米槠与杉木细根凋落物是否在自身群落中分解得更快?

Does Fine-root Litter of Castanopsis carlesii and Cunninghamia lanceolata Decompose Fastest in Its Own Community?

本研究应用网袋法对福建省万木林自然保护区米槠(Castanopsiscarlesii)、杉木(Cunninghamialanceolata)细根在米槠林群落和杉木林群落交叉分解进行了为期2年的研究。结果表明,0￣1mm、1￣2mm米槠细根在米槠群落比在杉木群落分解速率快,而相同径级杉木细根在两群落分解差异较大。0￣1mm杉木细根在杉木群落的分解速率高于米槠群落,而1￣2mm杉木细根在杉木群落的分解速率只及米槠群落的48%。米槠、杉木细根在两群落分解的差异表明,群落立地条件对细根分解存在较大的影响。

In the present study, we investigated the decomposition dynamics of the fine roots of Castanopsis carlesii and Cunninghamia lanceolata in both a Ca. carlesii forest and a Cu. lanceolata plantation. From a 2- year experiment, we found the following： （1） Fine roots of Ca. carlesii decomposed faster in its own forest than in a Cu. lanceolata plantation. The decomposition rate of fine roots of 0-1 and 1-2 mm-diameter classes of Ca. carlesii in its own forest was 2.0 and 4.7 times faster, respectively, than that in the Cu. lanceolata plantation. （2） The decomposition dynamics of fine roots of both diameter classes of Cu. lanceolata varied greatly between its own plantation and a Ca. carlesii forest. The decomposition rate of 0-1 mm fine roots of Cu. lanceolata in its own plantation was 1.5 times faster but for 1-2 mm roots only 0.48 times faster than that in a Ca. carlesii forest. These findings suggest that specific forest soil may have a strong effect on fine-root decomposition.