北京低山区油松林和元宝枫林凋落物酶活性研究

Enzyme activities in litter of Pinus tabulaeformis and Acer truncatum forests in lower mountain area, Beijing

森林凋落物中的酶直接催化凋落物中有机化合物的分解。为探讨不同林分凋落物中酶活性的差异,以北京低山区油松林、元宝枫林以及油松元宝枫混交林为对象,比较不同林分未分解层(L层)和半分解层(F层)凋落物的化学性质以及与碳氮转化相关酶活性的差异,并分析了凋落物化学性质对酶活性的影响。结果表明,与油松林相比,元宝枫林凋落物中L层的α-糖苷酶、β-糖苷酶、几丁质酶、酸性磷酸酶和多酚氧化酶分别高103.66%、158.17%、222.70%、32.18%、242.14%,F层的几丁质酶、亮氨酸氨基肽酶和多酚氧化酶分别高86.10%、63.10%、845.28%;而混交林凋落物中L层的α-糖苷酶、几丁质酶、酸性磷酸酶和多酚氧化酶比油松林凋落物分别高58.81%、58.28%、89.54%、210.64%,F层的几丁质酶、氨基酸氨基肽酶和多酚氧化酶分别高43.98%、46.43%、280.85%。因此,针叶树和阔叶树混交有利于针叶凋落物酶活性的提高,从而促进凋落物的分解。

Enzyme in the forest litter can directly catalyze compounds decomposition in the litter.This objective of this paper was to investigate the variation of enzyme activity in litter of the different forests.Three forest plots included Acer truncatum forest, Pinus tabulaeformis forest and mixed forest were established.The chemical properties and the enzyme activities（α-glycosidase, β-glycosidase, glucosaminidase, acid phosphatase, leucine aminopeptidase and polyphenol oxidase）involved in the transformations of carbon and nitrogen of litter were compared in litter layer and fragmentation layer of the different forests, and the correlation of litter chemical properties and the enzyme activities was analyzed.The results showed that the activities of α-glycosidase, β-glycosidase, glucosaminidase, acid phosphatase and polyphenol oxidase in litter layer of Acer truncatum forest was higher than Pinus tabulaeformis forest by 103.66%, 158.17%, 222.70%, 32.18%, 242.14%, respectively. Activities of glucosaminidase, leucine aminopeptidase and pdyphenol oxidase in fragmentation layer were increased by 86.1%, 63.1%, 845.28%; the activities of α-glycosidase, glucosaminidase, acid phosphatase and polyphenol oxidase in litter layer of mixed forest litter was higher than Pinus tabulaeformis forest by 58.81%, 58.28%, 89.54%, 210.64%, the activities of chitinase, leucine aminopeptidase and polyphenol oxidase in fragmentation layer was higher by 43.98%, 46.43%, 280.85%. In sum, coniferous and broadleaf mixed may stimulate the enzyme activity, thus accelerate the litter decomposition.