Aims The scaling relationship between nitrogen(N)and phosphorus(P)concentrations([N]and[P],respectively)in leaves manifests plants’relative investment between the two nutrients.However,the variation in this relations...Aims The scaling relationship between nitrogen(N)and phosphorus(P)concentrations([N]and[P],respectively)in leaves manifests plants’relative investment between the two nutrients.However,the variation in this relationship among taxa as well as its causes was seldom described.Methods The analysis was based on a dataset including 2483 leaf samples from 46 genera of angiosperm woody plants from 1733 sites across China.We calculated the leaf N–P scaling exponent(βL)with an allometric equation([N]=α[P]β),for each genus,respectively.We then performed phylogenetic path analyses to test how the climate and soil niche conditions of these genera contributed to the inter-genus variation inβL.Important Findings The genera living with lower soil P availability presented a more favoured P uptake relative to N,as shown by the higherβL,suggesting a resistant trend to P limitation.Additionally,genus-wiseβL was positively correlated with soil N–P scaling exponents(β_(S)),implying that the variation in leaf nutrients is constrained by the variability in their sources from soil.Finally,climatic factors including temperature and moisture did not affectβL directly,but could have an indirect influence by mediating soil nutrients.Phylogeny did not affect the inter-genus variation inβL along environmental gradients.These results reveal that the trade-off between N and P uptake is remarkably shaped by genus niches,especially soil nutrient conditions,suggesting that theβL could be considered as a functional trait reflecting characteristics of nutrient utilization of plant taxa in response to niche differentiation.展开更多
基金This work was funded by the National Natural Science Foundation of China(32025025,31988102 and 31770489)the Strategic Priority Research Programme of the Chinese Academy of Sciences(XDAO5O5OOOO).
文摘Aims The scaling relationship between nitrogen(N)and phosphorus(P)concentrations([N]and[P],respectively)in leaves manifests plants’relative investment between the two nutrients.However,the variation in this relationship among taxa as well as its causes was seldom described.Methods The analysis was based on a dataset including 2483 leaf samples from 46 genera of angiosperm woody plants from 1733 sites across China.We calculated the leaf N–P scaling exponent(βL)with an allometric equation([N]=α[P]β),for each genus,respectively.We then performed phylogenetic path analyses to test how the climate and soil niche conditions of these genera contributed to the inter-genus variation inβL.Important Findings The genera living with lower soil P availability presented a more favoured P uptake relative to N,as shown by the higherβL,suggesting a resistant trend to P limitation.Additionally,genus-wiseβL was positively correlated with soil N–P scaling exponents(β_(S)),implying that the variation in leaf nutrients is constrained by the variability in their sources from soil.Finally,climatic factors including temperature and moisture did not affectβL directly,but could have an indirect influence by mediating soil nutrients.Phylogeny did not affect the inter-genus variation inβL along environmental gradients.These results reveal that the trade-off between N and P uptake is remarkably shaped by genus niches,especially soil nutrient conditions,suggesting that theβL could be considered as a functional trait reflecting characteristics of nutrient utilization of plant taxa in response to niche differentiation.
