP, and 1624-964 cal yr BP to terra firme, varzea, and ecotonal forests, respectively. However, not all forests have reached maturity stages due to their location on terrains with a diverse history of terrace downcutting and deposition, which had a direct impact on local hydrology with the interaction of topographic gradients. The hydrology of the study area was also controlled by the distance from the main river valley. Capturing long-term disturbances over this region of still pristine forests may help elucidate the potential mechanisms that also determine trends in tree growth and forest diversity in other Neotropical regions.

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Section: Linkage To Past Climatementioning

confidence: 96%