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.

亚马孙流域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，但学界对真菌或原核生物群落的基础信息仍较为匮乏。尽管如此，近期生态学研究表明，与土壤真菌的互作在调控热带雨林树木的多样性与种群丰度方面扮演着关键角色。本研究采用454焦磷酸测序技术（454 pyrosequencing），对亚马孙流域西部三种主要热带森林类型——固定旱林（terra firme）、季节性泛滥林（seasonally flooded）与白砂质林（white sand）——的土壤真菌群落进行了表征分析。基于所得数据，本研究探讨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。研究结果显示，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，土壤真菌与树木的阿尔法多样性（α-diversity）和贝塔多样性（β-diversity）均存在显著相关关系。真菌与植物群落的贝塔多样性（β-diversity）亦与环境条件差异呈现显著相关。与以腐生营养（saprotrophy）为主要生存策略的真菌类群（如酵母菌）相比，以活体营养（biotrophic）策略（如病原菌、菌根真菌）为特征的真菌类群，其物种丰富度与植物物种丰富度之间的相关性更强，这表明这种关联至少部分源于植物与真菌之间的直接互作。本研究所得数据填补了重要生态系统中生物群落研究的一处空白，为“真菌群落参与调控热带树木多样性”这一假说提供了有力支撑。