Soil Carbon Stocks Research Articles

Land management of formerly subtropical Atlantic Forest reduces soil carbon stocks and alters microbial community structure and function

Soil carbon (C) sequestration has been proposed as one means to mitigate the effects of climate change and to guarantee food safety. However, forest conversion to managed land uses can deplete soil C stocks and affect soil microbial communities, potentially impacting a wide range of ecosystem services. Our objective was to investigate the effect of forest conversion to intensive land uses on soil C dynamics and soil microbial community structure and function in the subtropical portion of the Atlantic Forest biome. We evaluated four land uses - forest fragment, grassland, and agriculture with five or fifty years of cultivation. We analyzed soil C pools, edaphic variables, and soil bacterial/archaeal (16S) and fungal (ITS) communities. Forest conversion to managed land uses reduced soil C stocks and altered soil microbial community structure, with implications for soil C dynamics. Bacterial/archaeal and fungal community composition were strongly correlated with pH, base saturation, and calcium (Ca) and magnesium (Mg) content. However, soil C pools were not associated with potential extracellular enzyme activity or microbial diversity. Finally, the fungal species Mortierella minutissima ASV_1 and several bacterial groups were positively correlated with soil C stocks, potentially representing indicators of soil C storage. Our study indicates that land use change affects the interplay between soil microbial communities and soil C pools, with consequences to soil C storage. Our findings may support the development of soil C enhancement programs within the Atlantic Forest biome.

Response of soil microbial necromass carbon to litter and root carbon inputs in a mid-subtropical Castanopsis carlesii plantation

Microbial necromass carbon (MNC) is a crucial source for stable soil carbon pool, and understanding its response to carbon inputs from both aboveground (litter) and belowground (roots) in subtropical forest soils is essential for assessing soil carbon stocks in global ecosystems. In a Castanopsis carlesii plantation at the Sanming Forest Ecosystem National Observation and Research Station in Fujian Province, we conducted an experiment with five treatments, including root removal (NR), aboveground litter removal (NL), no litter input (removals of both aboveground litter and roots, NI), double aboveground litter addition (DL), and control (CK). After seven years, we collected soil samples in the 0-10 cm soil layer to examine changes in MNC content and its contribution to soil organic carbon (SOC). Results showed that NR treatment reduced MNC, bacterial necromass carbon (BNC), and fungal necromass carbon (FNC) by 15.9%, 20.2%, and 14.5%, respectively, while other treatments did not induce significant changes. The NR, NL, NI, and DL treatments did not affect the contributions of BNC, FNC, and MNC to SOC. Correlation and path analyses revealed that litter and root carbon input treatments could alter the MNC content directly or indirectly through changing soil available substrates and microbial community structure. Our results suggested that roots exert a stronger influence on the maintenance of MNC than aboveground carbon source in the mid-subtropical plantations.

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 & 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.

Conversion of tropical secondary forest into agricultural land: consequences for soil health and environmental stability

The objective of the study was to address the impacts of tropical forest conversion into agricultural land on changes in invertebrates’ communities, as well as soil chemical properties across 2–4 texturally distinct soils in La Mé and Grand Lahou, Côte d’Ivoire. The fieldwork was carried out in the humid period on two study sites: 1– rubber landscape (secondary forest, 7-, 12- and 25-year-old rubber plantations) and 2– oil palm landscape (secondary forest, 13-, 20- and 39-year-old oil palm plantations). Three sampling stands were established on each land-use type and age class, for a total of 24 sampling stands. Over a 40–50 m transect, topsoil (0–10 cm) invertebrates were sampled by using monoliths (50 cm × 50 cm × 10 cm), following the modified ‘Tropical soil biology and fertility’ method. Soils chemical properties were also determined. The results highlighted a decrease in taxonomic richness (–35 % and –42 %), Shannon index (–32 % and –37 %), Margalef index (–34 % and –41 %), soil carbon stock (–41 % and –15 %), nitrogen stock (–38 % and –11 %) and carbon sequestration (–41 % and –15 %), respectively, after the transformation of secondary forests into rubber and oil palm plantations. The clay soils and clay sandy soils favored the development and emergence of the soil invertebrates, and allowed a higher carbon and nitrogen storage, as well as a greater carbon sequestration. Whatever the site, the soil quality was more degraded under the monoculture tree plantations compared to the secondary forests. Our findings suggest leaving residues of the previous crop on the soil surface and the incorporation of woody trees with an understory of smaller trees during the early establishment periods of monoculture tree plantations, which can create a sustainable agroforestry system with improved nutrient recycling and soil fertility.

