Microbial organisms support the high species diversity associated with tropical forests, and likely drive functional processes, but microorganisms found in rainforest canopies are not well understood. We quantified the microbial diversity of suspended soils from two classical epiphytic model systems (bromeliads & bird's nest ferns) across two localities: the Nouragues Reserve in French Guiana and Danum Valley in Malaysian Borneo. Non-epiphytic suspended soils were also collected as controls at the Nouragues Reserve. Effects of epiphyte type and sample location on microbial community composition were determined using Phospholipid Fatty Acid (PLFA) analysis. Total microbial biomass remained constant across the suspended soil types, but PLFA peaks denoting the relative abundance of different microbes varied between bromeliads, bird's nest ferns and non-epiphytic control soils. Suspended soils associated with bird's nest ferns from Borneo contained a microbial community significantly different in composition from those of congeneric bird's nest ferns from Amazonia, due to shifts in the relative abundance of fungi and bacteria. Our findings reveal that epiphytes create convergent niches for microorganisms in tropical canopies, while highlighting the sensitive nature of suspended soil microbial communities.

微生物支持与热带森林有关的高物种多样性，并可能推动功能性过程，但是对热带雨林冠层中发现的微生物却知之甚少。我们从两个地区（法属圭亚那的努拉盖斯保护区和马来西亚婆罗洲的Danum谷地）的两个经典附生模型系统（bromeliads和燕窝蕨）对悬浮土壤的微生物多样性进行了定量。还从Nouragues保护区收集了非表生性悬浮土壤作为对照。使用磷脂脂肪酸（PLFA）分析确定了附生植物类型和样品位置对微生物群落组成的影响。在悬浮土壤中，微生物的总生物量保持不变，但凤梨，鸟类和鸟类之间的PLFA峰表示不同微生物的相对丰度有所不同。巢蕨和非附生控制土壤。与婆罗洲燕窝蕨相关的悬浮土壤中，由于真菌和细菌的相对丰度发生了变化，其微生物群落的组成与亚马逊亚马逊同类燕窝蕨的组成明显不同。我们的发现表明，附生植物为热带冠层中的微生物创造了会聚的生态位，同时突显了悬浮土壤微生物群落的敏感性。