Annual soil CO2 efflux in a cold temperate forest in northeastern China: effects of winter snowpack and artificial nitrogen deposition

• Published in: Scientific reports 2016-01, Vol.6 (1), p.18957-18957, Article 18957
• Main Authors: Liu, Boqi, Mou, Changcheng, Yan, Guoyong, Xu, Lijian, Jiang, Siling, Xing, Yajuan, Han, Shijie, Yu, Jinghua, Wang, Qinggui
• Format: Article
• Language: English
• Subjects: 704/158/1145; 704/158/2445; 704/158/2454; Carbon dioxide; Coniferous forests; Growing season; Humanities and Social Sciences; multidisciplinary; Nitrogen; Respiration; Science; Snow depth; Snowpack; Soil temperature; Temperate forests; Temperature effects; Winter
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep18957

We conducted a snow depth 0 cm (non-snowpack), 10 cm, 20 cm, 30 cm and natural depth) gradient experiment under four quantities of nitrogen addition (control, no added N; low-N, 5 g N m −2 yr −1 ; medium-N, 10 g N m −2 yr −1 ; and high-N, 15 g N m −2 yr −1 ) and took an-entire-year measurements of soil respiration ( R s) in Korean pine forests in northeastern China during 2013–2014. No evidence for effects of N on R s could be found during the growing season. On the other hand, reduction of snowpack decreased winter soil respiration due to accompanied relatively lower soil temperature. We found that winter temperature sensitivities ( Q 10 ) of R s were significantly higher than the growing season Q 10 under all the N addition treatments. Moderate quantities of N addition (low-N and medium-N) significantly increased temperature sensitivities ( Q 10 ) of R s, but excessive (high-N) addition decreased it during winter. The Gamma empirical model predicted that winter R s under the four N addition treatments contributed 4.8. ± 0.3% (control), 3.6 ± 0.6% (low-N), 4.3 ± 0.4% (medium-N) and 6.4 ± 0.5% (high-N) to the whole year R s. Our results demonstrate that N deposition will alter Q 10 of winter R s. Moreover, winter R s may contribute very few to annual R s budget.