Abstract
Soils have the potential to accumulate heavy metals and the capacity to do so is strongly related the properties of each soil. Soil organic matter is a key factor in the retention, release, and bioavailability of heavy metals, and here we have determined the accumulation of heavy metals in various types of humus in the Rybnik Forest District in southern Poland. In a novel approach, we analyzed relationships between heavy metals within soil organic matter fractions and evaluated the role of organic fractions in mediating metal mobility. Specifically, we tested whether (i) the type of forest humus determines the heavy metal accumulation; (ii) heavy metals accumulation is associated with soil organic matter fractions; and (iii) heavy metals have an inhibitory influence on biochemical properties especially enzymes activity in different humus types. Four types of humus were sampled (mor, moder, moder-mull, mull), physically fractioned, and a number of chemical and biochemical properties were analyzed. Calculated geo-accumulation index (Igeo) and enrichment factor (EF) confirmed soil pollution with Cd and Pb. The type of humus differed in the accumulation of heavy metals, which is associated to the variable concentration of organic matter remaining at each decay class. We found no relationship between enzymatic activity and heavy metals concentration except for a positive correlation between urease activity and nickel concentration. Considering wider evidence, we propose a biogeochemical link between nickel deposition and the production of soil-borne urease in these forest soils.
Highlights
Soil has the capacity to accumulate trace elements such as heavy metals
Soil organic matter can be divided into labile fraction called free light fraction, mineral soil light fraction which may become stabilized by occlusion inside aggregates, and stabilized fraction of SOM, known as heavy fraction which is mineralassociated fraction (MAF)
We confirmed that the humus type of forest soils determines the accumulation of heavy metals
Summary
Soil has the capacity to accumulate trace elements such as heavy metals. Soil organic matter (SOM) and clay minerals are the main component of soil that possess significant sorption capacity relative to metals through exchange sorption, complexing, or chelation. Soil organic matter is involved in retention, reduction of mobility, and reduction of bioavailability of heavy metals (Impellitteri et al 2002; Wolińska et al 2018). Soil organic matter can be divided into labile fraction called free light fraction (fLF), mineral soil light fraction which may become stabilized by occlusion inside aggregates (so-called occluded light fraction-oLF), and stabilized fraction of SOM, known as heavy fraction which is mineralassociated fraction (MAF) (von Lützow et al 2007; Błońska et al 2017). SOM associated with minerals can be stabilized due to its protection from mineralization (Li et al 2019), whereas the light fraction is more susceptible to changes to soil use and altered litter inputs (Grüneberg et al 2013; Błońska et al 2017)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
