Smouldering fire-induced changes in a Mediterranean soil (SE Spain): effects on germination, survival and morphological traits of 3-year-old Pinus pinaster Ait.

Abstract

In the present study, a smouldering fire was reproduced in a substrate from a Pinus pinaster forest in the southeastern Iberian Peninsula. Experiments were carried out, in laboratory, using soil monoliths to assess the short-term fire-induced effects on germination, survival and morphological traits in young (3-year-old) specimens of Pinus pinaster Ait. The fire caused a severe reduction in the litter and humus layer relative to a control (unburnt) soil.

Effects of pre-commercial thinning on growth and reproduction in post-fire regeneration of Pinus halepensis Mill

“…(Madrigal et al 2004) and Pinus halepensis (Navarro et al 2010b) in Spain, obtaining similar results to those of the present work. They found that thinning had a positive effect in all cases, with higher diameters one year after treatment; while our results did not show increased basal diameters until 2 or 4 years after thinning, depending on the analysis applied.…”

Effects of soil burn severity on germination and initial establishment of maritime pine seedlings, under greenhouse conditions, in two contrasting experimentally burned soils

“…However, the present results partially contrast with those of Madrigal et al (2010), who found, in a similar experiment with the same Cuenca soil with monoliths fully exposed outdoors to daylight, that seedlings growing in burned soil were shorter than those growing in the unburned soil and mainly attributed this to the relative reduction in water availability induced by pronounced reduction of soil organic layers. This contrast with the present results for Cuenca soils and suggests that under strong hydric stress, the positive effect of fertility caused by ash deposition would probably not occur, and that under an oceanic climate, Pinus pinaster regeneration does not appear to be affected in this heavytextured type of soil.…”

“…This may explain the observed low effect of soil burn severity on seed germination and the absence of any significant influence of the factors considered in the PLS path analysis. This contrasts with the reduced germination in burned soils, reported by Madrigal et al (2010), who found a significant decrease in germination in burned soils of the same type (Cuenca) but subjected to a higher level of drought in the burned seedbed, when fully exposed to daylight. …”

“…Current information on the effects of soil burn severity on seedling root/ shoot ratio is very scarce. Madrigal et al (2010) did not find any significant differences in the root/shoot ratio in Pinus pinaster seedlings growing in burned monoliths of Cuenca soils Root/shoot ratio (measured after destructive sampling of monoliths) of Pinus pinaster seedlings growing on burned and unburned soils from (a) Pontevedra (soil 1), and (b) Cuenca (soil 2). Bars are standard errors (n ¼ 5 monoliths for each combination of soil type  treatment).…”

“…Some authors (Ne'eman et al 1992;Kennard and Gholz 2001) have reported a positive influence, others (Giovannini et al 1990;Madrigal et al 2010) a negative influence and yet others (Blackwell et al 1995) an absence of any effect. These apparently contradictory results may be attributed to differences in vegetation competition due to different burn severity.…”