Plant phenols contents and their changes with nitrogen availability in peatlands of northeastern China

2020 ◽  
Vol 13 (6) ◽  
pp. 713-721
Author(s):  
Di Wu ◽  
Xian-Wei Wang ◽  
Shi-Qi Xu ◽  
Chong-Juan Chen ◽  
Rong Mao ◽  
...  

Abstract Aims Climate warming and increasing nitrogen (N) deposition have influenced plant nutrient status and thus plant carbon (C) fixation and vegetation composition in boreal peatlands. Phenols, which are secondary metabolites in plants for defense and adaptation, also play important roles in regulating peatland C dynamics due to their anti-decomposition properties. However, how the phenolic levels of different functional types of plants vary depending on nutrient availability remain unclear in boreal peatlands. Methods Here, we investigated total phenols contents (TPC) and total tannins contents in leaves of 11 plant species in 18 peatlands of the Great Hing’an Mountains area in northeastern China, and examined their variations with leaf N and phosphorus (P) and underlying mechanisms. Important Findings Shrubs had higher TPC than graminoids, indicating less C allocation to defense and less uptake of organic N in faster-growing and nonmycorrhizal graminoids than in slower-growing and mycorrhizal shrubs. For shrubs, leaf TPC decreased with increasing N contents but was not influenced by changing leaf phosphorus (P) contents, which suggested that shrubs would reduce the C investment for defense with increasing N availability. Differently, leaf TPC of graminoids increased with leaf N contents and decreased with leaf P contents. As graminoids are more N-limited and less P-limited, we inferred that graminoids would increase the defensive C investment under increased nutrient availability. We concluded that shrubs would invest more C in growth than in defense with increasing N availability, but it was just opposite for graminoids, which might be an important mechanism to explain the resource competition and encroachment of shrubs in boreal peatlands in the context of climate warming and ever-increasing N deposition.

2012 ◽  
Vol 9 (8) ◽  
pp. 11201-11237 ◽  
Author(s):  
J. F. J. Korhonen ◽  
M. Pihlatie ◽  
J. Pumpanen ◽  
H. Aaltonen ◽  
P. Hari ◽  
...  

Abstract. The productivity of boreal forests is considered to be limited by low nitrogen (N) availability. Increased atmospheric N deposition has altered the functioning and N cycling of these N-sensitive ecosystems. The most important components of N pools and fluxes were measured in a boreal Scots pine stand in Hyytiälä, Southern Finland. The measurement at the site allowed direct estimations of nutrient pools in the soil and biomass, inputs from the atmosphere and outputs as drainage flow and gaseous losses from two micro-catchments. N was accumulating to the system with a rate of 7 kg N ha−1 yr−1. Nitrogen input as atmospheric deposition was 7.4 kg N ha−1 yr−1. Dry deposition and organic N in wet deposition contributed over half of the input in deposition. Total outputs were 0.4 kg N ha−1 yr−1, the most important outputs being N2O emission to the atmosphere and organic N flux in drainage flow. Nitrogen uptake and retranslocation were as important sources of N for plant growth. Most of the uptaken N originated from decomposition of organic matter, and the fraction of N that could originate directly from deposition was about 30%. In conclusion, atmospheric N deposition fertilizes the site considerably.


2009 ◽  
Vol 6 (3) ◽  
pp. 4803-4828 ◽  
Author(s):  
M. Lund ◽  
T. R. Christensen ◽  
M. Mastepanov ◽  
A. Lindroth ◽  
L. Ström

Abstract. Peatlands are important ecosystems in the context of biospheric feedback to climate change, due to the large storage of organic C in peatland soils. Nitrogen deposition and increased nutrient availability in soils following climate warming may cause changes in these ecosystems affecting greenhouse gas exchange. We have conducted an N and P fertilization experiment in two Swedish bogs subjected to high and low background N deposition, and measured the exchange of CO2, CH4 and N2O using the closed chamber technique. During the second year of fertilization, both gross primary production and ecosystem respiration were significantly increased by N addition in the northernmost site where background N deposition is low, while gross primary production was stimulated by P addition in the southern high N deposition site. In addition, a short-term response in respiration was seen following fertilization, probably associated with rapid growth of nutrient-limited soil microorganisms. No treatment effect was seen on the CH4 exchange, while N2O emissions peaks were detected in N fertilized plots indicating the importance of taking N2O into consideration under increased N availability. In a longer term, increased nutrient availability will cause changes in plant competitive patterns. The related effect on the future net greenhouse gas exchange is likely dependent on the mixture of nutrients being made available and which plant functional types that benefit from it, in combination with other changes related to global warming.


