Nitrogen Addition Did Not Alter the Relationships Between the Leaf and Root Traits of Machilus Pauhoi seedlings

Abstract Leaves and roots are important resource acquisition organs of seedlings and both are sensitive to the environment. However, it is currently unclear whether leaf and root traits have a similar response model to nitrogen (N) deposition. Furthermore, the relationships between the responses of leaf and root traits to N deposition are still unknown.Exogenous nitrogen input experiments were conducted to simulate the effects of nitrogen deposition in Shunchang County, south of China. We measured the biomass, morphological characteristics, and nutrient concentrations (total of 12 functional traits of leaves and roots) of Machilus pauhoi seedlings. The responses of leaf and root traits to N addition were analyzed. In addition, the relationships between paired leaf and root traits were analyzed.We found that the responses of the leaves and roots to short-term nitrogen deposition were not consistent. The specific leaf area (SLA) (specific root length, SRL), tissue density (TD), carbon (C) content, N content, C/N, and N/phosphorus (P) of the leaf and root did not appear to respond to N addition. However, the biomass, P content, and C/P of the leaf and root markedly responded to N addition. The nutrient concentrations of the leaf and root were correlated, while the phenotypic traits were not. Furthermore, short-term N addition did not alter the relationship between the leaves and roots.Our results show that, in the context of global change of nitrogen deposition, the correlation between the leaves and roots of a plant has a certain tolerance for nitrogen deposition, which is of great significance for the efficient cultivation of quality seedlings and understanding how terrestrial forest ecosystems respond to nitrogen deposition.

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Effect of Short-Term Low-Nitrogen Addition on Carbon, Nitrogen and Phosphorus of Vegetation-Soil in Alpine Meadow

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph182010998 ◽

2021 ◽

Vol 18 (20) ◽

pp. 10998

Author(s):

Zhen’an Yang ◽

Wei Zhan ◽

Lin Jiang ◽

Huai Chen

Keyword(s):

Alpine Meadow ◽

Nitrogen Addition ◽

Ammonium Nitrogen ◽

N Deposition ◽

Total Carbon ◽

N Addition ◽

Short Term ◽

Nitrogen And Phosphorus ◽

Soil Rhizosphere ◽

And Function

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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Short-Term Nitrogen Addition Does Not Significantly Alter the Effects of Seasonal Drought on Leaf Functional Traits in Machilus pauhoi Kanehira Seedlings

Forests ◽

10.3390/f10020078 ◽

2019 ◽

Vol 10 (2) ◽

pp. 78 ◽

Cited By ~ 1

Author(s):

Hua Yu ◽

Dongliang Cheng ◽

Baoyin Li ◽

Chaobin Xu ◽

Zhongrui Zhang ◽

...

Keyword(s):

Functional Traits ◽

C:N Ratio ◽

Leaf Traits ◽

N Deposition ◽

Interactive Effects ◽

N Addition ◽

Subtropical China ◽

Short Term ◽

Leaf Functional Traits ◽

Seasonal Drought

Research Highlights: Short-term nitrogen (N) addition did not significantly alter the effects of seasonal drought on the leaf functional traits in Machilus pauhoi Kanehira seedlings in N-rich subtropical China. Background and Objectives: Seasonal drought and N deposition are major drivers of global environmental change that affect plant growth and ecosystem function in subtropical China. However, no consensus has been reached on the interactive effects of these two drivers. Materials and Methods: We conducted a full-factorial experiment to analyze the single and combined effects of seasonal drought and short-term N addition on chemical, morphological and physiological traits of M. pauhoi seedlings. Results: Seasonal drought (40% of soil field capacity) had significant negative effects on the leaf N concentrations (LNC), phosphorus (P) concentrations (LPC), leaf thickness (LT), net photosynthetic rate (A), transpiration rate (E), stomatal conductance (Gs), and predawn leaf water potential (ψPD), and significant positive effects on the carbon:N (C:N) ratio and specific leaf area (SLA). Short-term N addition (50 kg N·hm−2·year−1 and 100 kg N·hm−2·year−1) tended to decrease the C:N ratio and enhance leaf nutrient, growth, and photosynthetic performance because of increased LNC, LPC, LT, leaf area (LA), SLA, A, E, and ψPD; however, it only had significant effects on LT and Gs. No significant interactive effects on leaf traits were detected. Seasonal drought, short-term N addition, and their interactions had significant effects on soil properties. The soil total C (STC), nitrate N (NO3−-N) and soil total N (STN) concentrations were the main factors that affected the leaf traits. Conclusions: Seasonal drought had a stronger effect on M. pauhoi seedling leaf traits than short-term N deposition, indicating that the interaction between seasonal drought and short-term N deposition may have an additive effecton M. pauhoi seedling growth in N-rich subtropical China.

