Home-field advantage of CWD decomposition in subtropical forests varied by field sites

Previous studies have found that home-field advantage (HFA) appears to be widespread in the decomposition of litter, but few studies have examined HFA in the decomposition of coarse woody debris (CWD) in forest ecosystems. To test the HFA hypothesis for CWD decomposition, we quantified the respiration of CWD (R-CWD) for different tree species over a two-year study period. We used a dynamic chamber method to monitor R-CWD over time in two reciprocal translocation field experiments by placing CWD of the same decay stage from three tree species into two different forest types. The three species used were Cryptomeria japonica (CR), Platycarya strobilacea (PL) and Acer davidii (AC); the two forest types were broadleaf forest (home field for PL and AC; visiting field for CR) and coniferous forest (home field for CR; visiting field for PL and AC). We also characterized the microbial community of each CWD and the soil underneath as well as the control soil without CWD influence by the method of phospholipid fatty acids (PLFAs). We found that the R-CWD of PL and AC in the HF were significantly higher than that in the VF, while the opposite was true for the R-CWD of CR. Soil microbial community affected CWD microbial community, especially for the bacteria component, with field site explaining 17.4% of the total variation in CWD microbial community. Our results suggest that the difference in CWD decomposition between home and visiting field was directly explained by the difference in soil microbial community between home and visiting field, which may be attributed to the differences in soil nutrient and litter quality between the two field sites (forest types).