scholarly journals Mullahingamise sesoonne dünaamika kuusikute aegreas / Seasonal dynamics of soil respiration in a chronosequence of the Norway spruce stands

2011 ◽  
Vol 54 (1) ◽  
pp. 5-17 ◽  
Author(s):  
Mai Kukumägi ◽  
Veiko Uri ◽  
Olevi Kull

Abstract. Soil respiration resulting from microbial and root respiration is a major component of the forest carbon cycle. The response of soil respiration to varying environmental factors (soil temperature and soil moisture) was studied in a Norway spruce chronosequence composed of four age classes (4, 27, 36, and 84 year old) on Gleyic Podzol. Soil respiration was measured monthly with closed dynamic chamber system, soil temperature and soil moisture were measured simultaneously. Mean soil respiration rate averaged over three years was 3.3 μmol CO2 m-2s-1, ranging from 0.6 to 5.4 μmol CO2 m-2s-1, with the maximum occurring in August and the minimum in December. Stand age had a significant effect on soil respiration: the highest respiration rate was found in 27-year-old stand. Over three years an exponential relationship between soil respiration and soil temperature accounted for 68-81% of the seasonal variation, Q10 (the factor by which the respiration rate differs for a temperature interval of 10 °C) for the individual stands ranged between 4.4 and 5.4. The influence of soil moisture content on soil respiration was weak and revealed in dry conditions only. The results of this study can be used to help understand and predict the effect of harvest on soil respiration and how the respiration might respond to changing climate conditions.

2018 ◽  
Vol 40 (2) ◽  
pp. 153 ◽  
Author(s):  
Xuexia Wang ◽  
Yali Chen ◽  
Yulong Yan ◽  
Zhiqiang Wan ◽  
Ran Chao ◽  
...  

The response of soil respiration to simulated climatic warming and increased precipitation was evaluated on the arid–semi-arid Stipa steppe of Inner Mongolia. Soil respiration rate had a single peak during the growing season, reaching a maximum in July under all treatments. Soil temperature, soil moisture and their interaction influenced the soil respiration rate. Relative to the control, warming alone reduced the soil respiration rate by 15.6 ± 7.0%, whereas increased precipitation alone increased the soil respiration rate by 52.6 ± 42.1%. The combination of warming and increased precipitation increased the soil respiration rate by 22.4 ± 11.2%. When temperature was increased, soil respiration rate was more sensitive to soil moisture than to soil temperature, although the reverse applied when precipitation was increased. Under the experimental precipitation (20% above natural rainfall) applied in the experiment, soil moisture was the primary factor limiting soil respiration, but soil temperature may become limiting under higher soil moisture levels.


2021 ◽  
Vol 9 ◽  
Author(s):  
Huitao Shen ◽  
Lingkai Zhang ◽  
Henan Meng ◽  
Zhenhua Zheng ◽  
Yanxia Zhao ◽  
...  

Assessing the response of soil heterotrophic and autotrophic respiration to climate change is critical for forecasting terrestrial carbon cycle behavior in the future. In the present study, we conducted a drought experiment in Vitexnegundo var. heterophylla shrub ecosystem of the Middle Taihang Mountain. Three precipitation manipulation treatments (natural conditions/ambient precipitation (CK), reduced precipitation by 30% (PE30), and reduced precipitation by 60% (PE60)) were used to study the impact of different levels of precipitation exclusion on total soil respiration (Rs) and its heterotrophic (Rh) and autotrophic (Ra) components. Our results showed that the rates of Rs and its components were significantly decreased under the precipitation exclusion treatments. The proportion of Rh in Rs reduced from 72.6% for CK to 71.9% under PE60. The annual cumulative C fluxes of Rs decreased by 47.8 g C m−2 in PE30 and 106.0 g C m−2 in PE60, respectively. An exponential relationship was observed between the rate of each soil respiration component and soil temperature in all treatments ( p < 0.01). Moreover, each soil respiration component rate was better represented by a quadratic model which included soil moisture ( p < 0.01). However, including both of soil temperature and soil moisture did not explain more variation in soil respiration components compared than the regression model with soil moisture only. In addition, excluding precipitation increased the temperature sensitivity (Q10 values) of Rs and its Ra and Rh components compared to the control. Collectively, our findings suggest that increased drought will inhibit the release of carbon from the soil to the atmosphere, and will likely decrease the contribution of Rh to Rs in this semiarid shrubland ecosystem.


