Biopores and root features as new tools for improving paleoecological understanding of terrestrial sediment-paleosol sequences

Disentangling interactions between microbial communities and roots in deep subsoil

“…Central and Southeast Europe (Gocke et al, 2014a(Gocke et al, , 2014b, where they were observed to occur …”

Multiple stages of plant root calcification deciphered by chemical and micromorphological analyses

“…Nevertheless, deep‐rooting plants have the ability to penetrate sediments to a depth of several meters (Canadell et al, 1996). This was notably observed in several loess‐(paleo)soil and sand‐(paleo)soil sequences in Central and Southeast Europe (e.g., Gocke et al, 2014a), with high abundances of recent and fossilized roots (rhizoliths) as well as root‐derived biopores down to several meters depth below the recent soil or associated paleosol. The post‐sedimentary incorporation of root‐derived OM can lead to a large overprint of the initial signal in loess sediments, as shown for example for lipid biomarkers (e.g., n ‐alkanes, fatty acids, GDGTs; Huguet et al, 2013; Gocke et al, 2014b).…”

“…Recent and calcified roots were collected from a late Pleistocene loess–palaeosol sequence at the open cast mine of HeidelbergCement AG, Nussloch, SW Germany (49.19°N, 8.43°E, 217 m above sea level), as described in detail by Gocke et al (2010, 2011, 2014a, b). The sampled profile comprises 13.1 m of loess and soil units, including the recent soil, with 3 main paleosols and 14 incipient paleosols (Gocke et al, 2014b).…”

“…Rhizoliths at Nussloch were formed during various phases throughout the Holocene, with ages between 3 and 10 kyr (Frechen et al, 2007; Gocke et al, 2011; Pustovoytov and Terhorst, 2004) and were derived from roots of unknown trees or shrubs (likely hazel, oak, beech, and alder; Gocke et al, 2013). They occur continuously from the recent soil to 8.8 m depth, with frequencies reaching up to 196 m −2 at 2.55 m and are also present below 10 m underneath a major paloeosol (Lohne Soil) in lower frequencies (≤12 m −2 ; Gocke et al, 2014a). They can be found in various shapes and sizes (diameter between a few mm to ca.…”

“…The presence of carbonate rhizoliths in loess settings can therefore bias paleoenvironmental reconstructions. Corresponding data have to be interpreted with caution, as only limited knowledge about their formation mechanisms is available (e.g., Gocke et al, 2011, 2014a, b; Klappa, 1980; Li et al, 2015b; Sun et al, 2019a; Brazier et al, 2020).…”