Effects of prescribed fire on surface soil in a Pinus pinaster plantation, northern Portugal

Abstract

In order to decrease the risk of severe wildfire, prescribed fire has recently been adopted in Portugal and elsewhere in the Mediterranean as a major tool for reducing the fuel load instead of manual or mechanical removal of vegetation. There has been some research into its impact on soils in shrublands and grasslands, but to date little research has been conducted in forested areas in the region. As a result, the impact of prescribed fire on the physico-chemical soil characteristics of forest soils has been assumed to be minimal, but this has not been demonstrated. In this study, we present the results of a monitoring campaign of a detailed pre-and post-prescribed fire assessment of soil properties in a long-unburnt P. pinaster plantation, NW Portugal. The soil characteristics examined were pH, total porosity, bulk density, moisture content, organic matter content and litter/ash quantity. The results show that there was no significant impact on the measured soil properties, the only effect being confined to minor changes in the upper 1 cm of soil. We conclude that provided the fire is carried out according to strict guidelines in P. pinaster forest, a minimal impact on soil properties can be expected.

Soil Microbial Diversity, Biomass, and Activity in Two Pine Plantations of Southern Italy Treated with Prescribed Burning

“…Our results are consistent with former research showing that repeated PB in a P. halepensis plantation in Southern Italy had only short-term or no effects on chemical and microbial properties of the fermentation layer and the 5 cm soil layer underneath, with a superimposed predominance of the water factor [31]. Likewise, no or minimal effects of PB on soil physical and chemical properties were observed in a short-grass plain in Texas [37], a P. pinaster plantation in Portugal [68] and a P. palustris forest in South Caroline [69].…”

Effect of prescribed fire on soil properties and soil erosion in a Mediterranean mountain area

“…The direct and indirect effects of fire were often studied in soil surface (e.g., Arocena and Opio, 2003;Huseyin, 2006;Thomaz and Fachin, 2014;Meira-Castro et al, 2015;Armas-Herrera et al, 2016;Aznar et al, 2016), but some works showed that these effects reach deeper soil layers, at least down to 30 cm (Fonseca et al, 2011;Dennis et al, 2013;Heydari et al, 2017). The present work is in agreement with the results presented by the former authors, contributing to reinforce the idea that more attention should be given to the direct and indirect effects of fire at deeper depths.…”

Impacts of different prescribed fire frequencies on selected soil chemical properties in a semi-arid savannah thornveld

“…The importance of organic carbon on physical, chemical and biological soil properties is well documented (Granged et al, 2011a;Meira-Castro et al, 2014). In this study the results indicate that repeated annual burning cause a decline in soil C (Table 1) when compared to relatively infrequent burning (biennial, triennial and quadrennial).…”