バルサ材樹木は成長を支えるため年齢依存型の水利用戦略を採用（Balsa Wood Trees Adopt Age-dependent Water Use Strategy to Support Growth）

2026-06-04 中国科学院（CAS）

＜関連情報＞

• https://english.cas.cn/newsroom/research-news/202606/t20260605_1161153.shtml
• https://www.sciencedirect.com/science/article/abs/pii/S0168192326002285

成長の速いバルサ材（ Ochroma lagopus）植林地における年齢依存的な水利用戦略とその要因の解明 Unraveling the age-dependent water use strategy and its drivers in fast-growing balsa wood (Ochroma lagopus) plantations

Xia Yuan, Bin Yang, Xiai Zhu, Ping Zhang, Lang Wei, Wenjie Liu, Xiangzhong Li, Junen Wu, Yajun Chen
Agricultural and Forest Meteorology  Available online: 17 May 2026
DOI:https://doi.org/10.1016/j.agrformet.2026.111243

Graphical abstract

Highlight

• Fast-growing balsa wood exhibits an evident age-dependent water use strategy.
• Age-related traits and soil available P dominate balsa wood water uptake pattern.
• Balsa wood shifts from conservative to opportunistic water use strategies with age.
• Isotopic evidence reveals a trade-off between water- and nutrient-use efficiencies.

Abstract

Understanding water use strategies and their underlying drivers in artificial plantations is crucial for developing effective forest management practices. Balsa wood (Ochroma lagopus) is one of the fastest-growing economic plantation species and is in substantial international demand. However, the dynamics of its water use strategies and physiological adaptations remain poorly understood. In this study, we investigated balsa stands of different ages (1-, 2-, 3- and 4-yr) to examine their water uptake patterns and long-term intrinsic water use efficiency (WUE_i) using a multi-isotope approach (δ²H, δ¹⁸O, δ¹³C, and δ¹⁵N) combined with leaf nutrient traits (N and P concentrations). The results showed that 1- and 2-year-old balsa stands primarily extracted water from the 20–50 cm soil layer (accounting for 41.1–41.7% of total uptake), whereas 3- and 4-year-old stands relied more heavily on the 0–20 cm layer (52.5–58.5%). Age-related attributes (e.g., DBH, tree height, and root traits) and soil available phosphorus (AP) were the primary drivers of these dynamics. Balsa wood exhibited an age-related shift from a conservative to a more opportunistic water-use strategy, adapting to seasonal drought primarily through adjustments in WUEi rather than altering uptake depth. Furthermore, δ¹³C showed significant negative correlations with leaf C/P and C/N ratios, indicating a clear trade-off between water-use efficiency and nutrient-use strategy. These findings demonstrate that soil AP serves as a key factor shaping water uptake patterns and provide new insights into the water-use dynamics of fast-growing economic plantations and their adaptive mechanisms under resource-limited conditions.