造成地における自然環境復元手法に関
る実験研究
敦賀市
発電所法面を事例と
て
高
政鉉
キヴワヴド:自然環境復元 生物多様性 ミゾ゛ゲヴション 埋土種子 森林表土 緑
1. めに
近年 多く 成地 い 単 る防災や緑
ら 自然環境復元 求 られるこ 多く
いる 本論文 福井県敦賀 自然
公園区域 ける発電所増設 伴い ミゾ゛ゲヴシ
ョン 求 られ いる状況 い 早期 種
多様性 富 植物群落を形成 る 地域固有
遺伝子プヴャを 木本群落 形成 る 現
場発生土 モサ゜クャ 可能 ある 等 利点を
ち 最近注目され いる森林表土を用いた手法 在
来工法 比較実験研究を行い こ 手法 生物多
様性を確保 る自然環境復元手法 有効性を
い 検討 た
.研究方法
対象地 現存林 毎木調査を行 た後 現地 表
土を撒 出 た温室 ける発芽能力ポゾンシホャ
実験 現場 行 た法面実験 ら得られたタヴタを
用い こ 調査ン実験 相関関係を 析 た
改変予定地 る森林表土 程度
ポゾンシホャを備え いる を確認 るた
植生 立地条件 異 る ②地点 ら A
0
層 表土(L
層を含 ,概 イ ㎝厚)を採取 育苗箱 鹿沼土
(イ.0 ㎝厚)を 層基盤 イ.0 ㎝厚 約 イ ㎡( 実験区当たり約 0.② ㎡X② 実験験区) 規模 撒 出
た
た 成予定地 自然環境復元方法
適合性を検討 る目的 敦賀発電所法面 ける工
法 よび導入種子配合比較実験 行い 既設 土法
面( 東向 1:0.③) ペャタャを除去 急傾斜
地 い 生育基盤 確保 る土木繊維補強土
工法を 層 施工 そ 厚層基材吹付緑 工
法 施工を行 た
実施工法 連 繊維複合補強土工法( 層
20cm 厚+ 表層 イcm 厚) 長繊維混入補強土一体緑 工法( 工法同様) 接着繊維工法(表層 ③cm 厚) 併
用工法 層: 工法 層基盤+表層: 工法
表層 ある た導入種子配合 A 配合 現地
表土型:表土 を 工法 表層 イ㎝ 20れ
混入 , 工法 表層 2 ㎝ 20れ混入 B 配
合 現存植生型- :ィ 種類 木本+外来草本 C
配合 現存植生型- :B 配合 木本 D 配合
先駆植生型:ィ 種類 先駆性木本 ある そ
実験地 規模 1 実験区当り 20 ㎡ 幅員 イmX 斜面長 ィm 1① 実験区を設置 320 ㎡ ある
.結果及び考察
ポゾンシホャ実験 い 現地毎木調査出
現種 そ 調査 記録され た 埋土種子
個体群 発芽能力を持 いた木本種数
イ1% 出現 確認 た 現地表土 ポゾンシホャ
り高い 断される
一方 森林表土を用いた法面緑 実験 い
出現種数 い 室内 灌水 温度調節
維持ン管理 行われたポゾンシホャ実験 比
同様 ィ④% 発芽ン生長 確認され さら
周辺 ら 思われる 10 種 木本 侵入 周囲
調和 れた景観形成 可能性 指摘 る
従来 工法 比 る これ 急 緑
緑 成否 評価基準 ある発芽成立 た芝草
幼苗本数密度や植被率 量的 指標 ら る
多少劣勢 あ た 毎木調査出現種 うち
こ 手法 発芽 確認され た種 い
今後 追跡調査を ら 対策を検討
改変前 生物多様性を 植生復元を追求
ある 考える
最後 自然環境復元を行う際 種
多様性を確保 る 単 る緑 る く
動植物 ら成る持 可能 生態系を る 自然
非均質 heャerogeneouモ あるた 同 基
準 よび方法を用いるこ 避ける 必要
Experimental study of natural environmental revegetation method in constructed area
-Case study in cut-slope of power plant in Tsuruga city-
Jeung Hyun KOH
Keyword: Natural environmental revegetation, biodiversity, mitigation, seed bank, forest topsoil, revegetation
1. Introduction
Recently, in the lots of constructed area, natural
environmental revegetation of the protection of nature,
restoration of an ecosystem, etc. is being called for more
often. Then, in this paper, the comparison experiment research with the technique and traditional method of
construction using the forest topsoil which attracts
attention recently was carried out, and it tried about having
validity as the natural environmental revegetation
technique which can perform the reservation of biodiversity in this study site where is called for mitigation
in the situation with power plant extension in the nature
park zone in Tsuruga-city, Fukui prefecture.
2. Methods
After conducting investigation of the existing
vegetation of the study site, the correlation of these three
investigation and experiments was analyzed using the data obtained from the cut-slope experiment and potential
experiment in the greenhouse.
First, in order to check the potential of the forest topsoil
placed, A0 layer topsoil (L layers are included and in
general 5cm deep) is selected from seven points where vegetation differs from conditions and locations, and it
was placed in 5cm deep at a tray on a scale of about 5
square meters (about 0.7square meter X 7 plot) by making
the artificial soil ground (5cm deep) into a lower layer base.
Moreover, the comparison experiment of construction
method and the type of seed combination were also
conducted for the purpose which examines the conformity
as the natural environmental revegetation method to the planned reclamation site, the mortar of established
cut-slope (northeast, 1:0.8) was removed, and the
geo-textile method which can perform reservation of a
growth base in a steep slope was constructed in the lower
layer, and the revegetation method of construction with hydro-spray machine was constructed on it. Construction
methods are as follows (1)geofiber method [ 20cm deep
of lower layer and 5cm deep of surfaces] (2)roving wall
method [ same way of (1) ] (3)texol green method (8cm deep of surfaces] (4)mixed method [ lower layer of 20cm
by (1)method and surface of 8cm by (3)method].
Comparison of type of seed combination was also
carried out and like these A type [topsoil only], B type
[existing vegetation type + orchard glass], C type [existing vegetation type], D type [pioneer vegetation type]. And
the scale of the experiment is 320square meters.
3. Results and Discussion
First, although it did not exist as trees in a tree
investigation appearance kind and its investigation
whenever it preceded in the potential experiment, 51% of
appearance of the number of the buried seeds which set the kind considered to have been contained in topsoil in
the form of a buried seed as an underground individual
group can be checked, and it is judged that potential of
seed bank is high.
The results indicate that it was able to take the harmony which 49% of a sprout and growth are checked almost
similarly compared with the potential experiment to, and
ten sorts of invades from the circumference further, and
has biodiversity about the number of appearance kinds first in the cut-slope revegetation experiment using forest
topsoil on the other hand. However, compared with the
conventional method of revegetation, it was somewhat
inferior in strength, in view of quantitative indices, such as
grass-tree number density and sprout enactment, and rate of coverage which are the valuation basis of the success or
failure of revegetation. Finally, it is considered that it is
necessary continuing monitoring and study to pursue the