不同树种配置模式对碳汇造林初期土壤碳变化的影响

为研究不同树种模式模式碳汇造林对土壤碳的影响,该试验将立地条件基本一致的6个区组作为研究区,设计5个模式模式(各树种数量分数,模式1:台湾相思40%、木荷40%、马占相思10%、樟树10%;模式2:华润楠25%、红锥25%、樟树20%、米老排10%、木麻黄10%、水翁10%;模式3:马占相思30%、华润楠25%、山杜英25%、木麻黄10%、台湾相思5%、樟树5%;模式4:火力楠30%、秋枫20%、马占相思20%、台湾相思10%、米老排10%、木麻黄10%;模式5:台湾相思20%、木荷20%、樟树20%、木麻黄20%、火力楠15%、水翁5%),将12个树种随机种植在5个区组,另保留其植被原始状态的1个区组作为对照。4 a后对各指标进行测定,结果显示:在0—20 cm土壤层,5个模式与对照之间的碳含量差异显著(P<0.05);20—60 cm土壤层,模式2,3,4,5与对照之间的碳含量差异显著(P<0.05),模式1与对照碳含量之间无明显差异。土壤碳储量的大小顺序为:模式2>模式4>模式3>模式5>模式1>对照,5个模式土壤碳储量显著高于对照,模式2,3,4,5显著高于模式1,模式2,3,4,5之间差异不明显,模式2,4的土壤碳储量分别为(106.14±22.39),(104.72±28.63)Mg C/hm^( 2)。说明这2种模式土壤碳积累表现较高,碳汇能力表现较好。

Effect of different tree species allocation pattern on soil carbon change in early stage of afforestation

In order to study the effect of carbon sequestration afforestation on soil carbon under different tree species allocation patterns,5 allocation patterns of 12 tree species(according to different number proportion)were designed.The trees were randomly arranged in 5 blocks of the same site,with another block of the same site as control(CK).The results showed that in the 0—20 cm soil layer,there were significant differences in carbon content between 5 patterns and CK(P<0.05);in the 20—60 cm soil layer,significant difference occurred between Pattern 2,3,4,5 and CK(P<0.05),but no significant difference between Pattern 1 and CK.For the soil carbon storage,the order was presented as followed,Pattern 2>Pattern 4>Pattern 3>Pattern 5>Pattern 1>CK.The soil carbon storage of 5 allocation patterns was significantly higher than that of CK,with the soil carbon storage of Pattern 2,3,4 and 5 significantly higher than that of Pattern 1 while the difference was not significant among Pattern 2,3,4 and 5.The soil carbon storages of Pattern 2 and 4 were(106.14±22.39)and(104.72±28.63)Mg C/hm 2,respectively.So we concluded that such allocation patterns as Machilus chinensis 25%+Castanopsis hystrix 25%+Cinnamomum camphora 20%+Mytilaria laosensis 10%+Casuarina equisetifolia 10%+Cleistocalyx operculatus 10%and Michelia macclurei 30%+Bischofia javanica 20%+Acacia mangium 20%+Acacia confusa 10%+Mytilaria laosensis 10%+Casuarina equisetifolia 10%could bring higher soil carbon accumulation and better carbon sink capacity.