Dynamics of plant nutrient requirements and acquisition strategies after afforestation: A study on the Loess Plateau, China

• Published in: Forest ecology and management Vol. 544; p. 121141
• Main Authors: Liu, Weichao, Liu, Yingyi, Wu, Shaojun, Liu, Fuhe, Wen, Yuhao, Wang, Leyin, Liu, Quanyong, Han, Lei, Liu, Jiayi, Xu, Yadong, Ren, Chengjie, Han, Xinhui
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.09.2023
• Subjects: administrative management; Afforestation; allometry; China; Extracellular enzyme activities (EEAs); extracellular enzymes; forest ecology; growth models; microbial biomass; mineralization; net primary productivity; nitrogen; Nutrient requirement and acquisition strategies; Nutrient resorption; nutrient resorption (physiology); phosphorus; resorption; Robinia pseudoacacia; soil; Soil mineralization; China; NRE; ava-P; ALP; BG; FL; DBH; STN; STP; MBC; EEAs; SBD; MBN; MBP; SWC; Nmin; Pmin; Nutrient resorption; SOC; DIN; Afforestation; NRs; RC; Soil mineralization; Extracellular enzyme activities (EEAs); NAG; Nutrient requirement and acquisition strategies; LAP; RP
• DOI: 10.1016/j.foreco.2023.121141
• ISSN: 0378-1127

•N and P requirement of Robinia pseudoacacia increased significantly with stand age.•The dependence of plants on nutrient resorption decreased after afforestation.•The nutrient competition between plants and soil microbe is a win–win mechanism.•Soil EEAs were the factors directly affecting the mineralization process. Plant nutrient requirements and acquisition strategies are critical to understand the net primary productivity and community stability in terrestrial ecosystems. However, the current knowledge regarding this subject is limited, especially in the case of afforestation. Therefore, we selected four Robinia pseudoacacia (RP) forests (15-, 21-, 31-, and 46-year-old forests) in the Loess Plateau, and analyzed the nutrients in the plant organs, litter, and soil, along with the extracellular enzyme activities (EEAs), microbial biomass, and mineralization rate. In addition, the biomass of RP was determined using an allometric growth model. The results showed that during afforestation, the nitrogen and phosphorus requirement of RP increased significantly, from 3.97 to 18.14 g·m−2·year−1 and 0.17 to 0.71 g·m−2·year−1, respectively, while the nutrient resorption efficiency and the contributions of nutrient resorption to the total nutrient requirements significantly decreased. Meanwhile, the ratio of nitrogen to phosphorus resorption efficiency (NRE:PRE) significantly increased with afforestation, but were less than 1 which may indicate the phosphorus limitation of RP decreased. In addition, the vector angle significantly increased form 44.80° to 49.51° after afforestation, which may indicate the phosphorus limitation of soil microorganisms increased. Meanwhile, the vector angle was significantly positive with phosphorus mineralization rate and NRE:PRE, which may show that soil microorganisms activity alleviate the phosphorus limitation of plants. Collectively, our study contributes to a better understanding of nutrient cycling above and below the ground.