scholarly journals The response of soil carbon storage and microbially mediated carbon turnover to simulated climatic disturbance in a northern peatland forest. Revisiting the concept of soil organic matter recalcitrance

2015 ◽  
Author(s):  
Joel Kostka ◽  
◽  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Carbon ◽  
Carbon Storage ◽  
Carbon Turnover ◽  
Soil Carbon Storage

scholarly journals Long-term nitrogen addition suppresses microbial degradation, enhances soil carbon storage, and alters the molecular composition of soil organic matter

2019 ◽  
Vol 142 (2) ◽  
pp. 299-313 ◽  
Author(s):  
Jun-Jian Wang ◽  
Richard D. Bowden ◽  
Kate Lajtha ◽  
Susan E. Washko ◽  
Sarah J. Wurzbacher ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Carbon ◽  
Carbon Storage ◽  
Microbial Degradation ◽  
Nitrogen Addition ◽  
Molecular Composition ◽  
Soil Carbon Storage

scholarly journals A dual isotope approach to isolate soil carbon pools of different turnover times

2013 ◽  
Vol 10 (12) ◽  
pp. 8067-8081 ◽  
Author(s):  
M. S. Torn ◽  
M. Kleber ◽  
E. S. Zavaleta ◽  
B. Zhu ◽  
C. B. Field ◽  
...  
Keyword(s):  
Environmental Change ◽  
Soil Carbon ◽  
Carbon Storage ◽  
Co2 Efflux ◽  
Carbon Turnover ◽  
Soil Carbon Storage ◽  
Density Fraction ◽  
Dual Isotope ◽  
Slow Cycling ◽  
Soil Carbon Turnover

Abstract. Soils are globally significant sources and sinks of atmospheric CO2. Increasing the resolution of soil carbon turnover estimates is important for predicting the response of soil carbon cycling to environmental change. We show that soil carbon turnover times can be more finely resolved using a dual isotope label like the one provided by elevated CO2 experiments that use fossil CO2. We modeled each soil physical fraction as two pools with different turnover times using the atmospheric 14C bomb spike in combination with the label in 14C and 13C provided by an elevated CO2 experiment in a California annual grassland. In sandstone and serpentine soils, the light fraction carbon was 21–54% fast cycling with 2–9 yr turnover, and 36–79% slow cycling with turnover slower than 100 yr. This validates model treatment of the light fraction as active and intermediate cycling carbon. The dense, mineral-associated fraction also had a very dynamic component, consisting of ∼7% fast-cycling carbon and ∼93% very slow cycling carbon. Similarly, half the microbial biomass carbon in the sandstone soil was more than 5 yr old, and 40% of the carbon respired by microbes had been fixed more than 5 yr ago. Resolving each density fraction into two pools revealed that only a small component of total soil carbon is responsible for most CO2 efflux from these soils. In the sandstone soil, 11% of soil carbon contributes more than 90% of the annual CO2 efflux. The fact that soil physical fractions, designed to isolate organic material of roughly homogeneous physico-chemical state, contain material of dramatically different turnover times is consistent with recent observations of rapid isotope incorporation into seemingly stable fractions and with emerging evidence for hot spots or micro-site variation of decomposition within the soil matrix. Predictions of soil carbon storage using a turnover time estimated with the assumption of a single pool per density fraction would greatly overestimate the near-term response to changes in productivity or decomposition rates. Therefore, these results suggest a slower initial change in soil carbon storage due to environmental change than has been assumed by simpler (one-pool) mass balance calculations.

Soil carbon storage informed by particulate and mineral-associated organic matter

2019 ◽  
Vol 12 (12) ◽  
pp. 989-994 ◽  
Author(s):  
M. Francesca Cotrufo ◽  
Maria Giovanna Ranalli ◽  
Michelle L. Haddix ◽  
Johan Six ◽  
Emanuele Lugato
Keyword(s):  
Organic Matter ◽  
Soil Carbon ◽  
Carbon Storage ◽  
Soil Carbon Storage

scholarly journals Using Bulk Soil Radiocarbon Measurements to Estimate Soil Organic Matter Turnover Times: Implications for Atmospheric CO2 Levels

Radiocarbon ◽  
1996 ◽  
Vol 38 (2) ◽  
pp. 181-190 ◽  
Author(s):  
Kevin G. Harrison
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Carbon ◽  
Carbon Storage ◽  
Organic Matter Turnover ◽  
Native Soil ◽  
Soil Organic Matter Turnover ◽  
Anthropogenic Nitrogen ◽  
Derivatives Of ◽  
Anthropogenic Nitrogen Deposition

Although soil contains about three times the amount of carbon present in the preindustrial atmosphere, determining how perturbations (e.g., changing land use, CO2 fertilization, changing climate and anthropogenic nitrogen deposition) alter soil carbon storage and influence atmospheric CO2 levels has proved elusive. Not knowing the soil carbon turnover times causes part of this uncertainty. I outline a strategy for using radiocarbon measurements to estimate soil organic matter turnover times and inventories in native soil. The resulting estimates of carbon exchange produce reasonable agreement with measurements of CO2 fluxes from soil. Furthermore, derivatives of the model are used to explore soil carbon dynamics of cultivated and recovering soil. Because the models can reproduce observed soil 14C measurements in native, cultivated, and recovering ecosystems (i.e., the underlying assumptions appear reasonable), the native model was modified to estimate the potential rate of additional carbon storage because of CO2 fertilization. This process may account for 45–65% of the “missing CO2 sink.”

scholarly journals Long-term steady state <sup>13</sup>C labelling to investigate soil carbon turnover in grasslands

