Effect of soil temperature and soil moisture on CO2 flux from eroded landscape positions on black soil in Northeast China

Abstract. Soil respiration (SR) is a major component of ecosystem's carbon cycle and represents the second largest CO2 flux of the terrestrial biosphere. Soil temperature is considered to be the primary control on SR whereas soil moisture as the secondary control factor. However, soil moisture can become the dominant control on SR in very wet or dry conditions. Determining the trigger that switches-on soil moisture as the primary control factor of SR will provide a deeper understanding on how SR changes under projected future increased droughts. Specific objectives of this study were (1) to investigate the seasonal variations and the relationship between SR and both soil temperature and moisture in a Mediterranean riparian forest along a groundwater level gradient; (2) to determine soil moisture thresholds at which SR is rather controlled by soil moisture than by temperature; (3) to compare SR responses under different tree species present in a Mediterranean riparian forest (Alnus, glutinosa, Populus nigra and Fraxinus excelsior). Results showed that the heterotrophic soil respiration rate, groundwater level and 30 cm integral soil moisture (SM30) decreased significantly from riverside to uphill and showed a pronounced seasonality. SR rates showed significant differences among tree species, with higher SR for P. nigra and lower SR for A. glutinosa. The lower threshold of soil moisture was 20 and 17% for heterotrophic and total SR respectively. Daily mean SR rate was positively correlated with soil temperature when soil moisture exceeded the threshold, with Q10 values ranging from 1.19 to 2.14; nevertheless, SR became decoupled from soil temperature when soil moisture dropped below these thresholds.

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Impacts of planting systems on soil moisture, soil temperature and corn yield in rainfed area of Northeast China

European Journal of Agronomy ◽

10.1016/j.eja.2013.05.008 ◽

2013 ◽

Vol 50 ◽

pp. 66-74 ◽

Cited By ~ 24

Author(s):

Zhenwei Song ◽

Jinrui Guo ◽

Zhenping Zhang ◽

Taiji Kou ◽

Aixing Deng ◽

...

Keyword(s):

Soil Moisture ◽

Soil Temperature ◽

Northeast China ◽

Corn Yield

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The Effects of Predicted Soil Moisture and Temperature Increase on CO2 Exchange within a High Arctic Ecosystem

Inquiry@Queen's Undergraduate Research Conference Proceedings ◽

10.24908/iqurcp.9990 ◽

2018 ◽

Author(s):

Sarah Jackson

Keyword(s):

Soil Moisture ◽

Soil Temperature ◽

Co2 Flux ◽

High Arctic ◽

Co2 Exchange ◽

The Arctic ◽

Co2 Production ◽

Arctic Ecosystems ◽

Arctic Regions ◽

Snow Fences

With 2014 being the warmest year on record and 10 of the warmest years occurring after 1997, it is essential to understand the effects of this warming on CO2 exchange. It was also discovered that much of this warming is focused in the Arctic regions, which are sensitive to changes in temperature (Cole & McCarthy, 2015). My research examines the effects of enhanced snowfall and soil temperature on the exchange of CO2 between the land and the atmosphere in a high arctic environment. The research is taking place at Cape Bounty Arctic Watershed Observatory (CBAWO) on Melville Island, Nunavut as part of the International Tundra Experiment (ITEX). The goal of ITEX is to better understand the effects of increased summer temperature and increased snowfall on arctic ecosystems. This is a full factorial experiment including treatments varying precipitation (and likely soil moisture), soil temperature, moisture and temperature together, and a control that is at ambient soil moisture and temperature. Snow fences are used to enhance precipitation, while open-topped transparent chambers are used to increase soil temperature. In a companion lab experiment, I look at the effects of different soil moisture levels and temperatures on soil CO2 production in a more controlled environment. Two temperatures, two moisture levels, and eight replicates of each will be established in sealed incubation chambers, and soils will be incubated for 33 days. Presently a significant relationship has been found between soil moisture and CO2 flux within the field experiment.

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Stability of Ecosystem CO2 Flux in Response to Changes in Precipitation in a Semiarid Grassland

Sustainability ◽

10.3390/su11092597 ◽

2019 ◽

Vol 11 (9) ◽

pp. 2597 ◽

Cited By ~ 1

Author(s):

Kaiqiang Bao ◽

Haifeng Tian ◽

Min Su ◽

Liping Qiu ◽

Xiaorong Wei ◽

...