2014 ◽  
Vol 618 ◽  
pp. 380-387
Author(s):  
Jiang Ming Ma ◽  
Meng Wu ◽  
Ting Ting Zhan ◽  
Feng Tian ◽  
Shi Chu Liang

This experiment was conducted on the 4 years old Eucalyptus plantation in Beihai of Guangxi, southern China. From January to December 2013, in the spring, summer, autumn and winter, seasonal variation and diurnal variation of the soil respiration and its environmental factors had been observed, respectively. The results showed that: (1) Soil respirations has obvious seasonal characteristics, the soil respiration rate in each seasons showed that: summer> spring > autumn > winter. The heterotrophic respiration rate was higher than the autotrophic respiration rate. The contribution of autotrophic respiration rate in winter was higher than that in other three seasons. (2) Soil respiration has obvious diurnal characteristic, it could be expressed as a single-peak curve. But the maximum value of soil respiration appeared in different times in different seasons. (3) There existed positive correlation index exponential relationships between the soil temperature and the soil respiration rate and its components. Soil temperature changes could explain soil respiration, autotrophic respiration and heterotrophic respiration by 90.2%, 27.5% and 92.8%. Temperature sensitivity showed following order: the heterotrophic respiration rate> the soil respiration rate> the autotrophic respiration rate, in terms of affected by temperature, the heterotrophic respiration was higher than the autotrophic respiration. (4) There were notable positive correlations between soil moisture content and soil respiration rate. Obviously, soil moisture content could promote soil respiration in a certain range.


2010 ◽  
Vol 40 (4) ◽  
pp. 788-795 ◽  
Author(s):  
Xu Wang ◽  
Yanling Jiang ◽  
Bingrui Jia ◽  
Fengyu Wang ◽  
Guangsheng Zhou

CO2 efflux from forest soils is an important process in the global carbon cycle; however, effects of stand age and successional status remain uncertain. We compared soil respiration and its relationship to soil carbon content, forest floor mass, root biomass, soil temperature, and soil moisture content among three temperate forest ecosystems in Changbai Mountains, northeastern China, from 2003 to 2005. Forest types included an old-growth, mixed coniferous and broad-leaved primary forest (MN), a middle-aged, broad-leaved secondary forest (BL), and a young coniferous plantation forest (CP). Average annual soil CO2 efflux at BL (1477.9 ± 61.8 g C·m–2·year–1) was significantly higher than at CP (830.7 ± 48.7 g C·m–2·year–1) and MN (935.4 ± 53.3 g C·m–2·year–1). Differences in soil temperature among those sites were not statistically significant but contributed to the differences in annual CO2 efflux. In addition, the temperature response of soil CO2 efflux was higher at MN (Q10 = 2.78) than that at BL (Q10 = 2.17) and CP (Q10 = 2.02). Our results suggest that successional stage affects soil respiration by the differences in substrate quantity and quality, environmental conditions, and root respiration.


2020 ◽  
Vol 1 (2) ◽  
pp. 171-179

Soil respiration is a major component of global carbon cycle. Therefore, it is crucial to understand the environmental controls on soil respiration for evaluating potential response of ecosystems to climate change. In a temperate deciduous forest (located in Northern-Hungary) we added or removed aboveground and belowground litter to determine total soil respiration. We investigated the relationship between total soil CO2 efflux, soil moisture, and soil temperature. Soil CO2 efflux was measured at each plot using soda-lime method. Temperature sensitivity of soil respiration (Q10) was monitored via measuring soil temperature on an hourly basis, while soil moisture was determined monthly. Soil respiration increased in control plots from the second year after implementing the treatment, but results showed fluctuations from one year to another. The effect of doubled litter was less significant than the effect of removal. Removed litter and root inputs caused substantial decrease in soil respiration. We found that temperature was more influential in the control of soil respiration than soil moisture. In plots with no litter Q10 varied in the largest interval. For treatment with doubled litter layer, temperature sensitivity of CO2 efflux did not change considerably. The effect of increasing soil temperature is more conspicuous to soil respiration in litter removal treatments since lack of litter causes greater irradiation. When exclusively leaf litter was considered, the effect of temperature on soil respiration was lower in treatments with added litter than with removed litter. Our results reveal that soil life is impacted by the absence of organic matter, rather than by an excess of organic matter. Results of CO2 emission from soils with different organic matter content can contribute to sustainable land use, considering the changed climatic factors caused by global climate change.


2018 ◽  
Vol 15 (7) ◽  
pp. 2007-2019 ◽  
Author(s):  
Ping Yue ◽  
Xiaoqing Cui ◽  
Yanming Gong ◽  
Kaihui Li ◽  
Keith Goulding ◽  
...  

