The Relative Importance of Coarse-Scale Climate and Fine-Scale Nitrogen Availability Contrasts in Driving Home-Field Advantage Effects in Litter Decomposition

Understanding the relative importance of climates at coarse scales and nitrogen (N) availability at fine scales in driving litter decomposition is crucial for ecosystem functioning. In this study, we explored the relative importance of coarse-scale climatic contrast (China vs. France) and local soil fertility contrast related to N availability in determining ‘home-field advantage (HFA)’ effects. Four tree-species litters from four forest types with contrasting chemical properties from China and France were reciprocally transplanted in a litterbag decomposition experiment. The Decomposer Ability Regression Test showed highly significant HFA effects for the Chinese litter ( Castanopsis eyrei ), that is, the most recalcitrant litter with low P and N contents, and marginally significant HFA effects for the French litter ( Carpinus betulus ), that is, the most labile litter with high P and N contents. The climatic contrast was more important in determining HFA effects than the N availability contrast. Our findings highlight the importance of climate in determining the occurrence of HFA effects that likely can be attributed to differences in soil weathering intensity driving soil P legacy, an important coarse-scale component of soil fertility.