Unraveling algae and cyanobacteria biodiversity in bromeliad phytotelmata in different vegetation formations in Bahia State, Northeastern Brazil

ABSTRACT Knowledge of algal and cyanobacterial diversity of phytotelmata remains poorly-known, especially for bromeliads from different vegetation formations. We investigated the microalgae communities of four species of tank bromeliads from different vegetation formations in Bahia State, Northeast Brazil, highlighting the composition, richness and diversity of taxa. Sampling of water stored in bromeliads was carried out quarterly between 2014 and 2016, and abiotic variables and morphometric attributes of bromeliads were measured. A total of 89 taxa of algae and cyanobacteria were recorded for the four bromeliad species studied. The microalgae communities of the phytotelmata varied among vegetation formations, with one tank bromeliad, Alcantarea nahoumii, with more complex architecture (higher number of leaves and thus more cavities), being distinguished by its high species richness (73 taxa). The bromeliads exhibited little similarity in species composition, with only one species (Phacus polytrophos) occurring in all four species. Throughout the entire sampling period, classes with higher species richness, especially due to A. nahoumii, were Zygnematophyceae, Cyanophyceae and Chlorophyceae, which accounted for about 80 % of all species inventoried. Our results contribute to the knowledge of microalga communities of bromeliad phytotelmata in Brazil with regard to species richness and composition, as well as significant environmental characteristics.

摘要：人们对植物积水体（phytotelmata）中藻类和蓝细菌的多样性认知仍较为匮乏，针对不同植被带中凤梨科植物的相关研究尤为不足。本研究以巴西东北部巴伊亚州不同植被带内的4种积水凤梨（tank bromeliads）为研究对象，对其体内的微藻群落开展调查，重点解析类群组成、丰富度及多样性特征。研究于2014至2016年间按季度采集凤梨储水样本，并测定相关非生物变量与供试凤梨的形态计量学参数。本次调查共在4种供试凤梨中记录到89个藻类及蓝细菌类群。不同植被带的植物积水体微藻群落组成存在显著差异；其中一种结构更为复杂（叶片数量更多，储水腔更丰富）的积水凤梨Alcantarea nahoumii，其物种丰富度高达73个类群，表现出显著的区分性。供试凤梨的物种组成相似度极低，仅多养扁裸藻（Phacus polytrophos）在4种供试凤梨中均有分布。在整个采样周期内，物种丰富度居前的类群为接合藻纲（Zygnematophyceae）、蓝藻纲（Cyanophyceae）与绿藻纲（Chlorophyceae），这三个纲的物种数占总记录物种的80%左右，这一结果主要得益于Alcantarea nahoumii的贡献。本研究结果可为巴西境内凤梨科植物积水体微藻群落的物种丰富度、组成及关键环境特征相关研究提供重要的认知补充。