Variations of 7Be concentration in plants and its significance for 7Be in soil on the Loess Plateau, China: Based on three-year monitoring data

Abstract

<p><em>Aims</em>  With the wide application of <sup>7</sup>Be (Beryllium-7) in soil erosion investigations, absorption and interception of <sup>7</sup>Be by vegetation play an important role in documenting soil <sup>7</sup>Be redistribution, with a large impact on the precision of <sup>7</sup>Be measurements. However, the dynamic changes in plants and the relationship with soil <sup>7</sup>Be concentration remain unclear, and the significance of dead plants in <sup>7</sup>Be interception is under-researched.</p><p><em>Methods</em>  The samples of 6 plant species, multi-plants (including living, dead and both mixed) and soil reference on the Loess Plateau were collected to analyze the variations of <sup>7</sup>Be content during the growth period from 2010 to 2012.</p><p><em>Results</em><em> </em> The accumulation of <sup>7</sup>Be concentration is significantly higher in leaves than stems. The <sup>7</sup>Be mass and areal activity concentrations in multi-plants with seasonal trends ranged from 173.9 to 964.5 Bq kg<sup>–1</sup> and 21.5 to 440.1 Bq m<sup>–2</sup>. Precipitation accounted for the largest contribution to the accumulation of <sup>7</sup>Be in plants, followed by plant growth, species and parts. Plants accounted for <sup>7</sup>Be interception on slope up to 66% (living plants accounted for 7%~31% and dead accounted for 6%~44%). The interception of living plants is low at first, then increases with biomass accumulated.</p><p><em>Conclusions</em>  Our results highlight that <sup>7</sup>Be concentration in plants has great implications for <sup>7</sup>Be in soil, and is subject to precipitation, growth status and plant characteristics. The reference information obtained in this work will contribute to improving the accuracy of <sup>7</sup>Be tracer technology, and broadening the application scope and scale of <sup>7</sup>Be tracer technology.</p><p><strong>Keywords </strong> Beryllium-7 · Loess Plateau · Precipitation · Plant · Activity concentration</p>