全球智库信息集成服务系统(G2TT): Forest fine-root production and nitrogen use under elevated CO2: Contrasting responses in evergreen and deciduous trees explained by a common principle.

G2TT

来源类型	Article
规范类型	其他
DOI	10.1111/j.1365-2486.2008.01710.x
	Forest fine-root production and nitrogen use under elevated CO2: Contrasting responses in evergreen and deciduous trees explained by a common principle.
	Franklin O; McMurtrie RE; Iversen CM; Crous KY; Finzi AC; Tissue DT; Ellsworth D; Oren R
发表日期	2009
出处	Global Change Biology 15 (1): 132-144
出版年	2009
语种	英语
摘要	Despite the importance of nitrogen (N) limitation of forest carbon (C) sequestration at rising atmospheric CO2 concentration, the mechanisms responsible are not well understood. To elucidate the interactive effects of elevated CO2 (eCO2) and soil N availability on forest productivity and C allocation, we hypothesized that (1) trees maximize fitness by allocating N and C to maximize their net growth and (2) that N uptake is controlled by soil N availability and root exploration for soil N. We tested this model using data collected in Free-Air CO2 Enrichment sites dominated by evergreen (Pinus taeda; Duke Forest) and deciduous [Liquidambar styraciflua; Oak Ridge National Laboratory (ORNL)] trees. The model explained 80 -95% of variation in productivity and N-uptake data among eCO2, N fertilization and control treatments over 6 years. The model explains why fine-root production increased, and why N uptake increased despite reduced soil N availability under eCO2 at ORNL and Duke. In agreement with observations at other sites, the model predicts that soil N availability reduced below a critical level diminishes all eCO2 responses. At Duke, a negative feedback between reduced soil N availability and N uptake prevented progressive reduction in soil N availability at eCO2. At ORNL, soil N availability progressively decreased because it did not trigger reductions in N uptake; N uptake was maintained at ORNL through a large increase in the production of fast turnover fine roots. This implies that species with fast root turnover could be more prone to progressive N limitation of carbon sequestration in woody biomass than species with slow root turnover, such as evergreens. However, longer term data are necessary for a thorough evaluation of this hypothesis. The success of the model suggests that the principle of maximization of net growth to control growth and allocation could serve as a basis for simplification and generalization of larger scale forest and ecosystem models, for example by removing the need to specify parameters for relative foliage/stem/root allocation.
主题	Forestry (FOR)
关键词	Allocation Elevated carbon dioxide FACE experiments Fine-root longetivity Forest growth model Optimization Plant theory Soil N availability Soil N uptake
URL	http://pure.iiasa.ac.at/id/eprint/8891/
来源智库	International Institute for Applied Systems Analysis (Austria)
引用统计
资源类型	智库出版物
条目标识符	http://119.78.100.153/handle/2XGU8XDN/129016
推荐引用方式 GB/T 7714	Franklin O,McMurtrie RE,Iversen CM,et al. Forest fine-root production and nitrogen use under elevated CO2: Contrasting responses in evergreen and deciduous trees explained by a common principle.. 2009.