title: Evaporative demand determines branchiness of Scots pine.
abstract: Analysis of the branch area/stem area ratio of Scots pine growing in different climatic conditions in Europe and Siberia indicates that the branch area supported by a stem increases in warmer and drier conditions. The ratio was significantly correlated with several climatic variables, especially with potential evapotranspiration (Ep). The ratio was negatively correlated with stand density (ds). A regression model combining Epand dsaccounted for 85% of the total variation. These trends are believed to reflect hydraulic segmentation of trees and may represent a strategy to avoid cavitation in the tree, especially in the branches.
authors.affiliation: Department of Forest Ecology, PL 24, 00014, University of Helsinki, FIN-00014, Helsinki, Finland.
authors.forename: F
authors.initials: F
authors.lastname: Berninger
authors.affiliation: Department of Forest Ecology, PL 24, 00014, University of Helsinki, FIN-00014, Helsinki, Finland.
authors.forename: E
authors.initials: E
authors.lastname: Nikinmaa
authors.affiliation: Department of Forest Ecology, PL 24, 00014, University of Helsinki, FIN-00014, Helsinki, Finland.
authors.forename: P
authors.initials: P
authors.lastname: Hari
authors.affiliation: Institute of Forest Ecology and Silviculture, University of Florence, Via S. Bonaventura 13, I-50145, Florence, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Mencuccini
authors.affiliation: Institute of Ecology and Resource Management, University of Edinburgh, King's Buildings, Mayfield Road, EH9 3JU, Edinburgh, UK.
authors.forename: John
authors.initials: J
authors.lastname: Grace
keywords: Branchiness; Geographic variation; Hydraulic architecture; Pinus sylvestris; Pipe theory