南仁山亞熱帶雨林樹皮黏菌之組成及布類型

Abstract

黏菌為森林中常見的棲息生物。森林中常見的黏菌棲地有腐木、枯枝、枯幹及落葉等凋落物、活樹樹皮表面及動物的糞便等。樹皮黏菌所指的便是生長於活樹樹皮表面上的黏菌。本研究自1995年9月至1996年9月於南仁山亞熱帶雨林3公頃永久樣區中進行。由於地形、風力、溼度等不同因素的影響，樣區中植被可再細分為四個棲地，分別為強風區、緩風區、背風區和溪穀區（謝等，1992; Sun et al., 1996）。研究期間，每月固定採集各區中前十優勢樹種之樹皮，製備成濕室培養黏菌。結果共得17屬49種黏菌子實體。Arcyria cinerea (Bull.) Pers.出現頻率最高，佔13.42％，而出現頻率較高的屬依次為Physarum Pers. (21.8％)、Echinostelium de Bary (15.10％)、Arcyria Wiggers (14.76％)、Diderma Pers. (9.06％)和Licea Schrad. (8.39％)。其中，Echinostelium apitectum Whitney和E. paucifilum Whitney為台灣的新記錄種；Trabrooksia Keller（鑑定至屬）為台灣的新記錄屬；此外，Comatricha acanthodes Alexop.、C. laxa Rost.和Perichaena minor (G. Lister) Hagelst.為台灣的第二次紀錄，亦屬於較稀有的種類。 比較四個棲地中的黏菌社會，強風區與緩風區較相似，而溪穀區與背風區較相似。此與樣區中高等維管束植物社會的分佈類型具有一致性，因此，樹皮黏菌在不同棲地中的分佈可能直接或間接受到地環境梯度的影響。不同的樹種中以小葉赤楠出現的黏菌次數最多，平均每一濕室培養出1.92種黏菌，而鏽葉野牡丹出現的次數最少，研究期間只出現一次黏菌。樹皮黏菌出現的頻率及種數在夏末和秋初（7、8、9月）較低；有些黏菌屬於四季分佈型，然而有多種黏菌的出現只局限於某個或某幾個季節。比較不同種類黏菌生長的樹皮平均pH值與所有取樣樹皮平均pH值顯示，Cribraria confusa Nann.-Brem. & Yamam.、Echinostelium minutum de Bary、Licea operculata (Wingate) Martin和Physarum sp.所生長的樹皮pH值顯著低於所有取樣樹皮pH值，而Physarum oblatum Macbr.則顯著較高。此外，某些黏菌的出現似乎與其他附生於樹皮上的苔蘚類植物有關。

Corticolous Myxomycetes had been studied in a permanent 3-ha plot of a lowland subtropical rain forest in Nanjenshan area, southern Taiwan. From September 1995 to September 1996, bark samples of 40 dominant trees were collected monthly from four habitats — windward, intermediate, leeward, and creek respectively (Hsieh et al., 1992; Sun et al., 1996) for preparing moist chamber cultures. A total of 298 collections of myxomycete fruiting bodies in 17 genera and 49 species were obtained from the moist chamber cultures prepaerd. Among them, Arcyria cinerea (Bull.) Pers. (13.42%) was the predominant species. The genera occurred with higher frequency were Physarum Pers. (21.8%), Echinostelium de Bary (15.10%), Arcyria Wiggers (14.76%), Diderma Pers. (9.06%) and Licea Schrad. (8.39%). Echinostelium apitectum Whitney and E. paucifilum Whitney are new to Taiwan. Comatricha acanthodes Alexop., C. laxa Rost. and Perichaena minor (G. Lister) Hagelst. are found for the second times and the genus Trabrooksia Keller is first reported from Taiwan. Comparing the corticolous Myxomycetes occurring in the four habitats, both the community coefficient (CC) and the percentage of similarity (PS) reveal that windward habitat is more similar to intermediate habitat and creek habitat is more similar to leeward habitat. This is consistent with the distribution patterns of the vascular plant communities in the same study area and suggests that the distribution of corticolous Myxomycetes may be directly or indirectly affected by environmental factors. The frequency and number of species of corticolous myxomycetes were lower in late summer and early autumn (i.e. July, August, September). There are some species occurring all year round. However, occurrence of some species seems to restrict to only a certain season or seasons. Among the different tree species, in terms of myxomycete occurrence, bark of Syzygium buxifolium Hook. & Am. was the most productive and bark of Astronia ferruginea Elmer was the least with only one collection during the period of this study. By comparing the average pH values of bark samples, Cribraria confusa Nann.-Brem. & Yamam., Echinostelium minutum de Bary, Licea operculata (Wingate) Martin and Physarum sp. occurred on the bark with significantly lower pH value, and Physarum oblatum Macbr. occurred on those with significantly higher pH value.