The effects of fire severity on ectomycorrhizal colonization and morphometric features in Pinus pinaster Ait. seedlings

Abstract

Aim of the study: Mycorrhizal fungi in Mediterranean forests play a key role in the complex process of recovery after wildfires. A broader understanding of an important pyrophytic species as Pinus pinaster and its fungal symbionts is thus necessary for forest restoration purposes. This study aims to assess the effects of ectomycorrhizal symbiosis on maritime pine seedlings and how fire severity affects fungal colonization ability.Area of study: Central Spain, in a Mediterranean region typically affected by wildfires dominated by Pinus pinaster, a species adapted to fire disturbance.Material and Methods: We studied P. pinaster root apexes from seedlings grown in soils collected one year after fire in undisturbed sites, sites moderately affected by fire and sites highly affected by fire. Natural ectomycorrhization was observed at the whole root system level as well as at two root vertical sections (0-10 cm and 10-20 cm). We also measured several morphometric traits (tap root length, shoot length, dry biomass of shoots and root/shoot ratio), which were used to test the influence of fire severity and soil chemistry upon them.Main results: Ectomycorrhizal colonization in undisturbed soils for total and separated root vertical sections was higher than in soils that had been affected by fire to some degree. Inversely, seedling vegetative size increased according to fire severity.Research highlights: Fire severity affected soil properties and mycorrhizal colonization one year after occurrence, thus affecting plant development. These findings can contribute to a better knowledge of the factors mediating successful establishment of P. pinaster in Mediterranean forests after wildfires.Keywords: Wildfire; mycorrhizal fungi; Maritime pine; bioassay. Citation: Vásquez-Gassibe, P., Oria-de-Rueda, J.A., Santos-del-Blanco, L., Martín-Pinto, P. (2016). The effects of fire severity on ectomycorrhizal colonization and morphometric features in Pinus pinaster Ait. seedlings. Forest Systems, Volume 25, Issue 1, e050. http://dx

Wild mushrooms in Ethiopia: A review and synthesis for future perspective

“…According to Teketay (2001), deforestation is immense and estimated between 150000 -200000 ha of land per year. Factors contributing to habitat degradation, such as fires, are also affecting the fungal communities in forest systems (Vásquez-Gassibe et al, 2016), which is also a recurrent phenomenon in the natural forest systems in the country. This adversely influences the macrofungi and diminishes their diversity and production (Miller & Lodge, 1997).…”

Scorched Earth: Suillus colonization of Pinus albicaulis seedlings planted in wildfire-impacted soil affects seedling biomass, foliar nutrient content, and isotope signatures

“…In an experiment that used simulated (furnaceincinerated) burned soil, S. bovinus enhanced shoot biomass of P. pinaster seedlings; however nonmycorrhizal seedlings were larger in unburned soil where nutrient availability could have been higher (Sousa et al 2011). In a second study, Pinus pinaster seedlings planted in blocks of burned soil in the greenhouse were larger than controls in unburned soil, but this could not be attributed to mycorrhization since this was confounded with soil properties; they suggested that a control of sterilized burn soil should have been added (Vásquez-Gassibe et al 2016). In the field, growth and survival appear to increase when seedlings are both inoculated with Suillus and planted on burns (Lonergan et al 2014;Asebrook and Hintz 2015).…”

“…Greenhouse bioassays have been used to successfully detect viable ectomycorrhizal fungi in burn or simulated burn soil (Baar et al 1999;Kjøller and Bruns 2003;Izzo et al 2006;Peay et al 2009;Buscardo et al 2010;Kipfer et al 2010;Sousa et al 2011;Glassman et al 2016;Vásquez-Gassibe et al 2016). When uncolonized P. albicaulis seedlings were planted in unsterilized burn soil in the present greenhouse bioassay, no ectomycorrhizal fungi were detected.…”

“…Few studies have examined ectomycorrhizal fungi in burned soil in the greenhouse, and most were bioassays used to detect viable spores as assessed by their ability to form mycorrhizae on pines (Baar et al 1999;Kjøller and Bruns 2003;Buscardo et al 2010;Kipfer et al 2010;Glassman et al 2016). To test spore viability after fire, greenhouse bioassays have simulated the effects of wildfire by using 'heat-treated' field soil (Izzo et al 2006;Peay et al 2009;Kipfer et al 2010), adding ashes to field soil (Peay et al 2009), blasting soil in a furnace (Sousa et al 2011), and using blocks of soil cut from a burn (Vásquez-Gassibe et al 2016); other studies have used soil from a burn diluted with sand, peat or vermiculite to improve drainage and to increase the probability of picking up less common fungi (Baar et al 1999;Taylor and Bruns 1999;Kjøller and Bruns 2003). Most of these 'burn' bioassays examined Pinus-Suillus/Rhizopogon systems; these fungi are particularly important to pines because they have some level of host specificity, occur with both young and mature trees, and are involved in nitrogen uptake (Bruns et al 2002a).…”

“…However, we only found two studies that examined how Suillus species affect seedlings in burned soil in the greenhouse. Both used P. pinaster as the host because it is a Mediterranean species strongly impacted by wildfire and it is of interest in restoration (Sousa et al 2011;Vásquez-Gassibe et al 2016).…”