Linking flowering and reproductive allocation in response to nitrogen addition in an alpine meadow

As one of the nitrogen (N) limitation ecosystems, alpine meadows have significant effects on their structure and function. However, research on the response and linkage of vegetation-soil to short-term low-level N deposition with rhizosphere processes is scant. We conducted a four level N addition (0, 20, 40, and 80 kg N ha−1 y−1) field experiment in an alpine meadow on the Qinghai-Tibetan Plateau (QTP) from July 2014 to August 2016. We analyzed the community characteristics, vegetation (shoots and roots), total carbon (TC), nutrients, soil (rhizosphere and bulk) properties, and the linkage between vegetation and soil under different N addition rates. Our results showed that (i) N addition significantly increased and decreased the concentration of soil nitrate nitrogen (NO3−-N) and ammonium nitrogen, and the soil pH, respectively; (ii) there were significant correlations between soil (rhizosphere and bulk) NO3−-N and total nitrogen (TN), and root TN, and there was no strong correlation between plant and soil TC, TN and total phosphorus, and their stoichiometry under different N addition rates. The results suggest that short-term low-N addition affected the plant community, vegetation, and soil TC, TN, TP, and their stoichiometry insignificantly, and that the correlation between plant and soil TC, TN, and TP, and their stoichiometry were insignificant.

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Nitrogen addition reduces soil respiration but increases the relative contribution of heterotrophic component in an alpine meadow

Functional Ecology ◽

10.1111/1365-2435.13433 ◽

2019 ◽

Vol 33 (11) ◽

pp. 2239-2253 ◽

Cited By ~ 6

Author(s):

Jinsong Wang ◽

Bing Song ◽

Fangfang Ma ◽

Dashuan Tian ◽

Yong Li ◽

...

Keyword(s):

Soil Respiration ◽

Alpine Meadow ◽

Nitrogen Addition ◽

Relative Contribution

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Clipping defoliation eliminates the stimulating effects of nitrogen enrichment on the aboveground productivity of an alpine meadow

Plant Soil and Environment ◽

10.17221/543/2019-pse ◽

2020 ◽

Vol 66 (No. 1) ◽

pp. 47-56

Author(s):

Ning Zong ◽

Peili Shi

Keyword(s):

Aboveground Biomass ◽

Alpine Meadow ◽

Nitrogen Addition ◽

N Addition ◽

Aboveground Productivity ◽

Soil Inorganic N ◽

Aboveground Production ◽

Biomass Removal ◽

Grass Growth ◽

Degraded Grassland

To investigate how clipping (CL) regulates the effects of nutrient addition, an experiment, including CL and nitrogen (N) addition, was conducted in an alpine meadow. Nitrogen treatment increased community coverage (48–113% higher than the control) and aboveground biomass (29–117% higher than the control), which was mainly attributed to grass growth. Both N and N + CL treatments showed a tendency to reducing species richness, while significant reduction only occurred in 2016 and 2017 in CL treatment. Clipping showed a tendency to decrease community cover (3–37% lower than the control) and aboveground biomass (2–34% lower than the control), while N + CL treatment had no effect, indicating that clipping can eliminate the simulated effects of N addition. Nitrogen addition significantly increased soil inorganic N (SIN, 528–1230% higher than the control), while SIN in N + CL was 25–48% lower than N treatment. The decrease in stimulated effects in N + CL was attributed to SIN decrease, which resulted from the aboveground biomass removal by clipping. Our results show that clipping can take away aboveground biomass and cause soil nutrients to decrease, which slows down the degraded grassland recovery. This suggests that grazing exclusion may eliminate the effect of nitrogen deposition on aboveground production in alpine grasslands.

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Short-term effect of nitrogen addition on nitric oxide emissions from an alpine meadow in the Tibetan Plateau

Environmental Science and Pollution Research ◽

10.1007/s11356-016-6763-5 ◽

2016 ◽

Vol 23 (12) ◽

pp. 12474-12479 ◽

Cited By ~ 6

Author(s):

Yongheng Gao ◽

Xingxing Ma ◽

David J. Cooper

Keyword(s):

Nitric Oxide ◽

Tibetan Plateau ◽

Alpine Meadow ◽

Nitrogen Addition ◽

Term Effect ◽

The Tibetan Plateau ◽

Short Term ◽

Short Term Effect ◽

Nitric Oxide Emissions

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Nitrogen Addition and Arbuscular Mycorrhizal Fungi Beta Diversity: Patterns and Mechanisms

Frontiers in Environmental Science ◽

10.3389/fenvs.2021.701653 ◽

2021 ◽

Vol 9 ◽

Author(s):

Yawen Lu ◽

Xiang Liu ◽

Shurong Zhou

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Mycorrhizal Fungi ◽

Beta Diversity ◽

Alpine Meadow ◽

Alpha Diversity ◽

Arbuscular Mycorrhizal ◽

Nitrogen Addition ◽

Tibet Plateau ◽

Community Dissimilarity ◽

Qinghai Tibet Plateau

Global nitrogen eutrophication, which is disrupting the intimate plant–arbuscular mycorrhizal fungi (AMF) symbiosis, can alter the diversity and physiological functions of soil AMF greatly. However, shifts of beta diversity and the intrinsic patterns of AMF community dissimilarities in response to nitrogen addition remain unclear. Based on a 7-year nitrogen addition experiment in a Qinghai–Tibet Plateau alpine meadow, we detected the changes in soil AMF alpha diversity (richness and genus abundance) and the community composition beta diversity by partitioning the two components of Simpson and nestedness dissimilarities along (turnover) and within (variation) nitrogen addition treatments, and fitted with environmental factor dissimilarities. We found that nitrogen addition decreased AMF richness by decreasing the most dominant AMF genus of Glomus but increasing the abundance of the rare genera. The turnover of the AMF community overall beta diversity along the nitrogen addition gradients was induced by the increased nestedness dissimilarity, while the variation within treatments was explained by both increased Simpson and nestedness dissimilarities, which was significantly correlated with soil pH. Our study found both Simpson and nestedness dissimilarities worked on the AMF community dissimilarity after nitrogen addition and the significant variation within the same treatment, which would be important in the future for predicting global AMF or microbial diversity changes in response to nitrogen eutrophication.

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