Influence of Herbicides and Improvement Cutting, Fertilization, and Prescribed Fire on Planted Longleaf Pine Development

摘要

There is an interest in restoring longleaf pine (Pinus palustris Mill.) across its native range in the southeastern United States, and establishment of longleaf pine on much of its original range requires artificial regeneration and management of competing vegetation after planting. In Louisiana, two fertilization levels (No or Yes [36 kg/ha nitrogen and 40 kg/ha phosphorus]) in combination with three vegetation treatments (check, five prescribed fires [PFs], or multiyear vegetation control [IVM]) were applied to longleaf pine plantings established in a randomized complete block factorial design (alpha = 0.05). After 12 years, survival averaged 61% across the six-treatment combinations. Fertilization did not affect longleaf pine growth or stand production, and thus, native fertility was not limiting pine development. Longleaf pine bolewood production was significantly greater on IVM plots (165 m(3)/ha) than on check and PF plots (average of 113 m(3)/ha). In the 13th growing season, IVM plots had significantly less understory tree cover (51%) than checks (80%), but PF plots had the least tree cover (16%) and the most grass (5%) and forb (10%) cover. Fertilization significantly increased understory tree cover (58%) compared with that for unfertilized plots (40%), but woody vine cover was significantly less on fertilized plots (3%) than on unfertilized plots (6%).