Abstract. Soil respiration (Rs) is the most important source of carbon dioxide emissions from soil to atmosphere. However, it is unclear what the interactive response of Rs would be to environmental changes such as elevated precipitation, nitrogen (N) deposition and warming, especially in unique temperate desert ecosystems. To investigate this an in situ field experiment was conducted in the Gurbantunggut Desert, northwest China, from September 2014 to October 2016. The results showed that precipitation and N deposition significantly increased Rs, but warming decreased Rs, except in extreme precipitation events, which was mainly through its impact on the variation of soil moisture at 5 cm depth. In addition, the interactive response of Rs to combinations of the factors was much less than that of any single-factor, and the main response was a positive effect, except for the response from the interaction of increased precipitation and high N deposition (60 kg N ha−1 yr−1). Although Rs was found to show a unimodal change pattern with the variation of soil moisture, soil temperature and soil NH4+-N content, and it was significantly positively correlated to soil dissolved organic carbon (DOC) and pH, a structural equation model found that soil temperature was the most important controlling factor. Those results indicated that Rs was mainly interactively controlled by the soil multi-environmental factors and soil nutrients, and was very sensitive to elevated precipitation, N deposition and warming. However, the interactions of multiple factors largely reduced between-year variation of Rs more than any single-factor, suggesting that the carbon cycle in temperate deserts could be profoundly influenced by positive carbon–climate feedback.


2020 ◽  
Vol 100 (4) ◽  
pp. 488-502
Author(s):  
Scott X. Chang ◽  
Zheng Shi ◽  
Barb R. Thomas

Forest stand age can affect ecosystem carbon (C) cycling and net ecosystem productivity (NEP). In Canada, establishment of short-rotation plantations on previously agricultural lands has been ongoing, but the effect of stand development on soil respiration (Rs) and NEP in such plantations is poorly understood. These types of data are essential for constraining ecosystem models that simulate C dynamics over the rotation of a plantation. We studied Rs (including autotrophic, Ra, and heterotrophic, Rh) and NEP in 2008 and 2009 in a chronosequence of 5-, 8-, 14-, and 16-yr-old (ages in 2009) hybrid poplar (Populus deltoides × Populus × petrowskyana var. Walker) plantations in northern Alberta. The highest Rs and NEP were generally found in the 14-yr-old stand. Seasonal variations in Rs were similar among the plantations, with most of the variation explained by soil temperature at the 10 cm depth in 2008 with far less explained in 2009, a much drier year. In diurnal measurements, hysteresis was found between soil respiration and soil temperature, with the patterns of hysteresis different among stand ages. Soil respiration in the 14-yr-old plantation had the greatest sensitivity to temperature changes. Stand age did not affect the Rh:Rs ratio, whereas the NEP exhibited strong inter-annual variability. We conclude that stand age was a major factor affecting Rs and NEP, and such effects should be considered in empirical models used to simulate ecosystem C dynamics to evaluate potentials for C sequestration and the C source–sink relationship in short-rotation woody crop systems.


2009 ◽  
Vol 6 (3) ◽  
pp. 6147-6177 ◽  
Author(s):  
F. B. Zanchi ◽  
H. R. da Rocha ◽  
H. C. de Freitas ◽  
B. Kruijt ◽  
M. J. Waterloo ◽  
...  

Abstract. Soil respiration plays a significant role in the carbon cycle of Amazonian tropical forests, although in situ measurements have only been poorly reported and the dependence of soil moisture and soil temperature also weakly understood. This work investigates the temporal variability of soil respiration using field measurements, which also included soil moisture, soil temperature and litterfall, from April 2003 to January 2004, in a southwest Brazilian tropical rainforest near Ji-Paraná, Rondônia. The experimental design deployed five automatic (static, semi-opened) soil chambers connected to an infra-red CO2 gas analyzer. The mean half-hourly soil respiration showed a large scattering from 0.6 to 18.9 μmol CO2 m−2 s−1 and the average was 8.0±3.4 μmol CO2 m−2 s−1. Soil respiration varied seasonally, being lower in the dry season and higher in the wet season, which generally responded positively to the variation of soil moisture and temperature year round. The peak was reached in the dry-to-wet season transition (September), this coincided with increasing sunlight, evapotranspiration and ecosystem productivity. Litterfall processes contributed to meet very favorable conditions for biomass decomposition in early wet season, especially the fresh litter on the forest floor accumulated during the dry season. We attempted to fit three models with the data: the exponential Q10 model, the Reichstein model, and the log-soil moisture model. The models do not contradict the scattering of observations, but poorly explain the variance of the half-hourly data, which is improved when the lag-time days averaging is longer. The observations suggested an optimum range of soil moisture, between 0.115


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