Impact of European Beech Forest Diversification on Soil Organic Carbon and Total Nitrogen Stocks–A Meta-Analysis

Drought-sensitive European beech forests are increasingly challenged by climate change. Admixing other, preferably more deep-rooting, tree species has been proposed to increase the resilience of beech forests to drought. This diversification of beech forests might also affect soil organic carbon (SOC) and total nitrogen (TN) stocks that are relevant for a wide range of soil functions and ecosystem services, such as water and nutrient retention, filter functions and erosion control. Since information of these effects is scattered, our aim was to synthesize results from studies that compared SOC/TN stocks of beech monocultures with those of beech stands mixed with other tree species as well as monocultures of other tree species. We conducted a meta-analysis including 38 studies with 203, 220, and 160 observations for forest floor (i.e., the organic surface layer), mineral soil (0.5 m depth) and the total soil profile, respectively. Monoculture conifer stands had higher SOC stocks compared to monoculture beech in general, especially in the forest floor (up to 200% in larch forests). In contrast, other broadleaved tree species (oak, ash, lime, maple, hornbeam) showed lower SOC stocks in the forest floor compared to beech, with little impact on total SOC stocks. Comparing mixed beech-conifer stands (average mixing ratio with regard to number of trees 50:50) with beech monocultures revealed significantly higher total SOC stocks of around 9% and a smaller increase in TN stocks of around 4%. This equaled a SOC accrual of 0.1 Mg ha−1 yr−1. In contrast, mixed beech-broadleaved stands did not show significant differences in total SOC stocks. Conifer admixture effects on beech forest SOC were of additive nature. Admixing other tree species to beech monoculture stands was most effective to increase SOC stocks on low carbon soils with a sandy texture and nitrogen limitation (i.e., a high C/N ratio and low nitrogen deposition). We conclude that, with targeted admixture measures of coniferous species, an increase in SOC stocks in beech forests can be achieved as part of the necessary adaptation of beech forests to climate change.

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Admixing other tree species to European beech forests: Effects on soil organic carbon and total nitrogen stocks. A review.

10.5194/egusphere-egu2020-10430 ◽

2020 ◽

Author(s):

Stephanie Rehschuh ◽

Michael Dannenmann

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Total Nitrogen ◽

Tree Species ◽

Forest Floor ◽

Mineral Soil ◽

European Beech ◽

Summer Drought ◽

Beech Forests ◽

Soc Stocks

Drought-sensitive European beech forests are increasingly challenged by climate change. Admixing other, preferably more deep-rooting, tree species has been proposed to increase the resilience of beech forests to summer drought. This might not only alter soil water dynamics and availability, but also soil organic carbon (SOC) and total nitrogen (TN) storage in soils. Since information of these effects is scattered, our aim was to synthesize results from studies that compared SOC/TN stocks of beech monocultures with those of mixed beech stands as well as of other monocultures. We conducted a meta-analysis including 40 studies with 208, 231 and 166 observations for forest floor, mineral soil and the total soil profile, respectively. Pure conifer stands had higher SOC stocks compared to beech in general, especially in the forest floor with up to 200% (larch forests). Other broadleaved tree species (ash, oak, lime, maple, hornbeam) showed in comparison to beech lower SOC storage in the forest floor, with little impact on total stocks. &#160;Similarly, for mixed beech-conifer stands we found significantly increased SOC stocks of >10% and a small increase in TN stocks of approx. 4% compared to beech monocultures, which means a potential SOC storage increase of >0.1 t ha-1yr-1 (transformation of mineral soil to 100 cm depth). In contrast, mixed beech-broadleaved stands did not show a significant change in total SOC stocks. Currently, the influence climatic and soil parameters on SOC changes due to admixture of other tree species is analyzed based on this dataset. This is expected to facilitate an assessment which mixtures with beech have the largest potential towards increasing SOC stocks.

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Soil Organic Carbon Stocks in Afforested Agricultural Land in Lithuanian Hemiboreal Forest Zone

Forests ◽

10.3390/f12111562 ◽

2021 ◽

Vol 12 (11) ◽

pp. 1562

Author(s):

