Taxonomic and structural diversity indices predict soil carbon storage better than functional diversity indices along a dieback intensity gradient in semi-arid oak forests

Key messageThe use of structural diversity indices can be efficient tools to increase understanding changes in soil carbon storage as a key ecosystem function along the oak dieback intensity.Investigating relationships between biodiversity and functions within mass‐ratio niche complementary hypotheses is still challenging issue terrestrial ecology. These have not been studied gradient disturbance semi-arid forest ecosystems. To fill this gap, we investigated main -soil storage- various intensity (no, low, moderate or high intensity) protected intensively managed mixed forests western Iran. We used different approaches calculated functional divergence index (FDvar), community weighted mean trait values; CWM, taxonomic (richness, Shannon–Wiener evenness) (MI: mingling index, HD: height differentiation, DD: diameter differentiation). Soil was significantly influenced by type management, their interactions higher areas (95.90 ± 4.62 ton ha−1) than (76.52 2.04 ha−1). It showed humped-shaped pattern areas, it peaked at low (122.47 10.12 ha-1), indicating that maximized level. positively correlated with all indices, except for evenness, but negatively most composition (CWM LNC: leaf nitrogen concentration, H: woody species LDMC: dry-matter content). best predicted (Mingling index: R2 = 0.214) followed (species richness, 0.173) CWM LDMC, 0.158). Our results emphasize role played predict contrasted management conditions gradient. They also provide evidence support both hypotheses.