Vegetation patterns and the influence of rainfall after long-term fire suppression on a woody community of a Brazilian savanna

Abstract

We evaluated the structural and fl oristic characteristics of a Brazilian savanna fragment occupied by cerradão (CD) and cerrado sensu stri cto (CS) in response to the infl uence of rainfall and long-term fi re suppression. We carried out fl oristic, phytosociological and remote sensing studies in a cerrado fragment located in Corumbataí (SP, Brazil) after 43 years of complete fi re suppression. We surveyed 43 plots of 200 m 2 each (17 plots in CS and 26 plots in CD) and all individuals ≥ 0.32 cm diameter measured at 30 cm from the ground were included in the sample. We calculated phytosociological parameters for each species and classifi ed them in three ecological groups, namely savanna, generalist and forest species. The remote sensing analysis used aerial photographs and satellite images from 1962 to 2019 (i.e. 59 years). The structural study of community revealed high predominance of forest and generalist species when compared to savanna species. Non-linear correlation between CD expansion rates and total rainfall within the study period indicated a positive infl uence of the rainfall (R 2 = 0.42). Thus, our analysis indicated a tendency of a continuous and fast expansion of CD over areas of CS in the long-term absence of fi re combined with periods of heavy rain.

Soil organic carbon is buffered by grass inputs regardless of woody cover or fire frequency in an African savanna

“…World‐wide, savanna covers 22% of the land area (Ramankutty & Foley, 1999) and with an increase in WPE combined with a suppression of fire, previous work suggests that the potential for above‐ and below‐ground C storage is significant (Scurlock & Hall, 1998). Fire exclusion experiments demonstrate that fire exclusion often results in an increase in woody biomass (Higgins et al, 2007; Murphy et al, 2010; Singh et al, 2018) and canopy cover (Bird et al, 2000; Devine et al, 2015; Pinheiro et al, 2021; Singh et al, 2018; Smit et al, 2010). However, the rates are not similar, with the fastest woody invasion rates in the savannas of South America and the lowest rates in Australia (Murphy et al, 2014; Stevens et al, 2017).…”