All size classes of soil fauna and litter quality control the acceleration of litter decay in its home environment

Abstract

There is increasing evidence that litter decomposition is faster beneath the plant species it was derived from, an effect called home‐field advantage (HFA). Adaptation of soil biota to decompose the litter that they encounter most often has been proposed as the main mechanism to explain HFA. However, there is little direct evidence supporting this assumption and the contribution of different decomposer groups to the HFA is unknown. Furthermore, the large observed variation in the strength of the HFA may be linked to litter quality, with increasing HFA for more recalcitrant substrates. To test the relationship between HFA, litter quality and soil fauna, we performed a field litter bag experiment, with different mesh sizes and reciprocal litter transplants, across a successional gradient varying in litter quality inputs and soil fauna composition. The results show that the HFA was stronger in sites dominated by more recalcitrant litter inputs and provide evidence that a range of soil fauna size classes contribute to this effect. Our findings help explain the lack of HFA in ecosystems with simple litters and in studies where experimental artefacts (e.g. fine mesh sizes) affect the contribution from certain classes of soil fauna.