岭南垛基果林湿地土壤碳组分特征

Soil Carbon Components in Typical Duoji Fruit Forest Wetland

岭南垛基果林湿地是珠三角地区典型的湿地类型之一,其对土壤碳汇的贡献值得关注。为探讨果林种植类型对土壤有机碳的影响,对广州垛基果林湿地内种植黄皮(Clausenalansium)(HP),龙眼(Dimocarpuslongan)(LY)、杨桃(Averrhoa carambola)(YT),龙眼和黄皮间种(LH),杨桃、龙眼和黄皮间种(YLH)共5种种植类型下的表层(0~20 cm)土壤碳组分进行研究。结果表明,不同的植被类型对土壤的总有机碳(SOC)、可溶性有机碳(DOC)、微生物生物量碳(MBC)、易氧化有机碳(ROC)、惰性碳(NLC)含量都有影响,LY的SOC含量最高(22.6 g/kg),显著高于YLH (P<0.05),且NLC含量显著高于LH和YLH (P<0.05)。NLC含量与土壤养分呈正相关,与土壤容重呈负相关。YT的MBC含量显著高于LY、HP、LH (P<0.05),且MBC/SOC显著高于HP、LY(P<0.05)。YLH模式下,土壤DOC含量和DOC/SOC显著高于其他植被类型(P<0.05)。LH的ROC/SOC显著高于HP和LY,而NLC/SOC显著低于HP和LY。岭南垛基果林湿地中单独种植龙眼和黄皮有助于提高土壤有机碳稳定性,而混合种植模式下土壤有机碳活性最高。

Lingnan Duoji Fruit Forest Wetland is a semi-natural managed wetland in Pearl River Delta,which plays an important role in soil carbon sequestration.The soil organic carbon(SOC)components in surface layer(0-20 cm)under five planting types in Duoji Fruit Forest Wetland in Guangzhou were studied,including Clausena lansium(HP),Dimocarpus longan(LY),Averrhoa carambola(YT),D.longan and C.lansium interplanting(LH),A.carambola,D.longan and C.lansium interplanting(YLH).The results showed that the fruit-forest types significantly affected the contents of SOC,dissolved organic carbon(DOC),microbial biomass carbon(MBC),readily oxidizable carbon(ROC)and non-liable carbon(NLC).The SOC content of LY was the highest(22.6 g/kg),which was significantly higher than that of YLH(P<0.05),and the NLC content was also significant higher than LH and YLH.The NLC was positively related with soil N and P,negatively related with soil bulk density.The content of MBC in YT was higher than that in LY,HP and LH,while the MBC/SOC was higher than that in HP and LY.The DOC content and DOC/SOC in YLH were significantly higher than that of other types(P<0.05).The ROC/SOC of LH were significantly higher than that of HP and LY,while the NL/SOC were significantly lower than that of HP and LY(P<0.05).Therefore,it was suggested that the stability of soil organic carbon was improved by planting C.lansium and D.longan alone,while the activity of soil organic carbon was the highest under mixed planting mode.