Departmental Bulletin Paper 岩手県内のスギ人工林における林内光量と林床植生被度の関係

國崎, 貴嗣  ,  蓮沼, 友紀子  ,  上石, 有吾  ,  KUNISAKI, Takashi  ,  HASUNUMA, Yukiko  ,  AGEISHI, Yugo

46pp.11 - 20 , 2015-06-01 , 岩手大学農学部附属寒冷フィールドサイエンス教育研究センター
ISSN:0286-4339
Description
岩手県内のスギ無間伐人工林,または最近まで25年以上にわたって間伐されていなかったスギ人工林を対象に,林内相対光量と林床植生の被度との対応関係を調べた。林内相対光量子束密度(rPFD)が高くなるほど林床植生の被度は高くなり,rPFDが12.5%以上で被度5となった。rPFD12.5%における林床木本の平均樹高成長率は19cm/年と推定された。rPFD12.5%に対応する収量比数は0.598であり,過密なスギ人工林でこの値以下に誘導するには,本数間伐率50%以上の下層間伐が必要であると考えられる。
The relationship between light intensity under the canopy and floor vegetation cover were investigated in unthinned young and overcrowded mature plantations of Sugi (Cryptomeria japonica D. Don) in Iwate Prefecture. In 2012, thinning with an intensity of 38% of stand tree density was carried out in an overcrowded mature plantation, in 2014, a total of 20quadrats were established in the young and mature plantations, and floor vegetation cover, height increment of saplings and the relative photon flux density (rPFD) 0.8m above the ground were studied. The abundance of floor vegetation cover was positively correlated with the rPFD and was > 75% when the rPFD was higher than 12.5%. The mean height increment of saplings was estimated to be 19cm per year when the rPFD equaled 12.5%. A yield index based on a stand density diagram was 0.598 when the rPFD equaled 12.5%. Thinning with an intensity of 50% or more of stand tree density is probably needed to improve the light condition under the canopy and to maintain luxuriant ground vegetation in overcrowded plantations of Sugi.
Full-Text

https://iwate-u.repo.nii.ac.jp/?action=repository_action_common_download&item_id=9044&item_no=1&attribute_id=36&file_no=1

Number of accesses :  

Other information