Elevated nitrogen deposition may advance invasive weed, Solidago canadensis, in calcareous soils

2019 ◽  
Vol 12 (5) ◽  
pp. 846-856 ◽  
Author(s):  
Ling-Yun Wan ◽  
Shan-Shan Qi ◽  
Chris B Zou ◽  
Zhi-Cong Dai ◽  
Guang-Qian Ren ◽  
...  

Abstract Aims Change in nitrogen (N) availability regulates phosphorus (P) acquisition and potentially alters the competition among native species and invasive weeds. This study determines how current and projected N deposition affect the growth, the intraspecific and interspecific competitive ability of native and invasive plants in calcareous soils with low P availability. Methods A controlled greenhouse experiment was conducted using sparingly soluble hydroxyapatite (HAP) to simulate the calcareous soils with low P availability. The growth and competitive intensity between an invasive weed (Solidago canadensis) and a native weed (Pterocypsela laciniata) exposed to two levels of N addition representative of current and future N deposition in China were experimentally determined. Important Findings P acquisition and the growth of both S. canadensis and P. laciniata growing alone significantly increased with increasing N level. However, the effect of N addition was reduced when intraspecific or interspecific competition existed. N addition altered the competitive relationship between S. canadensis and P. laciniata allowing S. canadensis to out-compete P. laciniata due to variation in P acquisition from HAP. Elevated N deposition might assist the invasion of S. canadensis in the widely distributed calcareous soils under environmental changes.

2020 ◽  
Author(s):  
Guang-Qian Ren ◽  
Chris B Zou ◽  
Ling-Yun Wan ◽  
Jacob H Johnson ◽  
Jian Li ◽  
...  

Abstract Aims Projections of invasive species expansion under a warmer world often do not explicitly consider the concurring nitrogen (N) deposition. It remains largely unknown how the convoluted effect of climate warming and N deposition will shift the native and invasive species dynamics. Here, we hypothesize that the concurring increases in N and temperature would promote growth of invasive species greater than that of native species. Methods A controlled greenhouse experiment was conducted to quantify the growth response of an invasive species (Solidago canadensis L.) and a co-existing native species (Artemisia argyi Levl. et Van) under the effects of climate warming, N deposition and their interactions. Important Findings Due to the strong positive effect of N addition, the interactive effect of temperature increase and N addition resulted in an overall significant increase in growth of both invasive and native species, demonstrating that these manipulations may make microhabitats more favorable to plant growth. However, the relative increases in biomass, height and diameter of invasive S. canadensis were significantly lower than those of native A. argyi. This suggests that the vegetative growth superiority of invasive S. canadensis over the native species A. argyi is reduced by the enhanced N availability in the warmer world. Therefore, the inclusion of N deposition may mitigate the projection of invasive species S. canadensis expansion under climate warming.


2019 ◽  
Vol 16 (14) ◽  
pp. 2891-2904
Author(s):  
Tianpeng Li ◽  
Heyong Liu ◽  
Ruzhen Wang ◽  
Xiao-Tao Lü ◽  
Junjie Yang ◽  
...  

