Beryllium cycling through deciduous trees and implications for meteoric 10Be systematics

Application of meteoric 10 Be inventories and Be/ 9 ratios to determine surface ages, erosion rates, denudation rates requires understanding the conditions under which functions as an open vs. closed system near Earth's surface. Here, we investigate biologically mediated beryllium isotope mobility in oak-hickory forest eastern North America. We report concentrations soils, roots, leaves four deciduous tree species. The data show that is readily taken-up from soil by roots , cycled through leaves, redeposited on floor with autumn leaf abscission. Hickory (genus Carya ) dominates cycling a spatially averaged annual flux litterfall times higher than atmospheric deposition rate. Biocycling may thus modulate shape concentration ratio depth profiles soils. present biocycling model describes uptake redeposition litterfall, retention according exponential adsorption rule. This reproduces observed form foliage at study site. also indicates both declining bulge-type result biocycling, even where loss leaching significant, implying not be indicative quantitative retention. recommend considered models systematics hickory or other accumulating taxa are litter production high.