蘇花公路沿線植群多樣性分析

Vegetation Diversity Analysis along the Suhua Highway

臺9線蘇花公路自開通以來，除區域性或針對保護（留）區之相關植群調查外，至今尚無較全面性之植物資源調查及多樣性分析；是故本研究進行蘇花公路沿線植群生態調查，並加以分析其植群組成、結構與分布的差異。2012~2014年共計設置88個植群樣區，並記錄維管束植物139科 396屬661種；其中受威脅物種計有日本卷柏等23種。另利用矩陣群團分析，可將樣區分為樹杞－江某、澀葉榕－豬母乳、豬母乳－樹杞－菲律賓榕、豬母乳－澀葉榕、細葉饅頭果－小葉桑、青剛櫟－血桐－白肉榕、血桐－構樹－蟲屎、木麻黃－海檬果等八類林型，其中豬母乳－樹杞－菲律賓榕、豬母乳－澀葉榕、細葉饅頭果－小葉桑等三林型已趨於穩定之中後期演替階段，且亦以豬母乳－樹杞－菲律賓榕林型之多樣性最高；較多樣區符合幾何序列的木麻黃－海檬果林型，其種豐多度及豐富度亦皆最低，現場調查時發現此多分布於海岸較平緩區域，原因係較易受人為或自然干擾所致。此外，建議後續研究可再於楠櫧林帶（500~1,500 m）之東北近海區（NEC）的蘭陽溪下游（玉蘭～大元山以北），以及東部區北段（EN）的立霧溪（中橫東段、清水山）設置樣區綜合比較之，期能更完整地瞭解蘇花公路全線之植群多樣性，供爾後公路總局、當地縣政府及其他單位於於公路邊坡管理、行道樹、育林及崩塌地之植生復育等的參考。 Suhua Highway (Provincial Highway No.9) had no complete floristic information since the highway was opened, but only some related vegetation investigations of the regional sites and protected areas. Hence the investigation of ecological vegetation along the Suhua Highway was carried out in this study, and the composition, structure and distribution of the vegetation variation was analyzed thoroughly. 88 plots of vegetation were set up along the Suhua Highway and the nearby areas during 2012 to 2014. 661 species, 396 genera, and 139 families of vascular plants were recorded, including 23 species of the threatened species such as Selaginella nipponica. There were 8 forest types classified by the matrix cluster analysis: I. Ardisia sieboldii-Scheffl era octophylla Type; II. Ficus irisana-Ficus fi stulosa Type; III. Ficus fistulosa-Ardisia sieboldii-Ficus ampelas Type; IV. Ficus fistulosa-Ficus irisana Type; V. Glochidion rubrum-Morus australis Type; VI. Quercus glauca-Macaranga tanarius-Ficus virgata Type; VII. Macaranga tanarius-Broussonetia papyrifera-Melanolepis multiglandulosa Type; and VIII. Casuarina equisetfolia-Cerbera manghas Type. Among them, the Ficus fistulosa-Ardisia sieboldii -Ficus ampelas Type, Ficus fistulosa-Ficus irisana Type, and Glochidion rubrum-Morus australis Type were developed stably to climax gradually. The Ficus fistulosa-Ardisia sieboldii-Ficus ampelas Type had the highest diversity. More plots of the Casuarina equisetfolia-Cerbera manghas Type fitted to the geometric series and had the lowest abundance and richness. It was found that most of the plots stated above occurred on the gradualler areas along the coast with more human and natural disturbances. Moreover, it was suggested to set more plots on the the broad-leaved Machilus-Castanopsis forest (500~1,500 m) of downstream Lanyang Stream (Yulan to northward Mt. Dayuan) in the northeast coastal region (NEC), and Liwu River (the middle Central Cross-Island Highway and Mt. Chinhshui) in the east region north section (EN). It would be helpful to understand the vegetation diversity along the whole area of Suhua Highway completely. It might provide a reference to the Directorate General of Highways (MOTC), County Governments, and other researchers for the phytoremediation on the side slope of road, shade trees, afforestation, and landslide restoration.