Abstract
Non-structural carbohydrates (NSC) affect tree growth and survival when photosynthesis is impacted by climate change, such as seasonal drought and extreme precipitation. Nevertheless, it is still unclear whether Eucalyptus suffers growth limitation under natural conditions and if trees recover under artificial cultivation. In present study, we conducted a field control experiment to compare the NSC storage in Eucalyptus urophylla × Eucalyptus grandis trees on fertilization and dry-season irrigation to determine the variations of NSC under drought stress. The results indicated total soluble sugar (TSS) was the primary existing form of NSC. In spatial patterns, NSC concentration showed gradient differences from source organ to sink organ, and finally accumulated in root. The TSS concentration showed a decreased trend with height except leaf, while the trend of starch concentration was contrast. Surprisingly, fertilization and dry-season irrigation had not changed the carbon distribution among all tissues but reduced the TSS concentration in most organs. The fast-growing E. urophylla × E. grandis will consume the assimilates and carbohydrates of storage organs, but maintains the NSC concentration at a certain threshold. Our results help to comprehend the NSC allocation and improve the productivity of E. urophylla × E. grandis plantations in seasonal arid areas.
Highlights
In the context of global climate change, the precipitation patterns around the world are changing
The purpose of this study is to explore the response of non-structural carbohydrates at organ and height level of E. urophylla × E. grandis trees under dry-season irrigation with fertilization
Significant decrease of foliar starch concentration induced by W and F was only observed in 5/5H (−8% and −14%), while decrease caused by WF was only detected in 4/5H (−18%, Figure 2(a-2))
Summary
In the context of global climate change, the precipitation patterns around the world are changing. Vegetation decreases transpiration and photosynthesis rate due to less available water, resulting in declines of the physiological and morphological traits, decreasing forest productivity [2,3,4]. In Eucalyptus plantations, drought stress reduced physiological traits such as photosynthesis and transpiration, and morphological traits such as leaf area and growth [5,6]. Drought reduced nutrients and carbon storage in the soil, and microbial activity [7,8,9], which would reduce ecosystem stability and further limit forest productivity. Rainfall in South China is comparatively plenty, tree growth is always limited by drought under the uneven spatial and temporal distribution of precipitation [11]. As one of the three fastgrowing tree species in the world, Eucalyptus plays an important role in the forestry of
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
