Soil Formation and Mass Redistribution during the Holocene Using Meteoric 10Be, Soil Chemistry and Mineralogy

Alessandra Musso,Konrad Greinwald,Dmitry Tikhomirov,Fabian Maier,Clemens Geitner,Michael L Plötze,Fanny Petibon,Markus Egli,Anne Hartmann

doi:10.3390/geosciences12020099

Abstract

Soil development and erosion are important and opposing processes in the evolution of high-mountainous landscapes, though their dynamics are not fully understood. We compared soil development between a calcareous and a siliceous chronosequence in the central Swiss Alps at high altitudes, which both cover soil formation over the Holocene. We calculated element mass balances, long-term erosion rates based on meteoric 10Be and we determined the rates of soil formation. We also analyzed the shifts in the mineralogical composition, weathering indices, the particle size distribution, carbon stocks and oxalate extractable Fe, Al, and Mn. The siliceous soils had high chemical weathering rates at the early stage of soil formation that strongly decreased after a few millennia. The development of calcareous soil was characterized by high carbonate losses and a shift to finer soil texture. Soil erosion hampered the upbuilding of soil horizons in the early stages of soil development, which led to a delay in soil and vegetation development. This study shows how soil formation drivers change over time. In the early stages of soil development, the parent material predominantly drives soil formation while at later stages the vegetation becomes more dominant as it influences surface stability, hydrological pathways, and chemical weathering that determine water drainage and retention.

Highlights

Soils and their formation, i.e., the physical and chemical alteration of the parent material, have been studied for more than a century
The moraine was covered in boulders and cobbles of varying sizes and was vegetated with initial snowbed communities of the type Arabidion caeruleae and Saxifraga aizoides (Figures 2–4, Table 1)
The vegetation was dominated by Thlaspietum rotundifolii and Dryadetum octopetalae

Summary

Introduction

Soils and their formation, i.e., the physical and chemical alteration of the parent material, have been studied for more than a century. Dokuchaev [1] laid the foundation of soil science with his observations in the Russian steppe. He laid the ground for the factorial model of soil development, which Jenny developed further in 1941 in his publication, Factors of Soil Formation [2]. Jenny described soil formation as the product of five independent factors: climate, organisms, relief, parent material, and time. Simonson [3] presented a model which looks at soils from a process-oriented point of view (i.e., additions, removals, translocations)

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Conclusion