Effects of Soil Temperature and Moisture on Soil Respiration on the Tibetan Plateau

Abstract The Q10 value represents the soil respiration sensitivity to temperature often used for the parameterization of the soil decomposition process has been assumed to be a constant in conventional numerical models, whereas it exhibits significant spatial and temporal variation in the observations. This study develops a new parameterization method for determining Q10 by considering the soil respiration dependence on soil temperature and moisture obtained by multiple regression for each vegetation type. This study further investigates the impacts of the new parameterization on the global terrestrial carbon flux. Our results show that a nonuniform spatial distribution of Q10 tends to better represent the dependence of the soil respiration process on heterogeneous surface vegetation type compared with the control simulation using a uniform Q10. Moreover, it tends to improve the simulation of the relationship between soil respiration and soil temperature and moisture, particularly over cold and dry regions. The modification has an impact on the soil respiration and carbon decomposition process, which changes gross primary production (GPP) through controlling nutrient assimilation from soil to vegetation. It leads to a realistic spatial distribution of GPP, particularly over high latitudes where the original model has a significant underestimation bias. Improvement in the spatial distribution of GPP leads to a substantial reduction of global mean GPP bias compared with the in situ observation-based reference data. The results highlight that the enhanced sensitivity of soil respiration to the subsurface soil temperature and moisture introduced by the nonuniform spatial distribution of Q10 has contributed to improving the simulation of the terrestrial carbon fluxes and the global carbon cycle.

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Significance of soil temperature and moisture for soil respiration in a Chinese mountain area

Agricultural and Forest Meteorology ◽

10.1016/j.agrformet.2007.10.009 ◽

2008 ◽

Vol 148 (3) ◽

pp. 490-503 ◽

Cited By ~ 92

Author(s):

Hong-jian Li ◽

Jun-xia Yan ◽

Xiao-feng Yue ◽

Meng-ben Wang

Keyword(s):

Soil Respiration ◽

Soil Temperature ◽

Mountain Area ◽

Soil Temperature And Moisture

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Environmental Factors and Soil CO2Emissions in an Alpine Swamp Meadow Ecosystem on the Tibetan Plateau in Response to Experimental Warming

Journal of Chemistry ◽

10.1155/2016/2573185 ◽

2016 ◽

Vol 2016 ◽

pp. 1-7

Author(s):

Bin Wang ◽

Ben Niu ◽

Xiaojie Yang ◽

Song Gu

Keyword(s):

Tibetan Plateau ◽

Environmental Factors ◽

Soil Temperature ◽

Environmental Factor ◽

Seasonal Variations ◽

Environmental Control ◽

The Tibetan Plateau ◽

Control Mechanisms ◽

Experimental Warming ◽

Upward Trend

We examined the response of soil CO2emissions to warming and environmental control mechanisms in an alpine swamp meadow ecosystem on the Tibetan Plateau. Experimental warming treatments were performed in an alpine swamp meadow ecosystem using two open-top chambers (OTCs) 40 cm (OA) and 80 cm (OB) tall. The results indicate that temperatures were increased by 2.79°C in OA and 4.96°C in OB, that ecosystem CO2efflux showed remarkable seasonal variations in the control (CK) and the two warming treatments, and that all three systems yielded peak values in August of 123.6, 142.3, and 166.2 g C m−2 month−1. Annual CO2efflux also showed a gradual upward trend with increased warming: OB (684.1 g C m−2 year−1) > OA (580.7 g C m−2 year−1) > CK (473.3 g C m−2 year−1). Path analysis revealed that the 5 cm depth soil temperature was the most important environmental factor affecting soil CO2emissions in the three systems.

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Grazing intensity alters soil respiration in an alpine meadow on the Tibetan plateau

Soil Biology and Biochemistry ◽

10.1016/j.soilbio.2003.09.010 ◽

2004 ◽

Vol 36 (2) ◽

pp. 237-243 ◽

Cited By ~ 275

Author(s):

Guangmin Cao ◽

Yanhong Tang ◽

Wenhong Mo ◽

Yuesi Wang ◽

Yingnian Li ◽

...

