Seasonal patterns of soil respiration in intact and clear-cut northern hardwood forests

1994 ◽  
Vol 24 (8) ◽  
pp. 1711-1716 ◽  
Author(s):  
David E. Toland ◽  
Donald R. Zak
Keyword(s):  
Soil Respiration ◽  
Root Respiration ◽  
Microbial Respiration ◽  
Late Summer ◽  
Soda Lime ◽  
Forest Harvesting ◽  
Seasonal Patterns ◽  
Soil C ◽  
Northern Hardwood ◽  
Clear Cut

The flux of CO2 from forest soils is controlled by the respiration of plant roots and soil microorganisms, the rates of which are likely to change following forest harvesting. Root respiration should decrease, whereas microbial respiration should increase, in response to warmer soil temperatures and greater soil C availability following removal of the overstory. We investigated the influence of forest harvesting on seasonal patterns of soil respiration in two different northern hardwood ecosystems. One ecosystem was dominated in the overstory by Acersaccharum Marsh, and Quercusrubra L., and the other by A. saccharum and Tiliaamericana L.; two stands were studied in each ecosystem type. We measured daily rates of soil respiration using the soda-lime technique. Averaged across ecosystems, daily rates of soil respiration did not significantly differ between intact and clear-cut plots, nor did they differ between ecosystems or sites nested within ecosystems. Peak daily rates ranged from 2.75 to 3.00 g CO2-C•m−2•day−1 during mid to late summer in both intact and clear-cut plots. Soil temperature accounted for 43 and 58% of the variation in daily rates for intact and clear-cut plots, respectively. Annual soil respiration rates in intact (478 g CO2-C•m−2•year−1) and clear-cut (470 g CO2-C•m−1•year−1) plots did not differ significantly. Our results suggest that greater rates of microbial respiration in clear-cut plots proportionally offset a decrease in root respiration following clear-cut harvest.

scholarly journals Contribution of root respiration to soil respiration in a rape (Brassica campestris L.) field in Southwest China

2014 ◽  
Vol 60 (No. 1) ◽  
pp. 8-14 ◽  
Author(s):  
Q. Hao ◽  
C. Jiang
Keyword(s):  
Soil Respiration ◽  
Root Respiration ◽  
Southwest China ◽  
Brassica Campestris ◽  
Microbial Respiration ◽  
Belowground Biomass ◽  
Closed Chamber ◽  
Shoot Ratio ◽  
Root Shoot Ratio ◽  
Aboveground And Belowground Biomass

This study aimed to separate the respective contributions of root and microbial respiration to soil respiration in a rape field in Southwest China. The soil respiration was measured with a closed chamber technique and a regression method was used to apportion root and microbial respiration. Microbial and root respiration ranged from 70.67 to 183.77 mg CO<sub>2</sub>/m<sup>2</sup>/h and 21.99 to 193.09 mg CO<sub>2</sub>/m<sup>2</sup>/h, averaged 127.16 and 116.66 mg CO<sub>2</sub>/m<sup>2</sup>/h during the rape growing season, respectively. Root respiration coefficient ranged from 0.41 to 5.39 mg C-CO<sub>2</sub>/g C/h and was negatively correlated with root/shoot ratio, aboveground and belowground biomass, but positively correlated with root N content. The contribution of root respiration to soil respiration averaged 44.2%, ranging from 14.5% to 62.62%.

scholarly journals Seasonal Patterns of Soil Respiration and Related Soil Biochemical Properties under Nitrogen Addition in Winter Wheat Field

PLoS ONE ◽  
2015 ◽  
Vol 10 (12) ◽  
pp. e0144115 ◽  
Author(s):  
Guopeng Liang ◽  
Albert A. Houssou ◽  
Huijun Wu ◽  
Dianxiong Cai ◽  
Xueping Wu ◽  
...  
Keyword(s):  
Soil Respiration ◽  
Winter Wheat ◽  
Nitrogen Addition ◽  
Biochemical Properties ◽  
Seasonal Patterns ◽  
Wheat Field ◽  
Soil Biochemical Properties

scholarly journals Historical climate controls soil respiration responses to current soil moisture

