Palynological evidence of vegetation change during the last 10,000 years in the mid-valley of the Rio Doce, Brazil

Abstract

In order to reconstruct the vegetation history of the last 10.000 years, palynological analyses were carried out using 17 sedimentary samples of a core drilled in Parque Estadual do Rio Doce (PERD-MG). Twenty-one species of fern spores, 52 species of pollen grains and six species of fungi were identified. Phase 1 (10.375-9.350 cal. years BP) is characterized by a low concentration and diversity of pollen grains and is thus interpreted as a fluvial system with the presence of coarse-grained sediments. Phase 2 (9.062-8.195 cal. Years BP) is interpreted as a transition from a fluvial to lacustrine environment. Phase 3 (7.905-4.785 cal years BP) is characterized by increased trend of palynomorph concentration, highlighted by a high abundance and diversity of fern spores, which are indicative of a more a humid condition. The uppermost phase, Phase 4 (4.785-50 cal. Years AP), possessed a lower abundance of herbaceous flora, which is replaced by other vegetation groups (e.g. marsh, cerrado, Atlantic Forest). The uppermost sample represents the contemporary environment (~50 years), which is characterized as seasonally-flooded.

Forest–lake ecotones in a tropical forest: Terrestrial invertebrate inputs to lakes decrease with forest distance

“…The predominant vegetation is semideciduous seasonal forest, composed mainly of secondary vegetation surrounded by small portions of primary forest, varying from dense forests to dense savannas (Silva, 2001). The palynomorphs encompass five distinct vegetation structures (i.e., swamp, Cerrado, Atlantic Forest, gallery forest, and altitudinal forest) that experienced continuous historical changes from fluvial to lake ecosystems (Fonseca‐Silva et al, 2019). The native Atlantic Forest in this region is mainly composed of typical families of seasonal semideciduous forests, with the predominance of Fabaceae, Myrtaceae, Lauraceae, and Rubiaceae species (França & Stehmann, 2013).…”