Soil Carbon Sequestration Potential Research Articles

Evaluation of the soil carbon sequestration potential and toward digital soil mapping under semi-arid Mediterranean ecological condition

Evaluation of the soil carbon sequestration potential and toward digital soil mapping under semi-arid Mediterranean ecological condition

P-limitation regulates the accumulation of soil aggregates organic carbon during the restoration of Pinus tabuliformis forest

Artificial forest restoration is widely recognized as a crucial approach to enhance the potential of soil carbon sequestration. Nevertheless, there is still limited understanding regarding the dynamics of aggregate organic carbon (OC) and the underlying mechanisms driving these dynamics after artificial forest restoration. To address this gap, we studied Pinus tabuliformis forests and adjacent farmland in three recovery periods (13, 24 and 33 years) in the Loess Plateau region. Samples of undisturbed soil from the surface layer were collected and divided into three aggregate sizes: >2 mm (large aggregate), 0.25–2 mm (medium aggregate), and <0.25 mm (small aggregate). The aim was to examine the distribution of OC and changes in enzyme activity within each aggregate size. The findings revealed a significant increase in OC content for all aggregate sizes following the restoration of Pinus tabuliformis forests. After 33 years of recovery, the OC of large aggregates, medium aggregates and micro-aggregates increased by (30.23 ± 9.85)%, (36.71 ± 21.60)% and (37.88 ± 16.07)% respectively compared with that of farmland. Moreover, the restoration of Pinus tabuliformis forests lead to increased activity of hydrolytic enzymes and decreased activity of oxidative enzymes. It is noteworthy that the regulation of carbon in all aggregates is influenced by soil P-limitation. In large aggregates, P-limitation promotes the enhancement of hydrolytic enzyme activity, thereby facilitate OC accumulation. Conversely, in medium and small aggregates, P-limitation inhibits the increase in oxidative enzyme activity, resulting in OC accumulation. The results emphasize the importance of P-limitation in regulating OC accumulation during the restoration of Pinus tabulaeformis forest, in which large aggregates play a leading role.

An overall review on influence of root architecture on soil carbon sequestration potential

An overall review on influence of root architecture on soil carbon sequestration potential

Quantification and mapping of the carbon sequestration potential of soils via a quantile regression forest model

Quantification and mapping of the carbon sequestration potential of soils via a quantile regression forest model

Estimation of soil organic carbon by combining hyperspectral and radar remote sensing to reduce coupling effects of soil surface moisture and roughness

Soil organic carbon (SOC) is important in the global carbon cycle. Accurate estimation of SOC content in cultivated land is a prerequisite for evaluating the carbon sequestration potential and quality of soils. However, existing SOC prediction studies based on hyperspectral remote sensing neglect the spectral response of the physical properties of surface soil, leading to inadequate model generalization. With the exponential growth of remote sensing data, the development of pixel-level soil spectral correction methods based on multi-source remote sensing data has become an interesting and challenging topic. This method aims to minimize the effect of soil physical properties on spectra, thus addressing the poor spatiotemporal transferability of SOC prediction models due to uncertain variations in surface soil physical properties. In this study, a soil spectral correction strategy is constructed using satellite hyperspectral image (HSI) and synthetic aperture radar (SAR) images through multi-order polynomial regression and convolutional neural networks. This strategy considers soil physical variables such as soil moisture (SM) content and root mean square height (RMSH) of soil surface roughness. The soil spectral correction model and SOC content prediction model were established using 80 soil samples collected from Site 1. Afterward, the performance and transferability of both models were verified using the remaining 25 samples from Site 1 and 50 samples from Site 2. The results showed that: 1) The effect of SM and RMSH on the soil pixel spectrum can be significantly reduced after correcting HSI using soil spectral correction strategy. The correlation coefficients between the corrected pixel spectrum and the ground-based spectrum increase by over 60 % compared with those between the original spectrum and the ground-based spectrum. 2) Soil spectral correction improves the prediction accuracy and mapping capability of HSI for SOC content, with the highest RP2 of 0.743 and RMSEP of 3.455 g/kg at Site 1. 3) Compared with the original HSI-based SOC prediction model, the soil spectral correction strategy based on multi-order polynomial and convolutional neural network reduced the RMSEP of SOC prediction results at Site 2 by 5.082 g/kg and 5.454 g/kg, and the RP2 increased by 0.390 and 0.409, respectively. 4) When predicting SOC content from raw HIS, SM and RMSH contribute to more than 60 % of the bias, with SM having a larger bias than RMSH. The findings of this study emphasize the influence of soil physical properties on SOC prediction and contribute to the existing research on SOC mapping using HSI and SAR data.

