Did land plants alter erosion rates on Earth?

Posted by on Mar 28, 2021 in Uncategorized | No Comments

A discussion arises from the recent review article in Chemical Geology, where Tais W. Dahl and Susanne Arens concluded that land plants did not forever increase the physical weathering rates of the continental crust. This conclusion was reached from the records of preserved sediment rock volume and the timing of plant-assisted weathering as recorded in terrestrial deposits.

Physical weathering is the break down of rocks to smaller components (sediment). Vegetation influence that process too, but how does this all add up to changing the global production of sediment? Physical weathering is the break down of rocks to smaller components (sediment). Vegetation influence that process too, but how does this all add up to changing the global production of sediment?
Physical weathering is the break down of rocks to smaller components (sediment). Vegetation influence that process too, for example by roots mining into underlying rocks to form soil and the stabilization of hill slopes, but how do the vegetation-driven impacts all add up to change the global production of sediment? Photo from left: Feifei Zhang, Jitao Chen, and Tais W. Dahl at the Naqing section, South China.

Neil Davies and McMahon commented on this and rightfully pointed out that the problem is currently underdetermined, and highlighted bias associated with the generation of accommodation space in marine basins necessary for preserving sediment volume.

In a reply, Susanne and Tais clarified how the available records suggests erosions rates have been constant within ±30% during the appearance of land plants and subsequent forestation of the continents.