不同造林抚育措施对桉树人工林坡面径流特征的影响

Effects of different forestation-tending measures on slope surface runoff characteristics of Eucalypt plantation

【目的】探讨桉树人工林坡面径流特征及其影响因素，促进桉树人工林科学经营。【方法】建立10个坡面径流小区，以采伐迹地灌草坡作对照（CK），研究萌芽更新、人工割灌割草清理林地和除草、施基肥和追肥，火烧清理林地、植苗更新、化学除草、施基肥和追肥，人工割灌割草清理林地和除草、植苗更新、只施基肥不追肥，桉树萌芽更新1代3年生林地4种不同造林抚育措施干扰下桉树林地的坡面产流量和泥沙流失量，探讨桉树人工林的科学栽培和可持续经营途径。【结果】火烧清理林地、植苗更新、化学除草、施基肥和追肥的林地坡面产流总量和泥沙流失总量分别为117．54mm和1366．76kg／ha，比人工割灌割草清理林地和除草、植苗更新、只施基肥不追肥的林地分别高15．61％和84．65％，比萌芽更新、人工割灌割草清理林地和除草、施基肥和追肥的林地高12．46％和68．13％；桉树萌芽更新3年生林分林地的坡面产流总量和泥沙流失总量分别为81．22mm和263．50kg／ha，比萌芽更新造林当年的分别低22．30％和67．60％。比对照低23．80％和62．60％；不同造林抚育措施的坡面产流量和泥沙流失量与降水量间均呈极显著线性正相关（R=0．743～0．953）。【结论】火烧清理林地、植苗更新、化学除草、施基肥和追肥等耕作活动（造林抚育措施）及大量级降水是桉树人工林产生较高坡面径流量和泥沙流失量的主要原因。

[Objective]The slope runoff characteristics and the relative influencing factors of Eucalyptus plantation were studied to promote scientific management of Eucalyptus plantation. [Method]To examine the scientific cultivation and sustainable management of Eucalyptus plantation, 10 slope runoff plots were set up to study the effects of the slope runoff volume and sediment loss amount of four different kinds of afforestation and tending measures , which were the sprout regeneration, artificial to clear woodland and weeding with cutting shrub and cutting grass, basic fertilizing and topdressing; clearing woodland with the fire, seeding update, chemical weeding, basic fertilizing and topdressing; the artificial to clear woodland and weeding with cutting shrub and cutting grass, seeding update, basic fertilizing no topdressing; three-year Eucalyptus stand of the first sprouting regeneration, compared with the deforested bringing slope. [Result]The amount of slope runoff and sediment erosion of the woodland with fire clearing, seed- ing update, chemical weeding, basic fertilizing and topdressing was 117.54 mm and 1366.76 kg/ha, respectively, which was higher than that of woodland treated by artificial clearing woodland and weeding with cutting shrub and cutting grass, seeding update and basic fertilizing but no topdressing by 15.61% and 84.65%, respectively, and was also higher than that of woodland treated by sprouting regeneration, artificial clearing woodland and weeding with cut- ting shrub and cutting grass, basic fertilizing and topdressing by 12.46% and 68.13%. The amount of slope runoff and sediment erosion of three-year Eucalyptus stand of the first sprouting regeneration was 81.22 mm and 263.50 kg/ ha, respectively, which was lower than the first-year sprouting regeneration woodland by 22.3% and 67.6%, and was also lower than the deforested bringing slope by 23,8% and 62.6%, respectively. Moreover, there was extremely significant positive linear correlation among the rainfall, the slope surface flow and sediment erosion of woodlands with different afforestation tending measures （R=0.743-0.953）. [Conclusion ]Human cultivation and afforestation tending measures such as clearing land with the fire, seeding update, chemical weeding, basic fertilizing and topdressing, and heavy precipitation are the main causes of heavy surface runoff and sediment erosion of Eucalyptus plantation.