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Response of litter decomposition and the soil environment to one-year nitrogen addition in a Schrenk spruce forest in the Tianshan Mountains, China

Scientific Reports ◽

10.1038/s41598-021-04623-8 ◽

2022 ◽

Vol 12 (1) ◽

Author(s):

Zhaolong Ding ◽

Xu Liu ◽

Lu Gong ◽

Xin Chen ◽

Jingjing Zhao ◽

...

Keyword(s):

Nitrogen Deposition ◽

Litter Decomposition ◽

Forest Ecosystems ◽

N Deposition ◽

Tianshan Mountains ◽

Control Treatment ◽

N Addition ◽

Soil Environment ◽

N Application ◽

Positive Effect

AbstractHuman activities have increased the input of nitrogen (N) to forest ecosystems and have greatly affected litter decomposition and the soil environment. But differences in forests with different nitrogen deposition backgrounds. To better understand the response of litter decomposition and soil environment of N-limited forest to nitrogen deposition. We established an in situ experiment to simulate the effects of N deposition on soil and litter ecosystem processes in a Picea schrenkiana forest in the Tianshan Mountains, China. This study included four N treatments: control (no N addition), low N addition (LN: 5 kg N ha−1 a−1), medium N addition (MN: 10 kg N ha−1 a−1) and high N addition (HN: 20 kg N ha−1 a−1). Our results showed that N addition had a significant effect on litter decomposition and the soil environment. Litter mass loss in the LN treatment and in the MN treatment was significantly higher than that in the control treatment. In contrast, the amount of litter lost in the HN treatment was significantly lower than the other treatments. N application inhibited the degradation of lignin but promoted the breakdown of cellulose. The carbon (C), N, and phosphorus (P) contents of litter did not differ significantly among the treatments, but LN promoted the release of C and P. Our results also showed that soil pH decreased with increasing nitrogen application rates, while soil enzyme activity showed the opposite trend. In addition, the results of redundancy analysis (RDA) and correlation analyses showed that the soil environment was closely related to litter decomposition. Soil enzymes had a positive effect on litter decomposition rates, and N addition amplified these correlations. Our study confirmed that N application had effects on litter decomposition and the soil environment in a N-limited P. schrenkiana forest. LN had a strong positive effect on litter decomposition and the soil environment, while HN was significantly negative. Therefore, increased N deposition may have a negative effect on material cycling of similar forest ecosystems in the near future.

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Nitrogen addition mediates the response of foliar stoichiometry to phosphorus addition: a meta-analysis

Ecological Processes ◽

10.1186/s13717-021-00329-x ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Chengming You ◽

Changhui Peng ◽

Zhenfeng Xu ◽

Yang Liu ◽

Li Zhang ◽

...

Keyword(s):

