scholarly journals Nonlinear turnover rates of soil carbon following cultivation of native grasslands and subsequent afforestation of croplands

SOIL ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 415-431
Author(s):  
Guillermo Hernandez-Ramirez ◽  
Thomas J. Sauer ◽  
Yury G. Chendev ◽  
Alexander N. Gennadiev

Abstract. Land use conversions can strongly impact soil organic matter (SOM) storage, which creates paramount opportunities for sequestering atmospheric carbon into the soil. It is known that land uses such as annual cropping and afforestation can decrease and increase SOM, respectively; however, the rates of these changes over time remain elusive. This study focused on extracting the kinetics (k) of turnover rates that describe these long-term changes in soil C storage and also quantifying the sources of soil C. We used topsoil organic carbon density and δ13C isotopic composition data from multiple chronosequences and paired sites in Russia and United States. Reconstruction of soil C storage trajectory over 250 years following conversion from native grassland to continual annual cropland revealed a C depletion rate of 0.010 yr−1 (first-order k rate constant), which translates into a mean residence time (MRT) of 100 years (R2≥0.90). Conversely, soil C accretion was observed over 70 years following afforestation of annual croplands at a much faster k rate of 0.055 yr−1. The corresponding MRT was only 18 years (R2=0.997) after a lag phase of 5 years. Over these 23 years of afforestation, trees contributed 14 Mg C ha−1 to soil C accrual in the 0 to 15 cm depth increment. This tree-C contribution reached 22 Mg C ha−1 at 70 years after tree planting. Over these 70 years of afforestation, the proportion of tree C to whole-soil C increased to reach a sizable 79 %. Furthermore, assuming steady state of soil C in the adjacent croplands, we also estimated that 45 % of the prairie C existent at the time of tree planting was still present in the afforested soils 70 years later. As an intrinsic property of k modeling, the derived turnover rates that represent soil C changes over time are nonlinear. Soil C changes were much more dynamic during the first decades following a land use conversion than afterwards when the new land use system approached equilibrium. Collectively, results substantiated that C sequestration in afforested lands is a suitable means to proactively mitigate escalating climate change within a typical person's lifetime, as indicated by MRTs of a few decades.

2021 ◽  
Author(s):  
Guillermo Hernandez-Ramirez ◽  
Thomas J. Sauer ◽  
Yury G. Chendev ◽  
Alexander N. Gennadiev

Abstract. Land use conversions can strongly impact soil organic matter (SOM) storage, which creates paramount opportunities for sequestering atmospheric carbon into the soil. It is known that land uses such as annual cropping and afforestation can decrease and increase SOM, respectively; however, the rates of these changes over time remain elusive. This study focused on extracting the kinetics (k) of turnover rates that describe these long-term changes in soil C storage and also quantifying the sources of soil C. We used topsoil organic carbon density and δ13C isotopic composition data from multiple chronosequences and paired sites in Russia and United States. Reconstruction of soil C storage trajectory over 250 years following conversion from native grassland to continual annual cropland revealed a C depletion rate of 0.010 years−1 (first-order k rate constant), which translates into a mean residence time (MRT) of 100 years (R2 ≥ 0.90). Conversely, soil C accretion was observed over 70 years following afforestation of annual croplands at a much faster k rate of 0.055 years−1. The corresponding MRT was only 18 years (R2 = 0.997) after a lag phase of 5 years. Over these 23 years of afforestation, trees contributed 14 Mg C Ha−1 to soil C accrual in the 0 to 15 cm depth increment. This tree-C contribution reached 22 Mg C Ha−1 at 70 years after tree planting. Over these 70 years of afforestation, the proportion of tree-C to whole soil C increased to reach a sizeable 79 %. Furthermore, assuming steady state of soil C in the adjacent croplands, we also estimated that 45 % of the prairie-C existent at time of tree planting was still present in the afforested soils 70 years later. As intrinsic of k modelling, the derived turnover rates that represent soil C changes over time are nonlinear. Soil C changes were much more dynamic during the first decades following a land use conversion than afterwards when the new land use system approached equilibrium. Collectively, results substantiated that C sequestration in afforested lands is a suitable means to proactively mitigate escalating climate change within a typical person's lifetime, as indicated by MRTs of few decades.


2019 ◽  
Vol 192 ◽  
pp. 134-143 ◽  
Author(s):  
Ileana Frasier ◽  
Alberto Quiroga ◽  
Romina Fernández ◽  
Cristian Álvarez ◽  
Florencia Gómez ◽  
...  

Author(s):  
Meng Na ◽  
Xiaoyang Sun ◽  
Yandong Zhang ◽  
Zhihu Sun ◽  
Johannes Rousk

AbstractSoil carbon (C) reservoirs held in forests play a significant role in the global C cycle. However, harvesting natural forests tend to lead to soil C loss, which can be countered by the establishment of plantations after clear cutting. Therefore, there is a need to determine how forest management can affect soil C sequestration. The management of stand density could provide an effective tool to control soil C sequestration, yet how stand density influences soil C remains an open question. To address this question, we investigated soil C storage in 8-year pure hybrid larch (Larix spp.) plantations with three densities (2000 trees ha−1, 3300 trees ha−1 and 4400 trees ha−1), established following the harvesting of secondary mixed natural forest. We found that soil C storage increased with higher tree density, which mainly correlated with increases of dissolved organic C as well as litter and root C input. In addition, soil respiration decreased with higher tree density during the most productive periods of warm and moist conditions. The reduced SOM decomposition suggested by lowered respiration was also corroborated with reduced levels of plant litter decomposition. The stimulated inputs and reduced exports of C from the forest floor resulted in a 40% higher soil C stock in high- compared to low-density forests within 8 years after plantation, providing effective advice for forest management to promote soil C sequestration in ecosystems.