Abstract. Sulfur (S) availability plays a vital role in driving functions of terrestrial ecosystems, which can be largely affected by soil inorganic S fractions and pool size. Enhanced nitrogen (N) input can significantly affect soil S availability, but it still remains largely unknown if the N effect varies with frequency of N addition and mowing management in grasslands. To investigate changes in the soil S pool and inorganic S fractions (soluble S, adsorbed S, available S, and insoluble S), we conducted a field experiment with different frequencies (two times per year vs. monthly additions per year) and intensities (i.e., 0, 1, 2, 3, 5, 10, 15, 20, and 50 g N m−2 yr−1) of NH4NO3 addition and mowing (unmown vs. mown) over 6 years in a temperate grassland of northern China. Generally, N addition frequency, N intensity, and mowing significantly interacted with each other to affect most of the inorganic S fractions. Specifically, a significant increase in soluble S was only found at high N frequency with the increasing intensity of N addition. Increasing N addition intensity enhanced adsorbed S and available S concentrations at low N frequency in unmown plots; however, both fractions were significantly increased with N intensity at both N frequencies in mown plots. The high frequency of N addition increased the concentrations of adsorbed S and available S in comparison to the low frequency of N addition only in mown plots. Changes in soil S fractions were mainly related to soil pH, N availability, soil organic carbon (SOC), and plant S uptake. Our results suggested that N input could temporarily replenish soil-available S by promoting dissolution of soil-insoluble S with decreasing soil pH and mineralization of organic S due to increasing plant S uptake. However, the significant decrease in organic S and total S concentrations with N addition intensity in mown plots indicated that N addition together with biomass removal would eventually cause soil S depletion in this temperate grassland in the long term. Our results further indicated that using large and infrequent N additions to simulate N deposition can overestimate the main effects of N deposition and mowing management on soil S availability in semiarid grasslands.


2007 ◽  
Vol 29 (1) ◽  
pp. 101 ◽  
Author(s):  
J. W. Morgan

The relationship between fire frequency (annual v. infrequent) and nitrogen (N) limitation to foliage production in a temperate native grassland community in western Victoria, Australia, was assessed over one growing season using a simple ammonium nitrate addition experiment. Fire history affected the magnitude of the vegetation responses to N addition. At the community level, mean live biomass in infrequently-burned grasslands declined by 20 ± 8% in response to N addition. In contrast, mean biomass increased by 60 ± 15% in annually-burned grasslands in response to N addition. Both grasses and forbs responded positively to N addition in annually-burned grasslands, with forbs responding more substantially than grasses. Foliage production in annually-burned native grasslands therefore appears to be constrained by N availability. The results of this study may have important implications for understanding species coexistence and invasion by non-native species in temperate native grasslands.


2020 ◽  
Author(s):  
Luca Da Ros ◽  
Maurizio Ventura ◽  
Mirco Rodeghiero ◽  
Damiano Gianelle ◽  
Giustino Tonon

<p><strong>Abstract.</strong> Forests ability to store carbon is strongly connected with the amount of nitrogen (N) that forest ecosystems can retain; N is indeed considered the most limiting nutrient for terrestrial ecosystem's net primary productivity. Since the industrial revolution, human activities have more than doubled the rate of N input into the nitrogen cycle and this could alleviate N limitation thus stimulating plant growth. However, it has been suggested that when N availability exceeds biotic demand and abiotic sinks, additional N can trigger a negative cascade effect: nutrient imbalance, reduced productivity, increased losses of N, eutrophication and acidification of soil and water, leading toward forest decline and net greenhouse gases emissions. The consequences of increased N deposition on forest depend in large share on the fate of N in the ecosystem, which can be simulated and quantified by a fertilization at a known isotopic signature. Nevertheless, most of the tracer experiments performed so far added the fertilizer directly to the forest floor, neglecting the potential role of N uptake by the forest canopy. In the Italian Alps, we are conducting an experiment where both types of N additions (above and below the canopy layer) are performed in two different forest stands, to understand if canopy fertilization better simulates ecological consequences of increased atmospheric N deposition. These field-scale manipulation experiments are willing to test two different hypotheses: i) the N uptake by trees in the above-canopy N addition experimental sites is higher than under-canopy N addition ii) forest growth rate varies with the type of treatment. To describe the fate of the applied N, stable isotope techniques have been adopted: the forest sites, fertilized with NH<sub>4</sub>NO<sub>3</sub> at a known isotopic signature, are sampled for all the ecosystem components (plant, soil and water) periodically to determine the total N content and its isotopic signature. The δ<sup>15</sup>N values permit to calculate the recovery of N-fertilizer in tree tissues, soil and leaching-water, allowing us to understand how N allocation varies under these two fertilization strategies and how this affects C sequestration potential. Results regarding the short-term effects over the first 6 years of data collection will be presented.</p>


