七家灣溪濱岸植群之組成與結構

Composition and Structure of Riparian Vegetation in the Cijiawan Stream

為瞭解濱岸植群之組成與結構變化，本研究於七家灣溪主河段、桃山北溪、桃山西溪、高山溪及有勝溪等測站之濱岸，設置30個植群監測樣區。依據矩陣群團分析可區分為；高山藤繡球－臺灣赤楊型、蓪草－臺灣紫珠型、屏東木薑子型、臺灣二葉松－大頭茶型、栓皮櫟－臺灣二葉松型、臺灣二葉松－臺灣赤楊型，以及臺灣赤楊型等七型；其中以栓皮櫟－臺灣二葉松型居多，而臺灣赤楊型次之，屬高山藤繡球－臺灣赤楊型、蓪草－臺灣紫珠型、屏東木薑子型、臺灣二葉松－大頭茶型者為少數。又桃山西溪（#2）與繁殖場（#5）測站之濱岸植群較相似，以栓皮櫟、臺灣二葉松混生為主；而桃山北溪（#1）與一號壩（#4）測站之濱岸植群較相似，主要優勢種多為臺灣赤楊。此外，各測站之樣區中喬木層植物之重要值大於30者，地被層植物大於10者列為優勢種植物，此等資料可供如昆蟲、兩生類、鳥類、魚類等相關研究，供探討其生物資源之食性組成的依據；並可提供經營管理單位於林相改良、綠化之選種參考。 In order to realize the change of the composition and the structure of the riparian vegetation, 30 plots were set near by the riparian surveying stations in the major segment of Cijiawan Stream, Taoshan North Stream, Taoshan West Stream, Gaoshan Stream and Yousheng Stream. 95 families, 209 genera and 335 species of vascular plants were recorded. The vegetation in this area could be distinguished into 7 types by the matrix cluster analysis (MCA). These were: Hydrangea aspera-Alnus formosana type, Tetrapanax papyriferus-Callicarpa formosana type, Litsea akoensis type, Pinus taiwanensis-Gordonia axillaris type, Quercus variabilis-Pinus taiwanensis type, Pinus taiwanensis-Alnus formosana type and Alnus formosana type. Among them, Quercus variabilis-Pinus taiwanensis type was in the majority, and then Alnus formosana type was next to it. Hydrangea aspera-Alnus formosana type, Tetrapanax papyriferus-Callicarpa formosana type, Litsea akoensis type, and Pinus taiwanensis-Gordonia axillaris type were minorities. The riparian vegetation on the Taoshan West Stream station (#2) was similar to that of the Breeding Center station (#5). The major species were Q. variabilis and P. taiwanensis. The riparian vegetation on the Taoshan North Stream site (#1) was similar to that of the Dam I station (#4). The major dominant species were A. formosana. Besides, the overstorey with the IVI more than 30 and the understory with the IVI more than 10 in each site were selected to be the dominants. This information is useful to relevant investigations, insects, amphibians, birds, fish etc., to discuss the diet composition of biological resources. These could also be the references for the stand improvement and greenery.

In order to realize the change of the composition and the structure of the riparian vegetation, 30 plots were set near by the riparian surveying stations in the major segment of Cijiawan Stream, Taoshan North Stream, Taoshan West Stream, Gaoshan Stream and Yousheng Stream. 95 families, 209 genera and 335 species of vascular plants were recorded. The vegetation in this area could be distinguished into 7 types by the matrix cluster analysis (MCA). These were: Hydrangea aspera-Alnus formosana type, Tetrapanax papyriferus-Callicarpa formosana type, Litsea akoensis type, Pinus taiwanensis-Gordonia axillaris type, Quercus variabilis-Pinus taiwanensis type, Pinus taiwanensis-Alnus formosana type and Alnus formosana type. Among them, Quercus variabilis-Pinus taiwanensis type was in the majority, and then Alnus formosana type was next to it. Hydrangea aspera-Alnus formosana type, Tetrapanax papyriferus-Callicarpa formosana type, Litsea akoensis type, and Pinus taiwanensis-Gordonia axillaris type were minorities. The riparian vegetation on the Taoshan West Stream station (#2) was similar to that of the Breeding Center station (#5). The major species were Q. variabilis and P. taiwanensis. The riparian vegetation on the Taoshan North Stream site (#1) was similar to that of the Dam I station (#4). The major dominant species were A. formosana. Besides, the overstorey with the IVI more than 30 and the understory with the IVI more than 10 in each site were selected to be the dominants. This information is useful to relevant investigations, insects, amphibians, birds, fish etc., to discuss the diet composition of biological resources. These could also be the references for the stand improvement and greenery.