Premium
Warming leads to more closed nitrogen cycling in nitrogen‐rich tropical forests
Author(s) -
Lie Zhiyang,
Huang Wenjuan,
Liu Xujun,
Zhou Guoyi,
Yan Junhua,
Li Yuelin,
Huang Chumin,
Wu Ting,
Fang Xiong,
Zhao Mengdi,
Liu Shizhong,
Chu Guowei,
Kadowaki Kohmei,
Pan Xiaoping,
Liu Juxiu
Publication year - 2021
Publication title -
global change biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.146
H-Index - 255
eISSN - 1365-2486
pISSN - 1354-1013
DOI - 10.1111/gcb.15432
Subject(s) - cycling , leaching (pedology) , global warming , environmental science , nitrogen cycle , nitrogen , agronomy , soil water , biomass (ecology) , nutrient cycle , ecosystem , ecology , chemistry , climate change , biology , soil science , forestry , organic chemistry , geography
Warming may have profound effects on nitrogen (N) cycling by changing plant N demand and underground N supply. However, large uncertainty exists regarding how warming affects the integrated N dynamic in tropical forests. We translocated model plant‐soil ecosystems from a high‐altitude site (600 m) to low‐altitude sites at 300 and 30 m to simulate warming by 1.0°C and 2.1°C, respectively, in tropical China. The effects of experimental warming on N components in plant, soil, leaching, and gas were studied over 6 years. Our results showed that foliar δ 15 N values and inorganic N (NH 4 ‐N and NO 3 ‐N) leaching were decreased under warming, with greater decreases under 2.1°C of warming than under 1.0°C of warming. The 2.1°C of warming enhanced plant growth, plant N uptake, N resorption, and fine root biomass, suggesting higher plant N demand. Soil total N concentrations, NO 3 ‐N concentrations, microbial biomass N and arbuscular mycorrhizal fungal abundance were decreased under 2.1°C of warming, which probably restricted bioavailable N supply and arbuscular mycorrhizal contribution of N supply to plants. These changes in plants, soils and leaching indicated more closed N cycling under warming, the magnitude of which varied over time. The closed N cycling became pronounced during the first 3 years of warming where the sustained reductions in soil inorganic N could not meet plant N demand. Subsequently, the closed N cycling gradually mitigated, as observed by attenuated positive responses of plant growth and less negative responses of microbial biomass N to warming during the last 3 years. Overall, the more closed N cycling under warming could facilitate ecosystem N retention and affect production in these tropical forests, but these effects would be eventually mitigated with long‐term warming probably due to the restricted plant growth and microbial acclimation.