毛竹林地土壤团聚体稳定性及其对碳贮量影响研究

通过对集约经营毛竹林地土壤团聚体的测定,结果表明毛竹林地3个土壤层次各粒径团聚体分布特征为>5 mm的含量在土壤团粒结构中占主导地位,占总团聚体的比例为26.39%~42.38%;其次为1~5 mm含量,占14%~18%;<0.25 mm的含量最小,占2.31%~6.73%。毛竹林土壤团聚体平均重量直径平均值为0.90 mm,并且随着土壤层次的增加有逐渐增加的趋势。毛竹林地土壤总有机碳的积累与0.25~3.15 mm土壤团聚体中有机碳含量呈显著相关,与>3.15 mm和<0.25 mm团聚体有机碳含量相关不显著。毛竹林地0~20 cm土壤层中,分布在>5 mm和3.15~5 mm粒径土壤团聚体中的有机碳比例分别为14.86%和11.26%,低于20~40 cm和40~60 cm土壤。这也说明,长期集约经营毛竹林后,林地土壤有机碳含量下降的主要原因可能是>5 mm粒径土壤团聚体有机碳含量下降。

Moso Bamboo Plantation Soil Aggregate Stability and Its Impact on Carbon Storage

The intensive management Moso bamboo plantation soil aggregates and its carbon storage were analyzed.The results showed that soil granule structure of Moso bamboo plantation was dominated by >5 mm aggregate for all the three soil layers,accounting for 26.39%~42.38% of all soil aggregate.Soil aggregates of 1~5 mm and <0.25 mm accounted for 14%~18% and 2.31%~6.73%,respectively.Mean weight diameter of soil aggregate in Moso bamboo plantation was 0.90 mm,which tended to increase with descending soil layers.The accumulation of soil organic carbon was significantly related to organic carbon in 0.25~3.15 mm aggregate.However,the correlations between soil organic carbon accumulation and organic carbon in both >3.15 mm and <0.25 mm aggregates were not significant.Moso bamboo plantation soil aggregate ratio of organic carbon in> 5 mm and 3.15 ~ 5 mm aggregate in 0~20 cm were 14.86% and 11.26%,lower than its 20~40 cm and 40~60 cm layer.That is to say the > 5 mm soil diameter aggregate organic carbon content decreased maybe the main reasons of long-term intensive management Mao bamboo plantation soil organic carbon content decreased.