TY - JOUR
T1 - A model relating transpiration for Japanese cedar and cypress plantations with stand structure
AU - Komatsu, Hikaru
AU - Shinohara, Yoshinori
AU - Kumagai, Tomo'omi
AU - Kume, Tomonori
AU - Tsuruta, Kenji
AU - Xiang, Yang
AU - Ichihashi, Ryuji
AU - Tateishi, Makiko
AU - Shimizu, Takanori
AU - Miyazawa, Yoshiyuki
AU - Nogata, Mari
AU - Laplace, Sophie
AU - Han, Tseng
AU - Chiu, Chen Wei
AU - Ogura, Akira
AU - Saito, Takami
AU - Otsuki, Kyoichi
N1 - Funding Information:
We express our sincere thanks to members of Kyushu University Forest for their dedicated efforts in initiating the sites. We acknowledge Dr. Xinchao Sun (Graduate School of Life and Environmental Sciences, University of Tsukuba, Japan) for providing sapwood-area data for their site. Thanks are also due to two anonymous reviewers for providing critical comments. Meteorological data at the Kahoku sites were obtained from FFPRI Fluxnet database, managed by Forestry and Forest Products Research Insitute. This research has been supported by a CREST project (Development of Innovative Technologies for Increasing Watershed Runoff and Improving River Environment by the Management Practice of Devastated Forest Plantation), by the Ministry of Agriculture, Forestry and Fisheries, Japan , through a research project entitled “Development of technologies for mitigation and adaptation to climate change in Agriculture, Forestry and Fisheries (A-8)”, and by National Science Council of the Republic of China ( NSC:100-2313-B-002-033-MY3 ). Tomo'omi Kumagai acknowledges support from a Grant-in-Aid for Scientific Research (#25281005), and the granted project “Program for risk information on climate change” from the Ministry of Education, Science and Culture, Japan .
Publisher Copyright:
© 2014 Elsevier B.V.
PY - 2014/12/5
Y1 - 2014/12/5
N2 - Previous studies have revealed that changes in forest structure due to management (e.g., thinning, aging, and clearcutting) could affect the forest water balance. However, there are unexplained variability in changes in the annual water balance with changing structure among different sites. This is the case even when analyzing data for specific species/regions. For a more advanced and process-based understanding of changes in the water balance with changing forest structure, we examined transpiration (E) observed using the sap-flux method for 14 Japanese cedar and cypress plantations with various structure (e.g., stem density and diameter) in Japan and surrounding areas and developed a model relating E with structural parameters. We expressed E using the simplified Penman-Monteith equation and modeled canopy conductance (Gc) as a product of reference Gc (Gcref) when vapor pressure deficit is 1.0. kPa and functions expressing the responses of Gc to meteorological factors. We determined Gcref and parameters of the functions for the sites separately. E observed for the 14 sites was not reproduced well by the model when using mean values of Gcref and the parameters among the sites. However, E observed for the sites was reproduced well when using Gcref determined for each site and mean values of the parameters of the functions among the sites, similar to the case when using Gcref and the parameters of the functions determined for each site. These results suggest that considering variations in Gcref among the sites was important to reproduce variations in E, but considering variations in the parameters of the functions was not. Our analysis revealed that Gcref linearly related with the sapwood area on a stand scale (A) and that A linearly related with stem density (N) and powers of the mean stem diameter (dm). Thus, we proposed a model relating E with A (or N and dm), where Gcref was calculated from A (or N and dm) and the parameters of the functions were assumed to be the mean values among the sites. This model estimates changes in E with changing structure from commonly available data (N and dm), and therefore helps improve our understanding of the underlying processes of the changes in the water balance for Japanese cedar and cypress plantations.
AB - Previous studies have revealed that changes in forest structure due to management (e.g., thinning, aging, and clearcutting) could affect the forest water balance. However, there are unexplained variability in changes in the annual water balance with changing structure among different sites. This is the case even when analyzing data for specific species/regions. For a more advanced and process-based understanding of changes in the water balance with changing forest structure, we examined transpiration (E) observed using the sap-flux method for 14 Japanese cedar and cypress plantations with various structure (e.g., stem density and diameter) in Japan and surrounding areas and developed a model relating E with structural parameters. We expressed E using the simplified Penman-Monteith equation and modeled canopy conductance (Gc) as a product of reference Gc (Gcref) when vapor pressure deficit is 1.0. kPa and functions expressing the responses of Gc to meteorological factors. We determined Gcref and parameters of the functions for the sites separately. E observed for the 14 sites was not reproduced well by the model when using mean values of Gcref and the parameters among the sites. However, E observed for the sites was reproduced well when using Gcref determined for each site and mean values of the parameters of the functions among the sites, similar to the case when using Gcref and the parameters of the functions determined for each site. These results suggest that considering variations in Gcref among the sites was important to reproduce variations in E, but considering variations in the parameters of the functions was not. Our analysis revealed that Gcref linearly related with the sapwood area on a stand scale (A) and that A linearly related with stem density (N) and powers of the mean stem diameter (dm). Thus, we proposed a model relating E with A (or N and dm), where Gcref was calculated from A (or N and dm) and the parameters of the functions were assumed to be the mean values among the sites. This model estimates changes in E with changing structure from commonly available data (N and dm), and therefore helps improve our understanding of the underlying processes of the changes in the water balance for Japanese cedar and cypress plantations.
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U2 - 10.1016/j.foreco.2014.08.041
DO - 10.1016/j.foreco.2014.08.041
M3 - Article
AN - SCOPUS:84949132279
SN - 0378-1127
VL - 334
SP - 301
EP - 312
JO - Forest Ecology and Management
JF - Forest Ecology and Management
ER -