Greater hydraulic safety contributes to higher growth resilience to
drought across seven pine species in a semi-arid environment
- Chun-Yang Duan,
- Ming-Yong Li,
- Lidong Fang,
- Yu Cao,
- Dedong Wu,
- Hui Liu,
- Qing Ye,
- Guangyou Hao
Chun-Yang Duan
Institute of Applied Ecology Chinese Academy of Sciences
Author ProfileMing-Yong Li
Institute of Applied Ecology, Chinese Academy of Sciences
Author ProfileLidong Fang
Institute of Applied Ecology Chinese Academy of Sciences
Author ProfileHui Liu
South China Botanical Garden, Chinese Academy of Sciences
Author ProfileQing Ye
South China Botanical Garden, Chinese Academy of Sciences
Author ProfileAbstract
Quantifying interspecific variations of tree resilience to drought and
revealing the underlying mechanisms are of great importance to the
understanding of forest functionality particularly in water-limited
regions with foreseeable increase in temperature and the associated
drought stress. So far, comprehensive studies incorporating
investigations in interspecific variations of long-term growth patterns
of trees and the underlying physiological mechanisms are very limited.
Here, in a semi-arid site of northern China, tree radial growth rate,
inter-annual tree-ring growth responses to climate variability, as well
as physiological characteristics pertinent to xylem hydraulics, carbon
assimilation and drought tolerance were analyzed in seven pine species
growing in a common environment. Considerable interspecific variations
in radial growth rate, growth response to drought and physiological
characteristics were observed among the studied species. Higher
hydraulic efficiency is related to greater photosynthetic capacity but
not higher tree radial growth rate. Rather, radial growth of species
with higher hydraulic conductivity and photosynthetic capacity was more
sensitive to drought stress that is at least partially due to a
trade-off between hydraulic efficiency and safety across species. This
study thus demonstrates the importance of drought resilience rather than
instantaneous water and carbon flux capacity in determining tree growth
in water-limited environments.