Changing plant phosphorus acquisition strategies in relation to altered soil phosphorus fractions after wetland drainage

Abstract

Plant phosphorus (P) acquisition strategy is considered to be an intrinsic driver behind plant succession. However, variations in plant P acquisition strategies in connection to soil P fraction changes after wetland drainage remain unclear. To address this issue, here we conducted a study in six distinct wetlands that experienced long-term (>20 years) artificial drainage, with the adjacent waterlogged wetlands as a control. We analysed plant community composition, biomass and soil P fractions, and identified three plant P acquisition strategies based on soil acid phosphatase activity, plant P resorption efficiency, and soil arbuscular mycorrhizal fungi (AMF) content. We found that soil calcium-bound P (PCa) and enzyme-extractable P (Penzyme) were key factors influencing plant P acquisition. Soil PCa correlated negatively with acid phosphatase activity but positively with AMF content. Soil Penzyme negatively impacted P resorption efficiency. The wetlands were categorised into three types based on the change in plant richness and composition, with each exhibiting distinct plant P acquisition strategies. These changes in strategies after drainage corresponded with shifts in soil P fractions. Overall, our study highlights the role of soil P fractions in explaining plant P acquisition strategies after wetland drainage, suggesting P regulations on plant succession and ecosystem services. Read the free Plain Language Summary for this article on the Journal blog.