鼎湖山自然保护区黏菌的物种组成和多样性

Species composition and diversity of myxomycetes in Dinghu Mountain Nature Reserve

关键词:  黏菌, 广东, 群落, 丰富度, 季节, 高度

Key words:  myxomycetes, Guangdong, community, abundance, season, elevation

摘要:

为了揭示鼎湖山自然保护区黏菌的物种组成及物种多样性在不同生境的异同,该研究选择6个不同海拔高度的样地,从中收集地面基物和树皮基物进行湿室培养,通过物种鉴定和发生数量统计分析物种的组成和多样性。结果表明:共计获得6目8科18属49种黏菌,其中绒泡菌目(Physarales)最多(17种),其次为团毛菌目15种、发网菌目(Stemonitales)11种、无丝菌目(Liceales)4种、鹅绒菌目(Ceratiomyxales)和刺轴菌目(Echinosteliales)分别各1种。主要优势种为灰团网菌(Arcyria cinerea)(RA=27.03%)和垫形双皮菌(Diderma effusum)(RA=21.14%)。随着海拔的升高,黏菌物种多样性逐渐降低,Shannon-Wiener多样性指数最低值出现在海拔300 m处,为1.66±0.12; 而其优势集中性指数最高,为0.25±0.05。两个样地的海拔高度相距越大,共有的物种数越少,相似性指数越低。雨季共获得黏菌33种,旱季共获得黏菌40种,共有种为22种,相似性系数为60.27%,旱季基物上发生的黏菌Shannon-Wiener多样性指数显著高于雨季。地面基物上的黏菌物种数为39种,高于树皮基物的26种,且两者的Shannon-Wiener多样性指数具有显著性差异,表明黏菌对地面基物的偏好性大于树皮基物。

Abstract:

In an effort to investigate the species composition and diversity of myxomycetes in different habitats of Dinghu Mountain Nature Reserve in Guangdong Province, six sample plots were selected along an elevation gradient. Barks and ground substances were collected from the sample plots and then incubated via moist chamber culture in laboratory. The species were identified and then counted the number of its occurrence. Major diversity indexes were compared to investigate species composition and diversity. Forty-nine species of myxomycetes were classified as 18 genera of 8 families belonging to 6 orders. Among them, Physarales was abundant, including 17 species, followed by 15 species of Trichiales, 11 species of Stemonitales, 4 species of Liceales, 1 speices of Ceratiomyxales and 1 species of Echinosteliales. The species Arcyria cinerea and Diderma effusum were dominant with relative abundances of 27.03% and 21.14%, respectively. With increasing of elevation, species diversity of myxomycetes decreased. The elevation of 300 m was characterized by the lowest Shannon-Wiener diversity index(1.66±0.12), but with the highest dominant concentration index(0.25±0.05). With the increasing of the high difference of each two sites, the common species number and similarity index decreased. Thirty-three species of myxomycetes, classified as 13 genera of 7 families in 6 orders, were recorded in wet season, and forty species of myxomycetes, classified as 17 genera of 6 orders in 8 families, were recorded in dry season. Twenty-two species were the common species between two seasons, and the similarity index was 60.27%. The species diversity index were significantly higher in dry season than in wet season. The species diversity of myxomycetes were significantly higher in ground substances than in bark substances. This study indicated that myxomycetes preferred ground substances to barks substances.