Keyword(s):

Tibetan Plateau ◽

Soil Respiration ◽

Alpine Meadow ◽

Grazing Intensity ◽

The Tibetan Plateau

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Observed soil temperature trends associated with climate change in the Tibetan Plateau, 1960–2014

Theoretical and Applied Climatology ◽

10.1007/s00704-017-2337-9 ◽

2018 ◽

Vol 135 (1-2) ◽

pp. 169-181 ◽

Cited By ~ 13

Author(s):

Xuewei Fang ◽

Siqiong Luo ◽

Shihua Lyu

Keyword(s):

Climate Change ◽

Tibetan Plateau ◽

Soil Temperature ◽

The Tibetan Plateau ◽

Temperature Trends

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Diagnostic and model dependent uncertainty of simulated Tibetan permafrost area

The Cryosphere ◽

10.5194/tc-10-287-2016 ◽

2016 ◽

Vol 10 (1) ◽

pp. 287-306 ◽

Cited By ~ 16

Author(s):

W. Wang ◽

A. Rinke ◽

J. C. Moore ◽

X. Cui ◽

D. Ji ◽

...

Keyword(s):

Tibetan Plateau ◽

Soil Temperature ◽

Air Temperature ◽

Land Surface ◽

Ground Temperature ◽

Diagnostic Methods ◽

The Tibetan Plateau ◽

Temperature Profiles ◽

Land Surface Models ◽

Surface Models

Abstract. We perform a land-surface model intercomparison to investigate how the simulation of permafrost area on the Tibetan Plateau (TP) varies among six modern stand-alone land-surface models (CLM4.5, CoLM, ISBA, JULES, LPJ-GUESS, UVic). We also examine the variability in simulated permafrost area and distribution introduced by five different methods of diagnosing permafrost (from modeled monthly ground temperature, mean annual ground and air temperatures, air and surface frost indexes). There is good agreement (99 to 135  ×  104 km2) between the two diagnostic methods based on air temperature which are also consistent with the observation-based estimate of actual permafrost area (101  × 104 km2). However the uncertainty (1 to 128  ×  104 km2) using the three methods that require simulation of ground temperature is much greater. Moreover simulated permafrost distribution on the TP is generally only fair to poor for these three methods (diagnosis of permafrost from monthly, and mean annual ground temperature, and surface frost index), while permafrost distribution using air-temperature-based methods is generally good. Model evaluation at field sites highlights specific problems in process simulations likely related to soil texture specification, vegetation types and snow cover. Models are particularly poor at simulating permafrost distribution using the definition that soil temperature remains at or below 0 °C for 24 consecutive months, which requires reliable simulation of both mean annual ground temperatures and seasonal cycle, and hence is relatively demanding. Although models can produce better permafrost maps using mean annual ground temperature and surface frost index, analysis of simulated soil temperature profiles reveals substantial biases. The current generation of land-surface models need to reduce biases in simulated soil temperature profiles before reliable contemporary permafrost maps and predictions of changes in future permafrost distribution can be made for the Tibetan Plateau.

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Climate factors mediate soil respiration dynamics in Mediterranean agricultural environments: an empirical approach

Soil Research ◽

10.1071/sr14008 ◽

2014 ◽

Vol 52 (6) ◽

pp. 543 ◽

Cited By ~ 7

Author(s):

Sergio González-Ubierna ◽

María Teresa de la Cruz ◽

Miguel Ángel Casermeiro

Keyword(s):

Soil Respiration ◽

Soil Temperature ◽

Coefficient Of Determination ◽

Temperate Climate ◽

Climate Factors ◽

Simple Effect ◽

Soil Co2 Emissions ◽

Precipitation Pulses ◽

Mediterranean Conditions ◽

Soil Temperature And Moisture

Soil CO2 emissions, the result of soil respiration processes, may be essential in climate change modelling. The complex phenomenon of soil respiration is regulated by a range of mainly climate-related environmental factors. We tested the latest published empirical models in a field experiment in an agricultural soil under Mediterranean conditions. Soil respiration was monitored biweekly with a portable infrared gas analyser, and climate features were monitored for 1 year (2010–11). An additional rewetting assay (watering the soil) was done at the end of the experiment in summer when the soil water content was dry. We tested different approaches to represent the simple effect of climate factors on soil respiration and found Gaussian models to be the best. We also tested the most recent models designed to represent the synergic effects of climate factors, and our modification of the Martin and Bolstad model showed the best coefficient of determination. The results suggest that linear approaches and the use of a fixed Q10 value should be revised to represent climate and soil respiration relations, especially in high-variability environments where soil respiration variability is controlled by soil temperature and moisture interactions, while precipitation pulses induce CO2 emission peaks. Finally, our results showed that the influence of soil temperature and moisture on soil respiration is lower under Mediterranean conditions than in temperate climate types.

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