2007 ◽  
Vol 4 (3) ◽  
pp. 385-394 ◽  
Author(s):  
K. Klumpp ◽  
J. F. Soussana ◽  
R. Falcimagne
Keyword(s):  
Organic Matter ◽  
Steady State ◽  
Soil Organic Matter ◽  
Soil Carbon ◽  
Residence Time ◽  
Particulate Organic Matter ◽  
Mean Residence Time ◽  
Carbon Turnover ◽  
13C Labelling

Abstract. We have set up a facility allowing steady state 13CO2 labeling of short stature vegetation (12 m2) for several years. 13C labelling is obtained by scrubbing the CO2 from outdoors air with a self-regenerating molecular sieve and by replacing it with 13C depleted (−34.7±0.03‰) fossil-fuel derived CO2 The facility, which comprises 16 replicate mesocosms, allows to trace the fate of photosynthetic carbon in plant-soil systems in natural light and at outdoors temperature. This method was applied to the study of soil organic carbon turnover in temperate grasslands. We tested the hypothesis that a low disturbance by grazing and cutting of the grassland increases the mean residence time of carbon in coarse (>0.2 mm) soil organic fractions. Grassland monoliths (0.5×0.5×0.4 m) were sampled from high and low disturbance treatments in a long-term (14 yrs) grazing experiment and were placed during two years in the mesocosms. During daytime, the canopy enclosure in each mesocosm was supplied in an open flow with air at mean CO2 concentration of 425 µmol mol−1 and δ13C of −21.5±0.27‰. Fully labelled mature grass leaves reached a δ13C of −40.8 (±0.93) and −42.2‰ (±0.60) in the low and high disturbance treatments, respectively, indicating a mean 13C labelling intensity of 12.7‰ compared to unlabelled control grass leaves. After two years, the delta 13C value of total soil organic matter above 0.2 mm was reduced in average by 7.8‰ in the labelled monoliths compared to controls. The isotope mass balance technique was used to calculate for the top (0–10 cm) soil the fraction of 13C labelled carbon in the soil organic matter above 0.2 mm (i.e. roots, rhizomes and particulate organic matter). A first order exponential decay model fitted to the unlabelled C in this fraction shows an increase in mean residence time from 22 to 31 months at low compared to high disturbance. A slower decay of roots, rhizomes and particulate organic matter above 0.2 mm is therefore likely to contribute to the observed increased in soil carbon sequestration in grassland monoliths exposed to low disturbance.

How much more carbon can be sorbed to soil?

2020 ◽  
Author(s):  
Rose Abramoff ◽  
Katerina Georgiou ◽  
Bertrand Guenet ◽  
Margaret Torn ◽  
Yuanyuan Huang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Carbon ◽  
Carbon Storage ◽  
Critical Role ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Soil Carbon Storage ◽  
Carbon Decomposition ◽  
Organic Matter Stabilization ◽  
Sorption Potential

&lt;p&gt;Quantifying the upper limit of stable soil carbon storage and relative saturation is essential for guiding policies designed to increase soil carbon storage, such as &amp;#8216;4 per 1000&amp;#8217; sequestration initiative. Carbon stabilization processes are diverse, but one particular pool of carbon that is considered stable across climate zones and soil types is the mineral-associated fraction, measured using density or size fractionation. Some soil carbon decomposition models assume sorption to minerals is the main form of stabilization in this fraction. We estimate the global capacity of mineral soils in six soil orders to sorb additional dissolved organic carbon (DOC). We gathered data from 400 DOC sorption experiments representing 133 soil profiles across six soil orders. We used the relationship between DOC added and DOC sorbed to calibrate a modified Langmuir sorption equation, from which we quantified the DOC sorption potential in each soil. We found that the sorption potential is empirically related to climate variables (including mean annual temperature and mean annual precipitation) and soil geochemical variables (chiefly, percent clay, pH, and soil order). From this relationship, we then estimated the DOC sorption potential for 14631 profiles distributed globally. This amount was 1.4 (global median; 95% CI: 0.50, 2.8) kg C m&lt;sup&gt;-3&lt;/sup&gt;, totaling 102 Pg C globally across six soil orders, representing up to a 7% increase in the existing total C stock. We show that there is greater capacity for additional DOC sorption in subsoils (30cm-1m) compared to top-soils (0-30cm). The gap between the modest potential of mineral sorption processes found in this study and the large total capacity of long-term organic matter stabilization (2541 Pg C for the six soil orders of this study) indicates that other mechanisms such as aggregation, the sorption of microbial necromass, layering, and co-precipitation also play a critical role in stable organic matter formation and persistence.&lt;/p&gt;

scholarly journals Accelerated soil carbon turnover under tree plantations limits soil carbon storage

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Guangshui Chen ◽  
Yusheng Yang ◽  
Zhijie Yang ◽  
Jinsheng Xie ◽  
Jianfen Guo ◽  
...  
Keyword(s):  
Soil Carbon ◽  
Carbon Storage ◽  
Tree Plantations ◽  
Carbon Turnover ◽  
Soil Carbon Storage ◽  
Soil Carbon Turnover

Modeling Soil Carbon Storage in the “Espinal” Agroecosystem of Central Chile

2008 ◽  
Vol 22 (2) ◽  
pp. 148-158 ◽  
Author(s):  
Neal Stolpe ◽  
Cristina Muñoz ◽  
Erick Zagal ◽  
Carlos Ovalle
Keyword(s):  
Soil Carbon ◽  
Carbon Storage ◽  
Soil Carbon Storage ◽  
Central Chile
Sign in / Sign up

Export Citation Format

Share Document