Soil Respiration Measurements Research Articles

Effect of timber harvesting techniques and slopes on soil respiration of young and mature black pine stands in northwestern Türkiye

Releases of CO2 from forest soils was studied relative to different timber harvesting techniques, slope classes, and stand age. Three timber harvesting techniques (suspended skidding (SS), skidding by using a skidding cone (SC), and cable-pulling (CP)) were used in young and mature black pine stands at three different slopes (0 to 20% – S1, 20% to 33% – S2, and > 33% – S3). Soil respiration measurements were carried out at five-day intervals (1st, 5th, and 10th day) and 6 months later after the timber harvesting techniques. The soil respiration increased on the first day, decreased on the 5th and 10th days, and reached its lowest level on the 6th month. The SC technique in the young stands showed the highest soil respiration value on the slopes indicating that the cone placed on the head of the log during the skidding operations does not deform the soil. In the mature stands, all timber harvesting techniques and the undisturbed sites showed lower values than in the young stands on the S1. On the S2, mean value was higher in the mature stands. In contrast to the young stands, the undisturbed stands had the highest soil respiration.

Interaction Between Root Exudates and PFOS Mobility: Effects on Rhizosphere Microbial Health in Wetland Ecosystems

Perfluorooctanesulfonate (PFOS), a persistent organic pollutant, poses significant ecological risks. This study investigates the effects of PFOS on rhizosphere microbial communities of two wetland plants, Lythrum salicaria (LS) and Phragmites communis (PC). We conducted microcosm experiments to analyze the physiological status of soil microbes under varying PFOS concentrations and examined the role of root exudates in modulating PFOS mobility. Flow cytometry and soil respiration measurements revealed that PFOS exposure increased microbial mortality, with differential impacts observed between LS and PC rhizospheres. LS root exudates intensified microbial stress, whereas PC exudates mitigated PFOS toxicity. Thin-layer chromatography indicated that LS exudates decreased PFOS mobility, leading to higher local concentrations and increased microbial toxicity, while PC exudates enhanced PFOS mobility, reducing its local impact. Fourier-transform infrared spectroscopy and excitation-emission matrix fluorescence spectroscopy of root exudates identified compositional shifts under PFOS stress, highlighting distinct defense strategies in LS and PC. These findings underscore the importance of plant-microbe interactions and root exudate composition in determining microbial resilience to PFOS contamination.

Improvement of biological and physicochemical quality of agricultural soil after three years of ultra-high dilutions treatment

Soil health is crucial for healthy crops, but pesticides, fertilizers, fungicides, and soil disinfectants can harm beneficial organisms and increase harmful ones. Agricultural practices can also damage soil, disrupting nutrient release and absorption. An economical, side-effect-free solution for soil revitalization is needed [1]. Ultra-high diluted supplements are now used for plant treatment, offering a cost-effective and easy method often added to water. This study examines the effects of ultra-high diluted supplements on soil detoxification and restoration over three years. It measured soil respiration, water absorption, residual toxins, active nitrogen, heavy metals, rheological characteristics, and bacterial diversity [2]. This study investigates the impact of ultra-high diluted supplements on detoxifying and restoring soil's biological and physicochemical characteristics after three years of treatment. For this soil respiration, water absorption, elemental and toxins contents, rheological and bacterial diversity stadied. Treatmet starts by two 6-month detox treatments with 200C sulfur and 30C petroleum. The soil was then irrigated toxin-free for 6 months and recovered for two 4-month periods with Carbo Vegetabilis 30C. After a 4-month rest, a 2-month rotation with silica 200C and calcarea carbonica 30C was applied, followed by another 4-month rest. The final treatment involved three courses of Sulfur 200C, Berberis 6C, and Carbo Vegetabilis 30C over 6 months. The soil was irrigated and rested for the last 4 months, then sampled for new characteristics. Results showed increased essential elements and decreased toxic elements after three years. Soil microbial population decreased by 2 units, gas exchange improved by 6 units, and soil pH became more acidic by one unit. Beneficial bacteria for plant growth, metabolism, fertility, and health were present.

