scholarly journals Interannual variation in ecosystem respiration in an Inner Mongolian meadow steppe in response to livestock grazing

2021 ◽  
Vol 131 ◽  
pp. 108121
Author(s):  
Ruirui Yan ◽  
Yu Zhang ◽  
Miao Wang ◽  
Ruiqiang Li ◽  
Dongyan Jin ◽  
...  
Keyword(s):  
Interannual Variation ◽  
Ecosystem Respiration ◽  
Livestock Grazing ◽  
Meadow Steppe

scholarly journals Effects of Livestock Grazing on Interannual Variation of Soil Methane Uptake in an Inner Mongolian Meadow Steppe

2021 ◽  
Author(s):  
Ruirui Yan ◽  
Yu Zhang ◽  
Jiquan Chen ◽  
Linghao Li ◽  
Changliang Shao ◽  
...  
Keyword(s):  
Soil Nitrogen ◽  
Interannual Variation ◽  
Grazing Intensity ◽  
Belowground Biomass ◽  
Multivariate Regression Analysis ◽  
Livestock Grazing ◽  
Stocking Rate ◽  
Meadow Steppe ◽  
Factors Affecting ◽  
Steppe Ecosystem

Abstract Background and aims. This study aimed at identifying the effects of livestock grazing on interannual variation in soil CH4 uptake and underlying mechanisms in a meadow steppe ecosystem. Methods. A multi-year grazing experiment subject to six stocking rates was conducted to quantify CH4 fluxes as well as the changes in driving factors: vegetation traits, soil physicochemical properties and climatic parameters. The closed static chamber technique and a gas chromatograph were used to measure methane fluxes. Multivariate regression analysis was performed to explore empirical relationships. Results. With increasing stocking rate, the multi-year mean CH4 uptake rate decreased in a sigmoid curve-shaped manner, with the threshold point appearing in the light grazing treatment. The interannual changes in soil CH4 uptake were highly dependent on stocking rate, with increasing, leveling and decreasing trends detected with increasing grazing intensity. Major factors affecting CH4 fluxes included vegetation traits, soil moisture, and soil nitrogen content, with the soil NH4+-N content assuming the most important role. However, predominant factors regulating interannual changes in CH4 uptake were rainfall, belowground biomass, and soil nitrogen regime. Conclusions. The steppe ecosystem acted as a CH4 sink, irrespective of stocking rate and year. However, light grazing can be the threshold grazing intensity in terms of both the CH4 uptake potential and primary production in this steppe ecosystem. Our findings have important implications for further understanding magnitudes and regulations of CH4 uptake in grassland soils worldwide.

scholarly journals Temporal variations in atmospheric CO<sub>2</sub> on Rishiri Island in 2006–2013: responses of the interannual variation in amplitude to climate and the terrestrial sink in East Asia

2014 ◽  
Vol 5 (1) ◽  
pp. 809-848
Author(s):  
C. Zhu ◽  
H. Yoshikawa-Inoue
Keyword(s):  
East Asia ◽  
Interannual Variation ◽  
Climatic Factors ◽  
Ecosystem Respiration ◽  
Anthropogenic Activities ◽  
Time Lag ◽  
Co2 Concentration ◽  
Temporal Variations ◽  
Atmospheric Co2 ◽  
Growing Season Length

Abstract. Surface observation of the atmospheric CO2 mixing ratio implies the combined influences of both natural fluctuations and anthropogenic activities on the carbon cycle. Atmospheric CO2 has been measured on Rishiri Island in the outflow region of Eurasia since May 2006. We report the first 7 year temporal atmospheric CO2 variations from diurnal to interannual scales. In the diurnal scale, an obvious cycle appeared as a minimum in the afternoon and maximum at midnight in the summer months. Seasonally, the maximum CO2 concentration appeared around the beginning of April, while the minimum appeared around the middle of August. A mean growing season length of ~126 days was estimated. In the period from 2007 to 2012, the peak-to-peak amplitude increased until 2009 and decreased thereafter, with a mean value of 19.7 ppm. In the long term, atmospheric CO2 is increasing by a mean growth rate of 2.1 ppm year−1. Investigations on the driving climatic factors on the interannual variation in amplitude indicated that temperature in East Asia (40–60° N, 90–150° E) affected the CO2 amplitude by affecting the seasonal maximum, with a time lag of 1–2 years. On the contrary, precipitation did not likely affect CO2 amplitudes. The amplitude also responded to a natural carbon source/sink variation in East Asia. We suggest that temperature in the first year would affect carbon sinks in the second year in the fetch regions, which further affect CO2 amplitude mainly through ecosystem respiration. Circulation changes also likely contributed to the decreasing amplitude since 2009, as indicated by the simultaneous decrease in the 222Rn concentration in spring and summer.

