云南顶瓶梗霉对森林地表凋落物的降解效果

Degradation effect of Acrophialophora yunnanensis on forest surface litter

【目的】探究云南顶瓶梗霉GZUIFR 22.409对不同类型森林地表凋落物的降解效果,以期利用该真菌促进森林地表凋落物的降解,减少森林地表凋落物的载量,从而降低森林火险等级,并为利用微生物降解法降低贵州林区森林可燃物载量提供理论依据和基础数据。【方法】采集林地的针叶和阔叶地表凋落物,利用云南顶瓶梗霉活菌和粗酶分别处理凋落物,并按照野外调查地表凋落物床层参数设置床层后,于25 ℃温度和80%相对湿度条件下测定两类地表凋落物的失重动态,分析云南顶瓶梗霉活菌和粗酶对两类地表凋落物的降解效果。【结果】云南顶瓶梗霉活菌和粗酶对两类地表凋落物均具有降解作用且都在第16天降解率最大。对于针叶凋落物,粗酶的降解率为9.74%,菌的降解率为13.14%;经降解模型拟合,粗酶的降解系数k为0.004,降解t_(0.5)为165 d、t_(0.95)为740 d,菌的降解系数k为0.005,降解t_(0.5)为131 d、t_(0.95)为588 d;对于阔叶凋落物,粗酶的降解率为15.76%,菌的降解率为15.37%;经降解模型拟合,粗酶的降解系数k为0.007,降解t_(0.5)为93 d、t_(0.95)为422 d,菌的降解系数k为0.006,降解t_(0.5)为103 d、t_(0.95)为487 d。【结论】云南顶瓶梗霉活菌及其粗酶对针阔叶地表凋落物都有降解效果,对阔叶凋落物的降解效果优于针叶凋落物,应用该菌可在一定程度上能够达到减少森林地表可燃物载量的效果。因此云南顶瓶梗霉在调控森林地表凋落物载量方面具有较好的应用前景。

【Objective】We investigated the degradation effect of Acrophialophora yunnanensis GZUIFR 22.409 on different types of forest surface litter,in order to use the fungi to promote the degradation of forest surface litter,reduce the load of forest surface litter and thus reduce the forest fire danger grade,which will provide the theoretical basis and basic data for the microbial degradation method to reduce the forest fuel load in Guizhou forest area.【Method】The litters of coniferous and broad-leaved forest were collected and treated with living fungi and crude enzyme of A.yunnanensis,respectively.The weight loss dynamics of the two types of surface litter were determined at 25 ℃ and 80% relative humidity after setting up the table according to survey fuelbeds in the fields,and the degradation effects of the fungi and crude enzyme of A.yunnanensis on the two types of litter were analyzed.【Result】Both the fungi and the crude enzyme of A.yunnanensis could degrade two kinds of litters and all of them had the highest degradation rate at 16th day.For coniferous litter,the degradation rate of crude enzyme was 9.74% and that of the fungi was 13.14%.After fitting the degradation model,the degradation coefficient k of crude enzyme was 0.004,the degradation of t_(0.5) was 165 days,and the degradation of t_(0.95) was 740 days.The degradation coefficient k of the fungi was 0.005,the degradation of t_(0.5) was 131 days,and the degradation of t_(0.95) was 588 days.For broadleaved litter,the degradation rates of crude enzyme and the fungi was 15.76% and 15.37%,respectively.After fitting the degradation model,the degradation coefficient k of crude enzyme was 0.007,the degradation of t_(0.5) was 93 days and the degradation of t_(0.95) was 422 days,the degradation coefficient k of the fungi was 0.006,the degradation of t_(0.5) was 103 days and the degradation of t_(0.95) was 487 days.【Conclusion】Both the fungi and crude enzymes of A.yunnanensis had degradation effect on coniferous and broadleaf litter,and the degradation effect on broadleaved litter was better than that of coniferous litter.It can reduce the forest surface fuel load to a certain extent,and contribute to reducing the forest fire risk level in Guizhou forest area.Therefore,A.yunnanensis has a promising application in reducing litter loading on forest surface.