Assessing the long‐term effect of different organic amendments on the quality of acidic sandy soil

AbstractSandy soils are susceptible to the adverse effects of intensive land use and climate change, which can cause a decline in soil quality. As agricultural practices have an important role in soil processes, the objective of this research was to monitor the soil parameters determining the soil quality by studying the long‐term effects of different organic amendments on soil. The research was done in long‐term soil improvement experiments on Dystric Lamellic Arenosol. In addition to conventional organic fertilizers (farmyard manure with or without chemical fertilizers, green manure), alternative fertilizers such as sewage sludge compost were also applied. For the complex evaluation, we have been carrying out soil physical, chemical, and enzyme activity tests and field soil respiration measurements for 3 years. The beneficial effect of sewage sludge compost on the parameters determining the soil quality was more pronounced compared to the effect of conventional fertilization methods. The long‐term incorporation of sewage sludge compost into the soil significantly increased the soil organic matter content and pH, and improved the physico‐chemical parameters of the soil. The positive changes in soil parameters as a result of compost application contributed to the stimulation of soil life, which resulted in more intensive soil respiration and enzyme activities. The research confirmed the significance of the long‐term supply of organic matter on sandy soil that can be implemented sustainably through the agricultural utilization of sewage sludge compost and contributes to the enhancement of soil organic carbon storage and the improvement of soil quality in acidic sandy soil.

Contrasting effects of nitrogen addition and soil warming on soil respiration in an old-growth subtropical forest

Primary forest occupies 34 % of the global forest area and contributes to the mitigation of atmospheric carbon (C) dioxide through C sequestration in vegetation and soil. Environmental changes, including climate warming and increased nitrogen (N) deposition, have been found to affect soil C dynamics. However, there is a major gap in knowledge regarding the response and potential mechanisms of primary forest C cycling to climate warming and increased N deposition. We conducted a three year (2018–2020) field-based soil warming (+3 °C above ambient soil temperature), N addition (50 kg N ha−1 year−1) and their interaction experiment in an over 300-year-old primary forest in subtropical China, and measured soil respiration monthly. In addition, soil enzyme activities and physico-chemical properties were also analyzed. Three years of W treatment did not significantly increase soil respiration, while N treatment significantly decreased it by 24.29 %. Cumulative soil respiration in N and WN treatments decreased by 2.17 and 2.14 Mg C ha−1 year−1, while W treatment increased annual cumulative soil respiration by 0.95 Mg C ha−1 year−1. W treatment indirectly affected soil respiration through its negative impact on C-degrading enzymatic activities and soil moisture. N treatment directly impacted soil respiration and indirectly by effect on soil organic C. These findings demonstrate that soil respiration in the old-growth subtropical forest would cause a minor soil C-climate feedback to 3 °C warming within the first three years, and N deposition may have not strong interaction with warming.

Use of Long-Term Soil Respiration Measurements for Calculating the Net Carbon Balance in Ecosystems of the Central Chernozemic Region

Use of Long-Term Soil Respiration Measurements for Calculating the Net Carbon Balance in Ecosystems of the Central Chernozemic Region

Soil response in a Mediterranean forest ecosystem of Southeast Spain following early prescribed burning