Chemical Recalcitrance Rather Than Soil Microbial Community Determined Short-Term Biochar Stability in a Poplar Plantation Soil

The stability of biochar is fundamental to its soil carbon (C) sequestration potential. The relative importance of chemical recalcitrance and the soil microbial community on biochar stability is still unclear. To unveil the question, we conducted a 60-day incubation to explore the stability of two rice-straw-derived biochars pyrolyzed at 300 and 500 °C (denoted as BS300 and BS500), as well as the relative contribution of the soil microbial community and biochar chemical recalcitrance to biochar stability in a poplar plantation soil. Biochar-derived cumulative carbon dioxide (CO2) emission was estimated to be 41.3 and 6.80 mg C kg−1, accounting for 0.73 and 0.11% of the amended biochar-derived organic C (OC) in BS300 and BS500 treatments, respectively. The mean retention time (MRT) estimated by double-exponential model fitting was 49.4 years for BS300 and 231 years for BS500. Compared to control, BS300 and BS500 decreased β-D-glucosidase activity by 20.9 and 18.0%, while they decreased phenol oxidase activity by 31.8 and 18.9%, respectively. Furthermore, BS300 increased the soil microbial metabolic quotient (qCO2) by 155%, but BS500 decreased it by 13.4%. In addition, BS300 resulted in a 520% higher biochar-derived hot-water-extractable OC than BS500. Partial least-squares path modeling (PLSPM) showed that the path efficients of biochar’s chemical recalcitrance and microbial qCO2 were 0.52 and 0.25, respectively, and that of the soil microbial activity is neglected. We conclude from this short-term study that chemical recalcitrance imposed a greater effect than soil microbial community on biochar stability.

Carbon Sequestration Potential of Manure-Derived Hydrochar Aided by Secondary Stabilization.

Hydrothermal carbonization (HTC) is a process that produces a carbon-rich solid from wet organic materials through the application of heat and pressure. Carbonized solids, previously correlated to long-term soil stability, may be considered for carbon sequestration through incorporation into soil. Chars produced by pyrolysis are known for exceptional stability in soil, but pyrolysis is expensive when applied to wet biomass, such as manure. Chars produced from manure by HTC show considerably improved potential for carbon sequestration relative to untreated manure, although not as great as that of chars produced by pyrolysis. This study focuses on producing and evaluating chars by HTC paired with pyrolysis and different methods of chemical oxidation for long-term carbon sequestration in soil. It is shown that a two-step process of pyrolysis following HTC produces a char that outperforms those produced by either individual process (HTC or pyrolysis) in carbon yield, carbon content, and, more importantly, soil carbon sequestration potential. It was found that acid-catalyzed HTC followed by pyrolysis resulted in a char with a 13% increase in carbon yield, a 51% increase in carbon content, and an atomic O/C ratio 64% smaller than the char produced by conventional pyrolysis.

