Chin J Plan Ecolo ›› 2017, Vol. 41 ›› Issue (6): 597-609.DOI: 10.17521/cjpe.2017.0011

• Research Articles •     Next Articles

Soil microbial biomass and its seasonality in deciduous broadleaved forests with different stand ages in the Mao’ershan region, Northeast China

Xin-Qi WANG, Yi HAN, Chuan-Kuan WANG*()   

  1. Center for Ecological Research, Northeast Forestry University, Harbin 150040, China
  • Received:2017-05-31 Accepted:2017-01-17 Online:2017-06-10 Published:2017-07-19
  • Contact: Chuan-Kuan WANG
  • About author:

    KANG Jing-yao(1991-), E-mail: kangjingyao_nj@163.com

Abstract:

Aims Soil microbes play a key role in the biogeochemical cycling in terrestrial ecosystems and are important for the nutrient recovery of degraded soils due to disturbances. However, dynamics in soil microbial biomass during the development of the secondary forest after logging are little known. Our objectives were to examine the temporal dynamics and influencing factors of soil microbial biomass carbon content (Cmic) and nitrogen content (Nmic) along a temperate forest logging chronosequence.Methods The logging chronosequence included four sites with 0-year, 10-year, 25-year, and 56-year sites since clear cutting of a deciduous broadleaved forest and was established in 2014 in the Mao’ershan Forest Ecosystem Research Station, Northeast China. The Cmic and Nmic at all the sites were measured monthly during the growing season (from April to October) with the chloroform fumigation extraction method; the soil dissolved organic carbon content (Cdis), total nitrogen content (Ndis), soil water content and temperature were simultaneously measured. Important findings (1) There were significant differences in soil microbial biomass among the four sites: the means of Cmic at the 56-year and 0-year sites were significantly higher than those at the 25-year and 10-year sites; the means of Nmic at the 0-year and 56-year sites were significantly higher than those at the 10-year site, while the 25-year site had intermediate Nmic; The Cmic/Nmic ratios at the 56-year and 10-year sites were significantly higher than those at the 25-year and 0-year sites. (2) The Cmic and Nmic at the 0-year site tended to decrease at the end of the growing season compared to earlier times, while those at the rest sites showed an increasing trend or no significant change. Soil microbial biomass among the 10-year, 25-year, and 56-year sites differed at the early growing season, and its amplitude of variations decreased as the stand age increased. The Cmic/Nmic ratios at all sites showed a “W-shaped” seasonal pattern. (3) The main influencing factors of the seasonality of soil microbial biomass varied with the stand ages: they switched from soil water content at the 0-year and 10-year sites to the soil dissolved nutrients contents at the 10-year, 25-year, and 56-year sites. The seasonality of Cmic/Nmic ratios at the 0-year site was mainly influenced by soil temperature and Cdis, while those at the other three sites were driven by the Cdis/Ndisratio. It was concluded that with the forest development after clear cutting, the characteristics of vegetation and soil have been changing, inducing increased soil microbial biomass and thereby improved soil nutrient regime, which reflected strong links between aboveground changes in vegetation and belowground dynamics in soil microbes.

Key words: logging disturbance, chronosequence, microbial biomass carbon, microbial biomass nitrogen, seasonal dynamics, temperate forest