The escalation of global warming, high temperatures, and wildfire frequency in dry ecosystems, including semi-arid landscapes, has resulted in increased wildfire regimes, compromising ecosystem resistance and resilience. To mitigate these risks, prescribed burning (PB) is being employed as a preventive measure to modify fuel loads in forest ecosystems. However, fire can also impact soil structure and microbiota, which play critical roles in nutrient cycling, biodiversity conservation, and overall ecosystem functioning. Therefore, understanding post-fire processes is essential for sustainable forest management. However, while previous studies have explored the effects of prescribed fire management on semi-arid soil properties in Mediterranean forest ecosystems, gaps remain in our understanding of its specific impact on the physical structure, chemical composition, and biological activities of soils.In this study, we conducted early spring PB in SE Spain in 2021 and assessed the ecological and temporal effects of PB on semi-arid soils. Soil respiration (SR) measurements using automatic CO2 flow chambers were employed to evaluate microbiota recovery. To examine impacts on soil structure we evaluated physicochemical characteristics, soil hydraulic conductivity (SHC), and soil water repellency (SWR). No significant differences were observed in any of the variables studied after one year. However, immediate effects were detected shortly after the PB. Our research specifically targeted soil structure and microbiota in a semi-arid landscape with poor soils, characterized by slower recovery and potentially fragile ecosystems. These results provide valuable insights for forest management practices, indicating that prescribed fire management strategies in similar ecosystems are unlikely to cause adverse effects on soil health. However, further research is warranted to explore the potential effects of prescribed fire intensity and seasonality. Future studies can focus on investigating these factors to provide more targeted recommendations for effective forest management strategies and wildfire prevention efforts.

A cost-effective method for quantifying soil respiration

Soil respiration is a critical indicator of microbial activity, reflecting soil health and its ability to deliver essential ecosystem services and functions. Chamber-based measurements provide direct observations and are relatively simple to implement, making them a popular choice for soil respiration studies. However, current methods to quantify soil respiration are limited in their applicability by high costs, substrate requirements, accuracy concerns and substantial setup time. With an increasing emphasis on routine analysis of soil respiration, existing methods are insufficient to provide the temporal and spatial scale required to proliferate soil respiration data. This study assesses the potential of an affordable and commercially available Non-Dispersive Infrared (NDIR) CO2 detector, used in conjunction with an easy-to assemble closed chamber, to provide reliable and accessible soil respiration measurements. The CO2 detectors utilised in this study are cost-effective yet precise digital detectors, successfully validated against a laboratory reference sensor and the standard alkali trap method. Beyond that, the detector has effectively yielded consistent results across replicates and demonstrated sensitivity similar to standard methods. The proposed detector offers an alternative to traditional laboratory methods by removing the necessity to perform soil respiration analysis in a laboratory setting. The proliferation of soil respiration data would facilitate the increasing interest in accessible information on soil respiration from stakeholders, citizen scientists and decision makers.

Soil respiration across a variety of tree-covered urban green spaces in Helsinki, Finland

Abstract. As an increasing share of the human population is being clustered in cities, urban areas have swiftly become the epicentres of anthropogenic carbon (C) emissions. Understanding different parts of the biogenic C cycle in urban ecosystems is needed in order to assess the potential to enhance their C stocks as a cost-efficient means to balance the C emissions and mitigate climate change. Here, we conducted a field measurement campaign over three consecutive growing seasons to examine soil respiration carbon dioxide (CO2) fluxes and soil organic carbon (SOC) stocks at four measurement sites in Helsinki, representing different types of tree-covered urban green space commonly found in northern European cities. We expected to find variation in the main drivers of soil respiration – soil temperature, soil moisture, and SOC – as a result of the heterogeneity of urban landscape and that this variation would be reflected in the measured soil respiration rates. In the end, we could see fairly constant statistically significant differences between the sites in terms of soil temperature but only sporadic and seemingly momentary differences in soil moisture and soil respiration. There were also statistically significant differences in SOC stocks: the highest SOC stock was found in inactively managed deciduous urban forest and the lowest under managed streetside lawn with common linden trees. We studied the impacts of the urban heat island (UHI) effect and irrigation on heterotrophic soil respiration with process-based model simulations and found that the variation created by the UHI is relatively minor compared to the increase associated with active irrigation, especially during dry summers. We conclude that, within our study area, the observed variation in soil temperature alone was not enough to cause variation in soil respiration rates between the studied green space types, perhaps because the soil moisture conditions were uniform. Thus, irrigation could potentially be a key factor in altering the soil respiration dynamics in urban green space both within the urban area and in comparison to non-urban ecosystems.