2017 ◽  
Vol 114 (24) ◽  
pp. 6322-6327 ◽  
Author(s):  
Christine V. Hawkes ◽  
Bonnie G. Waring ◽  
Jennifer D. Rocca ◽  
Stephanie N. Kivlin
Keyword(s):  
Climate Change ◽  
Soil Moisture ◽  
Soil Respiration ◽  
Carbon Cycling ◽  
Large Scale ◽  
Microbial Respiration ◽  
Rainfall Gradient ◽  
Soil Microbial ◽  
Historical Climate ◽  
Moisture Dependence

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.

scholarly journals Distinct patterns in the diurnal and seasonal variability in four components of soil respiration in a temperate forest under free-air CO<sub>2</sub> enrichment

2011 ◽  
Vol 8 (10) ◽  
pp. 3077-3092 ◽  
Author(s):  
L. Taneva ◽  
M. A. Gonzalez-Meler
Keyword(s):  
Soil Respiration ◽  
Seasonal Variability ◽  
Ecosystem Respiration ◽  
Co2 Efflux ◽  
Diurnal Variability ◽  
Soil C ◽  
Free Air ◽  
C Cycle ◽  
Strong Control ◽  
Average Contribution

Abstract. Soil respiration (RS) is a major flux in the global carbon (C) cycle. Responses of RS to changing environmental conditions may exert a strong control on the residence time of C in terrestrial ecosystems and in turn influence the atmospheric concentration of greenhouse gases. Soil respiration consists of several components oxidizing soil C from different pools, age and chemistry. The mechanisms underlying the temporal variability of RS components are poorly understood. In this study, we used the long-term whole-ecosystem 13C tracer at the Duke Forest Free Air CO2 Enrichment site to separate forest RS into its autotrophic (RR) and heterotrophic components (RH). The contribution of RH to RS was further partitioned into litter decomposition (RL), and decomposition of soil organic matter (RSOM) of two age classes – up to 8 yr old and SOM older than 8 yr. Soil respiration was generally dominated by RSOM during the growing season (44% of daytime RS), especially at night. The contribution of heterotrophic respiration (RSOM and RL) to RS was not constant, indicating that the seasonal variability in RR alone cannot explain seasonal variation in RS. Although there was no diurnal variability in RS, there were significant compensatory differences in the contribution of individual RS components to daytime and nighttime rates. The average contribution of RSOM to RS was greater at night (54%) than during the day (44%). The average contribution of RR to total RS was ~30% during the day and ~34% during the night. In contrast, RL constituted 26% of RS during the day and only 12% at night. About 95% of the decomposition of soil C older than 8 yr (Rpre-tr) originated from RSOM and showed more pronounced and consistent diurnal variability than any other RS component; nighttime rates were on average 29% higher than daytime rates. In contrast, the decomposition of more recent, post-treatment C (Rpre-tr) did not vary diurnally. None of the diurnal variations in components of RH could be explained by only temperature and moisture variations. Our results indicate that the variation observed in the components of RS is the result of complex interaction between dominant biotic controls (e.g. plant activity, mineralization kinetics, competition for substrates) over abiotic controls (temperature, moisture). The interactions and controls among roots and other soil organisms that utilize C of different chemistry, accessibility and ages, results in the overall soil CO2 efflux. Therefore understanding the controls on the components of RS is necessary to elucidate the influence of ecosystem respiration on atmospheric C-pools at different time scales.

scholarly journals Soil respiration on an aging managed heathland: identifying an appropriate empirical model for predictive purposes

