A palynological perspective on a cave: Does pollen content differ in guano deposits within?

Abstract

Caves formed in some karst regions are important places where bat guano deposits containing abundant and well-presented pollen can be found. These guano deposits reflect the regional vegetation and have the potential to contribute to the reconstruction of paleovegetation by palynology. However, the exact mechanisms by which this pollen accumulation occurs and which factors affect it are not yet clear. This study pioneers the analysis of palynological data derived from annual guano accumulation, shedding light on how pollen distribution may take place in the cave from NW Turkey. In guano samples collected from various parts of the cave; notably, Quercus, Pinus, Poaceae, Cupressaceae/Taxaceae, Pistacia, Cuscuta, Silene, Fraxinus, Primula, Olea, and Abies emerged as the primary pollen components in the guano. The majority of the taxa represented in guano samples consist of pollen grains belonging to anemophilous plants; however, pollen belonging to entomophilous taxa in guano were much more abundant than those found in the atmosphere. The observed variations in total numbers and statistically significant differences among pollen types between sampling stations in the cave indicate that pollen ratios and distributions in the guano differ within the cave. Although palynological studies in cave guano sediments are quite limited, this study emphasizes the need to change the perspective on the sampling pattern within the cave. Therefore, further research in this area is essential.