Reproduction strategy of Chloris virgata under simulated atmospheric nitrogen deposition

2015 ◽  
Vol 66 (5) ◽  
pp. 516 ◽  
Author(s):  
Wang Changfu ◽  
Wang Ying
Keyword(s):  
Seed Size ◽  
N Deposition ◽  
Control Treatment ◽  
Reproductive Pattern ◽  
Atmospheric Nitrogen ◽  
Seed Number ◽  
Atmospheric N Deposition ◽  
Seed Vigour ◽  
Rhodes Grass ◽  
Chloris Virgata

Atmospheric nitrogen (N) deposition is an important issue of global climate change and it will significantly affect plant growth and reproduction, resulting in damage to ecological systems. However, little attention has been given to the effects of this factor on plant reproductive strategies. We investigated how variation in atmospheric N deposition affects the reproductive strategy of Chloris virgata (feathertop Rhodes grass). We simulated atmospheric N deposition to evaluate the trade-off between seed size and seed number, as well as its effects on offspring vigour. We found significant negative correlations between seed size and seed number per spike in the control and 20.0 g N m–2 treatments, as well as between seed size and seed number per plant in the control treatment. Seed number and seed weight per spike behaved similarly and were significantly lower in the control and 20.0 g N m–2 treatments than in the other N supply treatments. Spike number and seed yield behaved similarly, and the greatest gains in these values occurred from 2.5 to 20.0 g N m–2. Seed size reached its maximum values at low and high N levels, whereas seed N concentrations increased with N level. Although the germination percentage remained stable under different N levels, the highest germination rate occurred in the control treatment. Our findings showed that simulated atmospheric N deposition affected the reproductive pattern and seed vigour of C. virgata.

scholarly journals Coupled influence of precipitation regimes and seedling emergence time on the reproductive strategy in Chloris virgata

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8476
Author(s):  
Ying Wang ◽  
Jiawei Chen ◽  
Yige Huang ◽  
Zhongsheng Mu ◽  
Changfu Wang
Keyword(s):  
Seed Size ◽  
Reproductive Strategy ◽  
Seedling Emergence ◽  
Tiller Number ◽  
Seed Number ◽  
Emergence Time ◽  
Precipitation Regime ◽  
Precipitation Regimes ◽  
Chloris Virgata ◽  
Low Precipitation

Precipitation regime and seedling emergence time both influence plant growth and reproduction. However, little attention has been given to the effects of these combined factors on the reproductive strategy of Chloris virgata, which is a vital species in Songnen grassland. Here, we simulated the changes in the precipitation regime and seedling emergence time to evaluate tiller traits and seed production. The results showed that tiller number behaved similarly among three precipitation regimes when sowed on 15 May (T1), while it increased significantly with precipitation regimes when sowed on 15 June (T2) and 15 July (T3). Tiller number decreased significantly with the seedling emergence time under the same water supply treatment. The proportional allocation of reproductive tiller number to total tiller number was significantly higher at T3 than at T1 and T2. Seed number remained similar under different precipitation regimes at T2 and T3, whereas it was significantly lower under low precipitation than under other water levels at T1. Seed number reached the maximum values at T2 under the same level of precipitation treatment. Seed size was significantly lower under low precipitation compared to other water supply treatments and the lowest values in seed size, about 0.5 mg, occurred at T2 under all the precipitation regimes. The lowest values in spike number were under low precipitation at all seedling emergence times. Seed yield exhibited similar trends with seed size under different precipitation regimes, while the greatest gains in these values were at T1 under all the precipitation regimes. Our findings showed that simulated precipitation regimes and seedling emergence time affected the reproductive strategy of C. virgata. Typical and high precipitation, as well as early seedling emergence, will improve the seed yield and seed quality in this species.

scholarly journals Subalpine grassland carbon balance during 7 years of increased atmospheric N deposition

2016 ◽  
Vol 13 (12) ◽  
pp. 3807-3817 ◽  
Author(s):  
Matthias Volk ◽  
Jan Enderle ◽  
Seraina Bassin
Keyword(s):  
Carbon Balance ◽  
N Deposition ◽  
Control Treatment ◽  
Atmospheric N Deposition ◽  
Total N ◽  
Plant Yield ◽  
Soil C ◽  
Grassland Ecosystems ◽  
Unimodal Response ◽  
Microbial N

