珠防工程幼林综合持水能力研究

A Study of Integrated Water Conservation Capacity of Young Forests in the Shelter Belt Program of the Zhujiang River Valley

本文在对珠防工程监测样地调查、测定的基础上,从林冠层、枯落物层和土壤层3个水文层次对珠防二期工程幼林的综合持水能力进行了评价。3 a^4 a生珠防林幼林的综合持水量在2 355.25~2 457.08 t/hm2之间,比荒山高3.7%~8.2%。其中土壤贮水量、枯落物持水量、植冠层的持水量分别比荒山高3.65%~8.03%、21.4%~61.1%和42.9%~305.3%,而土壤贮水量、枯落物持水量增加不明显,植冠层持水量增加显著。植冠层和枯落物层的持水量比土壤持水量小得多,林分的贮水主体为林地土壤。珠防林幼林的综合持水能力因恢复措施以及林分类型不同而存在差异。人工造林幼林的综合持水能力比封山育林高;4 a生的针叶林的综合持水量最大,针阔混交林、竹林次之;3 a生的阔叶林的综合持水量最大,针阔混交林、针叶林次之。

This paper evaluates the water conservation effects of the young forests of the Shelter Belt Program （ Phase Ⅱ ） of the Zhujiang Valley from three hydrologic levels of crown canopy, litter layer and soil layer, based on field investigations and measurements. The integrated water conservation amount of the 3 to 4 year old young forests is between 2 355.25 - 2 457.08 t· hm ^-2, and 3.7% - 8.2% higher than that of bare mountains, in which the water conservation amounts of soil, litter and the crown canopy are separately 3.65% -8.03%, 21.4% -61. 1% and 42. 9% -305.3% higher than those of the bare mountains. Increases in water conservation are not distinct in soil and litter while distinct in the crown canopy. The water conservation amount of the crown canopy and litter is much less than that of soil, thus the main contributor of water conservation is soil. The capability of integrated water conservation of the young forests varies from different restoration measures and forest types. Ability of water conservation of young plantations is higher than that of mountain closure. In 4 year old forests, coniferous forests boast the highest water conservation, the mixed coniferous and broadleaf forests are the second highest, and then bamboo forests follow. In 3 year old forests, broadleaf forests boast the highest water conservation, the second highest is mixed coniferous and broadleaf forests and the next is conifer forests.