Data from: Strong coupling of plant and fungal community structure across western Amazonian rainforests

The Amazon basin harbors a diverse ecological community that has a critical role in the maintenance of the biosphere. Although plant and animal communities have received much attention, basic information is lacking for fungal or prokaryotic communities. This is despite the fact that recent ecological studies have suggested a prominent role for interactions with soil fungi in structuring the diversity and abundance of tropical rainforest trees. In this study, we characterize soil fungal communities across three major tropical forest types in the western Amazon basin (terra firme, seasonally flooded and white sand) using 454 pyrosequencing. Using these data, we examine the relationship between fungal diversity and tree species richness, and between fungal community composition and tree species composition, soil environment and spatial proximity. We find that the fungal community in these ecosystems is diverse, with high degrees of spatial variability related to forest type. We also find strong correlations between α- and β-diversity of soil fungi and trees. Both fungal and plant community β-diversity were also correlated with differences in environmental conditions. The correlation between plant and fungal richness was stronger in fungal lineages known for biotrophic strategies (for example, pathogens, mycorrhizas) compared with a lineage known primarily for saprotrophy (yeasts), suggesting that this coupling is, at least in part, due to direct plant–fungal interactions. These data provide a much-needed look at an understudied dimension of the biota in an important ecosystem and supports the hypothesis that fungal communities are involved in the regulation of tropical tree diversity.

亚马孙盆地孕育着多样的生态群落，其在维持生物圈稳态中发挥着至关重要的作用。尽管植物与动物群落已得到广泛关注，但真菌或原核生物群落（prokaryotic communities）的基础研究信息仍十分匮乏。尽管近期生态学研究已表明，土壤真菌互作在塑造热带雨林树木的多样性与种群丰度中发挥着显著作用，但相关基础数据仍存在缺口。本研究利用454焦磷酸测序（454 pyrosequencing）技术，对亚马孙西部盆地的三类主要热带森林类型——大陆性热带雨林（terra firme）、季节性淹水林与白沙林——中的土壤真菌群落进行了表征分析。基于所得数据，本研究探究了真菌多样性与树木物种丰富度之间的关联，以及真菌群落组成与树木物种组成、土壤环境及空间邻近性之间的关系。研究发现，这些生态系统中的真菌群落具有极高多样性，且其空间变异程度与森林类型密切相关。本研究还发现，土壤真菌与树木的α多样性（α-diversity）及β多样性（β-diversity）之间存在显著相关性。此外，真菌与植物群落的β多样性均与环境条件差异显著相关。与以腐生营养（saprotrophy）为主要生存策略的真菌类群（如酵母菌（yeasts））相比，以活体营养（biotrophic）策略生存的真菌类群（如病原菌（pathogens）、菌根（mycorrhizas））的物种丰富度与植物物种丰富度之间的相关性更强，这表明植物与真菌之间的耦合关系至少部分源于二者的直接互作。本研究数据填补了这一重要生态系统中被长期忽视的生物群落维度的研究空白，同时验证了“真菌群落参与调控热带树木多样性”这一假说。