scholarly journals Soil CO2Efflux in a Mixed Pine-Oak Forest in Valsaín (Central Spain)

2007 ◽  
Vol 7 ◽  
pp. 166-174 ◽  
Author(s):  
Rosa Inclán ◽  
Daniel De la Torre ◽  
Marta Benito ◽  
Agustín Rubio

Soil-surface CO2efflux and its spatial and temporal variation were investigated in a southern Mediterranean, mixed pine-oak forest ecosystem on the northern slopes of the Sierra de Guadarrama in Spain from February 2006 to July 2006. Measurements of soil CO2efflux, soil temperatures, and moisture were conducted in nine 1963-m2sampling plots distributed in a gradient around the ecotone betweenPinus sylvestrisL. andQuercus pyrenaicaLam. forest stands. Total soil organic matter, Walkey-Black C, particulate organic matter, organic matter fraction below 53 μm, total soil nitrogen content, total soil organic carbon content, and pH were also measured under three representative mature oak, pine, and mixed pine-oak forest stands. Soil respiration showed a typical seasonal pattern with minimums in winter and summer, and maximums in spring, more pronounced in oak and oak-pine stands. Soil respiration values were highest in pine stands during winter and in oak stands during spring and summer.Soil respiration was highly correlated with soil temperatures in oak and pine-oak stands when soil moisture was above a drought threshold of 15%. Below this threshold value, soil moisture was a good predictor of soil respiration in pine stands. Greater soil organic matter, particulate organic matter, Walkey-Black C, total organic C, and total N content in pine compared to oak sites potentially contributed to the greater total soil CO2efflux in these stands during the winter. Furthermore, opposing trends in the organic matter fraction below 53 μm and soil respiration between plots suggest that in oak stands, the C forms are less affected by possible changes in use. The effects of soil properties on soil respiration were masked by differences in soil temperature and moisture during the rest of the year. Understanding the spatial and temporal variation even within small geographic areas is essential to assess C budgets at ecosystem level accurately. Thus, this study bears important implications for the study of large-scale ecosystem dynamics, particularly in response to climatic change.

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.


2011 ◽  
Vol 43 (5) ◽  
pp. 1006-1013 ◽  
Author(s):  
J. Balogh ◽  
K. Pintér ◽  
Sz. Fóti ◽  
D. Cserhalmi ◽  
M. Papp ◽  
...  

2020 ◽  
Vol 8 (2) ◽  
pp. 365
Author(s):  
Yuves Menti ◽  
Sri Yusnaini ◽  
Henrie Buchari ◽  
Ainin Niswati

Soil respiration is an indicator of the activity of microorganisms in the soil. The treatment of soil tillage system and the use of organic mulch given to the soil will affect the activity of soil microorganisms. The research aims to study the effect of soil tillage systems, application of in situ mulch, and the interaction between both in soil respiration. This research was conducted from April to July 2017 at the Integrated Field Laboratory, Faculty of Agriculture, University of Lampung, using a Randomized Block Design (RBD) factorially prepared with two treatment factors. The first factor is the soil tillage system (T), which consists of minimum tillage (T0) and conventional tillage (T1). The second factor is the treatment of mulch (M), which consists of no mulch (M0) and the application of in-situ mulch 5 t. ha-1 (M1). The data obtained were tested for various homogeneity by the Bartlett test and additivity by the Tukey test. Data were analyzed by analysis of variance and continued with LSD test at a 5% level. The relationship between soil temperature, soil moisture content, soil organic matter, and soil pH with soil respiration was tested by correlation test. The results showed that the soil tillage system and application of in-situ mulch had no significant effect on soil respiration, and there was no interaction between the soil tillage system and application of in-situ mulch in soil respiration on observations before tillage, 1 day after planting (HST), 41 HST, and 88 HST. There is no correlation between soil temperature, soil moisture content, soil organic matter, and soil pH with soil respiration on pre-tillage observations, 1 HST, 41 HST, and 88 HST.


Geoderma ◽  
2021 ◽  
Vol 385 ◽  
pp. 114863
Author(s):  
Perry Taneja ◽  
Hitesh Kumar Vasava ◽  
Prasad Daggupati ◽  
Asim Biswas

2021 ◽  
Author(s):  
Moritz Mohrlok ◽  
Victoria Martin ◽  
Alberto Canarini ◽  
Wolfgang Wanek ◽  
Michael Bahn ◽  
...  

<p>Soil organic matter (SOM) is composed of many pools with different properties (e.g. turnover times) which are generally used in biogeochemical models to predict carbon (C) dynamics. Physical fractionation methods are applied to isolate soil fractions that correspond to these pools. This allows the characterisation of chemical composition and C content of these fractions. There is still a lack of knowledge on how these individual fractions are affected by different climate change drivers, and therefore the fate of SOM remains elusive. We sampled soils from a multifactorial climate change experiment in a managed grassland in Austria four years after starting the experiment to investigate the response of SOM in physical soil fractions to temperature (eT: ambient and elevated by +3°C), atmospheric CO<sub>2</sub>-concentration (eCO<sub>2</sub>: ambient and elevated by +300 ppm) and to a future climate treatment (eT x eCO<sub>2</sub>: +3°C and + 300 ppm). A combination of slaking and wet sieving was used to obtain three size classes: macro-aggregates (maA, > 250 µm), micro-aggregates (miA, 63 µm – 250 µm) and free silt & clay (sc, < 63 µm). In both maA and miA, four different physical OM fractions were then isolated by density fractionation (using sodium polytungstate of ρ = 1.6 g*cm<sup>-3</sup>, ultrasonication and sieving): Free POM (fPOM), intra-aggregate POM (iPOM), silt & clay associated OM (SCaOM) and sand-associated OM (SaOM). We measured C and N contents and isotopic composition by EA-IRMS in all fractions and size classes and used a Pyrolysis-GC/MS approach to assess their chemical composition. For eCO<sub>2</sub> and eT x eCO<sub>2 </sub>plots, an isotope mixing-model was used to calculate the proportion of recent C derived from the elevated CO<sub>2 </sub>treatment. Total soil C and N did not significantly change with treatments.  eCO<sub>2</sub> decreased the relative proportion of maA-mineral-associated C and increased C in fPOM and iPOM. About 20% of bulk soil C was represented by the recent C derived from the CO<sub>2</sub> fumigation treatment. This significantly differed between size classes and density fractions (p < 0.001), which indicates inherent differences in OM age and turnover. Warming reduced the amount of new C incorporated into size classes. We found that each size class and fraction possessed a unique chemical fingerprint, but this was not significantly changed by the treatments. Overall, our results show that while climate change effects on total soil C were not significant after 4 years, soil fractions showed specific effects. Chemical composition differed significantly between size classes and fractions but was unaffected by simulated climate change. This highlights the importance to separate SOM into differing pools, while including changes to the molecular composition might not be necessary for improving model predictions.    </p>


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