海南屯昌不同林龄槟榔人工林地下部分碳储量的分布特征

Distribution characteristics of carbon storage in the underground part of areca nut plantations with different forest ages in Tunchang,Hainan

以海南省屯昌县枫木林场3种林龄(幼龄林、中龄林、成熟林)的槟榔人工林为研究对象,探讨槟榔人工林地下部分0~100 cm土层中根系碳储量与土壤有机碳储量的分布特征.研究表明:0~100 cm土层中,槟榔人工林根系主要集中在表层(0~30 cm),且根系生物量随土层的加深而显著降低,表现为:成熟林(1244.26 g·m^(-3))>中龄林(993.26 g·m^(-3))>幼龄林(658.59 g·m^(-3));随林龄增长,根系碳储量表现为成熟林(6.23 t·hm^(-2))>中龄林(4.97 t·hm^(-2))>幼龄林(3.57 t·hm^(-2)).不同林龄槟榔人工林的土壤有机碳(0~100 cm土层)分布表现为:随土层加深,土壤有机碳含量显著减少,不同林龄之间土壤有机碳存在差异,但不显著,其中,幼龄林的有机碳范围在2.64~21.65 g·kg^(-1)之间,中龄林的含量范围为3.56~25.21 g·kg^(-1),成熟林的有机碳含量范围为4.37~31.77g·kg^(-1).不同林龄槟榔人工林的土壤有机碳储量表现为:成熟林(125.72 t·hm^(-2))>中龄林(107.58 t·hm^(-2))>幼龄林(90.83 t·hm^(-2)).槟榔幼龄林的土壤碳储量与有机碳、全氮、全磷、pH、容重、饱和含水量存在极显著差异(P<0.01);槟榔中龄林和成熟林的土壤碳储量与土壤有机碳存之间在显著差异(P<0.05),但与其他指标无显著性差异(P>0.05).通过与屯昌地区主要人工林土壤碳储量的对比可知,槟榔人工林的土壤碳储量丰富,碳汇能力显著,可以将其作为发展碳汇的主要树种.

In the report,the betel nut plantation of three forest ages(young aged forest,middle aged forest,and mature forest)in Fengmu Forest Farm,Tunchang County,Hainan Province,were used as the research object,and the distribution characteristics of root carbon storage and soil organic carbon storage in the 0~100 cm soil layer in the underground part of a plantation were elucidated.The results indicated that in the 0~100 cm soil layer,the root system of betel nut plantation is mainly concentrated in the surface layer(0~30 cm),and with the deepening of the soil layer,the root biomass decreases significantly,mature forest(1244.26 g·m^(-3))>medium aged forest(993.26 g·m^(-3))>young aged forest(658.59 g·m^(-3));with the growth of forest age,the change of the root carbon storage was as follows:mature forest(6.23 t·hm^(-2))>middle aged forest(4.97 t·hm^(-2))>young forest(3.57 t·hm^(-2)).The distribution of soil organic carbon in the 0~100 cm soil layer of areca nut plantations with different stand ages showed that with the deepening of the soil layer,the content of soil organic carbon decrease significantly,there are differences among the soil organic carbon of the different forest ages,however,it is not significant.the organic carbon content of young forest is 2.64~21.65 g·kg^(-1),the organic carbon content of middle-aged forest is 3.56~25.21 g·kg^(-1),and the organic carbon content of mature forest is 4.37~31.77 g·kg^(-1).There are significant differences among the soil carbon storage of the different forest ages,mature forest(125.72t·hm^(-2))>middle aged forest(107.58 t·hm^(-2))>young forest(90.83 t·hm^(-2)).There are the highly significant between the soil carbon storage and the organic carbon,total nitrogen,total phosphorus,pH,bulk density,saturated water content of the young Areca catechu forest(P<0.01).There was significant difference between soil carbon storage and soil organic carbon in betel nut middle aged forest and mature forest(P<0.05),but there was no significant difference with other indicators(P>0.05).By comparing with the carbon reserves of main plantations in Tunchang area,the soil carbon reserves of the betel nut plantations are richer,and the carbon sink capacity of the betel nut plantations are higher,which can be used as the tree species for developing carbon sink.