Keyword(s):

Soil Moisture ◽

Soil Temperature ◽

Ecosystem Respiration ◽

Co2 Flux ◽

Co2 Exchange ◽

Semiarid Grassland ◽

Considerable Uncertainty ◽

C Cycling ◽

Precipitation Regimes ◽

Carbon Dioxide Co2

Carbon dioxide (CO2) flux provides feedback between C cycling and the climatic system. There is considerable uncertainty regarding the direction and magnitude of the responses of this process to precipitation changes, hindering accurate prediction of C cycling in a changing world. We examined the responses of ecosystem CO2 flux to ambient precipitation and experimentally decreased (−35%) and increased precipitation (+20%) in a semiarid grassland in China between July 2013 and September 2015. The measured CO2 flux components included the gross ecosystem productivity (GEP), net ecosystem CO2 exchange (NEE), ecosystem respiration (Re), and soil respiration (Rs). The results showed that the seasonal and diurnal patterns of most components of ecosystem CO2 flux were minimally affected by precipitation treatments, with less than 4% changes averaged across the three growing seasons. GEP and NEE had a quadratic relationship, while Re and Rs increased exponentially with soil temperature. GEP, RE, and Rs, however, decreased with soil moisture. Decreased precipitation reduced the dependence of CO2 flux on soil temperature but partly increased the dependence on soil moisture; in contrast, increased precipitation had the opposite influence. Our results suggested a relatively stable CO2 flux in this semiarid grassland across the tested precipitation regimes.

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Does soil moisture overrule temperature dependence of soil respiration in Mediterranean riparian forests?

Biogeosciences ◽

10.5194/bg-11-6173-2014 ◽

2014 ◽

Vol 11 (21) ◽

pp. 6173-6185 ◽

Cited By ~ 22

Author(s):

C. T. Chang ◽

S. Sabaté ◽

D. Sperlich ◽

S. Poblador ◽

F. Sabater ◽

...

Keyword(s):

Soil Moisture ◽

Soil Respiration ◽

Soil Temperature ◽

Groundwater Level ◽

Tree Species ◽

Riparian Forest ◽

Co2 Flux ◽

Control Factor ◽

Primary Control ◽

Heterotrophic Soil Respiration

Abstract. Soil respiration (SR) is a major component of ecosystems' carbon cycles and represents the second largest CO2 flux in the terrestrial biosphere. Soil temperature is considered to be the primary abiotic control on SR, whereas soil moisture is the secondary control factor. However, soil moisture can become the dominant control on SR in very wet or dry conditions. Determining the trigger that makes soil moisture as the primary control factor of SR will provide a deeper understanding on how SR changes under the projected future increase in droughts. Specific objectives of this study were (1) to investigate the seasonal variations and the relationship between SR and both soil temperature and moisture in a Mediterranean riparian forest along a groundwater level gradient; (2) to determine soil moisture thresholds at which SR is controlled by soil moisture rather than by temperature; (3) to compare SR responses under different tree species present in a Mediterranean riparian forest (Alnus glutinosa, Populus nigra and Fraxinus excelsior). Results showed that the heterotrophic soil respiration rate, groundwater level and 30 cm integral soil moisture (SM30) decreased significantly from the riverside moving uphill and showed a pronounced seasonality. SR rates showed significant differences between tree species, with higher SR for P. nigra and lower SR for A. glutinosa. The lower threshold of soil moisture was 20 and 17% for heterotrophic and total SR, respectively. Daily mean SR rate was positively correlated with soil temperature when soil moisture exceeded the threshold, with Q10 values ranging from 1.19 to 2.14; nevertheless, SR became decoupled from soil temperature when soil moisture dropped below these thresholds.

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Spatial Variability of Soil Moisture in Relation to Land Use Types and Topographic Features on Hillslopes in the Black Soil (Mollisols) Area of Northeast China

Sustainability ◽

10.3390/su12093552 ◽

2020 ◽

Vol 12 (9) ◽

pp. 3552 ◽

Cited By ~ 1

Author(s):

Xinxin Guo ◽

Qiang Fu ◽

Yanhong Hang ◽

He Lu ◽

Fengjie Gao ◽

...

