Rhizospheric and heterotrophic respiration of a warm-temperate oak chronosequence in China

摘要: Abstract Plot trenching and root decomposition experiments were conducted in a warm-temperate oak chronosequence (40-year-old, 48-year-old, 80-year-old, 143-year-old) China. We partitioned total soil surface CO2 efflux (RS) into heterotrophic (RH) rhizospheric (RR) components across the growing season of 2009. found that temporal variation RR RH can be well explained by temperature (T5) at 5 cm depth using exponential equations for all forests. However, 40-year-old 48-year-old forests peaked September, while their T5 peaks occurred August. 80-year-old 143-year-old showed similar pattern to T5. The contribution RS (RC) and 48-year-old presented second peak September. Seasonal may accounted different successional stages. Cumulative during varied with forest age. estimated values 40-year-old, averaged 431.72, 452.02, 484.62 678.93 g C m−2, respectively, corresponding 191.94, 206.51, 321.13 153.03 g C m−2. RC increased from 30.78% 39.85% then declined 18.39% forest. organic carbon (SOC), especially light fraction (LFOC), stock 0–10 cm correlated RH. There was no significant relationship between fine biomass regardless stand Measured apparent sensitivity (Q10) (3.93 ± 0.27) significantly higher than (2.78 ± 0.73). Capillary porosity decreased as age it negatively cumulative RS. Our results emphasize importance partitioning respiration evaluating effect on its significance future model construction.