Plant phenols contents and their changes with nitrogen availability in peatlands of northeastern China. (16th September 2020)

• Record Type: Journal Article
• Authors: Wu, Di; Wang, Xian-Wei; Xu, Shi-Qi; Chen, Chong-Juan; Mao, Rong; Liu, Xue-Yan
• Editors: Bai, Edith
• Is Part Of: Journal of plant ecology. Volume 13:Number 6(2020:Dec.)
• Page Start: 713
• Page End: 721
• Publication Date: 2020-09-16
• Subjects: boreal peatlands -- plant phenols -- plant defense theory -- plant functional types -- nitrogen availability; 北方泥炭地 -- 植物酚类物质 -- 植物防御理论 -- 植物功能型 -- 氮有效性; Plant ecology -- Periodicals; Phytogeography -- Periodicals; 581.705
• DOI: 10.1093/jpe/rtaa061
• Languages: English
• ISSNs: 1752-9921

Abstract

Abstract: Aims: Climate warming and increasing nitrogen (N) deposition have influenced plant nutrient status and thus plant carbon (C) fixation and vegetation composition in boreal peatlands. Phenols, which are secondary metabolites in plants for defense and adaptation, also play important roles in regulating peatland C dynamics due to their anti-decomposition properties. However, how the phenolic levels of different functional types of plants vary depending on nutrient availability remain unclear in boreal peatlands. Methods: Here, we investigated total phenols contents (TPC) and total tannins contents in leaves of 11 plant species in 18 peatlands of the Great Hing'an Mountains area in northeastern China, and examined their variations with leaf N and phosphorus (P) and underlying mechanisms. Important Findings: Shrubs had higher TPC than graminoids, indicating less C allocation to defense and less uptake of organic N in faster-growing and nonmycorrhizal graminoids than in slower-growing and mycorrhizal shrubs. For shrubs, leaf TPC decreased with increasing N contents but was not influenced by changing leaf phosphorus (P) contents, which suggested that shrubs would reduce the C investment for defense with increasing N availability. Differently, leaf TPC of graminoids increased with leaf N contents and decreased with leaf P contents. As graminoids are more N-limited and less P-limited, we inferred that graminoids would increase the defensive C investment under increased nutrient availability. We concluded that shrubs would invest more C in growth than in defense with increasing N availability, but it was just opposite for graminoids, which might be an important mechanism to explain the resource competition and encroachment of shrubs in boreal peatlands in the context of climate warming and ever-increasing N deposition.