Low Dose ◽

Meta Analysis ◽

N Deposition ◽

Ecosystem Structure ◽

P Availability ◽

N Addition ◽

Short Term ◽

Positive Effects ◽

Foliar N ◽

P Addition

Abstract Background Changes in foliar nitrogen (N) and phosphorus (P) stoichiometry play important roles in predicting the effects of global change on ecosystem structure and function. However, there is substantial debate on the effects of P addition on foliar N and P stoichiometry, particularly under different levels of N addition. Thus, we conducted a global meta-analysis to investigate how N addition alters the effects of P addition on foliar N and P stoichiometry across different rates and durations of P addition and plant growth types based on more than 1150 observations. Results We found that P addition without N addition increased foliar N concentrations, whereas P addition with N addition had no effect. The positive effects of P addition on foliar P concentrations were greater without N addition than with N addition. Additionally, the effects of P addition on foliar N, P and N:P ratios varied with the rate and duration of P addition. In particular, short-term or low-dose P addition with and without N addition increased foliar N concentration, and the positive effects of short-term or low-dose P addition on foliar P concentrations were greater without N addition than with N addition. The responses of foliar N and P stoichiometry of evergreen plants to P addition were greater without N addition than with N addition. Moreover, regardless of N addition, soil P availability was more effective than P resorption efficiency in predicting the changes in foliar N and P stoichiometry in response to P addition. Conclusions Our results highlight that increasing N deposition might alter the response of foliar N and P stoichiometry to P addition and demonstrate the important effect of the experimental environment on the results. These results advance our understanding of the response of plant nutrient use efficiency to P addition with increasing N deposition.

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Effects of nitrogen addition on root traits and soil nitrogen in the long-term restored grasslands

Plant Soil and Environment ◽

10.17221/142/2021-pse ◽

2021 ◽

Vol 67 (No. 9) ◽

pp. 541-547

Author(s):

Guanghua Jing ◽

Zhikun Chen ◽

Qiangqiang Lu ◽

Liyan He ◽

Ning Zhao ◽

...

Keyword(s):

Root Length ◽

Morphological Traits ◽

Root Length Density ◽

Microbial Biomass Carbon ◽

Specific Root Length ◽

Root Traits ◽

N Deposition ◽

Root Diameter ◽

N Addition

Fine root traits are plastic and responsive to increased nitrogen (N) deposition. However, with the restoring of the ecosystem after grain for green, little research has been reported about the response of root traits in a long-term restored ecosystem to increased N deposition. Therefore, a successive N addition experiment was conducted in a long-term restored grassland on the Loess Plateau to analyse the effects of different N addition levels (0, 2.5, 5, 10, 20 g N/m2/year) on root morphological traits, soil carbon (C) and N. Our results showed that root morphological traits (except for root diameter) firstly increased and then declined, with the maximum in the N level of 5 g/m2/year. N addition significantly increased soil organic carbon, total nitrogen, ammonium nitrogen (NH4+-N) and nitrate-nitrogen (NO3–-N) with the increasing N addition level, especially in the soil surface layer. Specific root length and specific root area had remarkable negative correlations with NO3–-N, while root diameter and root length density had positive correlations with soil availability N and soil microbial biomass carbon. This study indicated that plants could have the threshold response to adapt to the N addition and prefer to slowly grow rather than quickly invest and return in order to adapt to the environmental stress.

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Biomass and Species Diversity of Different Alpine Plant Communities Respond Differently to Nitrogen Deposition and Experimental Warming

Plants ◽

10.3390/plants10122719 ◽

2021 ◽

Vol 10 (12) ◽

pp. 2719

Author(s):

Emmanuella A. Kwaku ◽

Shikui Dong ◽

Hao Shen ◽

Wei Li ◽

Wei Sha ◽

...

Keyword(s):

Nitrogen Deposition ◽

Plant Communities ◽

N Deposition ◽

Alpine Vegetation ◽

Vegetation Types ◽

Alpine Plant ◽

Alpine Grasslands ◽

Short Term ◽

Alpine Plant Communities

The ability of fragile ecosystems of alpine regions to adapt and thrive under warming and nitrogen deposition is a pressing conservation concern. The lack of information on how these ecosystems respond to the combined impacts of elevated levels of nitrogen and a warming climate limits the sustainable management approaches of alpine grasslands. In this study, we experimented using a completely random blocked design to examine the effects of warming and nitrogen deposition on the aboveground biomass and diversity of alpine grassland plant communities. The experiment was carried out from 2015 to 2018 in four vegetation types, e.g., alpine desert, alpine desert steppe, alpine marsh, and alpine salinised meadow, in the Aerjin Mountain Nature Reserve (AMNR) on the Qinghai–Tibetan Plateau (QTP). We found that W (warming) and WN (warming plus N deposition) treatment significantly increased the aboveground biomass of all the vegetation types (p < 0.05) in 2018. However, W and WN treatment only significantly increased the Shannon diversity of salinised meadows in 2018 and had no significant effect on the Shannon diversity of other vegetation types. Such results suggested that long-term nitrogen deposition and warming can consistently stimulate biomass accumulation of the alpine plant communities. Compared with other vegetation types, the diversity of alpine salinised meadows are generally more susceptible to long-term warming and warming combined with N deposition. Warming accounts many of such variabilities, while short-term N deposition alone may not significantly have an evident effect on the productivity and diversity of alpine grasslands. Our findings suggested that the effects of short-term (≤4 years) N deposition on alpine vegetation productivity and diversity were minimal, while long-term warming (>4 years) will be much more favourable for alpine vegetation.