Stable isotopes and nanoSIMS single-cell imaging reveals soil plastisphere colonizers able to assimilate sulfamethoxazole

The presence and accumulation of both, plastics and antibiotics in soils may lead to the colonization, selection, and propagation of soil bacteria with certain metabolic traits, e.g., antibiotic resistance, in the plastisphere. However, the impact of plastic-antibiotic tandem on the soil ecosystem functioning, particularly on microbial function and metabolism remains currently unexplored. Herein, we investigated the competence of soil bacteria to colonize plastics and degrade 13C-labeled sulfamethoxazole (SMX). Using single-cell imaging, isotope tracers, soil respiration and SMX mineralization bulk measurements we show that microbial colonization of polyethylene (PE) and polystyrene (PS) surfaces takes place within the first 30 days of incubation. Morphologically diverse microorganisms were colonizing both plastic types, with a slight preference for PE substrate. CARD-FISH bacterial cell counts on PE and PS surfaces formed under SMX amendment ranged from 5.36 × 103 to 2.06 × 104, and 2.06 × 103 to 3.43 × 103 hybridized cells mm−2, respectively. Nano-scale Secondary Ion Mass Spectrometry measurements show that 13C enrichment was highest at 130 days with values up to 1.29 atom%, similar to those of the 13CO2 pool (up to 1.26 atom%, or 22.55 ‰). Independent Mann-Whitney U test showed a significant difference between the control plastisphere samples incubated without SMX and those in 13C-SMX incubations (P < 0.001). Our results provide direct evidence demonstrating, at single-cell level, the capacity of bacterial colonizers of plastics to assimilate 13C-SMX from contaminated soils. These findings expand our knowledge on the role of soil-seeded plastisphere microbiota in the ecological functioning of soils impacted by anthropogenic stressors.

Water and nitrogen availability define emissions of carbon dioxide and nitrogen oxides from desert soil differently

Nitrogen (N), phosphorus (P), and water, together and individually, limit soil biological processes in dryland ecosystems and therefore, the availability of each nutrient is a key determinant of ecosystem processes and functions. To assess the importance of each limiting factor for microbial activity in desert soil, we manipulated water, N, and P availability separately and combined. N, P, and NP were added at rates of 10 N or/and P g m−2 under two water regimes: one wetting event, and bi-weekly wetting–drying cycles in addition to natural rainfall. We measured soil respiration, nitrous (N2O) and nitric oxides (NOx) emissions in situ, and potential nitrification and mineralization in laboratory. Soil respiration increased by ∼30% with raised water availability but wasn't affected by nutrients availability. NOx and to a smaller extent N2O emissions, however, increased with nutrient availability but not with water. Average soil NOx flux increased up to ∼19 folds from 0.03 ± 0.01 μg N m−2 min−1 to 0.52 ± 0.10 μg N m−2 min−1 with the addition of N and N + P but only slightly with addition of P alone (p = 0.06). The removal of both water and NP limitation accelerated only NOx, but nor CO2 neither N2O emissions pointed on other than N and P limitation of soil heterotrophic processes in this alkali desert soil. The potential soil microbial activity was unaffected by the removal of neither water nor NP limitations. Our findings suggest that water primarily influences soil respiration and N availability soil NOx emissions while desert soil is a minor source of N2O. We conclude that heterotrophic and autotrophic microbial activities in desert soils are influenced differently by water and nutrients. Increasing precipitation would likely boost soil respiration and N mineralization rates, leading to decreased soil nutrient organic carbon stocks, while increased N deposition would accelerate gaseous N loss.

