Initial nutrition and post-fire resprout of a Juniperus deppeana Steud. reforestation

Abstract

Low growth rate forest species are rarely studied. The initial growth of Juniperus deppeana was evaluated through a field fertilization experiment (N-P-K). The post-fire regrowth capacity of the seedlings was also evaluated. There levels of N and P and two levels for of K were combined for a total of 18 treatments, using six plants as replicates. Additionally, the increase in the root collar diameter (IBD) was evaluated for one and two-year-old plants. Six months after fertilization, only the N-P-K interaction was statistically significant (P<0-06) for IBD. The highest levels of N matched to highest IBD. After seven months of the establishment of the field experiment, a forest fire occurred, after which the regrowth capacity and the concentrations of macronutrients (N-P-K-Ca-Mg-S) were evaluated, taking into account the fertilization background. The main effects tested in the experiments were, fertilization, seedling age and fire damage. Most of the trees (84 %) resprouted after the fire. Plants with a legacy of fertilization had lower nutrients in plant tissue. Post-fire nutrient recovery of J. deppeana is determined by the redistribution of nutrients reserves in the soil and the plant. For slow growing species J. deppeana, plants aged two years are more suitable for reforestation due to their higher growth rates.