A LATE HOLOCENE VEGETATION HISTORY OF LOWLAND GUATEMALA: RECORDS FROM LAKE IZABAL, EASTERN GUATEMALA

Unlike other lakes in lowland Guatemala, Lake Izabal is surrounded by mountainous areas, which include the Santa Cruz mountain range to the north and the Minas mountain range to the south. Thus, orographic effect apparently contributes to higher precipitation and creates a microrefugium in the region surrounding the lake. In this study, a ~4.55 m-long Lake Izabal core spanning 1,250 cal. yr BP is used to provide a pioneering pollen reference collection for the region. This collection is vital for unravelling the variabilities in paleovegetation dynamics because of the unique features of the lake catchment basin vis-à-vis other lakes. The age-depth model for the core was developed based on extrapolation of six AMS ¹⁴C dates of woody debris in the sediments. The angiosperm-dominated pollen assemblage comprises ~78% dicots (Malvaceae, Malpighiaceae, Euphorbiaceae, etc.) and ~18% monocots, including Araceae, Arecaceae, Bromileaceae, while gymnosperms such as Pinus and Podocarpus (although abundant) constitute 4% of total pollen diversity. Pollen diversity and abundance analyses reveal a ~500-year recovery window for the tropical forest that followed the collapse of the prehistoric Maya Civilization at ~1,000 cal. yr BP. This recovery is marked by a relative increase in the abundance of forest taxa like Euphorbiaceae, Fabaceae, and Meliaceae that coincides with a decrease in disturbance elements that include Asteraceae, Amaranthaceae, and Poaceae. The insights from this research are useful for inferring how long it would require a forest in a conducive climate to recover following prolonged and indiscriminate anthropogenic activities, such as deforestation and over-cultivation.