Details

Autor(en) / Beteiligte

• Zhou, Jun
• Li, Xiao‐Long
• Peng, Fei
• Li, Chengyang
• Lai, Chimin
• You, Quangang
• Xue, Xian
• Wu, Yanhong
• Sun, Hongyang
• Chen, Yang
• Zhong, Hongtao
• Lambers, Hans

Titel

Mobilization of soil phosphate after 8 years of warming is linked to plant phosphorus‐acquisition strategies in an alpine meadow on the Qinghai‐Tibetan Plateau

Ist Teil von

• Global change biology, 2021-12, Vol.27 (24), p.6578-6591

Ort / Verlag

Oxford: Blackwell Publishing Ltd

Erscheinungsjahr

2021

Link zum Volltext

Quelle

Wiley Blackwell Single Titles

Beschreibungen/Notizen

• Phosphorus (P) is essential for productivity of alpine grassland ecosystems, which are sensitive to global warming. We tested the hypotheses that (1) mobilized ‘calcium‐bound inorganic P’ (Ca‐Pi) is a major source of plant‐available P in alpine meadows with alkaline soils after long‐term warming, (2) mobilization of Ca‐Pi is linked to effective plant carboxylate‐releasing P‐acquisition strategies under warming, and (3) the mobilization is also related to plant nitrogen (N)‐acquisition. We conducted an 8‐year warming experiment in an alpine meadow (4635 m above sea level) on the Qinghai‐Tibetan Plateau. A significant increase in P concentration in both aboveground and belowground biomass indicates an increased mobilization and assimilation of P by plants under warming. We observed a significant decrease in Ca‐Pi, no change in moderately‐labile organic P, and an increase in highly resistant organic P after warming. There was no increase in phosphatase activities. Our results indicate that Ca‐Pi, rather than organic P was the major source of plant‐available P for alpine meadows under warming. Higher leaf manganese concentrations of sedges and forbs after warming indicate that carboxylates released by these plants are a key mechanism of Ca‐Pi mobilization. The insignificant increase in Rhizobiales after warming and the very small cover of legumes show a minor role of N‐acquisition strategies in solubilizing phosphate. The insignificant change in relative abundance of mycorrhizal fungi and bacteria related to P cycling after warming shows a small contribution of microorganisms to Ca‐Pi mobilization. The significant increase in leaf N and P concentrations and N:P ratio of grasses and no change in sedge leaf N:P ratio reflect distinct responses of plant nutrient status to warming due to differences in P‐acquisition strategies. We highlight the important effects of belowground P‐acquisition strategies, especially plant carboxylate‐releasing P‐acquisition strategies on responses of plants to global changes in alpine meadows. Phosphorus (P) is essential for productivity of alpine grassland ecosystems, which are sensitive to global warming. The soil Calcium‐bound inorganic phosphorus (Ca‐Pi) significantly decreased and moderately‐labile organic P showed no change, while highly‐resistant organic P increased under an 8 year of warming in an alpine meadow on the Qinghai‐Tibet Plateau. Carboxylates released by sedge and forbs, indicated by the high leaf manganese concentrations, accelerated the Ca‐Pi mobilization, to meet the plant P demand under warming climate. Belowground P‐acquisition strategies, especially plant carboxylate‐releasing P‐acquisition strategies influence responses of plants to global changes in alpine meadows.