Exploring plant adaptation strategies to phosphorus limitation induced by nitrogen addition: foliar phosphorus allocation and root functional traits analysis in two dominant subalpine tree species

• Published in: Journal of plant ecology 2024-08, Vol.17 (4)
• Main Authors: Su, Yan, Tang, Yongfeng, Hu, Yi, Liu, Meiyu, Lu, Xuyang, Duan, Baoli
• Format: Article
• Language: English
• Subjects: Abies fabri; Adaptation; Adaptation (Physiology); Climate change; Dominant species; Environmental aspects; Exudates; Exudation; Forest management; Fractions; Global climate; Leaves; Metabolites; Morphology; Nitrogen; Nitrogen in the body; Nutrient content; Phosphatase; Phosphorus; Phosphorus in the body; Physiological aspects; Plant species; Roots (Botany); Salix rehderiana; Soil analysis; Subalpine environments; Trees; Wildlife conservation; Willow
• ISSN: 1752-993X; 1752-9921; 1752-993X
• DOI: 10.1093/jpe/rtae060

Abstract Plants adapt to the limitation of soil phosphorus (P) induced by nitrogen (N) deposition through a complex interaction of various root and leaf functional traits. In this study, a pot experiment was conducted to explore the effects of different levels of N addition (control, low N [LN]: 25 kg N ha−1 yr−1, high N [HN]: 50 kg N ha−1 yr−1) on tree growth, leaf nutrient content, foliar P fractions and root characteristics of two dominant tree species, the pioneer species Salix rehderiana Schneid and the climax species Abies fabri (Mast.) Craib, in a subalpine forest in southwestern China. The results demonstrated that LN addition had a minimal impact on leaf N and P contents. Conversely, HN addition significantly decreased the leaf P content in both species. Salix rehderiana exhibited more pronounced increases in specific root length and specific root area under P deficiency triggered by HN addition when compared with A. fabri. In contrast, A. fabri showed weaker morphological responses to N addition but had a higher proportion of foliar P to metabolic P, as well as higher root exudates rate and root phosphatase activity in response to HN addition. Abies fabri employs a synergistic approach by allocating a greater amount of leaf P to metabolite P and extracting P from the soil through P-mobilizing exudates and root phosphatase activity, while S. rehderiana exhibits higher flexibility in modifying its root morphology in response to P limitation induced by HN addition. This study provides insights into subalpine tree species adaptation to N-induced P limitation, emphasizing its significance for guiding forest management and conservation in the context of global climate change.