DOI: 10.1016/j.foreco.2013.07.012
Scopus记录号: 2-s2.0-84880982660
论文题名: Root functioning, tree water use and hydraulic redistribution in Quercus suber trees: A modeling approach based on root sap flow
作者: David T.S. ; Pinto C.A. ; Nadezhdina N. ; Kurz-Besson C. ; Henriques M.O. ; Quilhó T. ; Cermak J. ; Chaves M.M. ; Pereira J.S. ; David J.S.
刊名: Forest Ecology and Management
ISSN: 0378-1127
出版年: 2013
卷: 307 起始页码: 136
结束页码: 146
语种: 英语
英文关键词: Drought
; Groundwater
; Soil water
; Stable isotopes
; Xylem anatomy
Scopus关键词: Conceptual frameworks
; Environmental resources
; Environmental variables
; Pre-dawn leaf water potentials
; Soil water
; Stable isotopes
; Stable-isotope analysis
; Xylem anatomy
; Climate change
; Drought
; Groundwater
; Groundwater resources
; Isotopes
; Plants (botany)
; Soil moisture
; Water supply
; Forestry
; adaptive management
; anatomy
; drought stress
; evergreen tree
; functional role
; groundwater
; isotopic analysis
; management practice
; plant water relations
; root system
; sap flow
; soil water
; stable isotope
; translocation
; transpiration
; water table
; water uptake
; water use
; xylem
; Drought
; Forestry
; Ground Water
; Isotopes
; Plants
; Soil
; Water
; Water Supply
; Portugal
英文摘要: Mediterranean evergreen oaks have to survive a long summer drought. Roots may play a relevant role under these conditions. We studied their structure and function in a mature Quercus suber L. tree in central Portugal. The root system was mapped till the lowest water table level (4.5m depth). Xylem anatomy was analyzed in a vertical profile belowground. Sap flow was continuously monitored for 1.5yrs in the stem and roots of this intensively studied tree (heat field deformation method) and in the stem of four trees (Granier method), in relation to environmental variables and predawn leaf water potential. The sources of water uptake were assessed by stable isotope analyses in summer. Results showed a dimorphic root system with a network of superficial roots linked to sinker roots, and a taproot diverting into tangles of deep fine roots submerged for long periods, with parenchyma aerenchyma. Transpiration was not restricted in summer due to root access to groundwater. The isotopic δ18O signature of twig xylem water was similar to that of groundwater in the dry season. Two functional types of superficial roots were identified: shallow connected and deep connected roots. A modeling approach was built considering that each superficial root was linked to a sinker, with part of the root deep connected (between the stem and the sinker) and part shallow connected (between the sinker and topsoil). This conceptual framework simulated tree stem sap flow from root sap flow with a high efficiency (R2=0.85) in four plot trees.On an annual basis, soil water and groundwater contributions were 69.5% and 30.5% of stem flow, respectively. Annual hydraulic lift and hydraulic descent were 0.9% and 37.0% of stem flow, respectively. The trees maximize the exploitation of the environmental resources by using the topsoil water during most of the year, and groundwater together with hydraulic lift (nutrient supply) in the dry summer. This study shows that a dimorphic root system, with roots reaching groundwater, is an efficient strategy of Q. suber trees to cope with seasonal drought. Knowledge of the functional behavior of Q. suber trees under shallow water table conditions may contribute to the definition of better adapted management practices and to anticipate their responses to climate change. © 2013 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/66393
Appears in Collections: 影响、适应和脆弱性
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作者单位: Instituto Nacional de Investigação Agrária e Veterinária I.P., Quinta do Marquês, Av. da República, 2780-159 Oeiras, Portugal; Institute of Forest Botany, Dendrology and Geobiocenology, Mendel University, Zemedelska 3, 613 00 Brno, Czech Republic; Instituto Dom Luiz, Centro de Geofísica da Universidade de Lisboa, Faculdade de Ciências, Campo Grande, Ed. C8, Piso 3, Sala 26, 1749-016 Lisboa, Portugal; Instituto Superior de Agronomia, Universidade Técnica de Lisboa, Tapada da Ajuda, 1349-017 Lisboa, Portugal; Centro das Florestas e Produtos Florestais, Instituto de Investigação Científica Tropical, Tapada da Ajuda, 1349-017 Lisboa, Portugal; Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República - EAN, 2780-157 Oeiras, Portugal; Centro de Estudos Florestais, Universidade Técnica de Lisboa, Tapada da Ajuda, 1349-017 Lisboa, Portugal
Recommended Citation:
David T.S.,Pinto C.A.,Nadezhdina N.,et al. Root functioning, tree water use and hydraulic redistribution in Quercus suber trees: A modeling approach based on root sap flow[J]. Forest Ecology and Management,2013-01-01,307