杉木林下药用植物淋出物对林木枯落物分解及土壤酶活性的影响

Effect of Leachates from understory Medicinal Plants on Decomposition of Forest Litter and Soil Enzyme Activities

以浙江丽水松阳县杉木Cunninghamia lanceolata林林下7种常见药用植物三叶崖爬藤Tetrastigma hemsleyanum、多花黄精Polygonatum cyrtonema、蒲公英Taraxacum mongolicum、薄荷Mentha canadensis、蕺菜Houttuynia cordata、白及Bletilla striata、灵芝Ganoderma lucidum为对象,通过水浸法提取其茎叶淋出物浸提液,并将其配制成浓度为85 mg·mL^(-1)浸提液,使用喷雾器每次喷浇250 mL浸提液于培养钵中的林木枯落物,每隔2周喷浇一次,喷浇周期分别为1个月、3个月、6个月,研究药用植物淋出物对杉木枯落物分解的影响,以及通过土壤酶活性检测研究对其存在的潜在化感影响。结果表明:蒲公英、薄荷、鱼腥草浸提液对杉木枯落物处理后,其养分碳、氮、磷、钾、铜、锌、锰残余留量均有升高趋势,表明这三种植物抑制了杉木枯落物分解、延长其分解周转期,土壤酶(蔗糖酶、羧甲基纤维素酶、β-葡糖苷酶、脱氢酶、多酚氧化酶、蛋白酶、磷酸酶)活性显著降低,其他4种植物淋出物均能够显著加速分解残留物及提升土壤酶活性,因此建议杉木林下应该尽力避免种植蒲公英、薄荷、鱼腥草,同时通过降低套种密度减少药材植物的化感影响。

Stems and leaves were collected from Tetrastigma hemsleyanum,Polygonatum cyrtonema,Taraxacum mongolicum,Mentha canadensis,Houttuynia cordata,Bletilla striata,Ganoderma lucidum cultivated under Cunninghamia lanceolata plantation in Songyang county,Zhejiang Province.Leachates was extracted by water leaching method.Experiment was conducted on spraying 250 ml of leachates on C.lanceolata litter every two weeks within one month,3 months and 6 months for studying its effect on decomposition of litter and soil enzyme activities.The results showed that the residual amounts of nutrients such as carbon,nitrogen,phosphorus,potassium,copper,zinc and manganese increased in litter treated by leachates from T.mongolicum,M.canadensis and H.cordata,indicating their inhibition of decomposition of litter and extended its decomposition turnover time.The activities of soil enzymes(sucrase,carboxymethyl cellulase,β-glucosidase,dehydrogenase,polyphenol oxidase,protease and phosphatase)were significantly decreased.The left 4 species leaches could significantly accelerate the decomposition of residues and enhance soil enzyme activity.The result suggested that T.mongolicum,M.canadensis and H.cordata should be avoided under C.lanceolata forest.