Iveta Varnagirytė-Kabašinskienė ◽

Povilas Žemaitis ◽

Kęstutis Armolaitis ◽

Vidas Stakėnas ◽

Gintautas Urbaitis

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Forest Floor ◽

Agricultural Land ◽

Forest Stand ◽

Stand Age ◽

Soc Stock ◽

The Mean ◽

Soc Stocks ◽

Topsoil Layer

In the context of the specificity of soil organic carbon (SOC) storage in afforested land, nutrient-poor Arenosols and nutrient-rich Luvisols after afforestation with coniferous and deciduous tree species were studied in comparison to the same soils of croplands and grasslands. This study analysed the changes in SOC stock up to 30 years after afforestation of agricultural land in Lithuania, representing the cool temperate moist climate region of Europe. The SOC stocks were evaluated by applying the paired-site design. The mean mass and SOC stocks of the forest floor in afforested Arenosols increased more than in Luvisols. Almost twice as much forest floor mass was observed in coniferous than in deciduous stands 2–3 decades after afforestation. The mean bulk density of fine (<2 mm) soil in the 0–30 cm mineral topsoil layer of croplands was higher than in afforested sites and grasslands. The clear decreasing trend in mean bulk density due to forest stand age with the lowest values in the 21–30-year-old stands was found in afforested Luvisols. In contrast, the SOC concentrations in the 0–30 cm mineral topsoil layer, especially in Luvisols afforested with coniferous species, showed an increasing trend due to the influence of stand age. The mean SOC values in the 0–30 cm mineral topsoil layer of Arenosols and Luvisols during the 30 years after afforestation did not significantly differ from the adjacent croplands or grasslands. The mean SOC stock slightly increased with the forest stand age in Luvisols; however, the highest mean SOC stock was detected in the grasslands. In the Arenosols, there was higher SOC accumulation in the forest floor with increasing stand age than in the Luvisols, while the proportion of SOC stocks in mineral topsoil layers was similar and more comparable to grasslands. These findings suggest encouragement of afforestation of former agricultural land under the current climate and soil characteristics in the region, but the conversion of perennial grasslands to forest land should be done with caution.

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On the rebound: soil organic carbon stocks can bounce back to near forest levels when agroforests replace agriculture in southern India

SOIL Discussions ◽

10.5194/soild-2-871-2015 ◽

2015 ◽

Vol 2 (2) ◽

pp. 871-902 ◽

Cited By ~ 3

Author(s):

H. C. Hombegowda ◽

O. van Straaten ◽

M. Köhler ◽

D. Hölscher

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Tree Species ◽

Regional Scale ◽

Clay Fraction ◽

Carbon Stocks ◽

Southern India ◽

Reference Plot ◽

Soc Stock ◽

Soc Stocks

Abstract. Tropical agroforestry has an enormous potential to sequester carbon while simultaneously producing agricultural yields and tree products. The amount of soil organic carbon (SOC) sequestered is however influenced by the type of the agroforestry system established, the soil and climatic conditions and management. In this regional scale study, we utilized a chronosequence approach to investigate how SOC stocks changed when the original forests are converted to agriculture, and then subsequently to four different agroforestry systems (AFSs): homegarden, coffee, coconut and mango. In total we established 224 plots in 56 plot clusters across four climate zones in southern India. Each plot cluster consisted of four plots: a natural forest reference plot, an agriculture reference and two of the same AFS types of two ages (30–60 years and > 60 years). The conversion of forest to agriculture resulted in a large loss the original SOC stock (50–61 %) in the top meter of soil depending on the climate zone. The establishment of homegarden and coffee AFSs on agriculture land caused SOC stocks to rebound to near forest levels, while in mango and coconut AFSs the SOC stock increased only slightly above the agriculture stock. The most important variable regulating SOC stocks and its changes was tree basal area, possibly indicative of organic matter inputs. Furthermore, climatic variables such as temperature and precipitation, and soil variables such as clay fraction and soil pH were likewise all important regulators of SOC and SOC stock changes. Lastly, we found a strong correlation between tree species diversity in homegarden and coffee AFSs and SOC stocks, highlighting possibilities to increase carbon stocks by proper tree species assemblies.

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Pedogenic Threshold in Acidity Explains Context-Dependent Tree Species Effects on Soil Carbon

Frontiers in Forests and Global Change ◽

10.3389/ffgc.2021.679813 ◽

2021 ◽

Vol 4 ◽

Author(s):

