%0 Journal Article
%4 sid.inpe.br/mtc-m21c/2018/11.09.12.39
%2 sid.inpe.br/mtc-m21c/2018/11.09.12.39.46
%@doi 10.1002/ecs2.2457
%@issn 2150-8925
%T Unfolding long-term Late Pleistocene–Holocene disturbances of forest communities in the southwestern Amazonian lowlands
%D 2018
%8 Oct.
%9 journal article
%A Rossetti, Dilce de Fátima,
%A Gribel, Rogério,
%A Toledo, Peter Mann de,
%A Tatumi, Sonia H.,
%A Yee, Márcio,
%A Tudela, Diego R. G.,
%A Munita, Casimiro S.,
%A Coelho, Luiz de Souza,
%@affiliation Instituto Nacional de Pesquisas Espaciais (INPE)
%@affiliation Instituto Nacional de Pesquisas da Amazônia (INPA)
%@affiliation Instituto Nacional de Pesquisas Espaciais (INPE)
%@affiliation Universidade Federal de São Paulo (UNIFESP)
%@affiliation Universidade Federal de São Paulo (UNIFESP)
%@affiliation Universidade de São Paulo (USP)
%@affiliation Instituto de Pesquisas Energéticas e Nucleares (IPEN)
%@affiliation Instituto Nacional de Pesquisas da Amazônia (INPA)
%@electronicmailaddress dilce.rossetti@inpe.br
%@electronicmailaddress
%@electronicmailaddress peter.toledo@inpe.br
%B Ecosphere
%V 9
%N 10
%P e02457
%K Amazonian lowlands, distribution patterns, forest onset, geological history, Holocene, Late Pleistocene,long-term disturbances.
%X Linking the distribution of plant species to geology has generally been biased by the over-simplification 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 δ13C 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 PleistoceneHolocene terrains in intermediate elevations had terra firme forests, but shorter trees with lower basal areas and ecotonal forests appeared near the confines of the forestsavanna, while Holocene deposits recorded only seasonally flooded varzea forests. Several deposits of Late Pleistocene and Late PleistoceneHolocene age recorded an expansion of C4 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 61303533 cal yr BP, 34022800 cal yr BP, and 1624964 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.
%@language en
%3 Rossetti_et_al-2018-Ecosphere.pdf