DOI: 10.1111/gcb.13096
论文题名: Does canopy nitrogen uptake enhance carbon sequestration by trees?
作者: Nair R.K.F. ; Perks M.P. ; Weatherall A. ; Baggs E.M. ; Mencuccini M.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2016
卷: 22, 期: 2 起始页码: 875
结束页码: 888
语种: 英语
英文关键词: Picea sitchensis
; 15N labelling
; C sequestration
; Canopy fertilization
; Canopy nitrogen uptake
; Isotope trace
; Nitrogen deposition
; Soil fertilization
Scopus关键词: Picea sitchensis
; carbon
; nitrogen
; soil
; carbon sequestration
; chemistry
; metabolism
; plant root
; plant structures
; soil
; spruce
; tree
; Carbon
; Carbon Sequestration
; Nitrogen
; Nitrogen Isotopes
; Picea
; Plant Components, Aerial
; Plant Roots
; Soil
; Trees
英文摘要: Temperate forest 15N isotope trace experiments find nitrogen (N) addition-driven carbon (C) uptake is modest as little additional N is acquired by trees; however, several correlations of ambient N deposition against forest productivity imply a greater effect of atmospheric nitrogen deposition than these studies. We asked whether N deposition experiments adequately represent all processes found in ambient conditions. In particular, experiments typically apply 15N to directly to forest floors, assuming uptake of nitrogen intercepted by canopies (CNU) is minimal. Additionally, conventional 15N additions typically trace mineral 15N additions rather than litter N recycling and may increase total N inputs above ambient levels. To test the importance of CNU and recycled N to tree nutrition, we conducted a mesocosm experiment, applying 54 g N/15N ha-1 yr-1 to Sitka spruce saplings. We compared tree and soil 15N recovery among treatments where enrichment was due to either (1) a 15N-enriched litter layer, or mineral 15N additions to (2) the soil or (3) the canopy. We found that 60% of 15N applied to the canopy was recovered above ground (in needles, stem and branches) while only 21% of 15N applied to the soil was found in these pools. 15N recovery from litter was low and highly variable. 15N partitioning among biomass pools and age classes also differed among treatments, with twice as much 15N found in woody biomass when deposited on the canopy than soil. Stoichiometrically calculated N effect on C uptake from 15N applied to the soil, scaled to real-world conditions, was 43 kg C kg N-1, similar to manipulation studies. The effect from the canopy treatment was 114 kg C kg N-1. Canopy treatments may be critical to accurately represent N deposition in the field and may address the discrepancy between manipulative and correlative studies. © 2016 John Wiley & Sons Ltd.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/61505
Appears in Collections: 影响、适应和脆弱性
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作者单位: School of Geosciences, University of Edinburgh, Crew Building, Edinburgh, Midlothian, United Kingdom; Forest Research, Northern Research Station, Roslin, Midlothian, United Kingdom; National School of Forestry, University of Cumbria, Ambleside, United Kingdom; Institute of Biological and Environmental Sciences, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen, United Kingdom; Institució Catalana de Recerca i Estudis Avançats, Centre for Ecological Research and Forestry Applications, Cerdanyola del Vallès, Barcelona, Spain
Recommended Citation:
Nair R.K.F.,Perks M.P.,Weatherall A.,et al. Does canopy nitrogen uptake enhance carbon sequestration by trees?[J]. Global Change Biology,2016-01-01,22(2)