Abstract. Air pollution agents interact when affecting biological sinks for atmospheric CO2, e.g., the soil organic carbon (SOC) content of grassland ecosystems. Factors favoring plant productivity, like atmospheric N deposition, are usually considered to favor SOC storage. In a 7-year experiment in subalpine grassland under N- and O3-deposition treatment, we examined C fluxes and pools. Total N deposition was 4, 9, 14, 29 and 54 kg N ha−1 yr−1 (N4, N9, etc.); annual mean phytotoxic O3 dose was 49, 65 and 89 mmol m−2 projected leaf area. We hypothesized that between years SOC of this mature ecosystem would not change in control treatments and that effects of air pollutants are similar for plant yield, net ecosystem productivity (NEP) and SOC content, leading to SOC content increasing with N deposition. Cumulative plant yield showed a significant N and N  ×  N effect (+38 % in N54) but no O3 effect. In the control treatment SOC increased significantly by 9 % in 7 years. Cumulative NEP did show a strong, hump-shaped response pattern to N deposition with a +62 % increase in N14 and only +39 % increase in N54 (N effect statistically not significant, N  ×  N interaction not testable). SOC had a similar but not significant response to N, with highest C gains at intermediate N deposition rates, suggesting a unimodal response with a marginal (P = 0.09) N  ×  N interaction. We assume the strong, pollutant-independent soil C sink developed as a consequence of the management change from grazing to cutting. The non-parallel response of SOC and NEP compared to plant yield under N deposition is likely the result of increased respiratory SOC losses, following mitigated microbial N-limitation or priming effects, and a shift in plant C allocation leading to smaller C input from roots.

scholarly journals The reproductive strategy in a Chloris virgata population in response to precipitation regimes

2018 ◽  
Vol 5 (8) ◽  
pp. 180607 ◽  
Author(s):  
Wang Ying ◽  
Wang Chunxia ◽  
Zhang Jukui ◽  
Wang Chunqing
Keyword(s):  
Seed Size ◽  
Reproductive Strategy ◽  
Seed Mass ◽  
Seed Traits ◽  
Seed Number ◽  
Water Addition ◽  
Precipitation Regimes ◽  
High Precipitation ◽  
Chloris Virgata ◽  
Low Precipitation

Resource availability influences plant growth and reproduction. Here, a controlled experiment was conducted in order to evaluate the adaptation response of Chloris virgata to different precipitation conditions, and to further predict the reproductive strategy in a population of C. virgata under different precipitation regimes. Three regimes (low, typical and high) of water addition were used to simulate current precipitation patterns. In total 20 individuals for each treatment were analysed to compare tiller number, spike traits, seed traits, the relationship between seed size and seed number, and so on. In addition, the effects of different precipitation regimes on offspring vigour of C. virgata were also studied. Results indicated that tiller number, spike number, seed yield and seed number were unchanged under different water addition regimes, while seed size was about 0.5 mg at typical and high precipitation levels and was higher than that in the low precipitation level. The higher seed mass per spike and spike mass both occurred at typical and high precipitation levels. Significant positive correlations between seed mass and non-seed mass in C. virgata in response to precipitation regimes were largely allometric (size dependent), as was a significant negative correlation between seed size and seed number at low precipitation. The highest germination rates and seedling weights both occurred at typical and high precipitation levels. These findings showed that different precipitation regimes affected reproductive strategy of C. virgata. Chloris virgata will not benefit from low precipitation, while typical and high precipitation will improve seed traits and offspring vigour of this species.

scholarly journals Effects of Climate and Atmospheric Nitrogen Deposition on Early to Mid-Term Stage Litter Decomposition Across Biomes

2021 ◽  
Vol 4 ◽  
Author(s):  
TaeOh Kwon ◽  
Hideaki Shibata ◽  
Sebastian Kepfer-Rojas ◽  
Inger K. Schmidt ◽  
Klaus S. Larsen ◽  
...  
Keyword(s):  
Mass Loss ◽  
Litter Decomposition ◽  
Temporal Dynamics ◽  
Terrestrial Ecosystems ◽  
Global Scale ◽  
N Deposition ◽  
Atmospheric Nitrogen ◽  
Atmospheric N Deposition ◽  
Rooibos Tea ◽  
Current Mass