The Effect of Long-Term Crop Rotations for the Soil Carbon Sequestration Rate Potential and Cereal Yield

Depending on the type of agricultural use and applied crop rotation, soil organic carbon accumulation may depend, which can lead to less CO2 fixation in the global carbon cycle. Less is known about organic carbon emissions in different crop production systems (cereals, grasses) using different agrotechnologies. There is a lack of more detailed studies on the influence of carbon content in the soil on plant productivity, as well as the links between the physical properties of the soil and the absorption, viability, and emission of greenhouse gases (GHG) from mineral fertilizers. The aim of this study is to estimate the long-term effect of soil organic carbon sequestration potential in different crop rotations. The greatest potential for organic carbon sequestration is Norfolk-type crop rotation, where crops that reduce soil fertility are replaced by crops that increase soil fertility every year. Soil carbon sequestration potential was significantly higher (46.72%) compared with continuous black fallow and significantly higher from 27.70 to 14.19% compared with field with row crops and cereal crop rotations, respectively, intensive crop rotation saturated with intermediate crops. In terms of carbon sequestration, it is most effective to keep perennial grasses for one year while the soil is still full of undecomposed cereal straw from the previous crop. Black fallow without manure fertilization, compared to crop rotation, reduces the amount of organic carbon in the soil up to two times, the carbon management index by 2–5 times, and poses the greatest risk to the potential of carbon sequestration in agriculture.

How Does Specialization in Agricultural Production Affect Soil Health?

The aim of the study was to assess the impact of the specialization of agricultural production on selected parameters of soil health, i.e., soil organic carbon content (SOC), soil acidification, soil nutrient status, i.e., total nitrogen content (NT), available forms of phosphorus, potassium, and magnesium, and microelements content, as well as the content of selected potentially toxic metals (PTMs). For the study, 18 farms located in the Masovian Voivodeship in Central Poland were selected. They were grouped into six types, and each type was represented by three farms. The study included organic farms; farms specializing in: crop, vegetable, poultry, dairy cattle, and pigs production. A total of 144 soil samples were analyzed. The results showed that the specialization of agricultural production and fertilizer management had a significant impact on most of the tested soil health parameters, except SOC and NT content. Despite the high organic fertilizer doses introduced into soils in poultry (170 kg N per hectare as poultry manure) and pig farms (150 kg N per hectare as pig manure), there was no significant influence of these amendments on SOC content. This may indicate low organic carbon sequestration potential in some Polish agricultural soils. Organic farms had the lowest levels of plant nutrients in the tested soil samples, which may limit soil productivity. All the tested soils were strongly acidified, which could restrict both production and regulatory soil functions. Based on the synthetic index of soil fertility (SSFI), vegetable and poultry farms were characterized by very high fertility, while crop, dairy cattle, and pig farms fell into the medium fertility class. Organic farms were in the lowest fertility class. However, the study suggests that the SSFI may not be the best indicator for assessing soil fertility and health; therefore, further research is needed.

Effects of Water-Level Fluctuation on Soil Aggregates and Aggregate-Associated Organic Carbon in the Water-Level Fluctuation Zone of the Three Gorges Reservoir, China

Water-level fluctuation (WLF) can destroy soil aggregates and induce soil organic carbon (SOC) loss, potentially triggering impacts on the concentration of atmospheric carbon dioxide. However, responses of soil aggregate content and aggregate-associated organic carbon to WLF have not been well studied, especially in the water-level fluctuation zone (WLFZ) of the Three Gorges Reservoir (TGR). Therefore, samples from different elevations (145 m, 155 m and 165 m) in the WLFZ of the TGR were collected for experiments. The wet sieving method was used to divide soil into silt and clay (&lt;0.053 mm), micro-aggregate (0.053–0.25 mm) and macro-aggregate (&gt;0.25 mm). The K2Cr2O7-H2SO4 oxidation method was used to measure total SOC content in different soil aggregates. A modified Walkley and Black method was used to measure labile carbon in different soil aggregates. Results showed that macro-aggregate content substantially decreased, while micro-aggregate content remained stable and silt and clay fraction accumulated with a decrease in water-level elevations. Moreover, total SOC content and labile carbon in macro-aggregate were obviously higher than those in the micro-aggregate and the silt and clay fraction. Macro-aggregate contributed the most to SOC sequestration, while micro-aggregate contributed the least, and the contribution of macro-aggregate increased with a decrease in water-level elevations. We concluded that the macro-aggregate was the most active participant in the SOC sequestration process, and preferentially increasing the macro-aggregate content of the lowest water-level elevation was conducive to an improvement in soil carbon sequestration potential and would mitigate climate change.