scholarly journals Effects of livestock grazing on soil nitrogen mineralization on Hulunber meadow steppe, China

2016 ◽  
Vol 62 (No. 5) ◽  
pp. 202-209 ◽  
Author(s):  
R. Yan ◽  
G. Yang ◽  
B. Chen ◽  
X. Wang ◽  
Y. Yan ◽  
...  
Keyword(s):  
Nitrogen Mineralization ◽  
Soil Nitrogen ◽  
Livestock Grazing ◽  
Meadow Steppe ◽  
Soil Nitrogen Mineralization

scholarly journals Carbon budgets for an irrigated intensively-grazed dairy pasture and an unirrigated winter-grazed pasture

2016 ◽  
Author(s):  
John E. Hunt ◽  
Johannes Laubach ◽  
Matti Barthel ◽  
Anitra Fraser ◽  
Rebecca L. Phillips
Keyword(s):  
New Zealand ◽  
Eddy Covariance ◽  
Animal Feed ◽  
Ecosystem Respiration ◽  
Gross Primary Production ◽  
Grazing Intensity ◽  
Livestock Grazing ◽  
Eddy Covariance Method ◽  
Grazed Pasture ◽  
Intensively Managed

Abstract. Intensification of pastoral agriculture is occurring rapidly across New Zealand, including increasing use of irrigation and fertiliser application in some regions. While this enables greater gross primary production (GPP) and livestock grazing intensity, the consequences for the net ecosystem carbon budget (NECB) of the pastures are poorly known. Here, we determined the NECB over one year for an irrigated, fertilised, and rotationally-grazed dairy pasture and a neighbouring unirrigated, unfertilised, winter-grazed pasture. Primary terms in the NECB calculation were: net ecosystem production (NEP), biomass-carbon removed by grazing cows, and carbon (C) input from their excreta. Annual NEP was measured using the eddy-covariance method. Carbon removal was estimated with plate-meter measurements calibrated against biomass collections, pre- and post-grazing. Excreta deposition was calculated from animal feed intake. The intensively-managed pasture gained C (NECB = 103 ±42 g C m−2 yr−1) but would have been subject to a non-significant C loss if cattle excreta had not been returned to the pasture. The unirrigated pasture was C-neutral (NECB = −13 ±23 g C m−2 yr−1). While annual GPP of the former was almost twice that of the latter (2679 vs. 1372 g C m−2 yr−1), ecosystem respiration differed by only 68 % between the two pastures (2271 vs. 1352 g C m−2 yr−1). The irrigated pasture used the total annual water input 37 % more efficiently than the unirrigated pasture to produce biomass. The NECB results agree qualitatively with those from many other eddy-covariance studies of grazed grasslands, but they seem to be at odds with long-term carbon-stock studies of other New Zealand pastures.

scholarly journals Carbon budgets for an irrigated intensively grazed dairy pasture and an unirrigated winter-grazed pasture

2016 ◽  
Vol 13 (10) ◽  
pp. 2927-2944 ◽  
Author(s):  
John E. Hunt ◽  
Johannes Laubach ◽  
Matti Barthel ◽  
Anitra Fraser ◽  
Rebecca L. Phillips
Keyword(s):  
New Zealand ◽  
Eddy Covariance ◽  
Animal Feed ◽  
Ecosystem Respiration ◽  
Gross Primary Production ◽  
Grazing Intensity ◽  
Livestock Grazing ◽  
Eddy Covariance Method ◽  
Grazed Pasture ◽  
Intensively Managed

