Historical climate controls soil respiration responses to current soil moisture

Ecosystem carbon losses from soil microbial respiration are a key component of global carbon cycling, resulting in the transfer of 40–70 Pg carbon from soil to the atmosphere each year. Because these microbial processes can feed back to climate change, understanding respiration responses to environmental factors is necessary for improved projections. We focus on respiration responses to soil moisture, which remain unresolved in ecosystem models. A common assumption of large-scale models is that soil microorganisms respond to moisture in the same way, regardless of location or climate. Here, we show that soil respiration is constrained by historical climate. We find that historical rainfall controls both the moisture dependence and sensitivity of respiration. Moisture sensitivity, defined as the slope of respiration vs. moisture, increased fourfold across a 480-mm rainfall gradient, resulting in twofold greater carbon loss on average in historically wetter soils compared with historically drier soils. The respiration–moisture relationship was resistant to environmental change in field common gardens and field rainfall manipulations, supporting a persistent effect of historical climate on microbial respiration. Based on these results, predicting future carbon cycling with climate change will require an understanding of the spatial variation and temporal lags in microbial responses created by historical rainfall.

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Significance of soil respiration from biological activity in the degradation processes of different types of organic matter

10.37281/drcsf/1.2.10 ◽

2020 ◽

Vol 1 (2) ◽

pp. 171-179

Keyword(s):

Climate Change ◽

Organic Matter ◽

Soil Moisture ◽

Soil Respiration ◽

Soil Temperature ◽

Temperature Sensitivity ◽

Soil Co2 Efflux ◽

Co2 Efflux ◽

Soil Co2 ◽

Total Soil

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.

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Localized basal area affects soil respiration temperature sensitivity in a coastal deciduous forest

Biogeosciences ◽

10.5194/bg-17-771-2020 ◽

2020 ◽

Vol 17 (3) ◽

pp. 771-780 ◽

Cited By ~ 1

Author(s):

Stephanie C. Pennington ◽

Nate G. McDowell ◽

J. Patrick Megonigal ◽

James C. Stegen ◽

Ben Bond-Lamberty

Keyword(s):

Soil Moisture ◽

Soil Respiration ◽

Spatial Variability ◽

Temperature Sensitivity ◽

Large Scale ◽

Deciduous Forest ◽

Basal Area ◽

Soil Surface ◽

Study Sites ◽

Positive Effect

Abstract. Soil respiration (Rs), the flow of CO2 from the soil surface to the atmosphere, is one of the largest carbon fluxes in the terrestrial biosphere. The spatial variability of Rs is both large and poorly understood, limiting our ability to robustly scale it in space. One factor in Rs spatial variability is the autotrophic contribution from plant roots, but it is uncertain how the presence of plants affects the magnitude and temperature sensitivity of Rs. This study used 1 year of Rs measurements to examine the effect of localized basal area on Rs in the growing and dormant seasons, as well as during moisture-limited times, in a temperate, coastal, deciduous forest in eastern Maryland, USA. In a linear mixed-effects model, tree basal area within a 5 m radius (BA5) exerted a significant positive effect on the temperature sensitivity of soil respiration. Soil moisture was the dominant control on Rs during the dry portions of the year, while soil moisture, temperature, and BA5 all exerted significant effects on Rs in wetter periods. Our results suggest that autotrophic respiration is more sensitive to temperature than heterotrophic respiration at these sites, although we did not measure these source fluxes directly, and that soil respiration is highly moisture sensitive, even in a record-rainfall year. The Rs flux magnitudes (0.46–15.0 µmol m−2 s−1) and variability (coefficient of variability 10 %–23 % across plots) observed in this study were comparable to values observed in similar forests. Six Rs observations would be required in order to estimate the mean across all study sites to within 50 %, and 518 would be required in order to estimate it to within 5 %, with 95 % confidence. A better understanding of the spatial interactions between plants and microbes, as well as the strength and speed of above- and belowground coupling, is necessary to link these processes with large-scale soil-to-atmosphere C fluxes.

