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Relationship between stem diameter and transpiration for Japanese cypress trees: Implications for estimating canopy transpiration
Author(s) -
Tsuruta Kenji,
Komatsu Hikaru,
Kume Tomonori,
Otsuki Kyoichi,
Kosugi Yoshiko,
Kosugi Ken'ichiro
Publication year - 2019
Publication title -
ecohydrology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.982
H-Index - 54
eISSN - 1936-0592
pISSN - 1936-0584
DOI - 10.1002/eco.2097
Subject(s) - chamaecyparis , cypress , diameter at breast height , transpiration , canopy , vapour pressure deficit , botany , forestry , tree (set theory) , positive correlation , environmental science , mathematics , biology , horticulture , atmospheric sciences , geography , photosynthesis , physics , combinatorics , medicine
Previous studies reported relationships between stem diameter at breast height (DBH) and whole‐tree transpiration ( Q t ) across a variety of species and locations. It might be possible to develop a relationship between DBH and Q t with smaller variations when we focused on a single species. We attempted to develop such a relationship for Japanese cypress ( Chamaecyparis obtusa ), which is one of the major plantation species in Japan. We collated Q t for 51 Japanese cypress trees from nine different‐sized and different‐aged stands using the sap flux method. We found a strong linear correlation between DBH and the reference value of Q t at a vapour pressure deficit of 1 kPa ( R = .883). This was a consequence of a strong correlation between DBH and sapwood area ( A S_tree ; R = .973) and the absence of a correlation between DBH and sap flux density ( R = −.043). We confirmed that using the relationship between DBH and A S_tree , while assuming typical responses of sap flux density to meteorological factors, provides reasonable Q t estimates. This study also demonstrated how the DBH– Q t relationship can be applied to estimate changes in E C with changing forest management.