2011 ◽  
Vol 8 (9) ◽  
pp. 2805-2813 ◽  
Author(s):  
T. Zhang ◽  
W. Zhu ◽  
J. Mo ◽  
L. Liu ◽  
S. Dong

Abstract. It is well established that tropical forest ecosystems are often limited by phosphorus (P) availability, and elevated atmospheric nitrogen (N) deposition may further enhance such P limitation. However, it is uncertain whether P availability would affect soil fluxes of greenhouse gases, such as methane (CH4) uptake, and how P interacts with N deposition. We examine the effects of N and P additions on soil CH4 uptake in an N saturated old-growth tropical forest in southern China to test the following hypotheses: (1) P addition would increase CH4 uptake; (2) N addition would decrease CH4 uptake; and (3) P addition would mitigate the inhibitive effect of N addition on soil CH4 uptake. Four treatments were conducted at the following levels from February 2007 to October 2009: control, N-addition (150 kg N ha−1 yr−1), P-addition (150 kg P ha−1 yr−1), and NP-addition (150 kg N ha−1 yr−1 plus 150 kg P ha−1 yr−1). Static chamber and gas chromatography techniques were used to quantify soil CH4 uptake every month throughout the study period. Average CH4 uptake rate was 31.2 ± 1.1 μg CH4-C m−2 h−1 in the control plots. The mean CH4 uptake rate in the N-addition plots was 23.6 ± 0.9 μg CH4-C m−2 h−1, significantly lower than that in the controls. P-addition however, significantly increased CH4 uptake by 24% (38.8 ± 1.3 μg CH4-C m−2 h−1), whereas NP-addition (33.6 ± 1.0 μg CH4-C m−2 h−1) was not statistically different from the control. Our results suggest that increased P availability may enhance soil mathanotrophic activity and root growth, resulting in potentially mitigating the inhibitive effect of N deposition on CH4 uptake in tropical forests.


Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 724
Author(s):  
Yi Wang ◽  
Shirong Liu ◽  
Junwei Luan ◽  
Chen Chen ◽  
Chunju Cai ◽  
...  

Impacts of drought events and nitrogen (N) deposition on forests are increasingly concerning in the context of global climate change, but their effects, in particular, their interactive effects on soil respiration and its components remain unclear. A two-factor random block field experiment was conducted at a subtropical Moso bamboo forest in Southwest China to explore the response of soil respiration (Rs), autotrophic respiration (Ra), and heterotrophic respiration (Rh) to throughfall re-duction and N addition. Our results showed that throughfall reduction significantly decreased Rs, which is mainly attributed to the decrease in Ra as a result of the decline in fine roots biomass. The N addition led to microbial carbon limitation hence significantly decreased Rh, and thus Rs. We also observed the negative effect of throughfall reduction on Rs was exacerbated by N addition, which is attributed to the significant reduction in Ra under the interaction between throughfall reduction N addition. Our findings suggest that Ra tended to respond more sensitively to potential drought, while Rh responds more sensitively to N deposition, and consequently, increased soil N availability caused by N deposition might aggravate the negative effect of expected drought on soil carbon cycling.


2021 ◽  
Author(s):  
Aiyun XU ◽  
Xing Wang ◽  
Xiaojia Wang ◽  
Dongmei Xu ◽  
Bing Cao

