A Late Holocene Environmental History of a Bat Guano Deposit from Romania: An Isotopic, Pollen and Microcharcoal Study

Authors

Ferenc L. Forray, Babeş-Bolyai UniversityFollow
Bogdan P. Onac, University of South FloridaFollow
Ioan Tanţău, Babeş-Bolyai UniversityFollow
Jonathan G. Wynn, University of South FloridaFollow
Tudor Tămaş, Babeş-Bolyai UniversityFollow
Ioan Coroiu, Babeş-Bolyai University
Alexandra M. Giurgiu, Babes-Bolyai University

Document Type

Article

Publication Date

11-2015

Keywords

Cave guano, Carbon isotopes, Pollen, Microcharcoal, Environmental history, Late Holocene, Little Ice Age, Romania

Digital Object Identifier (DOI)

https://doi.org/10.1016/j.quascirev.2015.05.022

Abstract

A 1.5-m-long core from a bat guano deposit in Zidită Cave (western Romania) has provided a 900-year record of environmental change. Shifts in δ¹³C values of bulk guano (between −22.6 and −27.5‰) combined with guano-sourced pollen and microcharcoal information show significant changes in the structure of vegetation and plant biomass. Cave guano δ¹³C values reflect the dietary preferences of bats which are controlled by local vegetation dynamics, which in turn depend on local climatic conditions. Neither δ¹³C values nor pollen association in guano changed strikingly over the Medieval Warm Period (MWP) and Little Ice Age (LIA) transition. Instead, an overall decreasing trend of δ¹³C values between ca. AD 1200 and 1870–1900 defines the duration of LIA. A shift toward cooler and wetter conditions at ca. AD 1500 noticed in the pollen record by an increase in Fagus sylvatica and Alnus and the decrease of Carpinus betulus, may indicate the first major change at the beginning of the LIA. Evidence for two major cold spells occurring around AD 1500 and ca. AD 1870 comes from both δ¹³C and pollen record. In between these events, the cave region experienced a warmer and drier climate but colder and wetter than the MWP, favouring the expansion of Quercus, Fraxinus and Tilia simultaneously with the decrease of F. sylvatica and Poaceae. Human impact in the studied area is mainly related to agriculture, grazing and deforestation. The effects are most pronounced after AD 1845 when the pollen of cereals increases and Zea is recorded (AD 1845). Higher percentages of microcharcoal particles in the guano sequence are generally correlated with agricultural activities like land cleaning via controlled fires.

Was this content written or created while at USF?

Yes

Citation / Publisher Attribution

Quaternary Science Reviews, v. 127, p. 141-154

Scholar Commons Citation

Forray, Ferenc L.; Onac, Bogdan P.; Tanţău, Ioan; Wynn, Jonathan G.; Tămaş, Tudor; Coroiu, Ioan; and Giurgiu, Alexandra M., "A Late Holocene Environmental History of a Bat Guano Deposit from Romania: An Isotopic, Pollen and Microcharcoal Study" (2015). School of Geosciences Faculty and Staff Publications. 1901.
https://digitalcommons.usf.edu/geo_facpub/1901