scholarly journals Tree cover influences the soil C balance in Mediterranean cork oak-based silvopastoral systems

2022 ◽  
Vol 215 ◽  
pp. 105234
Author(s):  
Antonio Pulina ◽  
Sergio Campus ◽  
Chiara Cappai ◽  
Pier Paolo Roggero ◽  
Lorenzo Salis ◽  
...  
Keyword(s):  
Cork Oak ◽  
Tree Cover ◽  
Silvopastoral Systems ◽  
Soil C ◽  
C Balance ◽  
Soil C Balance

Soil carbon stabilization along climate and stand productivity gradients in black spruce forests of interior Alaska

2005 ◽  
Vol 35 (9) ◽  
pp. 2118-2129 ◽  
Author(s):  
E S Kane ◽  
D W Valentine ◽  
E AG Schuur ◽  
K Dutta
Keyword(s):  
Organic Matter ◽  
Primary Production ◽  
Soil Temperature ◽  
Black Spruce ◽  
Mineral Soil ◽  
Soil C ◽  
Stand Productivity ◽  
Interior Alaska ◽  
C Balance ◽  
Soil C Balance

The amount of soil organic carbon (SOC) in stable, slow-turnover pools is likely to change in response to climate warming because processes mediating soil C balance (net primary production and decomposition) vary with environmental conditions. This is important to consider in boreal forests, which constitute one of the world's largest stocks of SOC. We investigated changes in soil C stabilization along four replicate gradients of black spruce productivity and soil temperature in interior Alaska to develop empirical relationships between SOC and stand and physiographic features. Total SOC harbored in mineral soil horizons decreased by 4.4 g C·m–2 for every degree-day increase in heat sum within the organic soil across all sites. Furthermore, the proportion of relatively labile light-fraction (density <1.6 g·cm–3) soil organic matter decreased significantly with increased stand productivity and soil temperature. Mean residence times of SOC (as determined by Δ14C) in dense-fraction (>1.6 g·cm–3) mineral soil ranged from 282 to 672 years. The oldest SOC occurred in the coolest sites, which also harbored the most C and had the lowest rates of stand production. These results suggest that temperature sensitivities of organic matter within discrete soil pools, and not just total soil C stocks, need to be examined to project the effects of changing climate and primary production on soil C balance.

scholarly journals Ryegrass root and shoot residues differentially affect short-term priming of soil organic matter and net soil C-balance

2019 ◽  
Vol 93 ◽  
pp. 103096 ◽  
Author(s):  
Lumbani Mwafulirwa ◽  
Elizabeth M. Baggs ◽  
Nick Morley ◽  
Eric Paterson
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Short Term ◽  
Soil C ◽  
C Balance ◽  
Soil C Balance

scholarly journals Short-term impact of crop diversification on soil carbon fluxes and balance in rainfed and irrigated woody cropping systems under semiarid Mediterranean conditions

2021 ◽  
Author(s):  
María Martínez-Mena ◽  
Carolina Boix-Fayos ◽  
Efrain Carrillo-López ◽  
Elvira Díaz-Pereira ◽  
Raúl Zornoza ◽  
...  
Keyword(s):  
Soil Carbon ◽  
Carbon Balance ◽  
Climate Change Mitigation ◽  
Cropping Systems ◽  
Crop Diversification ◽  
Short Term ◽  
Soil C ◽  
Soil C Balance ◽  
Woody Crop ◽  
Change Mitigation

