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以贵州西南部喀斯特山区35年生和14年生花椒林为研究对象,并以未退耕旱地为对照,研究表层土壤(0~20 cm)水稳性团聚体分布及有机碳矿化特征,探讨土壤有机碳周转对不同花椒种植年限的响应。结果表明:随团聚体粒径的降低,两种年龄花椒林土壤水稳性团聚体含量呈现先增加后减少的倒“V”形分布,土壤水稳性团聚体分布主要出现在5~2、2~1和1~0.5 mm 3个粒级中;与旱地相比,花椒种植明显增加了全土和团聚体中有机碳和活性有机碳含量,并以14年生花椒林较高,而35年生花椒林存在较明显的衰减;随花椒种植年限的增加,土壤有机碳矿化累积量呈递减趋势,但土壤有机碳周转半衰期以14年生花椒林较长,显著高于旱地和35年生花椒林,表明14年生花椒林土壤有机碳更易累积,表现出较好的土壤碳固存能力;喀斯特山区种植花椒后,土壤有机碳存在“汇-源”的转换过程,因此花椒种植应注重长期维护管理,防止土壤质量的衰退。
Taking the 35-year-old and 14-year-old Chinese Zanthoxylum bungeanum in the Karst mountains of southwest Guizhou as the research object, the water-stable aggregate distribution and organic carbon mineralization of the surface soil (0-20 cm) Responses of carbon turnover to different pepper growing years. The results showed that with the reduction of aggregate size, the content of soil water - stable aggregates increased firstly and then decreased, and the distribution of soil water - stable aggregates mainly appeared in 5 ~ 2, 1 ~ 1 and 1 ~ 0.5 mm. Compared with dry land, the planting of pepper increased the content of organic carbon and active organic carbon in the whole soil and aggregates, and the 14-year-old pepper plantation was higher. The annual soil organic carbon mineralization showed a decreasing trend, but the half-life of soil organic carbon was longer in the 14-year-old pepper plantation, which was significantly higher than that in the dry land and 35-year-old plantation , Which indicated that soil organic carbon accumulation in 14-year-old Z. perenne forest was more likely to accumulate and showed better soil carbon sequestration ability. After planting Zanthoxylum bungeanum in the Karst mountains, soil organic carbon had a “sink-source” conversion process, Maintain management to prevent the decline of soil quality.