四種原生殼斗科樹種之苗木根系功能性狀及生物力學特性

Root Functional Traits and Biomechanical Properties of Four Endemic Fagaceae Species

李嶸泰(Jung-Tai Lee) ； 江怡蓁(Yi-Zeng Jiang)

《台灣林業科學》 37卷2期 (2022/06) Pp. 145-156

https://doi.org/10.7075/TJFS.202206_37(2).0004

摘要

在臺灣，颱風及季風暴雨常引發高山及丘陵地區嚴重的崩塌災害。崩塌地復育為當前林業經營之重要課題。卡氏櫧（Castanopsis carlesii）、青剛櫟（Cyclobalanopsis glauca）、三斗石櫟（Pasania hancei）及川上氏櫧（Pasania kawakamii）為崩塌地次級演替常見的原生殼斗科樹種，具有崩塌地復育之潛力，然其根系性狀及生物力學特性仍未被探討。本研究利用WinRHIZO分析系統、拉拔試驗及單根拉伸試驗等方法，調查此四樹種二年生苗木之根系性狀及根生物力學特性，以作為選擇植生復育樹種之參考。研究結果顯示，四種殼斗科樹種之根系結構均屬於垂直水平型（VH-type）。青剛櫟之生長表現、根系功能性狀均顯著優於川上氏櫧、三斗石櫟及卡氏櫧者；青剛櫟根系之最大拉拔抗力也顯著高於川上氏櫧、卡氏櫧及三斗石櫟者；青剛櫟、川上氏櫧及卡氏櫧之單根抗拉強度顯著高於三斗石櫟者；青剛櫟之單根抗拉力為四樹種中最高者；而青剛櫟、川上氏櫧及卡氏櫧之單根抗拉強度亦顯著高於三斗石櫟者。綜合以上結果證實，青剛櫟之生長表現、根系功能性狀、拉拔抗力及單根抗拉強度優於川上氏櫧、卡氏櫧及三斗石櫟者。因此，依據本研究結果建議造林樹種的選擇順序可考慮為青剛櫟＞川上氏櫧＞卡氏櫧＞三斗石櫟。

關鍵字

殼斗科樹種 ； 根系結構 ； 根功能性狀 ； 生物力學特性

並列摘要

In Taiwan, typhoons and monsoonal torrential rains often induce serious landslide hazards in mountains and hilly regions, and thus landslide restoration has become a pressing issue for forest management. Castanopsis carlesii, Cyclobalanopsis glauca, Pasania hancei, and P. kawakamii are endemic Fagaceae species that often occur during secondary succession on scars after a landslide. They have high potential for enhancing restoration of landslide scars. However, their root characteristics and biomechanical properties have not been explored. In this research, root traits and biomechanical properties were investigated with the WinRHIZO system, vertical uprooting, and tensile tests using 2-yr-old seedlings in order to provide criteria for species selection in landslide restoration. The results show that the root systems of these 4 species belong to the vertical and horizontal (VH)-type. Cyclobalanopsis glauca had remarkably higher root traits and functional traits than those of P. kawakamii, P. hancei, and Cas. carlesii. Additionally, the maximum pullout resistance for Cyc. glauca was notably higher than for P. kawakamii, Cas. carlesii, and P. hancei. Root tensile resistance for Cyc. glauca was significantly higher than for P. kawakamii, P. hancei, and Cas. carlesii. Root tensile strengths of Cyc. glauca, P. kawakamii, and Cas. carlesii were notably higher than that for P. hancei. Taken together, these results clearly demonstrate that Cyc. glauca has superior growth performance, functional traits, anchorage capability, and root tensile strength than P. kawakamii, Cas. carlesii, and P. hancei. Thus, it is suggested that the species priority ranking for these 4 species should be Cyc. glauca ＞ P. kawakamii ＞ Cas. carlesii ＞ P. hancei.

並列關鍵字

Fagaceae species ； root system architecture ； root functional traits ； root biomechanical properties