Litter decomposition is a key process for carbon and nutrient cycling in terrestrial ecosystems and is mainly controlled by environmental conditions, substrate quantity and quality as well as microbial community abundance and composition. In particular, the effects of climate and atmospheric nitrogen (N) deposition on litter decomposition and its temporal dynamics are of significant importance, since their effects might change over the course of the decomposition process. Within the TeaComposition initiative, we incubated Green and Rooibos teas at 524 sites across nine biomes. We assessed how macroclimate and atmospheric inorganic N deposition under current and predicted scenarios (RCP 2.6, RCP 8.5) might affect litter mass loss measured after 3 and 12 months. Our study shows that the early to mid-term mass loss at the global scale was affected predominantly by litter quality (explaining 73% and 62% of the total variance after 3 and 12 months, respectively) followed by climate and N deposition. The effects of climate were not litter-specific and became increasingly significant as decomposition progressed, with MAP explaining 2% and MAT 4% of the variation after 12 months of incubation. The effect of N deposition was litter-specific, and significant only for 12-month decomposition of Rooibos tea at the global scale. However, in the temperate biome where atmospheric N deposition rates are relatively high, the 12-month mass loss of Green and Rooibos teas decreased significantly with increasing N deposition, explaining 9.5% and 1.1% of the variance, respectively. The expected changes in macroclimate and N deposition at the global scale by the end of this century are estimated to increase the 12-month mass loss of easily decomposable litter by 1.1–3.5% and of the more stable substrates by 3.8–10.6%, relative to current mass loss. In contrast, expected changes in atmospheric N deposition will decrease the mid-term mass loss of high-quality litter by 1.4–2.2% and that of low-quality litter by 0.9–1.5% in the temperate biome. Our results suggest that projected increases in N deposition may have the capacity to dampen the climate-driven increases in litter decomposition depending on the biome and decomposition stage of substrate.

scholarly journals Atmospheric N deposition causes carbon balance gains in a seven year field experiment in subalpine grassland

2016 ◽  
Author(s):  
Matthias Volk ◽  
Jan Enderle ◽  
Seraina Bassin
Keyword(s):  
N Deposition ◽  
Control Treatment ◽  
Similar Response ◽  
Atmospheric N Deposition ◽  
Total N ◽  
Plant Yield ◽  
Soil C ◽  
Grassland Ecosystems ◽  
Unimodal Response ◽  
Microbial N

Abstract. Air pollution agents interact when affecting biological sinks for atmospheric CO2, e.g. the soil organic carbon (SOC) content of grassland ecosystems. Factors favoring plant productivity, like atmospheric N deposition, are usually considered to favor SOC storage. In a seven year experiment in subalpine grassland under N- and O3-deposition treatment, we examined C-fluxes and -pools. Total N deposition was 4, 9, 14, 29 and 54 kg N ha−1 yr−1 (N4, N9, etc.), annual mean phytotoxic O3 dose was 49, 65 and 89 mmol m−2 projected leaf area. We hypothesized that SOC of this mature ecosystem would not change in control treatments, but that effects of air pollutants on plant yield, net ecosystem productivity (NEP) and SOC content would develop in parallel, leading to SOC content to increase with N deposition. In the control treatment SOC increased significantly by 9 % in seven years. Cumulative plant yield showed a highly significant N effect (+38 % in N54), but no O3-effect. Cumulative NEP did show a strong, yet statistically insignificant, hump shaped response pattern to N deposition with a +62 % increase in N14, and only +39 % increase in N54. SOC had a similar response to N, with highest gains at intermediate N deposition rates (9 and 14 kg N ha−1 yr−1), suggesting an unimodal response, too. We assume the strong, pollutant-independent soil C sink developed as a consequence of the management change from grazing to cutting. The non-parallel response of SOC and NEP compared to plant yield under N deposition is likely the result of increased respiratory SOC losses, following mitigated microbial N-limitation or priming effects, and a shift in plant C allocation leading to smaller C input from roots.

