Disruption of terrestrial plant ecosystem in Miocene (sub) tropics: A palynological perspective from Fotan Formation, Southeast China

Abstract

Fern spikes in pollen sequences represent the initial colonization by pioneer species following massive destruction of vegetation. Here, two fern spikes were recognized in the palynological sequences of MP-1 and HK sections from the Miocene Fotan Formation in Zhangpu County, Fujian Province, Southeast China. Based on the occurrences of fern spikes and the law of vegetation succession, we found that at least two catastrophic events occurred in the study area during the Miocene. The contemporaneous flood basalt volcanism in this region is considered to be the main cause for the devastation of terrestrial plant ecosystem, which was followed by the increased runoff as well as the bloom of Concentricystes (algae) as a result of enhanced nutrient inputs after disturbances. Besides, in comparison with MP-1 section, the fern spike in HK section is characteristic of 1) the higher abundance and diversity in terms of the composition of fern spores, 2) the appearance of fungal spike, 3) the longer time of duration, and 4) the much higher abundance of Concentricystes, suggesting that the catastrophic event occurred during the deposition of HK section is more severe than that recorded by MP-1 section.