title: Annual soil CO2 efflux in a cold temperate forest in northeastern China: effects of winter snowpack and artificial nitrogen deposition.
abstract: 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 (Rs) in Korean pine forests in northeastern China during 2013-2014. No evidence for effects of N on Rs 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 (Q10) of Rs were significantly higher than the growing season Q10 under all the N addition treatments. Moderate quantities of N addition (low-N and medium-N) significantly increased temperature sensitivities (Q10) of Rs, but excessive (high-N) addition decreased it during winter. The Gamma empirical model predicted that winter Rs 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 Rs. Our results demonstrate that N deposition will alter Q10 of winter Rs. Moreover, winter Rs may contribute very few to annual Rs budget.
authors.affiliation: Center for Ecological Research, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China.|College of Agricultural Resource and Environment, Heilongjiang University, 74 Xuefu Road, Harbin, 150080, China.
authors.forename: Boqi
authors.initials: B
authors.lastname: Liu
authors.affiliation: Center for Ecological Research, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China.
authors.forename: Changcheng
authors.initials: C
authors.lastname: Mou
authors.affiliation: Center for Ecological Research, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China.|College of Agricultural Resource and Environment, Heilongjiang University, 74 Xuefu Road, Harbin, 150080, China.
authors.forename: Guoyong
authors.initials: G
authors.lastname: Yan
authors.affiliation: College of Agricultural Resource and Environment, Heilongjiang University, 74 Xuefu Road, Harbin, 150080, China.
authors.forename: Lijian
authors.initials: L
authors.lastname: Xu
authors.affiliation: College of Agricultural Resource and Environment, Heilongjiang University, 74 Xuefu Road, Harbin, 150080, China.
authors.forename: Siling
authors.initials: S
authors.lastname: Jiang
authors.affiliation: College of Agricultural Resource and Environment, Heilongjiang University, 74 Xuefu Road, Harbin, 150080, China.|Institute of forestry science of Heilongjiang province, 134 Haping Road, Harbin 150081, China.
authors.forename: Yajuan
authors.initials: Y
authors.lastname: Xing
authors.affiliation: State key laboratory of forest and ecology, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, 110015, China.
authors.forename: Shijie
authors.initials: S
authors.lastname: Han
authors.affiliation: State key laboratory of forest and ecology, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, 110015, China.
authors.forename: Jinghua
authors.initials: J
authors.lastname: Yu
authors.affiliation: Center for Ecological Research, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China.|College of Agricultural Resource and Environment, Heilongjiang University, 74 Xuefu Road, Harbin, 150080, China.
authors.forename: Qinggui
authors.initials: Q
authors.lastname: Wang