2012 ◽  
Vol 79 (4) ◽  
pp. 1191-1199 ◽  
Author(s):  
Sarah D. Eisenlord ◽  
Zachary Freedman ◽  
Donald R. Zak ◽  
Kai Xue ◽  
Zhili He ◽  
...  

ABSTRACTFuture rates of anthropogenic N deposition can slow the cycling and enhance the storage of C in forest ecosystems. In a northern hardwood forest ecosystem, experimental N deposition has decreased the extent of forest floor decay, leading to increased soil C storage. To better understand the microbial mechanisms mediating this response, we examined the functional genes derived from communities of actinobacteria and fungi present in the forest floor using GeoChip 4.0, a high-throughput functional-gene microarray. The compositions of functional genes derived from actinobacterial and fungal communities was significantly altered by experimental nitrogen deposition, with more heterogeneity detected in both groups. Experimental N deposition significantly decreased the richness and diversity of genes involved in the depolymerization of starch (∼12%), hemicellulose (∼16%), cellulose (∼16%), chitin (∼15%), and lignin (∼16%). The decrease in richness occurred across all taxonomic groupings detected by the microarray. The compositions of genes encoding oxidoreductases, which plausibly mediate lignin decay, were responsible for much of the observed dissimilarity between actinobacterial communities under ambient and experimental N deposition. This shift in composition and decrease in richness and diversity of genes encoding enzymes that mediate the decay process has occurred in parallel with a reduction in the extent of decay and accumulation of soil organic matter. Our observations indicate that compositional changes in actinobacterial and fungal communities elicited by experimental N deposition have functional implications for the cycling and storage of carbon in forest ecosystems.


2021 ◽  
Vol 30 (1) ◽  
pp. 115-124
Author(s):  
Arafat Rahman ◽  
MS Islam ◽  
Humyra B Murshed ◽  
MJ Uddin ◽  
ASM Mohiuddin ◽  
...  

An investigation was carried out in four designated wetlands to assess soil organic carbon (SOC) storage and evaluate soil nutrients of the northeastern Sylhet basin of Bangladesh. SOC storage was the highest in the Nikli wetland (4.1 Tg), followed by Hakaluki (4.0 Tg), Hail (2.8 Tg) and Balai wetland soils (2.6 Tg) at 100 cm depths. It is found that the total soil C storage across the medium low land (MLL) and low land (LL) sites covering the four wetlands of the Sylhet basin is about 13.5Tg. C storage across the MLL and LL sites at 100 cm depths was estimated about 5.1Tg and 8.4Tg respectively. It is found that SOC storage was higher in the low land sites in contrast to medium low land sites. The soil property varies depending on land types, soil depths and spatial distributions. Among the investigated wetland soils, Hakaluki wetland stored higher amount of SOC in the deeper soil layers whereas an inverse relationship between soil depth and SOC storage was noted for rest of the wetlands. It is apprehended that SOC storage thus gradually lessening in greater magnitude due to climate change and other anthropogenic reasons. An integrated management approach should be developed to restore the SOC sink. Dhaka Univ. J. Biol. Sci. 30(1): 115-124, 2021 (January)


2007 ◽  
Vol 44 (2) ◽  
pp. 315-320 ◽  
Author(s):  
J. L. Smith ◽  
J. M. Bell ◽  
H. Bolton ◽  
V. L. Bailey

Soil Research ◽  
2019 ◽  
Vol 57 (8) ◽  
pp. 894
Author(s):  
Parijat Saikia ◽  
Kushal Kumar Baruah ◽  
Satya Sundar Bhattacharya ◽  
Chandrima Choudhury

Soil organic carbon (C) management in agricultural fields can act improve soil health and productivity. However, reports on the C release pattern and the interactive effects of plant physiological parameters on soil C storage from subtropical regions of the world where rice is cultivated as a dominant food crop are inadequate. The interactions between plant metabolism, soil C storage, and organic-based nutrient management schemes have been little studied. Hence, a study was undertaken in rainfed winter rice to evaluate the effects of different levels of organics (crop residue (CR) and farmyard manure (FYM)) along with inorganic (NPK) inputs in an alluvial soil. The experiment was conducted in a typical humid subtropical climate in north-eastern India. The CR of the preceding rice crop (pre-monsoon) and cow dung based FYM were used as organic inputs for monsoon rice, which were applied in various combinations with inorganic fertilisers. We studied the influence of these selected nutrient management schemes on soil health attributes, C storage, and plant parameters. The highest gain in C storage (11.65%) was in soil under 80% NPK + CR (5 t ha–1) + FYM (10 t ha–1) treatment. Correspondingly, significant improvement (P < 0.05) in total C, dissolved organic C, and nitrogen availability in soil was evident under this treatment leading to augmentation of soil organic matter status and the net amount of sequestered C in soil after two years of rice cultivation. Such improvements resulted in greater flag leaf photosynthesis, biomass accumulation, and grain yield than the conventionally managed crops. Overall, this research showcases that organic-dominated nutrient management not only restored soil health but was also able to compensate 20% of the recommended NPK fertilisation without penalty on crop yield.


2013 ◽  
Vol 79 (8) ◽  
pp. 2847-2847 ◽  
Author(s):  
Sarah D. Eisenlord ◽  
Zachary Freedman ◽  
Donald R. Zak ◽  
Kai Xue ◽  
Zhili He ◽  
...  

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