Data collection
We synthesized studies related to soil invertebrate effects on forest leaf litter decomposition and searched articles published in the Web of Science, Elsevier ScienceDirect, SpringerLink, and Wiley. The keywords used for the literature searches were (‘decomposition’ OR ‘breakdown’ OR ‘degradation’ OR ‘decay’) AND (‘leaf’ OR ‘foliar’ OR ‘litter’) AND (‘forest’ OR ‘wood land’) AND (‘litterbag’ OR ‘naphthalene’ OR ‘mesh size’) AND (‘soil animal’ OR ‘soil fauna’ OR ‘soil invertebrate’ OR ‘soil detritivore’). We initially selected 2278 contributions based on the keyword list. Studies were included in our database when fulfilling all three of the following requirements:
(1) conducted leaf litter decay experiments in natural forests;
(2) used graded mesh sizes (fine (mesh size ≤ 1 mm) vs coarse (mesh size >1 mm)) or chemical agents (dose vs control) to establish treatments including invertebrate inclusion and exclusion under the same abiotic and biotic conditions; and,
(3) measured litter decomposition in terms of mass loss, mass remaining, or decomposition rate over a known decay duration.