Effects of temperature and moisture changes on functional gene abundance of soil nitrogen cycle in permafrost peatland

Document Type

Article

Publication Date

9-1-2021

Abstract

We sampled peatland soil columns in the Great Hing'an Mountains and studied the effect of temperature increasing on nitrogen cycle related functional gene abundance at different depths (0-150 cm) by indoor simulation incubation. We set up two moisture treatments, including soil original moisture content and flooding condition at 0-20 cm and 20-40 cm, to study the effect of moisture on nitrogen cycle related functional gene abundance in 0-20 cm and 20-40 cm. Temperature increasing significantly increased the abundance of nifH, nirK gene in active layer (0-60 cm), transition layer (60-80 cm) and permafrost layer (80-100 cm) . Temperature increasing significantly increased the abundance of nirS gene in active layer(0-40 cm), and transition layer(60-80 cm). Temperature increasing increased the content of soil NH¡-N in transition layer(60-80 cm) and NO3--N in permafrost layer(140-150 cm), while reduced the content of NO3 - N in transition layer(60-80 cm) and NH2-N in permafrost layer(120—150 cm) . Correlation analysis showed that NH^-N had significantly positive correlation with nifH and nirS gene abundance, and NO3-N had significant positive correlation with nir K gene abundance. These results indicated that temperature increasing promoted the nitrogen fixation and denitrification processes in transition layer(60-80 cm) by changing microbial abundance. Under the flooding condition, the abundance of nirS and nir K and the content of NH1 -N in surface soil were decreased, while the content of NO1-N in surface soil increased obviously. The concentration of denitrifying substrate was decreased by flooding, the denitrifying microbial activity was inhibited by flooding, and inhibited soil denitrification. The results are of great significance for clarifying the nitrogen cycle process under climate change in the future.

Publication Source (Journal or Book title)

Shengtai Xuebao

First Page

6707

Last Page

6717

This document is currently not available here.

Share

COinS