The potential of soil microbial communities to transform deoxynivalenol in agricultural soils—a soil microcosm study

Infestation of cereal fields with toxigenic Fusarium species is identified as an environmental source for the mycotoxin deoxynivalenol (DON). During rain events, DON may be washed off from infested plants and enter the soil, where microbial transformation may occur. Although some studies showed DON transformation potential of soil microbial communities in liquid soil extracts, these findings can not be transferred to environmental conditions. Accordingly, microbial transformation of DON in soil has to be investigated under realistic conditions, e.g., microcosms mimicking field situations. In this study, we investigated the potential of soil microbial communities to transform DON in six different agricultural soils at two levels (0.5 and 5 µg g–1). The dissipation and the formation of transformation products were investigated in a period of 35 days and compared to a sterilized control. In addition, we measured soil respiration and applied the phospholipid-derived fatty acid (PLFA) analysis to assess whether soil microbial community characteristics are related to the microbial transformation potential. Dissipation of DON in non-sterilized soils was fast (50% dissipation within 0.6–3.7 days) compared to the sterile control where almost no dissipation was observed. Thus, dissipation was mainly attributed to microbial transformation. We verified that small amounts of DON are transformed to 3-keto-deoxynivalenol (3-keto-DON) and 3-epi-deoxynivalenol (3-epi-DON), which were not detectable after 16-day incubation, indicating further transformation processes. There was a trend towards faster transformation in soils with active and large microbial communities and low fungi-to-bacteria ratio.

Ultra-low-cost manual soil respiration chamber

Abstract. Soil respiration measurement is important to assess natural carbon dioxide production. The closed-chamber technique allows relatively easy soil respiration monitoring. A planned spatially large-scale campaign incites us to implement our ultra-low-cost portative chamber. The chamber itself is entirely built from commercial parts with little, easy-to-perform, quick machining work. The resulting setup is an easy-to-operate, standalone, robust device. The used sensors are cost-effective yet accurate digital sensors that were successfully checked against some reference sensors. All of these characteristics made the described chamber accessible to build and use for a wide scientific and educational community. In this short note, we describe this simple device along with its sensors and apparent respiration quotient tip.

Long-term Measurement of Soil Respiration and Environmental Drivers in Oil Palm Peat Plantations (Young and mature) and Peat Swamp Forest

Long-term Measurement of Soil Respiration and Environmental Drivers in Oil Palm Peat Plantations (Young and mature) and Peat Swamp Forest

Soil respiration responses of moss and lichen biocoenoses to moderate and severe rain events after summer drought in a temperate early‐successional ecosystem

AbstractIt is commonly accepted that CO2 efflux increases with soil water content in aerated soils and that rewetting after periods of soil drying can result in respiration pulses. It has further been shown that soil pores may become water logged which can impede soil gas exchange. The present study aimed to quantify the carbon response of moss (Polytrichum piliferum) and lichen (Cladonia coniocraea) biocoenoses to different quantities of rain in an artificial catchment, which granted that the starting point of the development of both biocoenoses was the same. To address this aim, we conducted in situ soil moisture and soil respiration measurements, where soil respiration was hypothesised to emerge from a cryptogamic vegetation layer and from mineral soil beneath. We found that higher water‐holding capacity of the moss layer and higher accumulation of organic matter in the upper mineral soil under mosses result in higher amounts of water stored near the surface. As a consequence, evaporation of water as well as pulses of CO2 efflux after moderate rain following a period of drought were higher in the moss biocoenosis, where the upper mineral soil was of key importance. In contrast, the lichen biocoenosis facilitated penetration of rainwater into the deep soil. Superimposing rewetting pulses, near‐saturation of soil pores with water after severe rain resulted in gas exchange inhibition and diminished soil respiration until subsequent aeration in both biocoenoses.

