Han Qisheng, Huang Jian, Long Dongfeng, Wang Xiaobing, Liu Jianjun
College of Forestry, Northwest A&F University, Yangling, 712100, China.
College of Landscape Architecture and Arts, Northwest A&F University, Yangling, 712100, China.
Mycorrhiza. 2017 Jul;27(5):487-497. doi: 10.1007/s00572-017-0766-z. Epub 2017 Mar 9.
Alpine treeline ecotones represent ecosystems that are vulnerable to climate change. We investigated the ectomycorrhizal (ECM) community, which has potential to stabilize alpine ecosystems. ECM communities associated with Larix chinensis were studied in four zones along a natural ecotone from a mixed forest stand over pure forest stands, the timberline, and eventually, the treeline (3050-3450 m) in Tabai Mountain, China. Sixty operational taxonomic units (OTUs) of ECM fungi were identified by sequencing the rDNA internal transcribed spacer of ECM tips. The richness of ECM species increased with elevation. The soil C/N ratio was the most important factor explaining ECM species richness. The treeline zone harbored some unique ECM fungi whereas no unique genera were observed in the timberline and pure forest zone. Elevation and topography were equally important factors influencing ECM communities in the alpine region. We suggest that a higher diversity of the ECM fungal community associated with L. chinensis in the treeline zone could result from niche differentiation.
高山林线交错带代表着易受气候变化影响的生态系统。我们研究了外生菌根（ECM）群落，其具有稳定高山生态系统的潜力。在中国太白山，沿着一条从混交林经过纯林、林线，最终到林线（海拔3050 - 3450米）的自然交错带的四个区域，对与太白红杉相关的ECM群落进行了研究。通过对ECM根尖的rDNA内转录间隔区进行测序，鉴定出60个外生菌根真菌的操作分类单元（OTUs）。外生菌根物种的丰富度随海拔升高而增加。土壤碳氮比是解释外生菌根物种丰富度的最重要因素。林线区域含有一些独特的外生菌根真菌，而在林线和纯林区域未观察到独特的属。海拔和地形是影响高山地区外生菌根群落的同等重要因素。我们认为，林线区域与太白红杉相关的外生菌根真菌群落更高的多样性可能是由生态位分化导致的。