Optimizing nitrogen and phosphorus application to improve soil organic carbon and alfalfa hay yield in alfalfa fields.

Soil organic carbon (SOC) is the principal factor contributing to enhanced soil fertility and also functions as the major carbon sink within terrestrial ecosystems. Applying fertilizer is a crucial agricultural practice that enhances SOC and promotes crop yields. Nevertheless, the response of SOC, active organic carbon fraction and hay yield to nitrogen and phosphorus application is still unclear. The objective of this study was to investigate the impact of nitrogen-phosphorus interactions on SOC, active organic carbon fractions and hay yield in alfalfa fields. A two-factor randomized group design was employed in this study, with two nitrogen levels of 0 kg·ha-1 (N0) and 120 kg·ha-1 (N1) and four phosphorus levels of 0 kg·ha-1 (P0), 50 kg·ha-1 (P1), 100 kg·ha-1 (P2) and 150 kg·ha-1 (P3). The results showed that the nitrogen and phosphorus treatments increased SOC, easily oxidized organic carbon (EOC), dissolved organic carbon (DOC), particulate organic carbon (POC), microbial biomass carbon (MBC) and hay yield in alfalfa fields, and increased with the duration of fertilizer application, reaching a maximum under N1P2 or N1P3 treatments. The increases in SOC, EOC, DOC, POC, MBC content and hay yield in the 0-60 cm soil layer of the alfalfa field were 9.11%-21.85%, 1.07%-25.01%, 6.94%-22.03%, 10.36%-44.15%, 26.46%-62.61% and 5.51%-23.25% for the nitrogen and phosphorus treatments, respectively. The vertical distribution of SOC, EOC, DOC and POC contents under all nitrogen and phosphorus treatments was highest in the 0-20 cm soil layer and tended to decrease with increasing depth of the soil layer. The MBC content was highest in the 10-30 cm soil layer. DOC/SOC, MBC/SOC (excluding N0P1 treatment) and POC/SOC were all higher in the 0-40 cm soil layer of the alfalfa field compared to the N0P0 treatment, indicating that the nitrogen and phosphorus treatments effectively improved soil fertility, while EOC/SOC and DOC/SOC were both lower in the 40-60 cm soil layer than in the N0P0 treatment, indicating that the nitrogen and phosphorus treatments improved soil carbon sequestration potential. The soil layer between 0-30 cm exhibited the highest sensitivity index for MBC, whereas the soil layer between 30-60 cm had the highest sensitivity index for POC. This suggests that the indication for changes in SOC due to nitrogen and phosphorus treatment shifted from MBC to POC as the soil depth increased. Meanwhile, except the 20-30 cm layer of soil in the N0P1 treatment and the 20-50 cm layer in the N1P0 treatment, all fertilizers enhanced the soil Carbon management index (CMI) to varying degrees. Structural equation modeling shows that nitrogen and phosphorus indirectly affect SOC content by changing the content of the active organic carbon fraction, and that SOC is primarily impacted by POC and MBC. The comprehensive assessment indicated that the N1P2 treatment was the optimal fertilizer application pattern. In summary, the nitrogen and phosphorus treatments improved soil fertility in the 0-40 cm soil layer and soil carbon sequestration potential in the 40-60 cm soil layer of alfalfa fields. In agroecosystems, a recommended application rate of 120 kg·ha-1 for nitrogen and 100 kg·ha-1 for phosphorus is the most effective in increasing SOC content, soil carbon pool potential and alfalfa hay yield.

