腐烂等级和径级对天宝岩长苞铁杉林木质残体理化性质的影响

木质残体是森林生态系统的重要组成部分,其理化性质影响木质残体的分解.本研究以集中分布于天宝岩国家级自然保护区的长苞铁杉(Tsuga longibracteata)林木质残体为对象,将4个不同类型林分的木质残体划分为5个腐烂等级和4个径级,研究林分类型、腐烂等级、径级及其交互作用对木质残体理化性质的影响.结果 表明:从物...

Effects of decay grades and diameter classes on physicochemical properties of woody debris in Tsuga longibracteata forest in Tianbaoyan National Nature Reserve

Woody debris is a key component of forest ecosystem, and the physicochemical properties are important for its decomposition. In this study, we examined the effects of stand type, decay grade, diameter class, and their interaction on the physicochemical properties of woody debris of Tsuga longibracteata in four different stands in Tianbaoyan National Nature Reserve. Woody debris was classified into five decay grades and four diameter classes. The results showed that wood density of woody debris in T. longibracteata forests decreased with the increased decay grade, but moisture content increased. The diameter class had a significant effect on moisture content of woody debris only in the T. longibracteata pure forest. The interaction of decay grade and diameter class had no significant effect on the physical properties of woody debris in each stand. In terms of chemical properties, decay grade did not affect C content of woody debris, but significantly affected N content and C/N ratio of woody debris in three mixed forests. The diameter class had significant effects on P content of woody debris in the T. longibracteata pure forest and P content and C/N in the T. longibracteata+Rhododendron simiarum mixed forest. The interaction had no significant effect on the chemical composition of the woody debris across all stand types. Wood density was closely correlated with C and P contents of woody debris in the T. longibracteata+R. simiarum mixed forest, as well as C, N, P contents and C/N in the T. longibracteata+Phyllostachys edulis mixed forest. Moisture content had significant correlation with N, P, C/N of woody debris in the T. longibracteata pure forest and P, C/N in the T. longibracteata+P. edulis mixed forest. In conclusion, the physical properties of woody debris are important factors affecting nutrient content.