Abstract Background and aimsNitrogen (N) is the primary limiting factors for plant growth and development, and increasingly N deposition alters plant composition, consequently affecting ecosystem function have been widely acknowledged. However, the effects of N fertilization on native species in desert grassland ecosystem and underlying mechanisms of these effects are still poorly understood. This study was conducted to examine the growth response of Agropyron mongolicum keng to N addition and potential mechanisms underlying this effect.MethodsA.mongolicum Keng was subjected to five N addition levels (0, 0.8,1.6, 2.4, and 4.0g N m−2 yr−1) for six months under greenhouse conditions. A combination of linear and structural equation modelling was used to examine growth response of A.mongolicum Keng to N addition and test whether its response related to root morphological traits and N-use efficiency.ResultsGrowth responses of A. mongolicum Keng to increasing N addition appeared a unimodal-shaped with a N saturation threshold at 3.2g N m-1 yr-1. Its response closely related to the root surface area, volume, length, and forks number, N uptake and utilization efficiency. Besides, N-induced changes in soil available nutrient have an indirect impaction biomass of A. mongolicum Keng via regulation of root morphological traits and N-use efficiency.ConclusionsThese findings highlight the sensibility of A. mongolicum Keng to N addition and the importance of root morphological traits and N-use efficiency in affecting biomass. Therefore, these can provide important insights into potential changes of native species survival and development in nutrient-limited desert grassland caused by N deposition.


2011 ◽  
Vol 38 (9) ◽  
pp. 702 ◽  
Author(s):  
Hiroyuki Tobita ◽  
Akira Uemura ◽  
Mitsutoshi Kitao ◽  
Satoshi Kitaoka ◽  
Yutaka Maruyama ◽  
...  

The objective of this paper is to clarify the effects of multiple environmental conditions, elevated atmospheric CO2 concentration ([CO2]) and soil conditions on the physiological and morphological properties of Alnus hirsuta Turcz., an N2-fixing species, to predict its responses to environmental changes. We examined the responses of photosynthetic properties, leaf characteristics, biomass and N allocation of A. hirsuta to elevated [CO2], soil N and phosphorus availability, and soil drought by using the results of two experiments. The effects of P availability were more marked than those of N availability and soil drought. The photosynthetic responses of A. hirsuta to elevated [CO2] under high P were considered to be ‘photosynthetic acclimation’, while A. hirsuta presented the obvious ‘photosynthetic downregulation’ to elevated [CO2] under low P. Soil P availability affected the growth responses to elevated [CO2] through effects on these photosynthetic properties and biomass allocation. Though elevated [CO2] caused no marked change in the allometric relationships in biomass, with some exceptions, the responses of N allocation among tissue to elevated [CO2] differed from those of biomass allocation. These results suggest that it is necessary to evaluate N mass allocation as well as biomass when we consider the N2-fixing ability of Alnus under elevated [CO2].


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Lei Li ◽  
Bo Liu ◽  
Xiaopeng Gao ◽  
Xiangyi Li ◽  
Chengdao Li

AbstractPlant C:N:P stoichiometric relations drive powerful constraints on ecological interactions and processes. However, information about plant stoichiometric responses to N and P availability in desert grassland is limited. We conducted two field experiments with 7 levels of N (from 0.5 g to 24 g N ∙ m−2 yr−1) and P (from 0.05 g to 3.2 g P ∙ m−2 yr−1) additions in a desert grassland of Kunlun Mountain in the northwest of China to investigate the effects of these addition rates on the N and P stoichiometry of the dominant grass species Seriphidium korovinii. Nitrogen and P additions both affected plant stoichiometry. N addition suppressed P concentrations, whereas P addition had no effect on plant N concentrations. The N:P ratios of green aboveground biomass (AGB) were positively correlated with N addition ranging from 14.73 to 29.08, whereas those for P additions decreased ranging from 14.73 to 8.29. N concentrations were positively correlated with soil available N:P ratios, whereas, P concentrations were negatively correlated with soil availably N:P. Our results suggest that chemistry and stoichiometry of S. korovinii was directly affected by soil nutrient availability. Soil N availability affects S. korovinii stoichiometry to a greater extent that does soil P availability in this ecosystem. These findings suggest that N-deposition could affect the stoichiometry of this desert grassland ecosystem, and thereby potentially alter litter decomposition, plant community composition, nutrient cycling, and food-web dynamics of these desert ecosystems.


2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Chengming You ◽  
Changhui Peng ◽  
Zhenfeng Xu ◽  
Yang Liu ◽  
Li Zhang ◽  
...  

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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