臺灣東北角海藻群眾結構及植物地理之研究

Floristic Studies on the Benthic Marine Algae of Northeastern Taiwan

本文旨在調查研究臺灣東北部海域底棲性海藻的種類、分佈及季節消長，並進行其群聚結構及植物地理親緣之探討。本研究共記錄有50科、105屬、179種海藻，包括藍藻3種，綠藻42種，褐藻27種，紅藻107種。其中，有9種是臺灣的新記錄種。在六個採集站均出現的種類有42屬50種，是本區藻類相的主要群聚結構之代表。比較六個採集站之藻相，其Jaccard's相似值均在40%以上。利用UPGMA方法可將各站分為二亞群，其中第1站（南雅）為獨立一群，第2站至第6站則為共同一群。在垂直分佈方面，生長在飛沫帶的藻類有8種，在潮間帶上、中部有25種，在潮間帶下部及低潮線附近有85種，在亞潮帶有143種。所有藻類之生長具有明顯的季節性變化，一般在冬、春藻相最豐富，夏、秋的種數最少。利用矩陣及群聚分析上，發現其消長演替發生在12～1月及8～9月之間。根據海藻的植物地理分佈分析，本區海藻相不僅具有濃厚熱帶色彩，也有不少溫帶性種類，這些海藻之分佈與黑潮暖流和大陸沿岸冷流之交會有密切之關係。

The composition, distribution. seasonal succession and phytogeographic affinities of the benthic marine algae in the northeastern Taiwan were studied. A total of 50 families. 105 genera and 179 species of marine algae were identified, including 3 species of Cyanophyta. 42 species of Chlorophyta. 27 species of Phaeophyta and 107 species of Rhodophyta. Among them, 9 species are new records in Taiwan. There are 42 families and 52 species of algae appeared in all sampling stations, which are representatives of the major algal community of northeastern Taiwan. The Jaccard's similarities of composition were over 40% between the sampling stations. Based on the analysis with UPGMA-method, it can be divided into 2 clusters, with station I (Nan-ya) as a separate cluster and stations II to VI as a joint one. With respect to vertical distribution, 8 species of the marine algae grow along the supralittoral fringe. 25 species on the upper and middle littoral zone. 85 species on the lower littoral zone and 143 species in the sublittoral zone. Most of species are seasonal and more abundant in winter and spring than in summer and autumn. The seasonal succession occurs twice between December-January and August-September. According to the phytogeographic study. it was found that the algal flora of northeastern Taiwan is mainly tropical. together with a number of temperate species. Their distributions are closely related to the meeting of the warm Kuroshio Current and the cold China Coastal Current.