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Long-Term Warming Alters Carbohydrate Degradation Potential in Temperate Forest Soils

Applied and Environmental Microbiology ◽

10.1128/aem.02012-16 ◽

2016 ◽

Vol 82 (22) ◽

pp. 6518-6530 ◽

Cited By ~ 28

Author(s):

Grace Pold ◽

Andrew F. Billings ◽

Jeff L. Blanchard ◽

Daniel B. Burkhardt ◽

Serita D. Frey ◽

...

Keyword(s):

Climate Change ◽

Microbial Communities ◽

Soil Carbon ◽

Carbon Cycling ◽

Temperate Forest ◽

Mineral Soil ◽

Soil Microbial Communities ◽

Organic Horizon ◽

Soil Microbial ◽

Carbohydrate Degradation

ABSTRACTAs Earth's climate warms, soil carbon pools and the microbial communities that process them may change, altering the way in which carbon is recycled in soil. In this study, we used a combination of metagenomics and bacterial cultivation to evaluate the hypothesis that experimentally raising soil temperatures by 5°C for 5, 8, or 20 years increased the potential for temperate forest soil microbial communities to degrade carbohydrates. Warming decreased the proportion of carbohydrate-degrading genes in the organic horizon derived from eukaryotes and increased the fraction of genes in the mineral soil associated withActinobacteriain all studies. Genes associated with carbohydrate degradation increased in the organic horizon after 5 years of warming but had decreased in the organic horizon after warming the soil continuously for 20 years. However, a greater proportion of the 295 bacteria from 6 phyla (10 classes, 14 orders, and 34 families) isolated from heated plots in the 20-year experiment were able to depolymerize cellulose and xylan than bacterial isolates from control soils. Together, these findings indicate that the enrichment of bacteria capable of degrading carbohydrates could be important for accelerated carbon cycling in a warmer world.IMPORTANCEThe massive carbon stocks currently held in soils have been built up over millennia, and while numerous lines of evidence indicate that climate change will accelerate the processing of this carbon, it is unclear whether the genetic repertoire of the microbes responsible for this elevated activity will also change. In this study, we showed that bacteria isolated from plots subject to 20 years of 5°C of warming were more likely to depolymerize the plant polymers xylan and cellulose, but that carbohydrate degradation capacity is not uniformly enriched by warming treatment in the metagenomes of soil microbial communities. This study illustrates the utility of combining culture-dependent and culture-independent surveys of microbial communities to improve our understanding of the role changing microbial communities may play in soil carbon cycling under climate change.

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Metaphenomic Responses of a Native Prairie Soil Microbiome to Moisture Perturbations

mSystems ◽

10.1128/msystems.00061-19 ◽

2019 ◽

Vol 4 (4) ◽

Cited By ~ 9

Author(s):

Taniya Roy Chowdhury ◽

Joon-Yong Lee ◽

Eric M. Bottos ◽

Colin J. Brislawn ◽

Richard Allen White ◽

...

Keyword(s):

