西天目山柳杉根际土壤线虫群落组成与多样性分析

Analysis on Community Composition and Diversity of Nematodes in the Rhizosphere Soil of Japan Cedar (Cryptomeria fortunei ) in Western Tianmu Mountain

通过对浙江省天目山优势树种柳杉根际土壤线虫的群落和多样性的研究,明确西天目山的线虫资源以及土壤的健康程度。结果显示：在海拔500m和1000m的高度下,小杆属线虫的密度均较高。然而,头叶属、真头叶属、棱咽属、拟丽突属、丽突属、板唇属、矛线属、垫刃属和毛刺属线虫仅在年平均温度16.3℃、海拔500m高度的柳杉根际土壤中有发现。无咽属线虫只在年平均温度8~12℃、海拔1000m的土壤中有发现。在高海拔下,小杆属、滑刃属和中矛属线虫为极优势属类群;真滑刃属、根结属和针属线虫在高海拔下为稀有类群。海拔500m的线虫群落的多样性、丰富度和均匀度均高于海拔1000m条件下的。海拔500m处的柳杉根际土壤中食细菌线虫数量比例最高,而在海拔1000m下,杂食捕食类线虫占的比例最大。西天目山的土壤瓦斯乐斯卡指标值（WI）都大于1,健康程度均良好。

The study was related on the analysis of community composition and diversity of nematodes in the rhizosphere soil of Japan cedar （Cryptomeria fortunei ） in western Tianmu Mountain in Zhejiang Province. The result showed that the density of the nematodes in the genus ofRhabditis was higher than that in other genera, no matter which height above sea level （ASL） at 500 m and 1000 m. However, the nematodes in the genera of Cephalobus , Eucephalobus , Prismatolaimus , Acrobeloides , Acrobeles , Chiloplacus , Dorylaimus , Tylenchus andTrichodorus were found only at 500 m altitude where the average of annual temperature was 16.3℃. Only the nematodes in the genus ofAlaimus could be found at 1000 m ASL, where the annual temperature in average ranged from 8-12℃. At 1000 m ASL, the nematodes in the genera ofRhabditis, Aphelenchoides and Mesodorylaimus belonged to the extremely abundance group and Aphelenchus , Meloidogyne and Paratylenchus nematodes belonged to rarely group. The indexes of Shannon-Wiener diversity index （H ′ ）, Species Richness （SR ） and Simpson evenness （E ） at 500 m ASL were higher than that of at 1000 m ASL. At altitude of 500 m, the proportion of bacterivore nematodes was the highest, whereas at 1000 m, the proportion of predators-omnivores was the highest. Both WI （Wasilewska Index） values were greater than one, which shown the soil was healthy in western Tianmu Mountain at the two altitudes.