Effects of mixing pine and broadleaved tree/shrub litter on decomposition and N dynamics in laboratory microcosms |
| |
Authors: | Wei Li Kai-wen Pan Ning Wu Jin-chuang Wang Chun-mei Han Xiao-lan Liang |
| |
Institution: | (1) Chengdu Institute of Biology, Chinese Academy of Sciences, PO Box 416, 610041 Chengdu, People’s Republic of China;(2) Graduate School of the Chinese Academy of Sciences, 100039 Beijing, China |
| |
Abstract: | This study was carried out to compare the ecological function of exotic pine (Pinus radiata—Pr) and native pine (Pinus tabulaeformis—Pt) in terms of litter decomposition and its related N dynamics and to evaluate if the presence of broad-leaved tree species
(Cercidiphyllum japonicum—Cj) or shrub species (Ostryopsis davidiana—Od) litter would promote the decomposition of pine needles and N cycling. Mass remaining, N release of the four single-species
litters and mixed-species (Pt + Cj; Pr + Cj; Pt + Od; Pr + Od) litters and soil N dynamics were measured at microcosm scale
during an 84-day incubation period. The Pt and Pr litter, with poorer substrate quality, indicated slower decomposition rates
than did the Cj and Od litter. Due to their high C/N ratios, the N mass of Pt and Pr litter continuously increased during
the early stage of decomposition, which showed that Pt and Pr litter immobilized exogenous N by microbes. No significant differences
of soil inorganic, dissolved organic and microbial biomass N were found between the Pt and Pr microcosm at each sampling.
The results showed that the exotic Pr performed similar ecological function to the native Pt in terms of litter decomposition
and N dynamics during the early stage. The presence of Cj or Od litter increased the decomposition rates of pine needle litter
and also dramatically increased soil N availability. So it is feasible for plantation managers to consider the use of Cj as
an ameliorative species or to retain Od in pine plantations to promote the decomposition of pine litter and increase nutrient
circulation. The results also suggested that different species litters induced different soil dissolved organic nitrogen (DON).
As a major soluble N pool in soil, DON developed a different changing tendency over time compared with inorganic N, and should
be included into soil N dynamic under the condition of our study. |
| |
Keywords: | Litter decomposition N dynamics Microcosm Mixed-species litter Exotic species |
本文献已被 SpringerLink 等数据库收录! |
|