Ellen Desie ◽

Bart Muys ◽

Boris Jansen ◽

Lars Vesterdal ◽

Karen Vancampenhout

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Forest Soils ◽

Tree Species ◽

Litter Quality ◽

Species Selection ◽

Species Effects ◽

Tree Species Effects ◽

Soc Stocks ◽

The Way

Despite the general agreement that maximizing carbon storage and its persistence in forest soils are top priorities in the context of climate change mitigation, our knowledge on how to steer soil organic carbon (SOC) through forest management remains limited. For some soils, tree species selection based on litter quality has been shown a powerful measure to boost SOC stocks and stability, whereas on other locations similar efforts result in insignificant or even opposite effects. A better understanding of which mechanisms underpin such context-dependency is needed in order to focus and prioritize management efforts for carbon sequestration. Here we discuss the key role of acid buffering mechanisms in belowground ecosystem functioning and how threshold behavior in soil pH mediates tree species effects on carbon cycling. For most forests around the world, the threshold between the exchange buffer and the aluminum buffer around a pH-H2O of 4.5 is of particular relevance. When a shift between these buffer domains occurs, it triggers changes in multiple compartments in the soil, ultimately altering the way carbon is incorporated and transformed. Moreover, the impact of such a shift can be amplified by feedback loops between tree species, soil biota and cation exchange capacity (CEC). Hence, taking into account non-linearities related to acidity will allow more accurate predictions on the size and direction of the effect of litter quality changes on the way soil organic carbon is stored in forest soils. Consequently, this will allow developing more efficient, context-explicit management strategies to optimize SOC stocks and their stability.

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Differential long-term effects of climate change and management on stocks and distribution of soil organic carbon in productive grasslands

Biogeosciences Discussions ◽

10.5194/bgd-9-1055-2012 ◽

2012 ◽

Vol 9 (1) ◽

pp. 1055-1096 ◽

Cited By ~ 1

Author(s):

A. M. G. De Bruijn ◽

P. Calanca ◽

C. Ammann ◽

J. Fuhrer

Keyword(s):

Climate Change ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Climate Change Scenarios ◽

Long Term Effects ◽

Organic C ◽

Soil C ◽

The Impact ◽

Soc Stocks

Abstract. We studied the impact of climate change on the dynamics of soil organic carbon (SOC) stocks in productive grassland systems undergoing two types of management, an intensive type with frequent harvests and fertilizer applications and an extensive system where fertilization is omitted and harvests are fewer. The Oensingen Grassland Model was explicitly developed for this study. It was calibrated using measurements taken in a recently established permanent sward in Central Switzerland, and run to simulate SOC dynamics over 2001–2100 under three climate change scenarios assuming different elements of IPCC A2 emission scenarios. We found that: (1) management intensity dominates SOC until approximately 20 yr after grassland establishment. Differences in SOC between climate scenarios become significant after 20 yr and climate effects dominate SOC dynamics from approximately 50 yr after establishment, (2) carbon supplied through manure contributes about 60% to measured organic C increase in fertilized grassland. (3) Soil C accumulates particularly in the top 10 cm soil until 5 yr after establishment. In the long-term, C accumulation takes place in the top 15 cm of the soil profile, while C content decreases below this depth. The transitional depth between gains and losses of C mainly depends on the vertical distribution of root senescence and root biomass. We discuss the importance of previous land use on carbon sequestration potentials that are much lower at the Oensingen site under ley-arable rotation and with much higher SOC stocks than most soils under arable crops. We further discuss the importance of biomass senescence rates, because C balance estimations indicate that these may differ considerably between the two management systems.

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Soil organic carbon dynamics from agricultural management practices under climate change

Earth System Dynamics ◽

10.5194/esd-12-1037-2021 ◽

2021 ◽

Vol 12 (4) ◽

pp. 1037-1055

Author(s):

Tobias Herzfeld ◽

Jens Heinke ◽

Susanne Rolinski ◽

Christoph Müller

Keyword(s):

Climate Change ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Management Practices ◽

Residue Management ◽

Biophysical Model ◽

Management Systems ◽

Climate Change Scenarios ◽

Warm Temperate ◽

Soc Stocks

Abstract. Sequestration of soil organic carbon (SOC) on cropland has been proposed as a climate change mitigation strategy to reduce global greenhouse gas (GHG) concentrations in the atmosphere, which in particular is needed to achieve the targets proposed in the Paris Agreement to limit the increase in atmospheric temperature to well below 2 ∘C. We analyze the historical evolution and future development of cropland SOC using the global process-based biophysical model LPJmL, which was recently extended by a detailed representation of tillage practices and residue management (version 5.0-tillage2). We find that model results for historical global estimates for SOC stocks are at the upper end of available literature, with ∼2650 Pg C of SOC stored globally in the year 2018, ∼170 Pg C of which is stored in cropland soils. In future projections, assuming no further changes in current cropland patterns and under four different management assumptions with two different climate forcings, RCP2.6 and RCP8.5, results suggest that agricultural SOC stocks decline in all scenarios, as the decomposition of SOC outweighs the increase in carbon inputs into the soil from altered management practices. Different climate change scenarios, as well as assumptions on tillage management, play a minor role in explaining differences in SOC stocks. The choice of tillage practice explains between 0.2 % and 1.3 % of total cropland SOC stock change in the year 2100. Future dynamics in cropland SOC are most strongly controlled by residue management: whether residues are left on the field or harvested. We find that on current cropland, global cropland SOC stocks decline until the end of the century by only 1.0 % to 1.4 % if residue retention management systems are generally applied and by 26.7 % to 27.3 % in the case of residue harvest. For different climatic regions, increases in cropland SOC can only be found for tropical dry, warm temperate moist, and warm temperate dry regions in management systems that retain residues.