Soil taxonomical classification and organic carbon sequestration potential of coastal acid sulfate soils: Kari and Kayal ecosystems of Kerala, India

Soil taxonomical classification and organic carbon sequestration potential of coastal acid sulfate soils: Kari and Kayal ecosystems of Kerala, India

A high-resolution map of soil organic carbon in cropland of Southern China

An accurate and fine map of soil organic carbon (SOC) plays a vital role in understanding the global carbon cycle and achieving soil carbon sequestration potential. Although global and national maps of SOC are already available with various spatial resolutions, limited sample size, and relative coarse resolution hinder its accuracy and application in local regions. Here, we collected 13,424 soil samples and information of 45 environmental covariates from cropland in Jiangxi Province, Southern China during 2012 and 2013. Then, the optimal covariates were selected by a recursive feature elimination algorithm for mapping SOC. After that, we deployed the random forest (RF) to produce a fine map (30 m) of SOC in the cropland of Jiangxi Province and 100 times bootstrapping was performed to calculate the prediction uncertainty. Finally, we determined the impacts of various covariates on SOC variability using RF and partial least squares structural equation modeling. Our results showed that compared with the predictive model without soil management information, introducing soil management information improved the predictability of SOC with an increase in R2 by 7.35 % (0.73 vs 0.68) and decrease in RMSE by 7.03 % (2.91 vs 3.13 g kg−1). Our results well estimated the uncertainty of the predicted result with a PICP of 0.91 for a 90 % prediction interval. Soil properties and soil management activities make the largest contribution for modelling SOC. Specifically, the total nitrogen content, straw return amount, total potassium content, and multi-resolution valley bottom flatness were found as the most important factors for mapping SOC in the cropland of our study area. Overall, this study deepened our knowledge of the variation of SOC and also emphasizes that incorporating soil management information could help us to achieve more accurate predictions of SOC.

Soil organic carbon stocks and fertility in smallholder indigenous agroforestry systems of the North-Eastern mountains, Tanzania

Soil organic carbon and soil fertility are critical components of soil health and play a significant role in sustaining agricultural productivity. Indigenous agroforestry practices have been identified as an interesting avenue to sequester carbon and enhance soil fertility in tropical smallholder farms. However, that potential remains poorly quantified. To better understand the dynamics of soil organic carbon stocks and fertility, this study evaluated and compared 4 different smallholder indigenous agroforestry systems (i.e., Kihamba, Ginger, Miraba, and Mixed spices) in the northeastern volcanic and block mountains of Tanzania. Specifically, we compared old and young agroforestry systems in terms of soil organic carbon stocks and soil fertility (proxied by effective cation exchange capacity (eCEC)). In each agroforestry system, a network of old and young tree farm plots were selected for soil sampling at different depths and physico-chemical parameters were analyzed (soil organic carbon, texture, bulk density, pH-H2O, and eCEC). Our findings showed that there was no significant difference between young and old agroforestry systems in terms of soil organic carbon stocks, except in the Kihamba system on the slopes of Kilimanjaro. The highest soil carbon sequestering potential was found in the old Kihamba (located on Nitisols) compared to other systems on Acrisols. Young agroforestry in Ginger and Miraba appeared to have a higher capacity to sequester soil carbon than Mixed spices. Regarding eCEC levels, there was a significant difference between old and young agroforestry systems in both the Kihamba and Miraba system. At the 0–10 cm depth, the highest eCEC levels were found in young agroforestry for Kihamba, Miraba, and Mixed spices. Our results implied that specific management and restoration strategies should focus on optimizing soil fertility and carbon sequestration potential of agroforestry systems in the South Pare and Usambara Mountains characterized by low-fertility Acrisols.

Soil health and carbon storage in community gardens in the Perth metropolitan area, Australia

AbstractCommunity gardens, as common spaces where people gather to grow food, help foster public health, greener urban environments, life‐long learning and vibrant communities. However, despite being promoted as sustainable horticulture and conservation agriculture, their soil health and carbon (C) sequestration potential, with implication for climate change mitigation, remains underexplored. This study assessed soil samples collected from raised beds (gardening area) and adjacent bare ground (control) at six community gardens in the Perth metropolitan area, Australia. These sites covered three soil mapping units (SMUs): calcareous deep sands, coloured sand and pale sands The soil in raised beds exhibited superior characteristics than surrounding urban soil including lower bulk density, higher pH buffering capacity, available nutrients including nitrogen (N), phosphorus (P) and potassium (K), cation exchange capacity (CEC), total C and microbial biomass. Notably, we estimated that raised bed soils accumulated significant levels of C in the top 10 cm layer (0.55 kg/m2 or 5.5 T/ha). Our findings also indicate no significant heavy metal contamination in any of the community garden soils. Although the global area of community gardens is marginally small, these results suggest they hold potential for carbon sequestration, especially in urban and peri‐urban environments. The improved soil health and C storage potential in community garden soil are largely attributed to the regular application of compost produced within the community gardens.

