Pinus pseudostrobus Lindl. induced regeneration under different canopy densities and site conditioning

Abstract

The lack of regenerating practices in the wooded area under forest management of Nuevo San Juan Parangaricutiro, Michoacán, Mexico allowed the development of this study whith the following objective: to describe the induced regeneration of Pinus pseudostrobus in response to tree densities and differing site conditioning practices. The methodology consisted of the selection of 6 stands, the election of 6 tree densities, the establishment of 72 sites, site conditioning treatments (burning, cleaning, fallow and control), sowing of 420 seeds per site and factorial variance analysis. From the obtained results the following comes off: plant emergence after 2 months of applying the four and six treatments was 27.19 % (20 301 seedling h-1), differing from the control (29.77 %), from the 88-tree density (35.15 %) and 88-tree density interaction with the control (41.5 %). By the 5th and the 8th month period there were differences among treatments, with over 60 % survival for the fallow and the cleaning practices. The 88-tree and 140-tree interactions with fallow and cleaning showed 70 % and 90 % survival for that period, respectively. From the 5th month to the 1th month period there was a drastic mortality of over 70 % plants. In regard to plant height within the four and six treatments, differences were observed in the 5th and the 8thmonth period, with greatest plant height detected within the control and the cleaning practices, while the 0-tree density was superior to all treatments during the whole lapse of time.