2021 ◽  
Author(s):  
Silvia Caldararu ◽  
Katrin Fleischer ◽  
Lin Yu ◽  
Sönke Zaehle

<p>Increasing atmospheric CO<sub>2</sub> concentrations can be a driver for higher ecosystem productivity across the globe but nutrient availability may limit subsequent biomass growth. Concurrently, increased anthropogenic nitrogen (N) deposition introduces a relatively large amount of N into the system, thus potentially alleviating N limitation. However, this new N input could push ecosystems into being limited by other resources, most importantly phosphorus (P) in mid- and high-latitude systems, leading to what has been termed an NP imbalance. While the ecological theory behind the processes described above has been discussed on many occasions, it is yet unclear what the actual spatial and temporal patterns of such an imbalance are, as well as the ecpological processes and drivers behind such observed patterns.</p><p>Here, we use leaf N and P data from a large European monitoring network, ICP forests, in conjunction with a land surface model, QUINCY (QUantifying Interactions between terrestrial Nutrient CYcles and the climate system), to explore the patterns and drivers behind nutrient limitation at European forest sites. The overall trend in observed leaf N and P content as well as N:P ratio show an increasing nutrient limitation from 1990 to 2015, as well as a shift towards P limitation. However, the observed spatial patterns of change in leaf nutrient content vary strongly with soil nutrient availability, N deposition and leaf habit. The effect of leaf habit suggests that leaf growth strategies  play an important role in dealing with nutrient availability and controlling observed ecosystem responses. </p><p>We use the QUINCY model to explore the drivers behind the observed leaf nutrient trends. We perform simulations with fixed levels of atmospheric CO<sub>2</sub> as well as in the absence of anthropogenic nitrogen deposition. We show that the decrease in leaf N and P content is attributable to increased atmospheric CO<sub>2,</sub> while the changes in N:P stoichiometry are reproducible with increased N deposition. Additionally, the model can only predict observed trends when representing physiologically-realistic responses of leaf stoichiometry to nutrient availability. The use of a process-based model allows us to attribute drivers to the observed changes in leaf nutrient content. This research helps the development of data-constrained, process-based models which can potentially be used to predict changes in ecosystem nutrient limitation, and implicitly growth and carbon storage, under future scenarios</p>


2006 ◽  
Vol 16 (1) ◽  
pp. 39-42 ◽  
Author(s):  
T.K. Hartz ◽  
P.R. Johnstone

Limited soil nitrogen (N) availability is a common problem in organic vegetable production that often necessitates in-season fertilization. The rate of net nitrogen mineralization (Nmin) from four organic fertilizers (seabird guano, hydrolyzed fish powder, feather meal, and blood meal) containing between 11.7% and 15.8% N was compared in a laboratory incubation. The fertilizers were mixed with soil from a field under organic management and incubated aerobically at constant moisture at 10, 15, 20, and 25 °C. Nmin was determined on samples extracted after 1, 2, 4, and 8 weeks. Rapid Nmin was observed from all fertilizers at all temperatures; within 2 weeks between 47% and 60% of organic N had been mineralized. Temperature had only modest effects, with 8-week Nmin averaging 56% and 66% across fertilizers at 10 and 25 °C, respectively. Across temperatures, 8-week Nmin averaged 60%, 61%, 62%, and 66% for feather meal, seabird guano, fish powder, and blood meal, respectively. Cost per unit of available N (mineralized N + initial inorganic N) varied widely among fertilizers, with feather meal the least and fish powder the most expensive.


Nitrogen ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 137-150
Author(s):  
Jacynthe Dessureault-Rompré ◽  
Alexis Gloutney ◽  
Jean Caron

Vegetable crop production, which is expanding worldwide, is managed extremely intensively and is therefore raising concerns about soil degradation. The objective of this study was to analyze the impact of using rye mulch as a conservation practice on nutrient availability for lettuce grown in histosols. The rye cover crop was established in the fall of 2018 at two cultivated peatland sites. The following summer, lettuce crops were planted at both sites on the rye mulch cover and on control plots. Lysimeters were used to extract the soil solution once a week during lettuce growth. Various soil properties were analyzed in the soil sampled at the end of the lettuce growing season. The rye yield was higher at site 1 than at site 2 and the lettuce growth was reduced at site 1 under the rye mulch treatment. The rye mulch reduced mineral N and dissolved organic N availability at both sites. The N dynamics in histosols might be fast enough to supply the lettuce needs; however, the implantation difficulties must first be overcome to confirm that hypothesis. At the end of the lettuce growth period, soil total and active C pools and soluble organic soil N in the rye mulch treatment sample were significantly higher at site 1 than at site 2. The presence of rye mulch improved the carbon pool over a single growing season. The use of rye mulch as a soil conservation practice for vegetable crop production appears promising for histosols; however, more work is needed to gain a better understanding on the long-term effects of decomposing rye mulch and roots on soil nutrient availability, soil health and C sequestration, and on the nitrogen uptake pathways and growth of cash crops. Future works which would include consecutive years of study at multiple sites are also needed to be able to confirm and generalize the observations found in the present work.


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 66 (1) ◽  
pp. 58-65
Author(s):  
Christopher A Walter ◽  
Mark B Burnham ◽  
Mary Beth Adams ◽  
Brenden E McNeil ◽  
Lindsay N Deel ◽  
...  