Abstract Purpose Diversification practices such as intercropping in woody cropping systems have recently been proposed as a promising management strategy for addressing problems related to soil degradation, climate change mitigation and food security. In this study, we assess the impact of several diversification practices in different management regimes on the main carbon fluxes regulating the soil carbon balance under semiarid Mediterranean conditions. Methods The study was conducted in two nearby cropping systems: (i) a low input rainfed almond (Prunus dulcis Mill.) orchard cultivated on terraces and (ii) a levelled intensively irrigated mandarin (Citrus reticulata Blanco) orchard with a street-ridge morphology. The almond trees were intercropped with Capparis spinosa or with Thymus hyemalis While the mandarin trees were intercropped with a mixture of barley and vetch followed by fava bean. Changes caused by crop diversifications on C inputs into the soil and C outputs from the soil were estimated. Results Crop diversification did not affect soil organic carbon stocks but did affect the carbon inputs and outputs regulating the soil carbon balance of above Mediterranean agroecosystems. Crop diversification with perennials in the low-input rainfed woody crop system significantly improved the annual soil C balance in the short-term. However, crop diversification with annual species in the intensively managed woody crop system had not effect on the annual soil C balance. Conclusions Our results highlight the potential of intercropping with perennials in rainfed woody crop systems for climate change mitigation through soil carbon sequestration.

scholarly journals Introduction of Sorghum (Sorghum bicolor (L.) Moench) green manure in rotations of head salads and baby leaf crops under greenhouse

2016 ◽  
Vol 11 ◽  
Author(s):  
Luigi Morra ◽  
Domenico Cerrato ◽  
Maurizio Bilotto ◽  
Salvatore Baiano
Keyword(s):  
Organic Carbon ◽  
Total Nitrogen ◽  
Green Manure ◽  
Soil C ◽  
C Balance ◽  
Soil Biomass ◽  
Starting Point ◽  
Dry Biomass ◽  
One Year ◽  
And Control

This paper deals with the introduction in tunnel-greenhouses of sweet sorghum cultivated in short, summer cycle as green manure with the aim to amend soils with biomass grown on farm. This practice has been spreading in tunnels of Sele river Valley (Salerno, Italy) where baby leaf crops are cultivated in numerous cycles (up to 5-7) per year. Three sorghum varieties for forage or biomass (Goliath, BMR 201 and BMR 333) were cultivated in two farms at Eboli and San Marzano sul Sarno with the aims to study their responses in term of fresh and dry aboveground biomass yielded, C and N content of the biomass incorporated in soil, C balance in amended soils after one year of ordinary cash crop sequences. No differences, with regard to all the parameters measured, were pointed out among the tested varieties in each site. The sorghum cycle lasted 45 days at Eboli, yielding on average 98 and 13 t ha<sup>-1</sup> of fresh and dry biomass, respectively; soil biomass incorporation supplied, on average 5.8 t ha<sup>-1</sup> of organic carbon and 273 kg ha<sup>-1</sup> of total nitrogen. In the farm of San Marzano, sorghum cycle lasted 68 days, yielding 116 and 18 t ha<sup>-1</sup> of fresh and dry biomass, respectively; soil biomass incorporation supplied, on average 8 t ha<sup>-1</sup> of organic carbon and 372 kg ha<sup>-1</sup> of total nitrogen. After one year, the plots amended with sorghum biomass showed a soil organic carbon (SOC) concentration not different from the starting point while SOC decreased in fallow plots. At Eboli, initial SOC content was 12.3 g kg<sup>-1</sup>, but one year later it resulted 12.3, 12.8, 12.2 and 11.3 g kg<sup>-1</sup> in BMR 201, BMR 333, Goliath and control plots, respectively. At San Marzano initial SOC content was 11.4 g kg<sup>-1</sup>, but one year later it resulted 11, 12, 10.7 and 10.5 g kg<sup>-1</sup> in BMR 201, BMR 333, Goliath and control plots, respectively. The annual C balance put in evidence that the green manure with sorghum biomass caused SOC losses higher than those detected in fallow plots let us supposing a prime effect in boosting the soil microbial C mineralization. Only cv BMR 333 in the Eboli trial, pointed out a positive SOC change of 1.8 t ha<sup>-1</sup>. Further studies are requested to better understand the real efficacy of sorghum cover crop in soil amendment under tunnels devoted to intensive vegetable crop sequence.

scholarly journals Influence of climate change factors on carbon dynamics in northern forested peatlands