Climate Change ◽

United States ◽

Soil Moisture ◽

Metabolic Pathways ◽

Soil Microbial Communities ◽

The United States ◽

Soil Microbiome ◽

Soil Drying ◽

Soil Microbial ◽

And Function

ABSTRACT Climate change is causing shifts in precipitation patterns in the central grasslands of the United States, with largely unknown consequences on the collective physiological responses of the soil microbial community, i.e., the metaphenome. Here, we used an untargeted omics approach to determine the soil microbial community’s metaphenomic response to soil moisture and to define specific metabolic signatures of the response. Specifically, we aimed to develop the technical approaches and metabolic mapping framework necessary for future systematic ecological studies. We collected soil from three locations at the Konza Long-Term Ecological Research (LTER) field station in Kansas, and the soils were incubated for 15 days under dry or wet conditions and compared to field-moist controls. The microbiome response to wetting or drying was determined by 16S rRNA amplicon sequencing, metatranscriptomics, and metabolomics, and the resulting shifts in taxa, gene expression, and metabolites were assessed. Soil drying resulted in significant shifts in both the composition and function of the soil microbiome. In contrast, there were few changes following wetting. The combined metabolic and metatranscriptomic data were used to generate reaction networks to determine the metaphenomic response to soil moisture transitions. Site location was a strong determinant of the response of the soil microbiome to moisture perturbations. However, some specific metabolic pathways changed consistently across sites, including an increase in pathways and metabolites for production of sugars and other osmolytes as a response to drying. Using this approach, we demonstrate that despite the high complexity of the soil habitat, it is possible to generate insight into the effect of environmental change on the soil microbiome and its physiology and functions, thus laying the groundwork for future, targeted studies. IMPORTANCE Climate change is predicted to result in increased drought extent and intensity in the highly productive, former tallgrass prairie region of the continental United States. These soils store large reserves of carbon. The decrease in soil moisture due to drought has largely unknown consequences on soil carbon cycling and other key biogeochemical cycles carried out by soil microbiomes. In this study, we found that soil drying had a significant impact on the structure and function of soil microbial communities, including shifts in expression of specific metabolic pathways, such as those leading toward production of osmoprotectant compounds. This study demonstrates the application of an untargeted multi-omics approach to decipher details of the soil microbial community’s metaphenotypic response to environmental perturbations and should be applicable to studies of other complex microbial systems as well.

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Seasonal changes in soil respiration linked to soil moisture and phosphorus availability along a tropical rainfall gradient

Biogeochemistry ◽

10.1007/s10533-019-00602-4 ◽

2019 ◽

Vol 145 (3) ◽

pp. 235-254

Author(s):

Daniela F. Cusack ◽

Daniel Ashdown ◽

Lee H. Dietterich ◽

Avishesh Neupane ◽

Mark Ciochina ◽

...

Keyword(s):

Soil Moisture ◽

Soil Respiration ◽

Seasonal Changes ◽

Phosphorus Availability ◽

Rainfall Gradient ◽

Tropical Rainfall

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The response of soil physicochemical properties and soil microbial respiration to different land use types: A case of areas in Central-North Hungary region

Agrokémia és Talajtan ◽

10.1556/0088.2021.00079 ◽

2021 ◽

Author(s):

Tsedekech Gebremeskel Weldmichael ◽

Erika Michéli ◽

Barbara Simon

Keyword(s):

Land Use ◽

Soil Moisture ◽

Soil Properties ◽

Microbial Respiration ◽

Arable Land ◽

Available Nitrogen ◽

Soil Microbial ◽

Soil Microbial Respiration ◽

Land Use Types ◽

The Impact

Land use change may modify key soil attributes, influencing the capacity of soil to maintain ecological functions. Understanding the effects of land use types (LUTs) on soil properties is, therefore, crucial for the sustainable utilization of soil resources. This study aims to investigate the impact of LUT on primary soil properties. Composite soil samples from eight sampling points per LUT (forest, grassland, and arable land) were taken from the top 25 cm of the soil in October 2019. The following soil physicochemical parameters were investigated according to standard protocols: soil organic matter (SOM), pH, soil moisture, NH4+–N, NO3––N, AL-K2O, AL-P2O5, CaCO3, E4/E6, cation exchange capacity (CEC), base saturation (BS), and exchangeable bases (Ca2+, Mg2+, K+, and Na+). Furthermore, soil microbial respiration (SMR) was determined based on basal respiration method. The results indicated that most of the investigated soil properties showed significant difference across LUTs, among which NO3––N, total N, and K2O were profoundly affected by LUT (p ≤ 0.001). On the other hand, CEC, soil moisture, and Na+ did not greatly change among the LUTs (p ≥ 0.05). Arable soils showed the lowest SOM content and available nitrogen but the highest content of P2O5 and CaCO3. SMR was considerably higher in grassland compared to arable land and forest, respectively. The study found a positive correlation between soil moisture (r = 0.67; p < 0.01), Mg2+ (r = 0.61; p < 0.01), and K2O (r = 0.58; p < 0.05) with SMR. Overall, the study highlighted that agricultural practices in the study area induced SOM and available nitrogen reduction. Grassland soils were more favorable for microbial activity.