Productivity and Carbon Sequestration Potential of Arecanut Cultivars under Malnad Region of Karnataka

A field experiment was conducted at Agricultural and Horticultural Research Station, Thirtahhalli, KSNUAHS, Shivamogga, Karnataka, India, where arecanut palms of eight cultivars were evaluated for growth and yield performance for two consecutive years. The above-ground carbon sequestration potential and the soil carbon sequestration potential were assessed. The cultivar SAS-1 performed superior over other cultivars for all the growth parameters under study viz., palm height (9.02 m), stem diameter (18.07 cm), number of leaves (9.84) and internodal distance (17.38cm). However highest yield of fruit bunch per palm was recorded in the cultivar Mohithnagar (20.28 kg), followed by Thirthalli local (17.92 kg), Sreemangala (17.46 kg) and Tarikere Local (15.31 kg). Maximum chali/ dried ripe nut yield was recorded in Thithalli local (3.29 kg), Mohithnagar (3.10 kg) and Sreemangala (2.80 kg). Significantly higher values for standing biomass (15.49 t/ha), carbon stock (7.75 t/ha) and carbon sequestration (28.43 t/ha) were recorded in cultivar SAS-1. Soil parameters viz., bulk density, soil organic carbon and carbon stock in soil was analyzed in the rhizosphere of respective cultivars and maximum soil organic carbon (13.10g/kg and 11.43g/kg at 0-30 &amp; 30-60 cm depths respectively) and carbon stock (52.77 t/ha at 0-30 cm and 46.41 t/ha at 30-60 cm depth) were recorded in that of cultivar Sumangala.

Responses of Soil Fungi to Long‐Term Nitrogen‐Water Interactions Depend on Fungal Guilds in a Mixed Pinus koraiensis Forest

AbstractDifferent fungal guilds within the soil fungal community regulate forest ecosystem processes. Soil fungi are dictated by edaphic factors such as soil water and nutrient availabilities. However, how the total number of fungi and the composition of different fungal guilds in the soil vary under covarying pattern of nitrogen deposition and precipitation regime in temperate forests has not been well documented. In this study, we explored the effects of long‐term nitrogen‐water interactions on the diversity and composition of soil overall fungi and different fungal guilds, and their relationships with fine‐root and soil fungal mycelial traits in a temperate forest. The diversity of the totality of soil fungi or any fungal guilds did not change, but the community composition of saprotrophic and symbiotrophic fungi was significantly changed by nitrogen addition (N), showing increased abundance of soil symbiotrophic fungi but decreased abundance of soil saprotrophic fungi. Precipitation reduction (W) significantly altered soil overall and pathotrophic fungal community. Precipitation reduction combined with nitrogen addition (WN) significantly changed soil overall, pathotrophic and symbiotrophic fungal community composition. Soil pathotrophic, saprotrophic and symbiotrophic fungal community composition was variously related to fine‐root diameter, root tissue density, nitrogen and/or phosphorus concentration. Long‐term nitrogen‐water interactions decreased the complexity of soil fungal networks, reflected by the lower edges and average degree, but the higher average path distance and modularity. These findings of soil fungal guild‐specific responses to nitrogen‐water interactions will deepen our understanding of soil carbon sequestration potential and nutrient cycling in temperate forest ecosystems under future climate changes.