Soil Temperature, Organic-Carbon Storage, and Water-Holding Ability Should Be Accounted for the Empirical Soil Respiration Model Selection in Two Forest Ecosystems

Soil respiration (SR) is a main component of the carbon cycle in terrestrial ecosystems, and being strongly affected by changes in the environment, it is a good indicator of the ecosystem’s ability to cope with climate change. This research aims to find better empirical SR models using 25-year-long SR monitoring in two forest ecosystems formed on sandy Entic Podzol and loamy Haplic Luvisol. The following parameters were considered in the examined models: the mean monthly soil or air temperatures (Tsoil or Tair), the amount of precipitation during the current (P) and the previous (PP) months, and the storage of soil organic carbon (SOC). The weighted non-linear regression was used for model parameter estimations for the normal, wet, and dry years. To improve the model resolutions by magnitude, we controlled the slope and intercept of the linear model comparison between the measured and modeled data through the change in R0—SR at zero soil temperature. The mean bias error (MBE), root-mean-square error (RMSE), and determination coefficient (R2) were used for the estimation of the goodness of model performances. For the sandy Entic Podzol, it is more appropriate to use the models dependent on SOC (TPPC). While for the loamy Haplic Luvisol, the Raich–Hashimoto model (TPPrh) with the quadratic Tsoil or Tair dependency shows the better results. An application of Tsoil for the model parameterization gives better results than Tair: the TPPC model was able to adequately describe the cold-period SR (Tsoil ≤ 2 °C); the TPPrh model was able to avoid overestimations of the warm-period SR (Tsoil &gt; 2 °C). The TPPC model parameterized with Tsoil can be used for the quality control of the cold-period SR measurements. Therefore, we showed the importance of accounting for SOC and the water-holding ability when the optimal SR model is chosen for the analysis.

Effects of pre-commercial thinning on soil respiration and some soil properties in black pine (Pinus nigra) stands

Forestry practices may cause significant changes in soil characteristics as related to their properties and size. Although chemical attributes of the soil respond to the applications in the mid- or long-term while changes in soil respiration can react rapidly to forestry practices. Therefore, determining changes in soil attributes is needed to identify how the management practices would affect forest ecosystem function. Although there is much information on the effect of thinning practices on tree growth, there is a lack of knowledge on the impacts of pre-commercial thinning on soil properties, especially soil respiration. We aimed to determine pre-commercial thinning effects on some soil attributes in black pine sites. Four treatments with different intensities were applied to the stands studied. These practices were control (no pre-commercial thinning), 2000 (heavy), 4000 (moderate), and 6000 (light) individuals per hectare left, respectively. Measurements of soil respiration and soil temperature were carried out between 2014 and 2017 in spring, summer, autumn, and winter months. Soil characteristics, including pH, organic matter, nitrogen, and phosphor content, were measured just after and three years after the thinning. As a result, thinning increased soil respiration rate and soil temperature while decreased soil pH values. Results of the study showed that carbon balance in the ecosystem was significantly affected by thinnings, and adjusting the thinning intensity may be an efficient carbon management tool for reducing carbon emission from the soil.

A biophysical model to simulate seasonal variations of soil respiration in agroecosystems in China

Characterizing the seasonal patterns of soil respiration using a biophysical model is crucial for understanding the mechanisms of the terrestrial carbon (C) cycle. We developed a biophysical soil respiration model including four submodels that were associated with the functions of soil temperature, moisture, leaf area index (LAI), and soil organic C, and the model parameters were determined and calibrated. The modeling reproducibility was examined in various crop fields at our study site, and the modeling performance was also validated in twenty-five other agroecosystems in China. The monthly and annual soil respiration was estimated using the model, and the modeling uncertainty was evaluated. The results showed that the soil respiration model had good modeling reproducibility in various crop fields at our site. The measured soil respiration in the different agroecosystems in China validated our model well. The R2, root mean squared error (RMSE), model efficiency (ME), and mean absolute error (MAE) were within the ranges of 0.449‒0.932, 0.526‒1.465 μmol m−2 s−1, 0.176‒0.796, and 0.312‒1.377 μmol m−2 s−1, respectively, across the twelve agroecosystem sites for validation. The measured soil respiration was significantly (P < 0.001) correlated with the modeled soil respiration across all twenty-six validation sites. Adding LAI significantly improved the modeling of soil respiration when the performance of the model (with LAI) vs. that without LAI was compared. The modeled monthly soil respiration was within the range of 0.016 ± 0.001‒0.117 ± 0.006 Pg C mo−1 in 2010 in agroecosystems in China. The black soils in Northeast China are fertile, which resulted in high temperature sensitivity and a clear increasing tendency of soil respiration from winter to summer in 2010 in agroecosystems in Northeast China. The established biophysical soil respiration model was proven to be effective for characterizing the temporal variations of soil respiration in various agroecosystems in China.