Keyword(s):

Land Use ◽

Soil Moisture ◽

Spatial Variability ◽

Northeast China ◽

Soil Moisture Content ◽

Deep Layer ◽

Black Soil ◽

Topographic Features ◽

Land Use Types ◽

Topographic Attributes

Soil moisture, as a crucial factor in the eco-hydrological process, is of great importance for food production, land management in response to water and soil loss, geomorphic processes, and environmental protection. Understanding the spatial variability of soil moisture induced by different land use types and topographic features is conducive to advancing the adjustment of the land use structure and preventing soil erosion on the hillslopes in the black soil (Mollisols) area of Northeast China. Classical statistical methods and Canonical Correspondence Analysis were used to analyze the spatial heterogeneity of soil moisture at 0–20, 20–40, and 40–60 cm on slopes, to identify the main controlling factors and their relative contributions. The results suggested that: the average soil moisture content followed a decreasing order of grassland > shrubland > soybean land > maize land > adzuki bean (Vigna angularis) land > forestland; the profile soil moisture content (SMC) patterns could be divided into four types, related to the comprehensive influence of vegetation types, root system characteristics, and topographic attributes; the spatial variability of soil moisture was strongly influenced by slope gradient, followed by land use types and elevation and slope position, while slope aspect had the least impact; and finally, land use type had a greater impact on the deep layer than the surface layer, while on the contrary, the influence of the topographic attributes on the deep layer was smaller than on the surface layer. Land use types and topographical elements work together on the soil moisture variability and vertical patterns at differing depths. This study provides an insight into policy making of land resource management and can be used in the modeling of hydrological processes.

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CO2 flux emissions from Atlantic Rainforest soil: determining the most suitable sampling time

Ciência e Natura ◽

10.5902/2179460x40887 ◽

2020 ◽

Vol 42 ◽

pp. e20

Author(s):

Edney Leandro da Vitória ◽

Carla Da Penha Simon ◽

Ivoney Gontijo ◽

Ismael Lourenço de Jesus Freitas ◽

Paulo Roberto Rocha Junior

Keyword(s):

Soil Moisture ◽

Soil Temperature ◽

Co2 Emissions ◽

Co2 Emission ◽

Co2 Flux ◽

Tropical Soils ◽

Time Of Day ◽

Sampling Time ◽

Forest Fragment ◽

Close Relationship

Few studies have established protocols for measuring CO2 emissions in the soil. In order to determine the time of day which best represents the average daily CO2 emissions, the present study evaluated the variations in CO2 emissions throughout the day and the relationship between these emissions and the soil moisture and temperature, in an attempt to standardize data collection in tropical soils. The study was carried out in an Atlantic forest fragment of the coastal tablelands, Brazil. A close relationship between CO2 emission and soil temperature was observed, with CO2 emissions decreasing as daytime temperatures increased. The soil moisture had no direct relation with the CO2 emission, but was only related to the soil temperature. Two groups of CO2 emissions were observed, forming between the sampling time from 09:00 a.m. to 10:00 p.m., and from 11:00 p.m. to 08:00 a.m. Due to the small difference found between the mean group formed between 09:00 a.m. and 10:00 p.m., which was ~ 8% when compared to the general average, and also the fact that CO2 is easier to collect during this time, it is suggested that this period is the most suitable time to collect CO2 in the field.

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Moisture Distribution in Sloping Black Soil Farmland during the Freeze–Thaw Period in Northeastern China

Water ◽

10.3390/w11030536 ◽

2019 ◽

Vol 11 (3) ◽

pp. 536 ◽

Cited By ~ 3

Author(s):

Xianbo Zhao ◽

Shiguo Xu ◽

Tiejun Liu ◽

Pengpeng Qiu ◽

Guoshuai Qin

Keyword(s):

