『Abstract
Weathering of terrestrial Ca- and Mg-bearing silicate minerals
is an important control on atmospheric CO2
on geological time scales. It has been determined that vascular
plants can accelerate mineral weathering as compared to non-vascular
plants or non-vegetated surfaces. This indicates that the evolution
of vascular plants, particularly the deep-rooted trees, may play
a large role in the long-term carbon cycle and its regulation
of the atmosphere. The weathering impact of the separate evolutionary
appearances of the gymnosperms in the Palaeozoic and the angiosperms
in the Mesozoic, and the shifting ecological dominance from the
former to the latter, is currently poorly understood. This study
aims to contribute to our understanding of the quantitative weathering
rates of the angiosperms and gymnosperms by examining plant-mineral
interactions of the two tree types in a temperate field setting
underlain by granodiorite. Results include determinations of soil
element fluxes and etching of minerals. The observed root-mineral
interactions resulted in only slightly more weathering of Ca-bearing
minerals by the angiosperms. However, we observed significantly
more weathering of the Mg-bearing minerals by the gymnosperms.
These results suggest that increasing dominance of the angiosperms
in forests in the Mesozoic may have had a small or neutral impact
on accelerating overall mineral weathering and regulating CO2, but that this impact may be lithology-dependent.』
Introduction
Field area
Results and discussion
Conclusions
References