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Small scale spatial heterogeneity of soil respiration in an old growth temperate deciduous forest

Biogeosciences Discussions ◽

10.5194/bgd-6-9977-2009 ◽

2009 ◽

Vol 6 (5) ◽

pp. 9977-10005 ◽

Cited By ~ 7

Author(s):

A. Jordan ◽

G. Jurasinski ◽

S. Glatzel

Keyword(s):

Soil Moisture ◽

Soil Respiration ◽

Soil Temperature ◽

Spatial Heterogeneity ◽

Large Scale ◽

Stand Structure ◽

Small Scale ◽

Sampling Point ◽

Old Growth ◽

Old Growth Forest

Abstract. The large scale spatial heterogeneity of soil respiration caused by differences in site conditions is quite well understood. However, comparably little is known about the micro scale heterogeneity within forest ecosystems on homogeneous soils. Forest age, soil texture, topographic position, micro topography and stand structure may influence soil respiration considerably within short distance. In the present study within site spatial heterogeneity of soil respiration has been evaluated. To do so, an improvement of available techniques for interpolating soil respiration data via kriging was undertaken. Soil respiration was measured with closed chambers biweekly from April 2005 to April 2006 using a nested design (a set of stratified random plots, supplemented by 2 small and 2 large nested groupings) in an unmanaged, beech dominated old growth forest in Central Germany (Hainich, Thuringia). A second exclusive randomized design was established in August 2005 and continually sampled biweekly until July 2007. The average soil respiration values from the random plots were standardized by modeling soil respiration data at defined soil temperature and soil moisture values. By comparing sampling points as well as by comparing kriging results based on various sampling point densities, we found that the exclusion of local outliers was of great importance for the reliability of the estimated fluxes. Most of this information would have been missed without the nested groupings. The extrapolation results slightly improved when additional parameters like soil temperature and soil moisture were included in the extrapolation procedure. Semivariograms solely calculated from soil respiration data show a broad variety of autocorrelation distances (ranges) from a few centimeters up to a few tens of meters. The combination of randomly distributed plots with nested groupings plus the inclusion of additional relevant parameters like soil temperature and soil moisture data permits an improved estimation of the range of soil respiration, which is a prerequisite for reliable interpolated maps of soil respiration.

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Microbial community shifts reflect losses of native soil carbon with pyrogenic and fresh organic matter additions and are greatest in low-carbon soils

Applied and Environmental Microbiology ◽

10.1128/aem.02555-20 ◽

2021 ◽

Author(s):

Thea Whitman ◽

Silene DeCiucies ◽

Kelly Hanley ◽

Akio Enders ◽

Jamie Woolet ◽

...

Keyword(s):