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Responses of temperate steppe to simulated nitrogen deposition: from community structure to ecosystem functions

10.5194/egusphere-egu2020-21048 ◽

2020 ◽

Author(s):

Yongmei Huang

Keyword(s):

Nitrogen Deposition ◽

Net Primary Productivity ◽

Terrestrial Ecosystems ◽

N Deposition ◽

Tracer Experiment ◽

Ecosystem Functions ◽

N Recovery ◽

N Saturation ◽

N Addition ◽

Temperate Steppe

Effect of nitrogen deposition on terrestrial ecosystems are one of the hot spots in the study of global change, and the significantly different responses were reported widely among different ecosystems. In this study, field simulated nitrogen deposition experiment was carried out in a temperate steppe, norther China from 2011 to 2018. Treatments were designed as: CK (0 g N/m2), N2 level (2 g N/m2), N5 level (5 g N/m2), N10 level (10 g N/m2), N25 level (25 g N/m2) and N50 level (50 g N/m2). The results showed that the N addition did not cause a noticeable change in the net primary productivity and soil acidification. N addition caused a significant decline in community biodiversity with a major shift in species composition. N utilization strategy, photosynthetic capacity, and water use efficiency of three dominant species behaved differently under N deposition. Soil was the major sink for N deposition testified by the 15N isotope tracer experiment. N addition decreased soil microorganism and plant 15N recovery and increased soil of 30-40 cm layer 15N recovery. N saturation of the temperature steppe would occur when N deposition rate reached 5.4-8.4gN m-2a-1.

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How Do N Addition Affect Soil Fungal Community Assembly: Short- Versus Long-term Effects?

10.21203/rs.3.rs-113341/v1 ◽

2020 ◽

Author(s):

Jinhong He ◽

Shuo Jiao ◽

Xiangping Tan ◽

Hui Wei ◽

Xiaomin Ma ◽

...

Keyword(s):

Community Composition ◽

Relative Abundance ◽

Fungal Community ◽

N Deposition ◽

N Addition ◽

Short Term ◽

Α Diversity ◽

Soil Fungal Community ◽

Short And Long Term

Abstract Background: Soil fungi play critical roles in ecosystem processes and are sensitive to global changes. Elevated atmospheric nitrogen (N) deposition has been well documented to impact on fungal diversity and community composition, but how fungal community assembly respond to short- and long-term simulative N deposition remains poorly understood. Here, we carried out two field experiments to investigate the soil fungal community variations and assembly processes under short- (2 years) versus long-term (13 years) exogenous nitrogen addition (100 kg N ha-1 yr-1) in a N-rich tropical forest of China. Results: We observed that short-term N addition significantly increased fungal taxonomic and phylogenetic α-diversity, and shifted fungal community composition with significant increases in the relative abundance of Ascomycota and saprotrophic fungi, and decreases in the relative abundance of Basidiomycota and ectomycorrhizal (EcM) fungi. However, unremarkable effects were found under long-term N addition. The variations of fungal α-diversity, community composition, the relative abundance of major phyla, genera and functional guilds were mainly correlated with soil pH and the concentrations of NO3--N, and these correlations were much stronger under short- than long-term N addition. The results of null, neutral community models and the 39 normalized stochasticity ratio (NST) index consistently revealed that stochastic processes played predominant roles in the assembly of soil fungal community under N addition in the tropical forest, and that the relative contributions of stochastic processes were higher at short-term site. Furthermore, both short- and long-term N addition slightly loosened the co-occurrence networks of the fungal community. Conclusions: These findings highlighted that the responses of fungal community structure to N addition were duration-dependent, i.e., the fungal community was sensitive to the short-term N addition but become acclimatized to long-term N enrichment.