Organic carbon stock of loess soil in the Lower Orkhon River

We aimed to study the soil organic carbon (SOC) stock of the loess soil and conducted samplings on a non-sandy loess terrace at the Lower Orkhon River in Shaamar Soum of Selenge Province. We made a soil profile with a 200 cm depth and collected 11 soil samples from each layer. The SOC was determined according to the Turin method in the Soil Research Laboratory at the Institute of Geography and Geoecology of the Mongolian Academy of Sciences. Results indicated that the mean SOC of the 200 cm soil profile ranges between 1.78-7.52 g/kg and the organic carbon content of the paleosol was higher than that of loess layers. The SOC was 0.7 kg/m-2 at 0-26 cm, 1.1 kg/m-2 at 26-42 cm, 1.8 kg/m-2 at 42-60 cm, 1.2 kg/m-2 at 60-80 cm, 0.7 kg/m-2 at 80-92 cm, 0.6 kg/m-2 at 92-113 cm, 0.8 kg/m-2 at 113-130 cm, 0.7 kg/m-2 at 130-140 cm, 0.7 kg/m-2 at 140-150 cm, 0.7 kg/m-2 at 140-150 cm, 1.1 kg/m-2 at 150-170 cm, and 3.3 kg/m-2 at 170-200 cm depth. The SOC in the topsoil layer was 9.9 t/ha at 0-30 cm, 36.6 t/ha at 0-60 cm, 57.7 t/ha at 0-100 cm, and 128.4 t/ha at 0-200 cm layer. The loess soil distributed in the northern part of Mongolia had a dark color and paleosol layer with high organic contents. Therefore, there was no tendency for SOC reduction when the depth increased. The amount of the SOC at a depth of less than 1 m was higher than the loess soil distributed in the Plateau region of China but the SOCs were similar at a depth of up to 1 m. Орхон голын адаг орчмын хэмэрлэг хөрсний органик нүүрстөрөгчийн нөөц ХУРААНГУЙ: Энэхүү судалгаа нь хэмэрлэг хөрсний органик нүүрстөрөгч (SOC)-ийн нөөцийг судлахад чиглэсэн бөгөөд хөрсний хээрийн судалгааг Сэлэнгэ аймгийн Шаамар сумын нутаг Орхон голын зүүн дэнжийн чулуугүй-элсэрхэг хэмэрлэг дээр гүйцэтгэсэн болно. Бид 200 см-ийн гүнтэй хөрсний зүсэлт хийж, хөрсний давхарга бүрээс нийт 11 ширхэг хөрсний дээж авч лабораторийн шилжилгээнд хамруулсан. SOC-ийг Тюрины аргын дагуу ШУА-ийн Газарзүй, геоэкологийн хүрээлэнгийн Хөрс судлалын лабораторид толорхойлсон. Судалгааны үр дүнгээр 200 см-ийн хөрсний SOC-ийн агууламж нь 1.78-7.52 г/кг-ийн хооронд хэлбэлзэх ба органик нүүрстөрөгчийн агууламжаар дарагдмал үе давхарга нь хэмэрлэг үе давхаргынхаас өндөр байна. SOC-ийн нөөц хөрсний 0-26 см-ийн давхаргад 0.7 кг/м-2 байсан бол 26-42 см-т 1.1 кг/м-2, 42-60 см-т 1.8 кг/м-2, 60-80 см-т 1.2 кг/м-2, 80-92 см-т 0.7 кг/м-2, 92-113 см-т 0.6 кг/м-2, 113-130 см-т 0.8 кг/м-2, 130-140 см-т 0.7 кг/м-2, 140-150 см-т 0.7 кг/м-2, 150-170 см-т 1.1 кг/м-2, ба 170-200 см-т 3.3 кг/м-2. Хэмэрлэх хөрсний 0-30 см өнгөн давхарга дахь SOC нөөц 9.9 тн/га, 0-60 см-т 36.6 тн/га, 0-100 см-т 57.7 тн/га бол 0-200 см-т 128.4 тн/га-гийн SOC нөөцтэй. Монгол орны хойд хэсгээр тархсан хэмэрлэг нь бараан өнгийн органикийн агууламжаар өндөр дарагдмал үеүдтэй учраас хөрсний гүн нэмэгдэхэд органикийн нөөц буурах зүй тогтол илрэхгүй, 1 метрээс дооших гүнд байгаа органик нүүрстөрөгчийн нөөцөөр Хятадын тэгш өндөрлөгт тархсан хэмэрлэг хөрснийхөөс өндөр. Харин 1 метр хүртэл гүн дэх нөөцөөр ойролцоо байна. Түлхүүр үгс: Хэмэрлэг хөрс, Хөрсний органик, Органик нүүрстөрөгчийн нөөц, Орхон гол, Шаамар

Net global warming potential index rather than soil carbon stock change could provide better understanding of the carbon balance in soil systems.