Abstract. Intensification of pastoral agriculture is occurring rapidly across New Zealand, including increasing use of irrigation and fertiliser application in some regions. While this enables greater gross primary production (GPP) and livestock grazing intensity, the consequences for the net ecosystem carbon budget (NECB) of the pastures are poorly known. Here, we determined the NECB over one year for an irrigated, fertilised and rotationally grazed dairy pasture and a neighbouring unirrigated, unfertilised, winter-grazed pasture. Primary terms in the NECB calculation were: net ecosystem production (NEP), biomass carbon removed by grazing cows and carbon (C) input from their excreta. Annual NEP was measured using the eddy-covariance method. Carbon removal was estimated with plate-meter measurements calibrated against biomass collections, pre- and post-grazing. Excreta deposition was calculated from animal feed intake. The intensively managed pasture gained C (NECB  =  103 ± 42 g C m−2 yr−1) but would have been subject to a non-significant C loss if cattle excreta had not been returned to the pasture. The unirrigated pasture was C-neutral (NECB  =  −13 ± 23 g C m−2 yr−1). While annual GPP of the former was almost twice that of the latter (2679 vs. 1372 g C m−2 yr−1), ecosystem respiration differed by only 68 % between the two pastures (2271 vs. 1352 g C m−2 yr−1). The ratio of GPP to the total annual water input of the irrigated pasture was 37 % greater than that of the unirrigated pasture, i.e. the former used the water input more efficiently than the latter to produce biomass. The NECB results agree qualitatively with those from many other eddy-covariance studies of grazed grasslands, but they seem to be at odds with long-term carbon-stock studies of other New Zealand pastures.

scholarly journals Biophysical effects on the interannual variation in carbon dioxide exchange of an alpine meadow on the Tibetan Plateau

2017 ◽  
Vol 17 (8) ◽  
pp. 5119-5129 ◽  
Author(s):  
Lei Wang ◽  
Huizhi Liu ◽  
Jihua Sun ◽  
Yaping Shao
Keyword(s):  
Carbon Dioxide ◽  
Tibetan Plateau ◽  
Air Temperature ◽  
Interannual Variation ◽  
Alpine Meadow ◽  
Ecosystem Respiration ◽  
Gross Primary Production ◽  
Seasonal Pattern ◽  
Carbon Dioxide Exchange ◽  
The Tibetan Plateau

Abstract. Eddy covariance measurements from 2012 to 2015 were used to investigate the interannual variation in carbon dioxide exchange and its control over an alpine meadow on the south-east margin of the Tibetan Plateau. The annual net ecosystem exchange (NEE) in the 4 years from 2012 to 2015 was −114.2, −158.5, −159.9 and −212.6 g C m−2 yr−1, and generally decreased with the mean annual air temperature (MAT). An exception occurred in 2014, which had the highest MAT. This was attributed to higher ecosystem respiration (RE) and similar gross primary production (GPP) in 2014 because the GPP increased with the MAT, but became saturated due to the limit in photosynthetic capacity. In the spring (March to May) of 2012, low air temperature (Ta) and drought events delayed grass germination and reduced GPP. In the late wet season (September to October) of 2012 and 2013, the low Ta in September and its negative effects on vegetation growth caused earlier grass senescence and significantly lower GPP. This indicates that the seasonal pattern of Ta has a substantial effect on the annual total GPP, which is consistent with results obtained using the homogeneity-of-slopes (HOS) model. The model results showed that the climatic seasonal variation explained 48.6 % of the GPP variability, while the percentages explained by climatic interannual variation and the ecosystem functional change were 9.7 and 10.6 %, respectively.

scholarly journals Biophysical effects on the interannual variation in carbon dioxide exchange of an alpine meadow on the Tibetan Plateau

2016 ◽  
Author(s):  
Lei Wang ◽  
Huizhi Liu ◽  
Jihua Sun ◽  
Yaping Shao
Keyword(s):  
Carbon Dioxide ◽  
Tibetan Plateau ◽  
Air Temperature ◽  
Interannual Variation ◽  
Alpine Meadow ◽  
Ecosystem Respiration ◽  
Gross Primary Production ◽  
Seasonal Pattern ◽  
Carbon Dioxide Exchange ◽  
The Tibetan Plateau

Abstract. Eddy covariance measurements from 2012 to 2015 were used to investigate the interannual variation in carbon dioxide exchange and its control over an alpine meadow on the southeast margin of the Tibetan Plateau. The annual net ecosystem exchange (NEE) from 2012 to 2015 was −114.2, −158.5, −159.9 and −212.6 g C m−2 yr−1 and generally decreased with the mean annual air temperature (MAT). An exception occurred in 2014, which had the highest MAT. This was attributed to higher ecosystem respiration (RE) and similar gross primary production (GPP) in 2014 because the GPP increased with MAT but became saturated due to the photosynthesis capacity limit. In the spring (March to May) of 2012, lower air temperature (Ta) and drought events delayed grass germination and reduced GPP. In the late wet season (September to October) of 2012 and 2013, the lower Ta in September and its negative effects on vegetation growth caused earlier grass senescence and significantly lower GPP. This indicates that the seasonal pattern of Ta greatly affected the annual total GPP, which is consistent with the result of the homogeneity-of-slopes model. The model shows that the climatic seasonal variation explained 48.6 % of the GPP variability, and the percentage of climatic interannual variation and the ecosystem functional change were 9.7 % and 10.6 %, respectively.

