Species richness and composition of epiphytic bryophytes in flooded forests of Caxiuanã National Forest, Eastern Amazon, Brazil

ABSTRACT This study aimed to compare the richness and composition of the epiphytic bryoflora between várzea and igapó forests in Caxiuanã National Forest, Brazilian Amazon. Bryophytes were collected on 502 phorophytes of Virola surinamensis. Average richness per phorophyte and composition between forests and between dry and rainy periods was tested by two-way analysis and by cluster analysis, respectively. In total, 54 species of 13 families were identified. Richness was greater in igapó forest (44 species) compared to várzea forest (38 species). There was no significant difference in the number of species between the studied periods. Cluster analysis showed the bryoflora composition was different between várzea and igapó, but not between dry and rainy periods. Results did not corroborate the hypothesis that várzea forests harbor higher species richness than igapó forests.

摘要 本研究旨在对比巴西亚马逊卡舒亚纳国家森林公园（Caxiuanã National Forest）内瓦尔泽亚森林（várzea）与伊加波森林（igapó）的附生苔藓植物群落（epiphytic bryoflora）的物种丰富度与组成结构。研究人员在502株苏里南肉豆蔻（Virola surinamensis）的附生宿主植物（phorophyte）上采集苔藓植物样本。分别采用双因素方差分析与聚类分析，对不同森林类型间、干湿季间的单株附生宿主植物平均物种丰富度及群落组成进行显著性检验。本研究共鉴定出13科54种苔藓植物。伊加波森林的物种丰富度（44种）高于瓦尔泽亚森林（38种）。不同研究时段的物种数量无显著差异。聚类分析结果显示，瓦尔泽亚森林与伊加波森林的附生苔藓群落组成存在显著差异，但干湿季间并无显著区别。本研究结果并不支持“瓦尔泽亚森林的物种丰富度高于伊加波森林”的原有假说。