Analysis of pollen rain in a subandean forest fragment in Colombia

Abstract We carried out a modern pollen rain analysis and established its relationship with a Subandean forest fragment in the Cordillera Oriental of Colombia between 1,500 - 2,400 masl RAP transects were performed in order to identify plant species. In each transect, moss samples were collected randomly and processed at the laboratory in order to obtain pollen rain data. Based on pollen grains and vegetation identification and count, we developed pollen diagrams and diversity analysis, and determined the pollen rain and its relation with the vegetation. Cluster and Detrended correspondence analysis (DCA) were performed to determine altitude-associated ecological pollinic species assembly. A total of 66 palynomorphs were identified, being trees the dominant plant habit. The sites located at 2,100 and 2,400 m a.s.l. showed higher pollen diversity. Finally, the Cluster and the DCA show three main groups composed of species that generate a possible dividing line between the low and the high Subandean forest, resulting in new information that can be used for paleoecological interpretation.

摘要 本研究开展了现代花粉雨分析，并建立了其与哥伦比亚东科迪勒拉山脉海拔1500至2400米区域内副安第斯森林片段的关联。为识别植物物种，我们布设了RAP样带。在每条样带中，我们随机采集苔藓样本并于实验室进行处理，以获取花粉雨数据。基于花粉粒鉴定、植被识别与计数结果，我们绘制了花粉图谱并开展多样性分析，明确了花粉雨特征及其与当地植被的关联。我们采用聚类分析与除趋势对应分析（Detrended Correspondence Analysis, DCA），以确定与海拔相关的生态花粉物种组合。本研究共鉴定出66个孢粉形态类群，其中乔木为优势生活型植物。海拔2100米与2400米的样点展现出更高的花粉多样性。最终，聚类分析与除趋势对应分析（DCA）结果显示存在三个主要物种类群，这些类群可在低海拔与高海拔副安第斯森林之间形成潜在分界，本研究所得新信息可用于古生态学解释。