原著論文 ORIGINAL PAPER

日本産ガマ3種の地下部動態とその成長戦略

田中規夫¹⁾・ 浅枝隆²⁾・ 関渉²⁾

1)埼玉大学工学部建設工学科　〒338-8570　埼玉県さいたま市桜区下大久保255
2) 埼玉大学大学院理工学研究科　〒338-8570　埼玉県さいたま市桜区下大久保255

Norio TANAKA¹⁾, Takashi ASAEDA²⁾ and Wataru SEKI²⁾: Belowground dynamics and growth strategy of three Typha spp. in Japan. Ecol. Civil. Eng. 6(1), 25-34, 2003.

1) Department of Civil and Environmental Engineering, Faculty of Engineering, Saitama University, 255, shimookubo, Sakura, Saitama 338-8570, Japan
2) Graduate School of Science and Engineering, Saitama University, 255, shimookubo, Sakura, Saitama 338-8570, Japan

Abstract:Belowground dynamics and strategies were analyzed with respect to three species of Typha spp. in Japan. Root and shoot ratio(R/S) and root and rhizome ratio of them were closely related to the order of their maximum penetrating water depth. More rhizome were developed with deeper water depth, accordingly, biomass allocation for roots became smaller. Bioenergetic model of T. orientalis was formulated for analyzing their belowground strategy and indicated that nutrient flux from below to aboveground organs in heterotrophic season were smaller than T. angustifolia. T. latifolia, T. angustifolia and T. orientalis has each different strategy, enlargement, deep water penetration and preemption, respectively. Typha orientalis increases their density before flowering and the flowering season was the last among three species. Preemption of belowground space was the important strategy for T. orientalis.

Key words: belowground dynamics, preemption, Typha angustifolia, Typha latifolia, Typha orientalis

摘要

湿地植生の遷移は自然再生事業において維持管理上重要な視点となる．しかし，抽水植物の拡大特性や遷移については不明の点が多いため，抽水植物間の競合の優劣を考慮し立地条件を把握することが重要な課題となっている．本研究は，日本産ガマ科３種（コガマ，ガマ，ヒメガマ）の地下部動態の相違からその生長戦略を探り植生管理に必要な知見を得ることを目的とした． 　現地観測では，各器官毎の乾燥重量の季節動態，群落生産構造の調査（群落内の日射量と高さ毎のバイオマス計測），群落の密度，葉面積，植物体内に含まれるＮの含有率を計測し生長戦略を分析した．また，より詳細な過程を推論するため，生長モデルによる解析を行った．

2003年1月14日受付，2003年5月23日受理
1) e-mail: n-tanaka@post.saitama-u.ac.jp