Ectomycorrhizal fungal communities at forest edges
Ectomycorrhizal fungal communities at forest edges
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DOI：
10.1111/j.1365-2745.2005.00977.x
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发表时间：
2005-04-01
影响因子：
5.5
通讯作者：
Reich, PB
中科院分区：
文献类型：
--
作者：
Dickie, IA;Reich, PB
1 外生菌根真菌与已建立的外生菌根植被在空间上相关，但距已建立植被的距离对真菌的存在、丰度、多样性和群落组成的影响尚不清楚。2 我们使用大果栎幼苗对距离森林边缘 0 至 20 m 的外生菌根真菌进行原位生物测定，检查了美国明尼苏达州两个废弃农田的菌根群落。3真菌群落各个方面的距离。近树处菌根丰度一致较高，距树根15 m左右迅速下降，20 m处菌根丰度一致较低。所有距离森林边缘 0 至 8 m 的幼苗都有外生菌根，但许多 16-20 m 的幼苗在研究的两年中没有被感染。真菌的物种丰富度也随着距树木的距离而下降。4在距边缘不同距离处发现了不同种类的真菌。 “稀有”物种（仅发现一两次）在 0 米处占主导地位，即红菇属 (Russula spp)。 4 至 12 m 为优势，Astraeus sp。 Pezizalean 真菌在 12 m 至 20 m 处丰富。 Cenocaccum geophilum 是发现的最主要物种，在树木附近和远离树木的地方都很丰富，中等距离的相对丰度最低。5我们的数据表明，在距已建立的外生菌根植被一定距离（本研究中为 15.5 m）处萌发的幼苗感染水平较低，至少在生长的第一年是这样。与已建立的植被的距离代表了外生菌根真菌的一个重要梯度，不同的物种沿着这个梯度占据着不同的生态位。这为生态位分化作为影响外生菌根真菌多样性的一个因素提供了支持。 6幼苗的外生菌根感染在空间上是复杂的，靠近树木的地方感染率高，真菌多样性高，中距离处感染率高，但多样性较低，远离树木的感染率低，真菌多样性低。这种空间复杂性应被视为潜在影响外生菌根植被建立的因素。
1 Ectomycorrhizal fungi are spatially associated with established ectomycorrhizal vegetation, but the influence of distance from established vegetation on the presence, abundance, diversity and community composition of fungi is not well understood.2 We examined mycorrhizal communities in two abandoned agricultural fields in Minnesota, USA, using Quercus macrocarpa seedlings as an in situ bioassay for ectomycorrhizal fungi from 0 to 20 m distance from the forest edge.3 There were marked effects of distance on all aspects of fungal communities. The abundance of mycorrhiza was uniformly high near trees, declined rapidly around 15 m from the base of trees and was uniformly low at 20 m. All seedlings between 0 and 8 m distance from forest edges were ectomycorrhizal, but many seedlings at 16-20 m were uninfected in one of the two years of the study. Species richness of fungi also declined with distance from trees.4 Different species of fungi were found at different distances from the edge. 'Rare' species (found only once or twice) dominated the community at 0 m, Russula spp. were dominants from 4 to 12 m, and Astraeus sp. and a Pezizalean fungus were abundant at 12 m to 20 m. Cenococcum geophilum, the most dominant species found, was abundant both near trees and distant from trees, with lowest relative abundance at intermediate distances.5 Our data suggest that seedlings germinating at some distance from established ectomycorrhizal vegetation (15.5 m in the present study) have low levels of infection, at least in the first year of growth. Distance from established vegetation represents an important gradient for ectomycorrhizal fungi, with different species occupying distinct niches along this gradient. This provides support for niche differentiation as a factor contributing to ectomycorrhizal fungal diversity.6 Ectomycorrhizal infection of seedlings is spatially complex, with high infection and high fungal diversity near trees, high infection but lower diversity at intermediate distances, and low infection and low fungal diversity distant from trees. This spatial complexity should be considered as a factor potentially influencing the establishment of ectomycorrhizal vegetation.