The effect of snow reduction and Eisenia japonica earthworm traits on soil nitrogen dynamics in spring in a cool-temperate forest

• Published in: Applied soil ecology : a section of Agriculture, ecosystems & environment Vol. 144; pp. 1 - 7
• Main Authors: Makoto, Kobayashi, Bryanin, Semyon V., Takagi, Kentaro
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2019
• Subjects: Carry-over effect; Ecosystem function; Functional trait; Off-season; Winter climate change; Winter climate change; Off-season; Carry-over effect; Functional trait; Ecosystem function
• ISSN: 0929-1393
• DOI: 10.1016/j.apsoil.2019.06.019

Due to spring climate warming, snowpack has been decreasing and the snowmelt timing has simultaneously been advancing in the cool-temperate forests of northern Japan. To investigate the effect of advancing snowmelt at the end of the snow season on soil nitrogen dynamics via overwintering earthworms, we conducted a snow removal field experiment at the end of the snow season using mesocosms with and without earthworms. In this study, the differences in the effect of snow removal on soil nitrogen according to the presence/absence and body size of Eisenia japonica were also tested in both early spring (April) and late spring (May). The snow removal did not influence the survival rate, body weight, or cast production of E. japonica. In early spring, while the snow removal increased nitrification significantly by 61%, the effect of snow removal was similar irrespective of the earthworm treatments. This indicates that neither the presence of earthworms nor earthworm body size influences the effect of snow reductions at the end of the snow season on the soil nitrogen dynamics in early spring. On the other hand, in late spring, snow removal no longer had a significant effect on soil nitrogen dynamics, while ammonification and nitrification significantly increased by 195% and by 50%, respectively, in the mesocosms with adult earthworms compared to the mesocosms without E. japonica earthworms. These findings indicate that the effects of snow decrease and the simultaneous advancement of snowmelt timing at the end of the snow season on soil nitrogen appear only just after snowmelt; alternatively, the effect of earthworm body size on soil nitrogen dynamics is predominant in late spring in snowy cool-temperate forests. •Early snow melt increases soil nitrification.•Earthworm's trait (size) does not influence the effect of snow decrease in early spring.•Effect of earthworm on soil nitrification occurs in late spring.