Associations among arbuscular mycorrhizal fungi and seedlings are predicted to change with tree successional status
Associations among arbuscular mycorrhizal fungi and seedlings are predicted to change with tree successional status
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DOI：
10.1002/ecy.2122
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发表时间：
2018-03-01
期刊：
影响因子：
4.8
通讯作者：
Clark, James S.
中科院分区：
文献类型：
--
作者：
Bachelot, Benedicte;Uriarte, Maria;Clark, James S.
土壤中的丛枝菌根(AM)真菌可能影响热带树木的动态和森林演替。由于树种和AM真菌的功能特性和丰富度很可能是相互依赖的，因此对其机理了解甚少。我们使用广义联合属性模型来评估AM真菌是否与波多黎各亚热带山地森林的三种森林群落指标相关联。用来反映森林演替过程中变化的指标是不同演替状态的苗木丰富度、不同演替状态的苗木叶片损伤量和群落加权平均功能性状值(成虫比叶面积、成虫木材密度和种子质量)。我们使用高通量DNA测序来确定土壤中的真菌操作分类单位(OTU)。模型预测表明，与没有这些真菌时相比，当12种最常见的AM真菌丰富时，演替中后期物种的幼苗对叶片的损害较小。我们还发现，与没有这些真菌时相比，当12种最常见的AM真菌丰富时，中期演替物种的幼苗预计会更丰富。相反，当12种最常见的AM真菌丰富时，预测早期演替的树苗比没有这些真菌时要少。最后，我们发现，在12种最常见的AM真菌中，不同的AM真菌与早演替或晚演替物种的功能性状相关。综上所述，这些结果表明，早演替物种对AM真菌的依赖程度可能不如中、晚演替物种，AM真菌可能会加速森林演替。
Arbuscular mycorrhizal (AM) fungi in the soil may influence tropical tree dynamics and forest succession. The mechanisms are poorly understood, because the functional characteristics and abundances of tree species and AM fungi are likely to be codependent. We used generalized joint attribute modeling to evaluate if AM fungi are associated with three forest community metrics for a sub-tropical montane forest in Puerto Rico. The metrics chosen to reflect changes during forest succession are the abundance of seedlings of different successional status, the amount of foliar damage on seedlings of different successional status, and community-weighted mean functional trait values (adult specific leaf area [SLA], adult wood density, and seed mass). We used high-throughput DNA sequencing to identify fungal operational taxonomic units (OTUs) in the soil. Model predictions showed that seedlings of mid- and late-successional species had less leaf damage when the 12 most common AM fungi were abundant compared to when these fungi were absent. We also found that seedlings of mid-successional species were predicted to be more abundant when the 12 most common AM fungi were abundant compared to when these fungi were absent. In contrast, early-successional tree seedlings were predicted to be less abundant when the 12 most common AM fungi were abundant compared to when these fungi were absent. Finally, we showed that, among the 12 most common AM fungi, different AM fungi were correlated with functional trait characteristics of early- or late-successional species. Together, these results suggest that early-successional species might not rely as much as mid- and late-successional species on AM fungi, and AM fungi might accelerate forest succession.