The impact of biodiversity loss on soil functions is well established via laboratory experiments that generally consider soil biota groups in isolation from each other, a condition rarely present in field soils. As a result, our knowledge about anthropogenic induced changes in biodiversity and associated soil functions is limited. Here, we quantified an array of soil biological constituents (plants, earthworms, nematodes, bacteria, and fungi) to explore their interactions and to characterize their influence on various soil functions (habitat for soil organisms, air and water regulation, and recycling of nutrients and organic waste) along a legacy copper (Cu) pollution gradient. Increasing Cu concentrations had detrimental impact on both plant growth and species richness. Belowground soil biota showed similar response with their sensitivity to elevated Cu concentrations decreasing in the following order: earthworms > bacteria > nematodes > fungi. The observed loss of soil biota adversely affected natural soil bioturbation, aggregate formation/stabilization, decomposition and mineralization processes, and therefore resulted in compacted soil with narrow pore size distributions and overall smaller pores, restricted air and water storage/flow, and impeded carbon, nitrogen, and phosphorous cycling. The simultaneous evolution of soil biodiversity and functions along the Cu gradient emphasized the key role of soil life in controlling ecosystem services. Furthermore, results indicated that different soil biodiversity and functional indicators started to decline (10% loss) within a copper concentration range of 110-800 mg total Cu kg-1.
Soil Science Society of America. Journal, 2014, Vol 78, Issue 4, p. 1239-1250
Bacteria; Biodiversity; Copper; Fungi; Soils; Stabilization; Water pollution; Water recycling; Aggregate formation; Copper contamination; Cu concentrations; Ecosystem services; Laboratory experiments; Mineralization process; Narrow pore size distributions; Pollution gradient