Last millennium environmental changes and climate inferences in the Southeastern Atlantic forest, Brazil

Abstract

This study presents paleoenvironmental data based on pollen, elemental and isotopic compositions of organic matter (TOC, N, δ 13 C and δ 15 N) and 14 C dating of 170 cm lake sediment record. Samplings have been made in Lagoa Grande at Parque Estadual Turístico do Alto Ribeira -PETAR, Southern São Paulo State, Southeastern Brazil. The variations in relative frequencies (in percentage) of arboreal pollen along the core range between 40 and 80%. The δ 13 C values ranged from -23 to -30 and C/N of ∼10 to 15, indicating the contribution of terrestrial C 3 plants and algae in the sediment organic matter. The δ 15 N results presented values from 3 to 4.5 , also suggesting a mixture of algae and terrestrial C 3 plants. The 14 C dating indicates modern age for the shallow horizons to ∼1030 BP at the base of the core. A probable wetter climate in the period of ∼370 BP to ∼340 BP was inferred from the data set, which corresponds to a part of the period covered by the Little Ice Age (LIA).

New insights into vegetation, climate and fire history of southern Brazil revealed by a 40,000 year environmental record from the State Park Serra do Tabuleiro

“…This finding is consistent with our data, in which we found an increase of certain woody taxa that are characteristic of moister and warmer conditions, such as Weinmannia. An interpretation inferred from a lake sediment from São Paulo state indicates a warmer and probably wetter period for southeastern Brazil between *370 and 340 B.P., which fits into the LIA (Pessenda et al 2010). The LIA is known as a period of cooling in Europe between about A.D. 1200 and 1700.…”

From an Estuary to a Freshwater Lake: A Paleo-Estuary Evolution in the Context of Holocene Sea-Level Fluctuations, SE Brazil

“…Total organic C (TOC) and N are expressed as percentage of dry weight, with analytical precision of 0.09% and 0.07%, respectively. Isotopic compositions ( 13 C and  15 N) are measured with respect to VPDB and atmospheric nitrogen, respectively, and are expressed as per mil (‰) with a standard deviation of ±0.2‰ (Pessenda et al 2010). …”

Manejo y cultivo de plantas en sierras húmedas del NE de Brasil ca. 670-530 BP: evidencias palinológicas del yacimiento Evaristo I

“…Los indicadores paleoambientales, paleoclimáticos y de paleopaisaje en el semiárido del NE brasileño en el contexto de las ocupaciones humanas prehistóricas, todavía son escasos y puntuales, debido a las dificultades metodológicas y discontinuidades sedimentarias de los yacimientos (Chaves 2002;Nascimento et al 2009;Mützenberg 2010;Pessenda et al 2010). Los estudios paleoclimáticos de la transición Pleistoceno-Holoceno (entre 12,000-11,000 BP) indican un aumento de la humedad, expansión forestal y microclimas más fríos (De Oliveira et al 1999;Behling et al 2000).…”

“…En torno a 3000 BP, el semiárido presenta un clima más seco, semejante al actual (Cruz Junior et al 2009), con intensificación de la desertificación y sustitución de vegetación higrofítica por xerofítica en diversas áreas, sobre todo a partir de 1300 BP, coincidiendo en este intervalo con los periodos de ocupación antrópica. Mientras tanto, la presencia actual de islas o refugios de vegetación húmeda en puntos del semiárido nororiental puede ser justificada por la expansión de las plantas atlánticas y amazónicas, indicador de microclimas más húmedos durante el Holoceno (Ab'Sáber 1994; Pessenda et al 2010).…”

“…Los valores de δ 13 C (-25,1‰) procedente del carbón datado de la UE011 ( fig. 4), indican plantas arbustivo-arbóreas de metabolismo C 3 , de caráter xerófito, como ejemplo de los paleosuelos (~3200 BP) de la FLONA de la Chapada do Araripe (Pernambuco) (Pessenda et al 2010). Las plantas herbáceas nitrófilas anuales registradas, tipo Amaranthaceae-Chenopodiaceae ( fig.…”