Ectomycorrhizae morphotypes in a Pinus patula Schiede ex Schltdl. & Cham. stand chronosequence in eastern Mexico

Abstract

Forest activity for timber purposes in Mexico is based on the harvesting of various pine species, one of the mostly used is Pinus patula. Ectomycorrhizal (ECM) fungi increase seedling survival, and, therefore, their use ensures the success of forest plantations. Reforestation with native pine species increases the diversity of ectomycorrhizal fungi. The aim of this work was to compare species diversity associated with stand age and to determine the changes in the fungal community at the morphotype level. The study was carried out in a commercial plantation, with stands aged 2, 5, 7, 9, 14 to 25 and > 50 years. Mycorrhizal roots were collected at the beginning of the rainy season and grouped according to their morphology, and the diversity index, percentage of abundance and relative frequency were determined. Twenty-eight morphotypes were determined, including two of the Laccaria genus, two of Tomentella and one of Cortinarius. There is a positive correspondence between the number of morphotypes and the age of the pines. Mature stands (14-25 and >50 yr-old) were more diverse than young (2 to 9 yr-old) stands, with the exception of the 7 year-old stand, which showed similar diversity values to the mature stands. Probable morphotypes of Laccaria spp. were more abundant and frequent in the youngest stand (33 %). Throughout the chronosequence, unique and shared morphotypes were recorded. This work requires further research; however, it shows that stand age is an important factor in the composition of the ECM fungal communities and a key element in forest management plans.