ATMOSPHERIC N DEPOSITION TO THE COASTAL AREA OF THE BLACK SEA: SOURCES, INTRA-ANNUAL VARIATIONS AND IMPORTANCE FOR BIOGEOCHEMISTRY AND PRODUCTIVITY OF THE SURFACE LAYER

2017 ◽  
Author(s):  
Alla Varenik ◽  
Alla Varenik ◽  
Sergey Konovalov ◽  
Sergey Konovalov
Keyword(s):  
Primary Production ◽  
Black Sea ◽  
Marine Ecosystem ◽  
C:N Ratio ◽  
N Deposition ◽  
Local Source ◽  
The Black Sea ◽  
Coastal Zones ◽  
Atmospheric N Deposition ◽  
Urban Location

Atmospheric precipitations can be an important source of nutrients to open and coastal zones of marine ecosystem. Jickells [1] has published that atmospheric depositions can sup-port 5-25% of nitrogen required to primary production. Bulk atmospheric precipitations have been collected in a rural location at the Black Sea Crimean coast – Katsiveli settlement, and an urban location – Sevastopol city. Samples have been analyzed for inorganic fixed nitrogen (IFN) – nitrate, nitrite, and ammonium. Deposi-tions have been calculated at various space and time scales. The monthly volume weighted mean concentration of IFN increases from summer to winter in both locations. A significant local source of IFN has been revealed for the urban location and this source and its spatial influence have been quantified. IFN deposition with atmospheric precipitations is up to 5% of its background content in the upper 10 m layer of water at the north-western shelf of the Black Sea. Considering Redfield C:N ratio (106:16) and the rate of primary production (PP) in coastal areas of the Black Sea of about 100-130 g C m-2 year-1 we have assessed that average atmospheric IFN depositions may intensify primary production by 4.5% for rural locations, but this value is increased many-fold in urban locations due to local IFN sources.

ATMOSPHERIC N DEPOSITION TO THE COASTAL AREA OF THE BLACK SEA: SOURCES, INTRA-ANNUAL VARIATIONS AND IMPORTANCE FOR BIOGEOCHEMISTRY AND PRODUCTIVITY OF THE SURFACE LAYER

2017 ◽  
Author(s):  
Alla Varenik ◽  
Alla Varenik ◽  
Sergey Konovalov ◽  
Sergey Konovalov
Keyword(s):  
Primary Production ◽  
Black Sea ◽  
Marine Ecosystem ◽  
C:N Ratio ◽  
N Deposition ◽  
Local Source ◽  
The Black Sea ◽  
Coastal Zones ◽  
Atmospheric N Deposition ◽  
Urban Location

Atmospheric precipitations can be an important source of nutrients to open and coastal zones of marine ecosystem. Jickells [1] has published that atmospheric depositions can sup-port 5-25% of nitrogen required to primary production. Bulk atmospheric precipitations have been collected in a rural location at the Black Sea Crimean coast – Katsiveli settlement, and an urban location – Sevastopol city. Samples have been analyzed for inorganic fixed nitrogen (IFN) – nitrate, nitrite, and ammonium. Deposi-tions have been calculated at various space and time scales. The monthly volume weighted mean concentration of IFN increases from summer to winter in both locations. A significant local source of IFN has been revealed for the urban location and this source and its spatial influence have been quantified. IFN deposition with atmospheric precipitations is up to 5% of its background content in the upper 10 m layer of water at the north-western shelf of the Black Sea. Considering Redfield C:N ratio (106:16) and the rate of primary production (PP) in coastal areas of the Black Sea of about 100-130 g C m-2 year-1 we have assessed that average atmospheric IFN depositions may intensify primary production by 4.5% for rural locations, but this value is increased many-fold in urban locations due to local IFN sources.

Atmospheric nitrogen deposition in world biodiversity hotspots: the need for a greater global perspective in assessing N deposition impacts

2006 ◽  
Vol 12 (3) ◽  
pp. 470-476 ◽  
Author(s):  
GARETH K. PHOENIX ◽  
W. KEVIN HICKS ◽  
STEVE CINDERBY ◽  
JOHAN C. I. KUYLENSTIERNA ◽  
WILLIAM D. STOCK ◽  
...  
Keyword(s):  
Nitrogen Deposition ◽  
N Deposition ◽  
Global Perspective ◽  
Atmospheric Nitrogen Deposition ◽  
Biodiversity Hotspots ◽  
Atmospheric Nitrogen
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