Programa de Pós-Graduação em Ciências Biológicas, Departamento de Micologia, Universidade Federal de Pernambuco, Av. da Engenharia s/n, Cidade Universitária, Recife, Pernambuco, Brazil.
Institut für Biologie, Freie Universität Berlin, Altensteinstr 6, 14195, Berlin, Germany.
Microb Ecol. 2018 Feb;75(2):447-458. doi: 10.1007/s00248-017-1042-7. Epub 2017 Aug 4.
Arbuscular mycorrhizal fungi (AMF) are symbiotic fungi with a broad distribution, and many taxa have physiological and ecological adaptations to specific environments, including semiarid ecosystems. Our aim was to address regional distribution patterns of AMF communities in such semiarid environments based on spore morphological techniques. We assessed AMF spores at the bottom and top of inselbergs distributed throughout the tropical dry forest in the Northeast region of Brazil. Across 10 replicate inselbergs and the surrounding area, spanning a range of altitude between 140 and 2000 m, we scored the AMF soil diversity and properties in 52 plots. We fitted parsimonious ordination analyses and variance partitioning models to determine the environmental factors which explained the variation in AMF community, based on morphological spore analysis. The diversity of AMF was similar at the bottom and top of inselbergs; however, we detected high variation in abundance and richness across sites. We formulated a parsimonious richness model that used physical soil factors as predictors. The AMF community structure could be best explained through the variables coarse and total sand, iron, organic matter, potassium, silt, and sodium which together accounted for 17.8% of total variance. Several AMF species were indicators of either deficiency or high values of specific soil properties. We demonstrated that habitat isolation of the inselbergs compared with surrounding areas did not trigger differences in AMF communities in semiarid regions of Brazil. At the regional scale, soil predictors across sites drove the distribution of symbiotic mycorrhizal fungi.
丛枝菌根真菌（AMF）是分布广泛的共生真菌，许多类群具有对特定环境（包括半干旱生态系统）的生理和生态适应能力。我们的目的是基于孢子形态学技术，研究半干旱环境中 AMF 群落的区域分布模式。我们评估了分布在巴西东北部热带干旱森林中的孤岛底部和顶部的 AMF 孢子。在跨越 10 个重复的孤岛及其周围地区，海拔范围在 140 至 2000 米之间，我们在 52 个样方中对 AMF 土壤多样性和特性进行了评分。我们拟合简约排序分析和方差分解模型，基于形态学孢子分析确定解释 AMF 群落变化的环境因素。孤岛底部和顶部的 AMF 多样性相似；然而，我们在各个地点检测到丰度和丰富度的高度变化。我们提出了一个简约的丰富度模型，将物理土壤因子作为预测因子。AMF 群落结构可以通过粗砂和总砂、铁、有机质、钾、粉砂和钠等变量得到最佳解释，这些变量共解释了总方差的 17.8%。一些 AMF 物种是特定土壤性质缺乏或高值的指示物。我们证明，与周围地区相比，孤岛的生境隔离并没有在巴西半干旱地区引发 AMF 群落的差异。在区域尺度上，站点之间的土壤预测因子驱动了共生菌根真菌的分布。
