DOI: 10.1111/gcb.12532
论文题名: Increased nitrogen leaching following soil freezing is due to decreased root uptake in a northern hardwood forest
作者: Campbell J.L. ; Socci A.M. ; Templer P.H.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2014
卷: 20, 期: 8 起始页码: 2663
结束页码: 2673
语种: 英语
英文关键词: Climate change
; Root uptake
; Snow
; Soil frost
; Soil solution
; Stable isotopes
Scopus关键词: ammonium
; climate change
; concentration (composition)
; dissolved inorganic nitrogen
; forest ecosystem
; freezing
; frost
; global warming
; leaching
; nitrate
; root
; snow
; snowpack
; stable isotope
; United States
; ammonium derivative
; nitric acid derivative
; nitrogen
; snow
; soil
; Acer
; chemistry
; forest
; freezing
; metabolism
; plant root
; soil
; United States
; Acer
; Ammonium Compounds
; Forests
; Freezing
; New Hampshire
; Nitrates
; Nitrogen
; Plant Roots
; Snow
; Soil
英文摘要: The depth and duration of snow pack is declining in the northeastern United States as a result of warming air temperatures. Since snow insulates soil, a decreased snow pack can increase the frequency of soil freezing, which has been shown to have important biogeochemical implications. One of the most notable effects of soil freezing is increased inorganic nitrogen losses from soil during the following growing season. Decreased nitrogen retention is thought to be due to reduced root uptake, but has not yet been measured directly. We conducted a 2-year snow-removal experiment at Hubbard Brook Experimental Forest in New Hampshire, USA to determine the effects of soil freezing on root uptake and leaching of inorganic nitrogen simultaneously. Snow removal significantly increased the depth of maximal soil frost by 37.2 and 39.5 cm in the first and second winters, respectively (P < 0.001 in 2008/2009 and 2009/2010). As a consequence of soil freezing, root uptake of ammonium declined significantly during the first and second growing seasons after snow removal (P = 0.023 for 2009 and P = 0.005 for 2010). These observed reductions in root nitrogen uptake coincided with significant increases in soil solution concentrations of ammonium in the Oa horizon (P = 0.001 for 2009 and 2010) and nitrate in the B horizon (P < 0.001 and P = 0.003 for 2009 and 2010, respectively). The excess flux of dissolved inorganic nitrogen from the Oa horizon that was attributable to soil freezing was 7.0 and 2.8 kg N ha-1 in 2009 and 2010, respectively. The excess flux of dissolved inorganic nitrogen from the B horizon was lower, amounting to 1.7 and 0.7 kg N ha-1 in 2009 and 2010, respectively. Results of this study provide direct evidence that soil freezing reduces root nitrogen uptake, demonstrating that the effects of winter climate change on root function has significant consequences for nitrogen retention and loss in forest ecosystems. © 2014 John Wiley & Sons Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/62247
Appears in Collections: 影响、适应和脆弱性
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作者单位: Northern Research Station, USDA Forest Service, Durham, NH 03824, United States; Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, United States
Recommended Citation:
Campbell J.L.,Socci A.M.,Templer P.H.. Increased nitrogen leaching following soil freezing is due to decreased root uptake in a northern hardwood forest[J]. Global Change Biology,2014-01-01,20(8)