A 9000 year record of cyclic vegetation changes identified in a montane peatland deposit located in the Eastern Carpathians (central-Eastern Europe): Autogenic succession or regional climatic influences?

摘要

We present a high-resolution, continuous plant macrofossil remains record complemented by a pollen sequence from Tăul Muced bog, in the Eastern Carpathian Mountains (Romania). The record spans the last 9000 years and we test whether peatland development in the Eastern Carpathians is linked to climate change or to autogenic succession. We find that Sphagnum magellanicum was the dominant peat-forming species for ca. 8000 years but we also identify ten phases of increased representation of Eriophorum vaginatum at approximately 8100, 7550, 6850, 6650, 5900, 4650, 3150, 1950, 1450, 750 cal yr. BP. Visual inspection and wavelet analysis show that the episodic increases in the relative abundances of Eriophorum vaginatum were simultaneous with decreased abundances of Sphagnum magellanicum and Sphagnum angustifolium. Comparison with published palaeoclimatic records in this region suggests that these cyclical successions of S. magellanicum and E. vaginatum appear to be primarily a result of climate changes, with E. vaginatum developing mainly during dry phases and S. magellanicum during wetter periods. We therefore suggest that the development of this peatland was largely influenced by changing climatic conditions, although the role of autogenic plant succession cannot be excluded. Our results show the value of ombrotrophic peat deposits as archives of past climate change.