2013 ◽  
Vol 10 (5) ◽  
pp. 3007-3038 ◽  
Author(s):  
G. R. Kopittke ◽  
E. E. van Loon ◽  
A. Tietema ◽  
D. Asscheman
Keyword(s):  
Soil Respiration ◽  
Soil Temperature ◽  
Cultural Landscapes ◽  
Plant Biomass ◽  
Model Fit ◽  
Selection Procedures ◽  
Soil C ◽  
Experimental Planning ◽  
Improve Model ◽  
Level Model

Abstract. Heathlands are cultural landscapes which are managed through cyclical cutting, burning or grazing practices. Understanding the carbon (C) fluxes from these ecosystems provides information on the optimal management cycle time to maximise C uptake and minimise C output. The interpretation of field data into annual C loss values requires the use of soil respiration models. These generally include model variables related to the underlying drivers of soil respiration, such as soil temperature, soil moisture and plant activity. Very few studies have used selection procedures in which structurally different models are calibrated, then validated on separate observation datasets and the outcomes critically compared. We present thorough model selection procedures to determine soil heterotrophic (microbial) and autotrophic (root) respiration for a heathland chronosequence and show that soil respiration models are required to correct the effect of experimental design on soil temperature. Measures of photosynthesis, plant biomass, photosynthetically active radiation, root biomass, and microbial biomass did not significantly improve model fit when included with soil temperature. This contradicts many current studies in which these plant variables are used (but not often tested for parameter significance). We critically discuss a number of alternative ecosystem variables associated with soil respiration processes in order to inform future experimental planning and model variable selection at other heathland field sites. The best predictive model used a generalized linear multi-level model with soil temperature as the only variable. Total annual soil C loss from the young, middle and old communities was calculated to be 650, 462 and 435 g C m−2 yr−1, respectively.

scholarly journals Biological and physical influences on soil <sup>14</sup>CO<sub>2</sub> seasonal dynamics in a temperate hardwood forest

2013 ◽  
Vol 10 (12) ◽  
pp. 7999-8012 ◽  
Author(s):  
C. L. Phillips ◽  
K. J. McFarlane ◽  
D. Risk ◽  
A. R. Desai
Keyword(s):  
Soil Moisture ◽  
Soil Carbon ◽  
Root Respiration ◽  
Late Summer ◽  
Co2 Production ◽  
Forest Site ◽  
Surprising Result ◽  
Sampling Campaign ◽  
Microbial Turnover ◽  
High Frequency Sampling

Abstract. While radiocarbon (14C) abundances in standing stocks of soil carbon have been used to evaluate rates of soil carbon turnover on timescales of several years to centuries, soil-respired 14CO2 measurements are an important tool for identifying more immediate responses to disturbance and climate change. Soil Δ14CO2 data, however, are often temporally sparse and could be interpreted better with more context for typical seasonal ranges and trends. We report on a semi-high-frequency sampling campaign to distinguish physical and biological drivers of soil Δ14CO2 at a temperate forest site in northern Wisconsin, USA. We sampled 14CO2 profiles every three weeks during snow-free months through 2012 in three intact plots and one trenched plot that excluded roots. Respired Δ14CO2 declined through the summer in intact plots, shifting from an older C composition that contained more bomb 14C to a younger composition more closely resembling present 14C levels in the atmosphere. In the trenched plot, respired Δ14CO2 was variable but remained comparatively higher than in intact plots, reflecting older bomb-enriched 14C sources. Although respired Δ14CO2 from intact plots correlated with soil moisture, related analyses did not support a clear cause-and-effect relationship with moisture. The initial decrease in Δ14CO2 from spring to midsummer could be explained by increases in 14C-deplete root respiration; however, Δ14CO2 continued to decline in late summer after root activity decreased. We also investigated whether soil moisture impacted vertical partitioning of CO2 production, but found this had little effect on respired Δ14CO2 because CO2 contained modern bomb C at depth, even in the trenched plot. This surprising result contrasted with decades to centuries-old pre-bomb CO2 produced in lab incubations of the same soils. Our results suggest that root-derived C and other recent C sources had dominant impacts on respired Δ14CO2 in situ, even at depth. We propose that Δ14CO2 may have declined through late summer in intact plots because of continued microbial turnover of root-derived C, following declines in root respiration. Our results agree with other studies showing declines in the 14C content of soil respiration over the growing season, and suggest inputs of new photosynthates through roots are an important driver.

