民勤退化人工梭梭种群雨养恢复试验研究

通过对民勤人工梭梭种群更新、平茬矮化和林地结皮改造试验,探讨梭梭种群雨养恢复关键技术措施。结果表明:民勤人工梭梭种群以半固定沙丘、沙地上更新较好,更新苗平均密度为1 130～2 280株.hm-2,但当年生幼苗保存率低,为20.6%～53.3%,这主要受降水和风蚀环境的限制;人工梭梭全平茬处理明显促进了梭梭枝条生长和萌发,平茬后当年高生长量平均58.9 cm,新枝平均长度27.0 cm,二次枝萌发数平均16.9个,分别为半平茬梭梭的1.1倍、1.6倍和1.3倍;梭梭林地结皮的穴状破坏加速了降水水分入渗过程,降水入渗深度可达70 cm,结皮带状和片状处理对降水产生一定的截留,降水在50～70 cm之间入渗。

Rain-fed Recovery of Degenerated Artificial Haloxylon ammodendron Population in Minqin

Based on the experiment of population renewal, dwarf stumping and forest crust reform of artificial Haloxylon ammodendron population in Minqin, the key technical measures were investigated for rain-fed recovery of degenerated artificial H. ammodendron population . The results indicated that the population renewal of artificial H. ammodendron population at the semi-fixed sand dune and sandy progressed well, in which the average density of renewal seeding was 1 130～2 280 plants·hm~(-2), but the preserving rate of annual seeding was very low, ranging from 20.6% to 53.3%, effected mainly by the rainfall and wind-erosion. Full-stumping significantly promoted the growth of sprout and shooting, with the annual average height of 58.9 mm, average new-branch length 27.0 cm and average number of second branch 16.9, which were 1.1, 1.6 and 1.3 times of half-stumping. Hole-shape damage of H. ammodendron forest crust could accelerated rainfall water infiltration with the infiltration depth of 70 cm, on the other hand, zonal and flake damage of on the crust could produce interception to rainfall with the infiltration depths of 50～70 cm.