Leaf and root nutrient concentrations and stoichiometry along aridity and soil fertility gradients. (19th February 2019)

• Record Type: Journal Article
• Authors: Liu, Guofang; Ye, Xuehua; Huang, Zhenying; Dong, Ming; Cornelissen, Johannes H. C.
• Editors: de Bello, Francesco
• Is Part Of: Journal of vegetation science. Volume 30:Number 2(2019:Mar.)
• Page Start: 291
• Page End: 300
• Publication Date: 2019-02-19
• Subjects: aridity index gradient -- dryland -- ecological stoichiometry -- fine root -- intraspecific variation -- nitrogen fixer -- plant functional type -- soil fertility gradient -- species turnover; Plant ecology -- Periodicals; Plant communities -- Periodicals; Plant populations -- Periodicals; 581.7
• DOI: 10.1111/jvs.12717
• Languages: English
• ISSNs: 1100-9233

Abstract

Abstract: Questions: Leaf nitrogen (N), phosphorus (P) concentrations and N : P ratio have been extensively studied along environmental gradients, but whether and how leaves and roots show similar responses to climatic and fertility gradients is little studied. Also, the responses of leaf and root N and P in different plant functional types (PFT; legumes, grasses, forbs and shrubs) to environmental gradients are poorly known. We examined the following two hypotheses: (a) P concentration and N : P ratios in leaves or fine roots would not be modulated by soil N for legumes while they would be for non‐legume PFTs; (b) Species turnover would have stronger influence on the responses of N and P concentrations and N : P ratios of plant tissues along aridity and soil fertility gradients than intraspecific variation. Study site: Ordos Plateau, China. Methods: We collected samples of leaf and fine roots covering 95 species of 28 families across 17 sites affiliated to four vegetation types on the dry Ordos Plateau of North China and compared variations in N and P concentrations and N : P ratios in both leaves and fine roots among PFTs. Results: We found that legumes had higher N concentrations in leaves and fine roots than the non‐legume PFTs. Leaf and fine root P and N : P ratios increased with increasing soil N for most non‐legume PFTs, but the relationships were decoupled for legumes. Species turnover had a stronger contribution to these relationships of N and P in leaves and fine roots along aridity and soil N gradients than intraspecific variation. Conclusions: When modeling vegetation nutrient stocks and cycling, the predictive power could be improved by taking into account not only influences of soil fertility but also of climate on leaf and root tissue N and soil N on tissue P and N : P ratio, especially for non‐legume functional types. Abstract : By collecting samples of leaf and fine roots covering 95 species of 28 families across 17 sites affiliated to four vegetation types on the dry Ordos Plateau of North China, we found that N : P ratios in leaf and fine root increased with increasing soil N for non‐legume PFTs, but the relationships were decoupled for legumes due to differences in P limitation.