Nitrogen addition suppresses soil positive priming effect in temperate plantations: Evidence from an 8‐year in situ field experiment

Abstract The microbial‐driven soil priming effect (PE) determines soil carbon emissions and is essential for accurately predicting the feedbacks between the terrestrial carbon cycle and global changes. In recent years, human activities have resulted in increased atmospheric nitrogen (N) deposition, but there is limited understanding of the long‐term effects of N deposition on soil microbial communities and their impact on soil PE in temperate plantations. This study utilized Korean pine plantation soils with 8 years of in situ N addition to investigate the mechanisms of the impact of long‐term N addition on PE through carbon (13C) isotope tracing and high‐throughput sequencing techniques. We found that N addition significantly changed the soil bacterial community structure, while the effect on the fungal community structure did not reach a significant level. Addition of 13C‐glucose resulted in soil‐positive PE, which exhibited a significant decreasing trend with increasing N addition. Compared with the control (0 kg N ha−1 year−1), the net carbon balance of the low N (20 kg N ha−1 year−1) showed no significant change, while the medium N (40 kg N ha−1 year−1) and high N (80 kg N ha−1 year−1) significantly increased by 35.47% and 35.79%, respectively, implying that glucose carbon was trapped in the soil much more than organic carbon decomposition. The PLS‐PM explained 69.0% of the total variation in PE among different N additions, showing that bacterial core taxa were the main driver of PE and that carbon enzyme activities (β‐1,4‐glucosidase and polyphenol oxidase) were a direct factor in regulating PE. Our results provide insights into accurately assessing the soil carbon sequestration potential of plantations under the influence of N deposition. Read the free Plain Language Summary for this article on the Journal blog.

Aboveground and Soil Carbon Stock of Teak Plantations under Varied Rainfall Regimes

Aims: Forest plantations are considered to be the most effective approach to reducing the atmosphere's rising carbon dioxide levels. The variation in the carbon stock under important plantation species and the heterogeneity across climatic regimes, however, are urgently needed.&#x0D; Place and Methodology: Research was conducted on seven-year-old teak plantations in Karnataka, India, to determine the above-ground and soil carbon sequestration potential of teak plantations under various rainfall regimes.&#x0D; Results: The teak plantations under high rainfall zone (RFZ) accumulated maximum above-ground biomass revealing the positive effect of rainfall the productivity. This was reflected in the total above-ground carbon sequestration of the plantations leading to maximum carbon storage under the high RFZ followed by medium and low RFZ. Further, the variation of the SOC along the soil depth was evident in the present study.&#x0D; Conclusion: According to the findings, rainfall significantly impacted above-ground carbon sequestration and SOC, with high rainfall leading to the greatest sequestration. The climate sensitivity of carbon sequestration demands elaborate studies to improve carbon storage in the plantations in future climate change scenarios.

Effects of land use/cover changes on soil organic carbon stocks in Qinghai-Tibet plateau: A comparative analysis of different ecological functional areas based on machine learning methods and soil carbon pool data

Understanding the process of land use/cover changes (LUCC) can provide experience on the enhancement of soil organic carbon (SOC) stocks and carbon sequestration potential for different areas. This study is uniquely to divide different ecological functional areas, and originally combine the machine learning method and soil carbon pool dataset for regional comparative analysis, to compare and quantitatively analyze the drivers of LUCC and the changes in SOC stocks effected by LUCC over 30 years. The results show that topography and climate changes are the main drivers affecting LUCC in four natural areas, while soil factors and population changes do not cause significant effects. The total SOC stocks in Qinghai was increased by 71.18 Tg C and 107.19 Tg C in 0–30 cm and 0–300 cm layers, respectively, and the highest SOC stocks within 0–300 cm were in Pastoral area. Desert and Gobi area had the lowest SOC stocks in both 0–30 cm and 0–300 cm layers. SOC stocks increased in both 0–30 cm and 0–300 cm layers only in Sanjiangyuan Natural Reserve, while the Desert and Gobi area showed a decrease in both over 30 years. This study emphasizes the significant impact of grassland changes on SOC stocks, indicating the importance of considering these changes in land management and ecological protection policies. The initial and original SOC stocks of pre-LUCC may influence the SOC stocks in post-LUCC. The response of SOC stocks changes to LUCC was varies in different areas. The heterogeneity of different ecological functional areas is affected by multiple factors and SOC stocks will become more complex among these areas in the future. These findings contribute to the development of ecological protection policies and the enhancement of regional land management strategies.