Pedological and isotopic relations of a highland tropical peatland, Mountain Range of the Espinhaço Meridional (Brazil)

Abstract

The evolution of organic matter sources in soil is related to climate and vegetation dynamics in the past recorded in paleoenvironmental Quaternary deposits such as peatlands. For this reason, a Histosol of the mineralotrophic peatland from the Pau-de-Fruta Special Protection Area -SPA, Espinhaço Meridional, State of Minas Gerais, was described and characterized to evidence the soil constituent materials and properties as related to changes in environmental conditions, supported by the isotopic and elementary characterization of soil C and N and 14 C ages. Samples were collected in a depression at 1,350 m asl, where Histosols are possibly more developed due to the great thickness (505 cm). Nowadays, the area is colonized by vegetation physiognomies of the Cerrado Biome, mainly rocky and wet fields (Campo Rupestre and Campo Úmido), aside from fragments of Semidecidual Seasonal Forest, called Capões forests. The results this study showed that early the genesis of the analyzed soil profile showed a high initial contribution of mostly herbaceous organic matter before 8,090 ± 30 years BP ( 14 C age). In the lower-mid Holocene, between 8,090 ± 30 years AP ( 14 C age) to ± 4,100 years BP (interpolated age), the vegetation gradually became more woody, with forest expansion, possibly due to increased humidity, suggesting the existence of a more woody Cerrado in the past than at present. Drier climate conditions than the current were concluded ± 2,500 years BP (interpolated age) and that after 430 years BP ( 14 C age) the forest gave way to grassland, predominantly. After the dry season, humidity increased to the current conditions. Due to these climate

Surface mapping, organic matter and water stocks in peatlands of the Serra do Espinhaço meridional - Brazil

“…The highest OM and OC contents are related to lower MM contents and OMD is higher in predominantly hemic materials compared to the sapric soils (Table 1). These results corroborate studies conducted by Silva et al (2009), Campos et al (2010 and Horák et al (2011).…”

“…According to Ebeling et al (2011) and Andriesse (1984), the characteristically low pH values of peat environments are directly related to the organic acids formed during the process of OM mineralization. The dark color and pH values (in CaCl 2 ) in the peat bogs of SdEM confirm the values found by Campos et al (2010) and Horák et al (2011), ranging between 2.6 and 4.4 and also coincide with the results of Silva et al (2009 Table 2). Out of the 77 samples, 51 % were classified as sapric (Embrapa, 2006).…”

Composição lignocelulósica e isótopica da vegetação e da matéria orgânica do solo de uma turfeira tropical: I - composição florística, fitomassa e acúmulo de carbono

“…O CLU é formado predominantemente por espécies herbáceas, adaptadas a condições de drenagem deficiente (Munhoz & Felfili, 2008). As ilhas de FES ou popularmente "Capões de Mata" são formadas por espécies de hábito arbóreo-arbustivo e ocorrem espaçadamente na turfeira (Horák et al, 2011).…”

“…Associações de plantas de ciclo C 3 e C 4 também foram identificadas em turfeiras tropicais (Parolin et al, 2006;Vidotto et al, 2007;Campos et al, 2010;Horák et al, 2011) e temperadas (Hillaire-Marcel et al, 1989;Aucour et al, 1994).…”

“…al, 2010;Horák et al, 2011), que apresentam variações na produção de fitomassa e na composição lignocelulósica do material vegetal (Silva, 2011), podendo, hipoteticamente, influenciar na taxa de acúmulo de MOS.…”