In this new post, Xibin Sun—a PhD candidate at Sun Yat-sen University, China—presents his work ‘Widespread controls of leaf nutrient resorption by nutrient limitation and stoichiometry’. Xibin discusses were the idea for this study came from and the joys of working in and around nature.
About the paper
Leaf nutrient resorption is a process by which plants relocate nutrients from senescing leaves to other living tissues—it is an important strategy for nutrient conservation in plants. This paper proposes three basic controls on leaf nutrient resorption, namely; nutrient concentration control, nutrient limitation control, and stoichiometry control. Nutrient concentration control means that when a nutrient is already abundant in green leaves, the resorption efficiency of that nutrient is low, and vice versa. nutrient limitation control means that plants resorb a nutrient more strongly if their growth is more limited by that nutrient relative to other nutrients. Stoichiometry control means that plants resorb nutrients from senescent leaves in proportions that match the ratio in green leaves.
Among these controls, “nutrient concentration control” has been demonstrated to exist globally in previous studies, while the latter two have not been systematically evaluated. Therefore, this study focused on 3395 data points from 109 peer-reviewed studies in order to prove the global ubiquity of both nutrient limitation and stoichiometry in controlling leaf resorption. We found nutrient limitation control existed globally, but was only applicable for the resorption of nitrogen, phosphorus, and potassium. Stoichiometry control existed globally for all studied elements (carbon, nitrogen, phosphorus, sulfur, potassium, calcium, and magnesium), and coexisted with nutrient limitation control. The findings in the paper are very important for modelling and predicting biogeochemical cycles in terrestrial ecosystems.
In fact, the idea of this study comes from some clues in the previous studies. For example, we have found some evidence for the global ubiquity of both nutrient limitation and stoichiometry in a previous study that was conducted at an ecosystem scale. We also noticed a global study that reported the global existence of ‘nutrient concentration control’. Then, an idea arose: can we test the global existence of the other two controls by using the global data?
About the Research
A major challenge of conducting this research was the writing of the paper because the findings and articulation of the results are complicated for general readers. I spent a lot of time reviewing the literature, refining the framework of the paper and completing the writing. Throughout the process of conducting this research, I gained the courage to explore new research directions and try new approaches.
Our next plan is to focus on the responses of leaf nutrient resorption to global changes. To our knowledge, numerous global change experiments have examined the effects of one or two global change drivers on leaf nitrogen and phosphorus resorption. However, very few global syntheses explored the effects of these global change drivers on leaf nitrogen and phosphorus resorption. According to our preliminary analysis, we think that leaf nitrogen and phosphorus resorption may have opposite responses to global change drivers.
About the author
I am a PhD candidate at Sun Yat-sen University, China. I would describe myself as a nature enthusiast and this is the reason that I became an ecologist. I am grateful that I not only have the opportunity to appreciate nature, but also to uncover its mysteries through my research.
Enjoyed the blogpost? Read the research here!
