DOI: 10.1016/j.foreco.2014.10.010
Scopus记录号: 2-s2.0-84909592162
论文题名: Deep soil: Quantification, modeling, and significance of subsurface nitrogen
作者: James J. ; Knight E. ; Gamba V. ; Harrison R.
刊名: Forest Ecology and Management
ISSN: 0378-1127
出版年: 2015
卷: 336 起始页码: 194
结束页码: 202
语种: 英语
英文关键词: Deep soil
; Douglas-fir
; Forest management
; Forest soil
; Nitrogen cycling
; Sampling depth
Scopus关键词: Ecology
; Ecosystems
; Forestry
; Nitrogen
; Nonlinear equations
; Nutrients
; Deep soils
; Douglas fir
; Forest soils
; Nitrogen cycling
; Sampling depths
; Soils
; coniferous tree
; forest management
; nitrogen cycle
; numerical model
; nutrient limitation
; nutrient uptake
; soil horizon
; soil nitrogen
; terrestrial ecosystem
; Forest Management
; Nitrogen
; Research
; Soil
; Pacific Ocean
; Pacific Ocean (Northwest)
; Pseudotsuga
; Pseudotsuga menziesii
英文摘要: Nitrogen (N) is one of the primary limiting nutrients in Pacific Northwest forests, as well as many other terrestrial ecosystems around the world. Efforts to quantify total soil N and to monitor N cycling have often sampled soils to a depth of 0.2m, occasionally to 1.0m depth, or the bottom of the B horizon. However, tree roots often extend many meters into the soil redistributing water to the surface during droughts and contributing to nutrient uptake. This study examined the systematic sampling depth for ecosystem N analyses in the Pacific Northwest, and compared best-fit models of N in deep soil layers with observed quantities. At 22 sites across the Pacific Northwest Douglas-fir zone, O horizon and mineral soil bulk density samples were collected at depths of 0.1m, 0.5m, 1.0m, 1.5m, 2.0m, and 2.5m. Mineral soil was screened to 4.75mm and analyzed for total N content. Systematic sampling shallower than 2.0m produced significantly smaller estimates of total N. On average, only 3% of total soil N was in the O horizon, and 31% was below 1.0m depth (almost 2700kgha-1 of N). Over 45% of soil N was below 1.0m at three sites. A nonlinear mixed effect model using the Langmuir equation predicted total N to 2.5m with -12.4% mean error given data to 1.0m, and -7.6% mean error with data to 1.5m. Shallow sampling of soil N in studies of biogeochemical cycling, forest management impacts, or ecosystem monitoring at best provides a biased estimate and at worst produces misleading conclusions. Research and monitoring efforts seeking to quantify soil N or measure fluxes should sample deep soil to create a more complete picture of soil pools and changes over time. © 2014 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/65627
Appears in Collections: 影响、适应和脆弱性
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作者单位: University of Washington, School of Environmental and Forest Sciences, Box 352100, Seattle, WA, United States; São Paulo State University, College of Agricultural Sciences, Botucatu, SP, Brazil
Recommended Citation:
James J.,Knight E.,Gamba V.,et al. Deep soil: Quantification, modeling, and significance of subsurface nitrogen[J]. Forest Ecology and Management,2015-01-01,336