Contrasting soil dynamics in the Serra da Estrela mountain plateau –  Portugal

<p>Limited data are available on how soil erosion rates compare between surfaces of different ages because short-term processes often overprint the longer-term erosion signal. This study investigated the soil dynamics among a formerly glaciated ('young', maximum glacial extent at 22&#8211;30 ka BP) and a non-glaciated ('old') area in the Serra da Estrela (Portugal). To disentangle soil distribution rates over different timeframes, isotopes for long-term (¹⁰Be), mid-term (&#948;¹³C) and short-term (^239+240Pu) periods were applied together with principles of the percolation theory.</p><p>Soils at the formerly glaciated area have a lower degree of weathering and lower carbon content compared to soils of the &#8216;older&#8217;, non-glaciated area. &#160;The distribution of selected isotopes along the soil profiles revealed temporal differences in soil mixing process. The formerly glaciated surface resulted in higher long-term average erosion rates compared to the non-glaciated area. Yet, soil redistribution rates over the last few decades are up to one order of magnitude higher than the millennia rates. Human impact (bush fires, grazing) is considered the probable cause for the currently strong soil degradation.</p>