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How much should we increase carbon inputs to the soil to reach a 4per1000 objective of soil organic carbon storage in European agricultural sites: a multi-modelling approach

10.5194/egusphere-egu21-1666 ◽

2021 ◽

Author(s):

Elisa Bruni

Keyword(s):

Climate Change ◽

Organic Matter ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Anthropogenic Emissions ◽

Climate Mitigation ◽

Experimental Conditions ◽

Interesting Approach ◽

Soc Stocks ◽

Modelling Approach

Anthropogenic greenhouse gases emissions are the main driving force of climate change. They need to be strongly reduced during the next Century until carbon neutrality in order to keep the international 2&#176;C objective of the Paris Agreement on Climate. The &#8220;4per1000&#8221; initiative was launched in 2015 as a climate mitigation option, with an aspiration to increase global soil organic carbon (SOC) stocks by 4&#8240; per year to compensate for the anthropogenic emissions of carbon dioxide in the atmosphere. The &#8220;4per1000&#8221; is not applicable everywhere, hence a full compensation of anthropogenic emissions is unlikely. Nevertheless, where possible, it has been identified as an interesting approach to mitigate climate change and, at the same time, ensure food security through improved soil fertilization. To reach such an objective one must either reduce carbon outputs (e.g. erosion and respiration) or increase the inputs of biomass to the soil.Here, we use a multi-modelling approach to study the challenges of SOC storage potential through increased organic inputs in agricultural sites. The aim is to respond to the following question: &#8220;What is the amount of carbon inputs that needs to be brought to soils as a means to increase SOC stocks by 4&#8240; per year?&#8221; This scientific question belongs to the family of inverse problems and is addressed by using a multi-modelling approach, to improve the predictions and associated uncertainties of model outputs.The amount of required carbon inputs to reach the 4per1000 is estimated over 30 years of simulations with five different models (Century, RothC, ICBM, AMG and Millennial) and is compared to more than 15 long-term arable experiments of organic matter addition in Europe. This allows estimating the feasibility of a 4per1000 objective in temperate, north-temperate and Mediterranean regions with different treatments of organic matter inputs. As a final step, we evaluate the sensitivity of the predicted carbon inputs requirement to future projections of climate change.The 4per1000 initiative is an interesting approach to contribute for the mitigation of climate change through agriculture. Here, we will present preliminary results of a multi-modelling analysis showing that the necessary inputs to reach the 4per1000 target are realistic for some experimental conditions, but might be too high to be implemented at a larger scale.

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Loss of available soil organic carbon from afforestation plots: effect of tree species composition and warming

10.5194/egusphere-egu2020-19705 ◽

2020 ◽

Author(s):

Zhenhui Jiang ◽

Anna Gunina ◽

Lucas Merz ◽

Yihe Yang ◽

Yakov Kuzyakov ◽

...

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Species Composition ◽

Temperature Sensitivity ◽

Tree Species ◽

Enzyme Activities ◽

Environmental Changes ◽

European Beech ◽

Microbial Biomass C ◽

Tree Species Composition

Afforestation with pure and mixed-species is an important strategy to improve soil organic carbon (SOC) stocks and restore degraded lands. However, what remains unclear is the stability of SOC to microbial degradation after afforestation and the effect of tree species composition. Moreover, it is important to reveal how sensitive the SOC in afforestation lands is to environmental changes, such as warming. To study the combined effects of warming and the tree species composition on decomposition of SOC by microorganisms and enzyme activities, soils were collected from the monocultural and mixtures of Silver birch (Betula Pendula) and European beech (Fagus Silvatica) (BangorDiversity, UK, 12 years since afforestation) and were incubated for 169 days at 0, 10, 20, 30 &#176;C at 60 % of WHC. The field experiment is arranged into a completely randomized design with n=4. The CO2 efflux was measured constantly, whereas activities of &#946;-glucosidase, chitinase and acid phosphatase, and content of microbial biomass C (MBC) were obtained at the end of the incubation.&#160;Results showed that soil cumulative CO2 efflux increased by 34.7&#8211;107% with the temperature. Potential enzyme activities were dependent on tree species composition. Warming, but not tree species exhibited a significant impact on the temperature sensitivity (Q10) of soil cumulative CO2 efflux and enzyme activities. The greatest temperature sensitivity (Q10) of total CO2 efflux was found at 10&#8211;20 &#176;C and was 2.0&#8211;2.1, but that of enzyme activities were found as 0.9&#8211;1.1 at 0&#8211;10 &#176;C. These results suggest that warming has an asynchronous effect on the SOC decomposition and enzyme activity, and enzymes cannot account for the temperature sensitivity of soil respiration. Thus, thermal adaptations of SOC mineralization is independent of the adaptation of the enzyme pool.