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Effects of nitrogen deposition on litter decomposition and nutrient release mediated by litter types and seasonal change in a temperate forest

Canadian Journal of Soil Science ◽

10.1139/cjss-2019-0037 ◽

2020 ◽

Vol 100 (1) ◽

pp. 11-25 ◽

Cited By ~ 1

Author(s):

Guoyong Yan ◽

Xiongde Dong ◽

Binbin Huang ◽

Honglin Wang ◽

Ziming Hong ◽

...

Keyword(s):

Mass Loss ◽

Litter Decomposition ◽

Nutrient Release ◽

N Deposition ◽

Pinus Koraiensis ◽

N Addition ◽

Entire Study ◽

Mixed Litter ◽

Negative Effect ◽

Four Levels

We conducted a field experiment with four levels of simulated nitrogen (N) deposition (0, 2.5, 5, and 7.5 g N m−2 yr−1, respectively) to investigate the response of litter decomposition of Pinus koraiensis (PK), Tilia amurensis (TA), and their mixture to N deposition during winter and growing seasons. Results showed that N addition significantly increased the mass loss of PK litter and significantly decreased the mass loss of TA litter throughout the 2 yr decomposition processes, which indicated that the different responses in the decomposition of different litters to N addition can be species specific, potentially attributed to different litter chemistry. The faster decomposition of PK litter with N addition occurred mainly in the winter, whereas the slower decomposition of TA litter with N addition occurred during the growing season. Moreover, N addition had a positive effect on the release of phosphorus, magnesium, and manganese for PK litter and had a negative effect on the release of carbon, iron, and lignin for TA litter. Decomposition and nutrient release from mixed litter with N addition showed a non-additive effect. The mass loss from litter in the first winter and over the entire study correlated positively with the initial concentration of cellulose, lignin, and certain nutrients in the litter, demonstrating the potential influence of different tissue chemistries.

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Nutrient resorption and stoichiometric responses of poplar (Populus deltoids) plantations to N addition in a coastal region of eastern China

Journal of Plant Ecology ◽

10.1093/jpe/rtab015 ◽

2021 ◽

Author(s):

Dalong Jiang ◽

Qian Li ◽

Qinghong Geng ◽

Menghua Zhang ◽

Chonghua Xu ◽

...

Keyword(s):

Eastern China ◽

Coastal Region ◽

Nutrient Resorption ◽

Green Leaf ◽

Nutrient Concentrations ◽

N Addition ◽

Resorption Efficiency ◽

Nutrient Resorption Efficiency ◽

Poplar Plantations ◽

Populus Deltoids

Abstract Aims Leaf nutrient resorption is sensitive to changes in soil nutrients. However, the effects of N deposition on nutrient resorption efficiency (NuRE) in plant macro-nutrients remain unclear. Poplar (Populus deltoids) is one of the most extensively cultivated hardwood species worldwide. We explored general patterns and dominant drivers of NuRE and stoichiometry of poplar plantations in response to N addition. Methods We conducted a 4-year N-addition experiment to explore NuRE and stoichiometric responses to N addition in two poplar (Populus deltoids) plantations (8- and 12-year-old stands) in a coastal region of eastern China. We measured soil and foliar (green and senesced leaves) concentrations of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) for a series of N addition treatments including N0 (0 kg N ha ‒1 yr ‒1), N1 (50 kg N ha ‒1 yr ‒1), N2 (100 kg N ha ‒1 yr ‒1), N3 (150 kg N ha ‒1 yr ‒1), and N4 (300 kg N ha ‒1 yr ‒1). Important Findings Consistent for (both) 8- and 12-year-old stands, N addition did not affect the NuRE and stoichiometry (with the exception of CaRE and CaRE:MgRE ratio). NRE-PRE scaling slopes were consistently less than 1.0 under N addition. These results suggest that NRE generally decouples from PRE within each N treatment. Moreover, these results point to robust control of green leaf nutritional status on nutrient resorption processes as indicated by the positive relationships between nutrient resorption efficiency and green leaf nutrient concentrations. Our findings provided a direct evidence that growth in 12-year-old poplar plantations was N-limited in a coastal region of eastern China.

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