Effects of liming on soil respiration and its sensitivity to temperature in Cunninghamia lanceolata plantations.

The primary distribution area of acid deposition coincides with areas of Chinese fir (Cunninghamia lanceolata) plantations. Liming is an effective method of restoring acidified soil. To understand the effects of liming on soil respiration and temperature sensitivity within the context of acid deposition, we measured soil respiration and its components in Chinese fir plantations for one year beginning in June 2020, with 0, 1 and 5 t·hm-2 calcium oxide being added in 2018. The results showed that liming considerably increased soil pH and exchangeable Ca2+ concentration, and that there was no significant difference among different levels of lime application. Soil respiration rate and components in the Chinese fir plantations exhibited seasonal variations, with the highest values during the summer and the lowest values during the winter. Although liming did not alter seasonal dynamics, it strongly inhibited heterotrophic respiration rate and increased autotrophic respiration rate of soil, with minor effect on total soil respiration. The monthly dynamics of soil respiration and temperature were largely consistent. There was a clear exponential relationship between soil respiration and soil temperature. Liming increased temperature sensitivity Q10 of soil respiration and autotrophic respiration but reduced that of soil heterotrophic respiration. In conclusion, liming promoted soil autotrophic respiration and strongly inhibited soil heterotrophic respiration in Chinese fir plantations, which would facilitate soil carbon sequestration.

Response of soil respiration to hydrothermal effects of gravel–sand mulch in arid regions of the Loess Plateau, China

Gravel–sand mulching is a traditional no–tillage technique used for more than 300 years on the Loess Plateau. Applying gravel–sand mulch (mixture of gravel and sand) has an impact on the soil environment, soil microorganisms, and crop yield. However, we know surprisingly little of how respiration dynamics at the soil surface is affected by gravel–sand mulching. To study the response of soil respiration (Rs) dynamics to different in gravel–sand mulch thickness and its driving factors, we recorded Rs under a gradient of gravel–sand mulch thickness consisting of six layers (0 cm [CK], 3 cm, 5 cm, 7 cm, 9 cm, 11 cm), in situ, during the growing season by using the LI–6400–09 soil respiration measurement system on the Loess Plateau in northwest China. The trends of all six treatments in diurnal and monthly variation of soil respiration followed a single–peaked curve; the diurnal dynamics trends were consistent with soil temperature changes. With gravel–sand mulch applied, the daily peak of soil respiration decreased, and the peak in Rs under the gravel–sand mulch treatments lagged that of bare land by 2 h. Monthly changes in soil respiration were consistent with soil temperature and precipitation changes, with peaks concentrated in July and August. Compared with bare land (CK), the monthly average soil respiration is lowest at 0.67 µmol∙m–2∙s–1 under a 11–cm thick mulch layer, and reduced by 26.63–61.03% by all mulch applications. Gravel–sand mulch reduced the temperature sensitivity of soil respiration, while soil temperature and soil water content were the main factors determining soil respiration. The thickness of gravel–sand has a significant, negative exponential function relationship with the changes in monthly soil respiration. Further, compared with bare land, the presence of gravel–sand mulch reduced the positive impact of precipitation on Rs. Soil temperature (T), gravel–sand mulch thickness (M), and soil pH were all significant predictors of soil respiration (Rs) (multiple regression model: Rs = 8.561 + 0.077 T – 0.056 M – 0.989 pH), together accounting for 73% of its variation. Hence, by considering all these three factors simultaneously we can better explain the changes to soil respiration in response to gravel–sand mulch. Overall, our results show that as the thickness of the gravel–sand layer increases, soil respiration decreases.