Daños por factores abióticos y bióticos en bosques de oyamel (Abies religiosa (Kunth) Schltdl. et Cham.) de la Reserva de la Biósfera Mariposa Monarca

Abstract

Forest damage is the reduction of the vigor and survival of trees from biotic (pests and diseases) and abiotic (environmental extremes) factors. In the Monarch Butterfly Biosphere Reserve (MBBR) fir forests, Scolytus mundus and Pseudohylesinus spp. (both from Scolytidae) bark beetles are important pests which have caused deterioration. The goal was to determine relationships between forest damage with biotic and abiotic factors in the MBBR of Michoacán State, based on the damage caused by these bark beetles. Five progressive damage levels were monthly recorded (0 = no damage, 1 = trunk resin, 2 = foliage discoloration, 3 = dead tree tip and 4 = dead tree) from August 201 to August 2013 in nine sites of the MBBR; also were recorded the weather conditions (temperature, humidity and precipitation), and physiographic (altitude, exposure and slope) and forestry characteristics (tree’s high, foliage coverage, age, density and perimeter at the chest level) of each site. There were no relationships of the forest damage with the weather, physiographic and forestry conditions, which suggests that these factors have minimal influence on forest damage in the MBBR and probably other factors are more important, such as human activities or ecological interactions.