ICOM1 Abstract

BONET, JOSE A., JUAN J. BECERRIL, JORDI ROMA & CARLOS COLINAS. Dep. Proteccion de cultivos, Centro UdL-IRTA, Av. Rovira Roure 177, E-25198 Lleida, Spain.- The relationship between orientation, thinning and forest age on the production of sporocarps of ectomycorrhizal fung i in Pinus sylvestris forests of the Central Pyrenees Harvest of edible sporocarps of ectomycorrhizal fungi in the Pyrenees has increased over the past five years with interest in managing forested lands for mushroom production. This study was designed to examine the influences of silvicultural treatments and forest conditions on sporocarp production over four years. Weekly collections were made from research plots from mid-Sept. through Nov. Results presented here were obtained from 1994 and 1995. The average fresh weight of sporocarps of ectomycorrhizal fungi was 105 kg/ha (dry weight =11 kg/ha). Of this total, 61 kg/ha fw. (dw. = 6 kg/ha) were edible sporocarps. The most abundant genus among the edible sporocarps was Suillus (33%) with 12 kg/ha fw. of Suillus luteus. Next in abundance was Tricholoma (30%), with 18 kg/ha fw. of Tricholoma imbricatum. Mature plots (65-75 yr.) had high productions of Suillus variegatus and Cortinarius sp.while plots of 45-55 yr. were dominated by Inocybe sp. In young plots (25-35 yr.) the most abundant genus was Laccaria. Diversity of taxa collected increased significantly in mature forest plots. Orientation was significant in the phenology of the harvest, with east and south orientations similar. Harvest initiated and endured longer on south-facing plots. The L. deliciosus harvest began on plots with a southern aspect and continued westward, ultimately to plots with a northern exposure. With regard to thinning, the only taxonomic group that showed significant increase in production in thinned forests was the genus Cortinarius although Suillus luteus showed a tendecy to increase production with thinning and the genus Inocybe showed the opposite tendency.