2006 ◽  
Vol 86 (Special Issue) ◽  
pp. 269-280 ◽  
Author(s):  
C. C. Trettin ◽  
R. Laiho ◽  
K. Minkkinen ◽  
J. Laine
Keyword(s):  
Climate Change ◽  
Organic Matter ◽  
Management Practices ◽  
Atmospheric Temperature ◽  
Soil C ◽  
Altered Hydrology ◽  
Biogeochemical Models ◽  
C Dynamics ◽  
C Balance ◽  
C Cycle

Peatlands are carbon-accumulating wetland ecosystems, developed through an imbalance among organic matter production and decomposition processes. Soil saturation is the principal cause of anoxic conditions that constrain organic matter decay. Accordingly, changes in the hydrologic regime will affect the carbon (C) dynamics in forested peatlands. Our objective is to review ecological studies and experiments on managed peatlands that provide a basis for assessing the effects of an altered hydrology on C dynamics. We conclude that climate change influences will be mediated primarily through the hydrologic cycle. A lower water table resulting from altered precipitation patterns and increased atmospheric temperature may be expected to decrease soil CH4 and increase CO2 emissions from the peat surface. Correspondingly, the C balance in forested peatlands is also sensitive to management and restoration prescriptions. Increases in soil CO2 efflux do not necessarily equate with net losses from the soil C pool. While the fundamentals of the C balance in peatlands are well-established, the combined affects of global change stressors and management practices are best considered using process-based biogeochemical models. Long-term studies are needed both for validation and to provide a framework for longitudinal assessments of the peatland C cycle. Key words: Peatland, carbon cycle, methane, forest, wetland.

Influence of tree cover on herbaceous layer development and carbon and water fluxes in a Portuguese cork-oak woodland

2014 ◽  
Vol 59 ◽  
pp. 35-45 ◽  
Author(s):  
Maren Dubbert ◽  
Alexander Mosena ◽  
Arndt Piayda ◽  
Matthias Cuntz ◽  
Alexandra Cristina Correia ◽  
...  
Keyword(s):  
Cork Oak ◽  
Tree Cover ◽  
Water Fluxes ◽  
Herbaceous Layer ◽  
Oak Woodland ◽  
Layer Development

scholarly journals Fire-regime variability impacts forest carbon dynamics for centuries to millennia

2017 ◽  
Author(s):  
Tara W. Hudiburg ◽  
Philip E. Higuera ◽  
Jeffrey A. Hicke
Keyword(s):  
Carbon Balance ◽  
Fire Regime ◽  
Fire Regimes ◽  
Ecosystem Models ◽  
Soil C ◽  
Ecosystem Carbon ◽  
C Balance ◽  
Net Ecosystem Carbon Balance ◽  
Forest C

Abstract. Wildfire is a dominant disturbance agent in forest ecosystems, shaping important biogeochemical processes including net carbon (C) balance. Long-term monitoring and chronosequence studies highlight a resilience of biogeochemical properties to large, stand-replacing, high-severity fire events. In contrast, the consequences of repeated fires or temporal variability in a fire regime (e.g., the characteristic timing or severity of fire) are largely unknown, yet theory suggests that such variability could strongly influence forest C trajectories for millennia. Here we combine a 4500-year paleoecological record of fire activity with ecosystem modeling to investigate how fire-regime variability impacts soil C and net ecosystem carbon balance. We found that C trajectories in a paleo-informed scenario differed significantly from an equilibrium scenario (with a constant fire return interval), largely due to variability in the timing and severity of past fires. Paleo-informed scenarios contained multi-century periods of positive and negative net ecosystem C balance, with magnitudes significantly larger than observed under the equilibrium scenario. Further, this variability created legacies in soil C trajectories that lasted for millennia, and was of a magnitude great than simulated under an equilibrium, climate-warming scenario (i.e., 2 °C growing season warming). Our results imply that fire-regime variability is a major driver of C trajectories in stand-replacing fire regimes. Predicting carbon balance in these systems, therefore, will depend strongly on the ability of ecosystem models to represent a realistic range of fire-regime variability over the past several centuries to millennia.

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