“…However, while nitrogen deposition increases nitrogen availability, it simultaneously causes soil acidification, which will also affect carbon allocation to soils (and hence the belowground food web) by changing the concentration of H þ ions and soil base cations (Van Breemen and Van Dijk, 1988;Kuperman and Edwards, 1997). In addition, a number of studies have focused on how the diversity or taxonomic group of belowground communities (mostly soil microbes) changes in response to nitrogen enrichment (Campbell et al, 2010;Ramirez et al, 2010), but the changes lack consistency García-Palacios et al, 2015). Surprisingly, few studies have simultaneously examined how multiple trophic levels of the belowground food web (e.g., microbes and nematodes) are affected by nitrogen enrichment (Fierer et al, 2009;Eisenhauer et al, 2012).…”