scholarly journals Remotely monitoring ecosystem respiration from various grasslands along a large-scale east-west transect across Northern China

2020 ◽  
Author(s):  
Xuguang Tang ◽  
Yanlian Zhou ◽  
Hengpeng Li ◽  
Li Yao ◽  
Zhi Ding ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Alpine Meadow ◽  
Ecosystem Respiration ◽  
Northern China ◽  
Climate Projections ◽  
Desert Steppe ◽  
Meadow Steppe ◽  
Typical Steppe ◽  
Environmental Controls ◽  
Grassland Ecosystems

Abstract Background: Grassland ecosystems play an important role in the terrestrial carbon cycles through carbon emission by ecosystem respiration (Re) and carbon uptake by plant photosynthesis (GPP). Surprisingly, given Re occupies a large component of annual carbon balance, rather less attention has been paid to developing the estimates of Re compared to GPP.Results: Based on 11 flux sites over the diverse grassland ecosystems in northern China, this study examined the amounts of carbon released by Re as well as the dominant environmental controls across temperate meadow steppe, typical steppe, desert steppe and alpine meadow, respectively. Multi-year mean Re revealed relatively less CO2 emitted by the desert steppe in comparison with other grassland ecosystems. Meanwhile, C emissions of all grasslands were mainly controlled by the growing period. Correlation analysis revealed that apart from air and soil temperature, soil water content exerted a strong effect on the variability in Re, which implied the great potential to derive Re using relevant remote sensing data. Then, these field-measured Re data were up-scaled to large areas using time-series MODIS information and remote sensing-based piecewise regression models. These semi-empirical models appeared to work well with a small margin of error (R2 and RMSE ranged from 0.45 to 0.88 and from 0.21 to 0.69 g C m-2 d-1, respectively). Conclusions: Generally, the piecewise models from the growth period and dormant season performed better than model developed directly from the entire year. Moreover, the biases between annual mean Re observations and the remotely-derived products were usually within 20%. Finally, the regional Re emissions across northern China's grasslands was approximately 100.66 Tg C in 2010, about 1/3 of carbon fixed from the MODIS GPP product. Specially, the desert steppe exhibited the highest ratio, followed by the temperate meadow steppe, typical steppe and alpine meadow. Therefore, this work provides a novel framework to accurately predict the spatio-temporal patterns of Re over large areas, which can greatly reduce the uncertainties in global carbon estimates and climate projections.

Variation of Livestock Grazing Intensity Modified the Magnitude of Carbon Sequestration and Flow within the Plant-Soil System of a Meadow Steppe Ecosystem

2021 ◽  
Author(s):  
Dongyan Jin ◽  
Ruirui Yan ◽  
Linghao Li ◽  
Jiaguo Qi ◽  
Jiquan Chen ◽  
...  
Keyword(s):  
Grazing Intensity ◽  
Substantial Effect ◽  
Livestock Grazing ◽  
Meadow Steppe ◽  
Soil System ◽  
Plant Soil ◽  
C Pools ◽  
Steppe Ecosystem ◽  
Isotope Ratio Mass Spectrometer ◽  
Grazing Intensities

Abstract Aims: Livestock grazing, one of the principal utilization patterns, usually exerts a substantial effect on the carbon allocations between the above- and belowground components of a grassland ecosystem. The major aims of this study were to evaluate the proportions of 13C allocation to various C pools of the plant-soil system of a meadow steppe ecosystem in response to livestock grazing intensity.Methods: In situ stable 13C isotope pulse labeling was conducted in the plots of a long-term grazing experiment with 4 levels of grazing intensities. Plant and soil materials were sampled at on eight occasions (0, 3, 10, 18, 31, 56 and 100 days after labeling) to analyze the decline in 13C over time, and their composition signature of 13C were analyzed by the isotope ratio mass spectrometer technique.Results: We found a significantly larger decline in assimilated 13C for the heavily grazed swards compared to other grazing intensities, with the relocation rate of 13C from shoots to belowground C pool being the highest. In contrast, light grazing significantly allocated 13C assimilates in the belowground pool, especially in the live root and topsoil C-pools.Conclusions: The effects of livestock grazing on the carbon transfers and stocks within the plant-soil system of the meadow steppe were highly intensity dependent, and different carbon pools differed in response to gradient changes in grazing intensity.

Sign in / Sign up

Export Citation Format

Share Document