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Projected soil organic carbon stocks in German croplands under different climate change scenarios

10.5194/egusphere-egu2020-8004 ◽

2020 ◽

Author(s):

Catharina Riggers ◽

Christopher Poeplau ◽

Axel Don ◽

Cathleen Frühauf ◽

René Dechow

Keyword(s):

Climate Change ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Arable Land ◽

Future Climate Change ◽

Climate Projections ◽

Climate Change Scenarios ◽

Model Ensemble ◽

C Input ◽

Soc Stocks

Mineralization of soil organic carbon (SOC) is driven by temperature and soil moisture. Thus, climate change might affect future SOC stocks with implications for greenhouse gas fluxes from soils and soil fertility of arable land. We used a model ensemble of different SOC models and climate projections to project SOC stocks in German croplands up to 2099 under different climate change scenarios of the Intergovernmental Panel of Climate Change. Current SOC stocks and management data were derived from the German Agricultural Soil Inventory. We estimated the increase in carbon (C) input required to preserve or increase recent SOC stocks. The model ensemble projected declining SOC stocks in German croplands under current management and yield levels. This was true for a scenario with no future climate change (-0.065 Mg ha-1 a-1) as well as for the climate change scenarios (-0.070 Mg ha-1 a-1 to -0.120 Mg ha-1 a-1). Thereby, preserving current SOC stocks would require an increase in current C input to the soil of between 51 % (+1.3 Mg ha-1) and 93 % (+2.3 Mg ha-1). We further estimated that a C input increase of between 221 % and 283 % would be required to increase SOC stocks by 34.4 % in 2099 (4 &#8240; a-1). The results of this study indicate that increasing SOC stocks under climate change by a noticeable amount will be challenging since SOC losses need to be overcompensated.

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On the rebound: soil organic carbon stocks can bounce back to near forest levels when agroforests replace agriculture in southern India

SOIL ◽

10.5194/soil-2-13-2016 ◽

2016 ◽

Vol 2 (1) ◽

pp. 13-23 ◽

Cited By ~ 23

Author(s):

H. C. Hombegowda ◽

O. van Straaten ◽

M. Köhler ◽

D. Hölscher

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Tree Species ◽

Regional Scale ◽

Clay Fraction ◽

Carbon Stocks ◽

Southern India ◽

Home Garden ◽

Soc Stock ◽

Soc Stocks

Abstract. Tropical agroforestry has an enormous potential to sequester carbon while simultaneously producing agricultural yields and tree products. The amount of soil organic carbon (SOC) sequestered is influenced by the type of the agroforestry system established, the soil and climatic conditions, and management. In this regional-scale study, we utilized a chronosequence approach to investigate how SOC stocks changed when the original forests are converted to agriculture, and then subsequently to four different agroforestry systems (AFSs): home garden, coffee, coconut and mango. In total we established 224 plots in 56 plot clusters across 4 climate zones in southern India. Each plot cluster consisted of four plots: a natural forest reference, an agriculture reference and two of the same AFS types of two ages (30–60 years and > 60 years). The conversion of forest to agriculture resulted in a large loss the original SOC stock (50–61 %) in the top meter of soil depending on the climate zone. The establishment of home garden and coffee AFSs on agriculture land caused SOC stocks to rebound to near forest levels, while in mango and coconut AFSs the SOC stock increased only slightly above the agriculture SOC stock. The most important variable regulating SOC stocks and its changes was tree basal area, possibly indicative of organic matter inputs. Furthermore, climatic variables such as temperature and precipitation, and soil variables such as clay fraction and soil pH were likewise all important regulators of SOC and SOC stock changes. Lastly, we found a strong correlation between tree species diversity in home garden and coffee AFSs and SOC stocks, highlighting possibilities to increase carbon stocks by proper tree species assemblies.

Download Full-text