Soil Moisture ◽

Moisture Content ◽

Soil Temperature ◽

Gaussian Distribution ◽

Soil Moisture Content ◽

Black Soil ◽

Moisture Distribution ◽

Frozen Ground ◽

Freeze Thaw ◽

Thaw Period

This paper outlines dynamics of near-surface hydrothermal processes and analyzes the characteristics of moisture distribution during the freeze–thaw period in a typical black soil zone around Harbin, Northeastern China, a region with a moderate depth of seasonally frozen ground and one of the most important granaries in China. At Field Site 1, we analyzed the soil temperature and soil moisture content data from November 2011 to April 2012 from soil depths of 1, 5, 10, and 15 cm in sunny slope, and from depths of 1, 5, and 10 cm in shady slope black soil farmland. At Field Site 2, soil samples were collected from a168mlong sloping black soil field at locations 10, 50, 100, and 150 m from the bottom of the slope at different depths of 0–1 cm, 1–5 cm, and 5–10 cm at the same location. Analysis of the monitored Site 1 soil temperature and soil moisture content data showed that the soil moisture content and soil temperature fit line is consistent with a Gaussian distribution rather than a linear distribution during the freeze–thaw period. The soil moisture content and time with temperature fit line is in accordance with a Gaussian distribution during the freeze–thaw period. Site 2 soil samples were analyzed, and the soil moisture contents of the sloping black soil farmland were obtained during six different freeze–thaw periods. It was verified that the soil moisture content and time with temperature fit line is in accordance with a Gaussian distribution during the six different freeze–thaw periods. The maximum surface soil moisture content was reached during the early freeze–thaw period, which is consistent with the natural phenomenon of early spring peak soil moisture content under temperature rise and snow melt. The soil moisture contents gradually increased from the top to the bottom in sloping black soil farmland during the freeze–thaw period. Since the soil moisture content is related to soil temperature during the freeze–thaw cycle, we validated the correlation between soil temperature spatiotemporal China Meteorological Assimilation Driving Datasets for the Soil and Water Assessment Tool (SWAT) model–Soil Temperature (CMADS-ST) data and monitored data. The practicality of CMADS-ST in black soil slope farmland in the seasonal frozen ground zone of the study area is very good. This research has important significance for decision-making for protecting water and soil environments in black soil slope farmland.

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Effects of multiple environmental factors on CO<sub>2</sub> emission and CH<sub>4</sub> uptake from old-growth forest soils

Biogeosciences ◽

10.5194/bg-7-395-2010 ◽

2010 ◽

Vol 7 (1) ◽

pp. 395-407 ◽

Cited By ~ 43

Author(s):

H. J. Fang ◽

G. R. Yu ◽

S. L. Cheng ◽

T. H. Zhu ◽

Y. S. Wang ◽

...

Keyword(s):

Soil Moisture ◽

Soil Temperature ◽

Co2 Emission ◽

Co2 Flux ◽

Soil Co2 ◽

Old Growth ◽

Soil Co2 Flux ◽

Old Growth Forest ◽

Old Growth Forests ◽

Ch4 Uptake

Abstract. To assess contribution of multiple environmental factors to carbon exchanges between the atmosphere and forest soils, four old-growth forests referred to as boreal coniferous forest, temperate needle-broadleaved mixed forest, subtropical evergreen broadleaved forest and tropical monsoon rain forest were selected along eastern China. In each old-growth forest, soil CO2 and CH4 fluxes were measured from 2003 to 2005 applying the static opaque chamber and gas chromatography technique. Soil temperature and moisture at the 10 cm depth were simultaneously measured with the greenhouse gas measurements. Inorganic N (NH4+-N and NO3−-N) in the 0–10 cm was determined monthly. From north to south, annual mean CO2 emission ranged from 18.09 ± 0.22 to 35.40 ± 2.24 Mg CO2 ha−1 yr−1 and annual mean CH4 uptake ranged from 0.04 ± 0.11 to 5.15 ± 0.96 kg CH4 ha−1 yr−1 in the four old-growth forests. Soil CO2 flux in the old-growth forests was mainly driven by soil temperature, followed by soil moisture and NO3−-N. Temperature sensitivity (Q10) of soil CO2 flux was lower at lower latitudes with high temperature and more precipitation, probably because of less soil organic carbon (SOC). Soil NO3− accumulation caused by environmental change was often accompanied by an increase in soil CO2 emission. In addition, soil CH4 uptake decreased with an increase in soil moisture. The response of soil CH4 flux to temperature was dependent upon the optimal value of soil temperature in each forest. Soil NH4+-N consumption tended to promote soil CH4 uptake in the old-growth forests, whereas soil NO3−-N accumulation was not conducive to CH4 oxidation in anaerobic condition. These results indicate that soil mineral N dynamics largely affects the soil gas fluxes of CO2 and CH4 in the old-growth forests, along with climate conditions.

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