Phosphorus fractions allocation patterns based on optimality theory: a global analysis

Ning Dong¹, Wang yiru¹, Yuki Tsujii², Ian Wright³, David Ellsworth³, Sandy P. Harrison⁴ , Iain Colin Prentice⁵

¹College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China

²Forestry and Forest Products Research Institute (FFPRI), 1 Matsunosato, Tsukuba, Ibaraki, 305-8687 Japan

³ Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, 2751, Australia

⁴Department of Geography and Environmental Science, University of Reading, Whiteknights, Reading RG6 6AB, United Kingdom

⁵Georgina Mace Centre for the Living Planet, Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, UK

Phosphorus (P) can be separated into five functional fractions: orthophosphate P (Pi), metabolite P (PM), nucleic acid P (PN), lipid P (PL), and residual P (PR). These fractions regulate vital functional processes, such as photosynthesis, protein synthesis, dark respiration. We have compiled a comprehensive global P fractional dataset along with leaf spectrum traits, such as LMA and leaf N. We found that leaf exists P allocation pattern according to plant function group as expected. PM shows an independent dimension, and increase toward hot and dry condition, and PN is closed related to LES traits. Soil P increase all P fractions and leaf P. lipid P (PL) decline with VPD and soil CN ratio, and increase with soil P. Together, these various environmental factors explain almost 50% of global variation in both PL and organic P. These findings provide a promising route towards an optimality-based approach to modelling leaf P and their relationships to properties of climate and soils.