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Your search keyword '"Liu, Xiuyuan"' showing total 4 results
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4 results on '"Liu, Xiuyuan"'

1. High-level nitrogen additions accelerate soil respiration reduction over time in a boreal forest.

Author

Xing A, Du E, Shen H, Xu L, Zhao M, Liu X, and Fang J

Subjects
Carbon, Carbon Sequestration, China, Forests, Respiration, Taiga, Nitrogen analysis, Soil
Abstract

Increased nitrogen (N) inputs are widely recognised to reduce soil respiration (Rs), but how N deposition affects the temporal dynamics of Rs remains unclear. Using a decade-long fertilisation experiment in a boreal larch forest (Larix gmelini) in northeast China, we found that the effects of N additions on Rs showed a temporal shift from a positive effect in the short-term (increased by 8% on average in the first year) to a negative effect over the longer term (decreased by 21% on average in the 11th year). The rates of decrease in Rs for the higher N levels were almost twice as high as those of the low N level. Our results suggest that the reduction in Rs in response to increased N input is accelerated by high-level N additions, and experimental high N applications are likely to overestimate the contribution of N deposition to soil carbon sequestration in a boreal forest., (© 2022 John Wiley & Sons Ltd.)

Published
2022
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2. Nonlinear responses of ecosystem carbon fluxes to nitrogen deposition in an old-growth boreal forest.

Author

Xing A, Du E, Shen H, Xu L, de Vries W, Zhao M, Liu X, and Fang J

Subjects
Carbon, Forests, Soil, Taiga, Ecosystem, Nitrogen analysis
Abstract

Nitrogen (N) deposition is known to increase carbon (C) sequestration in N-limited boreal forests. However, the long-term effects of N deposition on ecosystem carbon fluxes have been rarely investigated in old-growth boreal forests. Here we show that decade-long experimental N additions significantly stimulated net primary production (NPP) but the effect decreased with increasing N loads. The effect on soil heterotrophic respiration (Rh) shifted from a stimulation at low-level N additions to an inhibition at higher levels of N additions. Consequently, low-level N additions resulted in a neutral effect on net ecosystem productivity (NEP), due to a comparable stimulating effect on NPP and Rh, while NEP was increased by high-level N additions. Moreover, we found nonlinear temporal responses of NPP, Rh and NEP to low-level N additions. Our findings imply that actual N deposition in boreal forests likely exerts a minor contribution to their soil C storage., (© 2021 John Wiley & Sons Ltd.)

Published
2022
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3. Long term effect of nitrogen addition on understory community in a Chinese boreal forest.

Author

Xing A, Xu L, Shen H, Du E, Liu X, and Fang J

Subjects
Biodiversity, China, Plants, Air Pollutants analysis, Environmental Monitoring, Nitrogen analysis, Taiga
Abstract

Increasing atmospheric nitrogen (N) deposition is an important driver of biodiversity change. By conducting an eight-year N addition experiment (0, 20, 50 and 100 kg N ha -1  yr -1 ), we investigated the long-term effect of simulated N deposition on understory species composition and richness in a boreal forest, northeast China. We found that moss cover decreased significantly with increasing N addition. N addition had no significant effect on vascular plants species richness but changed the plant community composition. The relative coverage of evergreen shrubs decreased, while that of graminoids increased under high-level N addition (100 kg N ha -1  yr -1 ). Under the high-level N treatment, Deyeuxia angustifolia cover increased significantly after 4 years, while that of Vaccinium vitis-idaea decreased significantly after 3 years and almost disappeared after 5 years. The negative effect of N addition on mosses and evergreen shrubs accumulated over time, while the positive effect on graminoids increased during the first 4 years and did not change significantly thereafter. Our results suggest that the effect of N deposition varies across functional groups and shifts over time., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Published
2019
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4. Effects of nitrogen additions on biomass, stoichiometry and nutrient pools of moss Rhytidium rugosum in a boreal forest in Northeast China.

Author

Du E, Liu X, and Fang J

Subjects
Biomass, Carbon metabolism, China, Environmental Monitoring, Environmental Pollutants toxicity, Nitrogen toxicity, Phosphorus metabolism, Trees, Bryopsida drug effects, Environmental Pollutants analysis, Nitrogen analysis, Photosynthesis drug effects
Abstract

Global nitrogen (N) deposition has been enhanced with anthropogenic N emissions, and its impacts on mosses are receiving more and more attention. This study investigates how N deposition influence the biomass and stoichiometry of moss Rhytidium rugosum, using a 3-year N enrichment experiment with 0, 2, 5 and 10 g N m(-2) yr(-1) in a boreal forest in Northeast China. Low N additions caused an N redundancy and moderate to high N additions resulted in a biomass loss. N additions reduced biomass ratios of green to brown tissues and increased N and phosphorus (P) contents, suggesting changes in photosynthetic capacity and litter decomposition. Biomass N pools showed a unimodal response to the N additions, and P pools decreased under moderate and high N additions. Our findings indicate significant stoichiometric and biomass changes caused by N deposition may lead to a substantial carbon and nutrient loss in boreal moss carpets., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Published
2014
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