33 34Many studies have shown the effects of aboveground plant species on soil organisms 35 due to differences in litter quality. However, the calcium concentration in soil has 36 received less attention as a controlling factor of soil invertebrate communities, despite 37 its being an essential element for many animals, especially crustaceans. Litter of 38 Japanese cedar (Cryptomeria japonica) plantations, which account for 19% of the 39 forested area in Japan, has a higher calcium concentration compared to other taxa such 40 as broad-leaved trees. We predicted that C. japonica plantations affect soil invertebrates 41 by altering calcium availability. We compared soil properties including exchangeable 42 calcium concentration and soil invertebrate communities between C. japonica 43 plantations and natural broad-leaved forests. Exchangeable calcium was significantly 44 higher in soil from cedar plantations than in that from broad-leaved forests. The 45 invertebrate community composition differed between the two forest types and was best 46 explained by the exchangeable calcium concentration. In particular, two major taxa of 47 soil crustaceans (Talitridae and Ligidium japonicum) were found only in cedar 48 plantations. Our results suggest that calcium concentrations in soil are altered in C. 49 japonica plantations and that this affects soil invertebrate communities. 50 51