Climate Change ◽

Organic Matter ◽

Soil Moisture ◽

Microbial Community ◽

Global Climate Change ◽

Global Climate ◽

Short Term ◽

Soil Microbial ◽

Fresh Organic Matter ◽

Pyrogenic Organic Matter

Soil organic carbon (SOC) plays an important role in regulating global climate change, carbon and nutrient cycling in soils, and soil moisture. Organic matter (OM) additions to soils can affect the rate at which SOC is mineralized by microbes, with potentially important effects on SOC stocks. Understanding how pyrogenic organic matter (PyOM) affects the cycling of native SOC (nSOC) and the soil microbes responsible for these effects is important for fire-affected ecosystems as well as for biochar-amended systems. We used an incubation trial with five different soils from National Ecological Observatory Network sites across the US and 13C-labelled 350°C corn stover PyOM and fresh corn stover OM to trace nSOC-derived CO2 emissions with and without PyOM and OM amendments. We used high-throughput sequencing of rRNA genes to characterize bacterial, archaeal, and fungal communities and their response to PyOM and OM in soils that were previously stored at -80°C. We found that the effects of amendments on nSOC-derived CO2 reflected the unamended soil C status, where relative increases in C mineralization were greatest in low-C soils. OM additions produced much greater effects on nSOC-CO2 emissions than PyOM additions. Furthermore, the magnitude of microbial community composition change mirrored the magnitude of increases in nSOC-CO2, indicating a specific subset of microbes were likely responsible for the observed changes in nSOC mineralization. However, PyOM responders differed across soils and did not necessarily reflect a common “charosphere”. Overall, this study suggests that soils that already have low SOC may be particularly vulnerable to short-term increases in SOC loss with OM or PyOM additions. Importance Soil organic matter (SOM) has an important role in global climate change, carbon and nutrient cycling in soils, and soil moisture dynamics. Understanding the processes that affect SOM stocks is important for managing these functions. Recently, understanding how fire-affected organic matter (or “pyrogenic” organic matter (PyOM)) affects existing SOM stocks has become increasingly important, both due to changing fire regimes, and to interest in “biochar” – pyrogenic organic matter that is produced intentionally for carbon management or as an agricultural soil amendment. We found that soils with less SOM were more prone to increased losses with PyOM (and fresh organic matter) additions, and that soil microbial communities changed more in soils that also had greater SOM losses with PyOM additions. This suggests that soils that already have low SOM content may be particularly vulnerable to short-term increases in SOM loss, and that a subset of the soil microbial community is likely responsible for these effects.

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Determinants of soil respiration in a semi-arid savanna ecosystem, Kruger National Park, South Africa

Koedoe ◽

10.4102/koedoe.v53i1.1041 ◽

2011 ◽

Vol 53 (1) ◽

Cited By ~ 7

Author(s):

Rudzani A. Makhado ◽

Robert J. Scholes

Keyword(s):

Climate Change ◽

Soil Moisture ◽

Soil Respiration ◽

Soil Temperature ◽

Protected Areas ◽

Global Climate ◽

Soil Carbon Dioxide ◽

Global Carbon Budget ◽

Savanna Soils ◽

Global Carbon

Soil respiration, which is a combination of root respiration and microbial respiration, represents one of the main carbon fluxes in savannas. However, it is remarkable how little is known about these components – regarding either process-level mechanisms or quantitative estimates, especially in savanna ecosystems. Given the extensive area of savannas worldwide, this limits our ability to understand and predict the critical changes in the global carbon budget that underlie the phenomenon of global climate change. From May 2000 to April 2001, bi-weekly soil respiration measurements from two savanna types were made in 14 sampling collars (diameter = 100 mm), using a PP Systems EGM-2 respirometer. Results indicated that there was a difference in the rate of respiration between the more clayey Acacia and sandier Combretum savanna soils (p = 0.028). The mean (± s.d.) soil respiration in the Acacia savanna was 0.540 g/m2/h ± 0.419 g/m2/h, whilst it was 0.484 g/m2/h ± 0.383 g/m2/h in the Combretum savanna. We also found that soil respiration was sensitive to soil moisture and soil temperature. The rate of soil respiration at both sites rose to a maximum when soil temperature was at 28 °C and declined at higher temperatures, despite different temperature sensitivities. Soil respiration increased approximately linearly with an increase of soil moisture. In both savanna sites soil is subject to a combination of high temperature and water stress, which controls the fluxes of soil carbon dioxide. We found that the two sites differed significantly in their soil moisture characteristics (p < 0.0001) but not with regard to temperature (p = 0.141), which implies that soil moisture is the main factor responsible for the differences in respiration between Acacia and Combretum savannas.Conservation implications: It is argued for many protected areas that they perform a climate change buffering function. Knowing the soil respiration rate and determining its controlling factors contribute to improved understanding of whether protected areas will be net sources or sinks of carbon in the future.

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