Soil and root respiration in mature Alaskan black spruce forests that vary in soil organic matter decomposition rates

2005 ◽  
Vol 35 (1) ◽  
pp. 161-174 ◽  
Author(s):  
Jason G Vogel ◽  
David W Valentine ◽  
Roger W Ruess
Keyword(s):  
Soil Respiration ◽  
Root Respiration ◽  
Forest Type ◽  
Black Spruce ◽  
Decomposition Rates ◽  
Spruce Forests ◽  
Moisture Deficit ◽  
Soil Temperatures ◽  
Boreal Ecosystem ◽  
Site Identification

Climate warming at high latitudes is expected to increase root and microbial respiration and thus cause an increase in soil respiration. We measured the root and microbial components of soil respiration near Fairbanks, Alaska, in 2000 and 2001, in three black spruce (Picea mariana (Mill) B.S.P.) forests. We hypothesized faster decomposition correlates with greater amounts of both root and microbial contributions to soil respiration. Contrary to our prediction, the site with the coolest summer soil temperatures and slowest decomposition (site identification "high-np") had significantly (p < 0.05) greater growing season soil respiration (485 g C·m–2·year–1) than the two other sites (372 and 332 g C·m–2·year–1). Spruce C allocation to root respiration was significantly greater, and fine-root N concentration was 10% and 12% greater (p < 0.05) at high-np than at the other two sites. High-np spruce foliage was also more enriched in 13C and depleted in 15N, suggesting either lower available moisture or slower N turnover. Either factor could drive greater C allocation to roots; however, a literature review suggests moisture deficit corresponds to greater C allocation to roots in black spruce forests across the boreal ecosystem. Controls on spruce C allocation need to be resolved before making the generalization that soil respiration will increase with warming in this forest type.

scholarly journals Temporal patterns in principal Salmonella serotypes in the USA; 1996–2014

2018 ◽  
Vol 146 (4) ◽  
pp. 437-441 ◽  
Author(s):  
M. R. Powell ◽  
S. M. Crim ◽  
R. M. Hoekstra ◽  
M. S. Williams ◽  
W. Gu
Keyword(s):  
Late Summer ◽  
Temporal Patterns ◽  
Confidence Bands ◽  
Seasonal Patterns ◽  
Spline Regression ◽  
Surveillance Network ◽  
Safety Measures ◽  
Annual Trend ◽  
The Usa ◽  
Salmonella Serotypes

AbstractAnalysing temporal patterns in foodborne illness is important to designing and implementing effective food safety measures. The reported incidence of illness due to Salmonella in the USA. Foodborne Diseases Active Surveillance Network (FoodNet) sites has exhibited no declining trend since 1996; however, there have been significant annual trends among principal Salmonella serotypes, which may exhibit complex seasonal patterns. Data from the original FoodNet sites and penalised cubic B-spline regression are used to estimate temporal patterns in the reported incidence of illness for the top three Salmonella serotypes during 1996–2014. Our results include 95% confidence bands around the estimated annual and monthly curves for each serotype. The results show that Salmonella serotype Typhimurium exhibits a statistically significant declining annual trend and seasonality (P < 0.001) marked by peaks in late summer and early winter. Serotype Enteritidis exhibits a significant annual trend with a higher incidence in later years and seasonality (P < 0.001) marked by a peak in late summer. Serotype Newport exhibits no significant annual trend with significant seasonality (P < 0.001) marked by a peak in late summer.

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