Abstract Storms are among the greatest natural disturbances in temperate forests, and increased nitrogen (N) availability is thought to increase storm damage. However, the extent to which N availability increases damage from snowfall is less clear. To test how N availability might affect the susceptibility of trees to snow damage in a temperate forest, we took advantage of an opportunistic storm and surveyed damage in fertilized and unfertilized stands, and across a native N availability gradient. In response to a severe, early season snow storm—a consequence of Superstorm Sandy—the percentages of both basal area and stems damaged were lower in a fertilized watershed than in an unfertilized watershed. Across the native N availability gradient, the percentage of basal area damaged by snow decreased with higher soil N. The effects of N availability on damage were also affected by tree species. Our results suggest that N availability decreases damage from snow storms, contrary to our hypotheses drawn from broader studies. Understanding the relation between storm damage and N availability is important, considering the global increase in N deposition, and since severe storms are likely to become more prevalent with climate change.


2009 ◽  
Vol 6 (10) ◽  
pp. 2135-2144 ◽  
Author(s):  
M. Lund ◽  
T. R. Christensen ◽  
M. Mastepanov ◽  
A. Lindroth ◽  
L. Ström

Abstract. Peatlands are important ecosystems in the context of biospheric feedback to climate change, due to the large storage of organic C in peatland soils. Nitrogen deposition and increased nutrient availability in soils following climate warming may cause changes in these ecosystems affecting greenhouse gas exchange. We have conducted an N and P fertilization experiment in two Swedish bogs subjected to high and low background N deposition, and measured the exchange of CO2, CH4 and N2O using the closed chamber technique. During the second year of fertilization, both gross primary production and ecosystem respiration were significantly increased by N addition in the northernmost site where background N deposition is low, while gross primary production was stimulated by P addition in the southern high N deposition site. In addition, a short-term response in respiration was seen following fertilization in both sites, probably associated with rapid growth of nutrient-limited soil microorganisms. No treatment effect was seen on the CH4 exchange, while N2O emission peaks were detected in N fertilized plots indicating the importance of taking N2O into consideration under increased N availability. In a longer term, increased nutrient availability will cause changes in plant composition, which will further act to regulate the peatland greenhouse gas exchange.


2018 ◽  
Vol 115 (3) ◽  
pp. 549-554 ◽  
Author(s):  
Marijn Bauters ◽  
Travis W. Drake ◽  
Hans Verbeeck ◽  
Samuel Bodé ◽  
Pedro Hervé-Fernández ◽  
...  

Atmospheric nitrogen (N) deposition is an important determinant of N availability for natural ecosystems worldwide. Increased anthropogenic N deposition shifts the stoichiometric equilibrium of ecosystems, with direct and indirect impacts on ecosystem functioning and biogeochemical cycles. Current simulation data suggest that remote tropical forests still receive low atmospheric N deposition due to a lack of proximate industry, low rates of fossil fuel combustion, and absence of intensive agriculture. We present field-based N deposition data for forests of the central Congo Basin, and use ultrahigh-resolution mass spectrometry to characterize the organic N fraction. Additionally, we use satellite data and modeling for atmospheric N source apportionment. Our results indicate that these forests receive 18.2 kg N hectare−1years−1as wet deposition, with dry deposition via canopy interception adding considerably to this flux. We also show that roughly half of the N deposition is organic, which is often ignored in N deposition measurements and simulations. The source of atmospheric N is predominantly derived from intensive seasonal burning of biomass on the continent. This high N deposition has important implications for the ecology of the Congo Basin and for global biogeochemical cycles more broadly.


2013 ◽  
Vol 10 (2) ◽  
pp. 1083-1095 ◽  
Author(s):  
J. F. J. Korhonen ◽  
M. Pihlatie ◽  
J. Pumpanen ◽  
H. Aaltonen ◽  
P. Hari ◽  
...  

Abstract. The productivity of boreal forests is considered to be limited by low nitrogen (N) availability. Increased atmospheric N deposition has altered the functioning and N cycling of these N-sensitive ecosystems by increasing the availability of reactive nitrogen. The most important components of N pools and fluxes were measured in a boreal Scots pine stand in Hyytiälä, Southern Finland. The measurements at the site allowed direct estimations of nutrient pools in the soil and biomass, inputs from the atmosphere and outputs as drainage flow and gaseous losses from two micro-catchments. N was accumulating in the system, mainly in woody biomass, at a rate of 7 kg N ha−1 yr−1. Nitrogen input as atmospheric deposition was 7.4 kg N ha−1 yr−1. Dry deposition and organic N in wet deposition contributed over half of the inputs in deposition. Total outputs were 0.4 kg N ha−1 yr−1, the most important outputs being N2O emission to the atmosphere and organic N flux in drainage flow. Nitrogen uptake and retranslocation were equally important sources of N for plant growth. Most of the assimilated N originated from decomposition of organic matter, and the fraction of N that could originate directly from deposition was about 30%. In conclusion, atmospheric N deposition fertilizes the site considerably, but there are no signs of N saturation. Further research is needed to estimate soil N2 fluxes (emission and fixation), which may amount up to several kg N ha−1 yr−1.


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