Wildfire effects on the soil seed bank of a maritime pine stand — The importance of fire severity

Water repellency of air-dried and sieved samples from limestone soils in central Portugal collected before and after prescribed fire

“…The date (22 nd April 2009) was selected according with optimal weather conditions to conduct a prescribed fire, including low air temperature (<20°C), low wind velocity (<5 m s −1 ), and high air humidity (40-70 %). Fire severity was assessed at each of the 63 sampling sites using (1) the twig severity index (Maia et al 2012), (2) thermo-sensitive paints (TP's) placed at the soil surface (OMEGALAQ® Liquid Temperature Lacquers, n=94), and (3) K-type thermocouples (ø1.5 mm, TC-direct, Netherlands) connected to data loggers (EL-USB-TC; 0.5°C resolution, 1°C logger accuracy, Lascar Electronics, UK). At each sampling site, two thermocouples (TC's) were installed at the soil mineral surface (i.e., underneath the litter layer) and at 2 cm depth.…”

“…Considering the fuel moisture (Table 2) and the weather conditions, together with TP's and TC's results, as well as the twig severity index (Maia et al 2012), the prescribed fire was classified as a low severity one, according to the classification established by Robichaud and Hungerford (2000).…”

Post-fire soil erosion mitigation: a review of the last research and techniques developed in Portugal

“…3). Other severity indices such as the Twig Method Severity Index (TMSI; Moreno and Oechel, 1989) and the NIR-based Maximum Temperature Reached (Guerrero et al, 2007;Maia et al, 2012) can be more precise but also more labour-intensive. Extreme sediment losses of 20 to even 170 Mg ha -1 year -1 have been observed following high severity wildfires in North America Spigel and Robichaud, 2007;Riechers et al, 2008) as well as in Europe, (Spain, France, Greece and Portugal; as it was recently reviewed by Shakesby, 2011).…”

Does soil burn severity affect the post-fire runoff and interrill erosion response? A review based on meta-analysis of field rainfall simulation data

“…Most of the soil burn indices that have been proposed are based on the amount of surface litter layer consumed, the visually-observable changes of the mineral soil surface, the amount and colour of the deposited ashes, and/or the amount of charcoal present after the combustion of the aboveground biomass (Ryan and Noste, 1985;Neary et al, 2005;Shakesby and Doerr, 2006;Jain et al, 2012;Vega et al, 2013a). An indicator that is more closely linked to the soil heating regime itself is that of the maximum soil temperatures reached (MTR) estimated from Near Infrared (NIR) spectroscopy of laboratory-heated and field soil samples (Arcenegui et al, 2008;Guerrero et al, 2007;Maia et al, 2012). The use of distinct burn-severity classifications will hamper a direct comparison of the results obtained by different studies.…”

“…Wildfires often produce mosaics of areas with different soil burn severities Maia et al, 2012;Vega et al, 2013a). These spatial patterns in burn severity are often important in identifying areas with a high risk of post-fire erosion (Benavides-Solorio and MacDonald, 2005;Mayor et al, 2007;Gimeno-Garcia et al, 2007;Chafer, 2008).…”