This study was conducted to determine the soil organic carbon (SOC) stock change factor for green manure crops that was developed by the Intergovernmental Panel on Climate Change (IPCC) Tier 2 method and compare this with the net global warming potential (GWP) index that is used to evaluate the contribution of green manuring to global warming. Four treatments were barley (Hordeum vulgare L.; B), hairy vetch (Vicia villosa R.; HV), a barley/hairy vetch mixture (BHV) and a conventional treatment (C). The aboveground biomass of green manure crops was incorporated into the soil on 25 May 2018, 26 April 2019, 29 April 2020, 30 April 2021 and 2 May 2022. Maize (Zea mays L.) was transplanted as the subsequent crop after the incorporation of green manures. SOC stock decreased with green manures, even though carbon input with green manures, including B, HV and BHV, was greater than that with C. The mean value of the SOC stock change factor for green manure crops, including B, HV and BHV was 0.627 and was significantly lower than that of the C. However, the net GWP also decreased with the incorporation of green manure crops, and the mean value of the relative net GWP index across B, HV and BHV was 0.853. These conflicting results were caused by different estimation methods between annual SOC change (△SOC) and net GWP. The estimation of SOC stock change using △SOC suggested by the IPCC method may overestimate the contribution of green manure crops to global warming. The net GWP method with comprehensive input and output of carbon in the soil system could provide a better understanding of the carbon balance in soil systems. In the current study, the comparison of △SOC and net GWP was conducted for at one site of upland soil for 5years. Therefore, further research on estimating the effect of green manure crops on net GWP in various types of soil for longer years should be conducted.

Агроэкологическая характеристика черноземов Каменной степи: влияние растительных сообществ и распашки

Changes in soil carbon stocks have a significant impact on atmospheric CO2 concentrations and the global carbon balance. Despite the proven effectiveness of agroforestry in erosion control and prevention of soil fertility loss, there are many controversial data suggesting that the impact of afforestation on Chernozem soils should be further investigated. The Kamennaya Steppe site (arable land surrounded by shelterbelt forests) is a reference site for monitoring studies at the Voronezh Carbon Test Site, where the carbon balance of agro-ecosystems is being studied and the ecological role of shelterbelt forests in changing soil properties and carbon sequestration is being evaluated. The study was focused on the evaluation of agro-ecological characteristics and the impact of tillage on Chernozems of Kamennaya Steppe under different vegetation types. The study of the chemical properties of chernozems was carried out using classical chemical methods; the analysis of heavy metals was carried out using the voltampermetric method. Comprehensive agro-ecological evaluation showed that the studied Vorony-Calcic Chernozems had a high content of humus, which reached 7-8% in the upper horizons, enriched with mineral nutrition elements, and had favorable physical and chemical properties. Forest and grassland vegetation contribute to enrichment of the soil with organic residues, while tillage and mineralization of organic matter on arable land led to a decrease in humus content. Data analysis suggested that the study area did not suffer from contamination. Furthermore, it was found that the organic matter of the studied chernozems was able to bind the studied metals and retain them in an unavailable state. This phenomenon was supported by rather high correlations between humus and total heavy metal content (r = 0.946 for Pb and r = 0.975 for Cd at p < 0.00001). It should be emphasized that shelterbelt forests could act as a biogeochemical barrier to the lateral migration of heavy metals. Cadmium is a rather mobile element potentially capable to migrate to adjacent environments. Therefore, regular monitoring of the agro-ecological condition of the Chernozems of the Kamennaya Steppe is required.

Study of Soil Carbon Reserves in Conservation Area in Gili Meno, North Lombok

Gili Meno is a small island located to the north of Lombok Island which is included in a conservation area with high potential as a tourist destination. As a tourist destination, there has been a conversion of green land into hotels and other tourist facilities which has led to changes in land use patterns. In order to reduce the increase in earth's surface temperature due to GHG emissions, especially CO2, CO2 mitigation efforts are needed by squesting carbon into the soil. Research on soil carbon stocks on Gili Meno has been carried out using descriptive methods with survey techniques, namely by taking soil samples in several types of land cover at two depths, namely 0-10 cm and 10-20 cm. The soil samples taken were used for analysis of c-organic and some physical characteristics of the soil. Based on the data obtained, mangrove land cover has the largest potential carbon reserves, namely 89.36 tons.ha-1, then followed by shrub land cover, then coconut plantations, and finally open land and settlements with values respectively 57, 50 ton.ha-1, 44.11 ton.ha-1, and 36.15 ton.ha-1. The high soil carbon reserves in the mangrove ecosystem compared to other land covers reflect that the carbon storage potential of mangrove land covers is better compared to other land cover types. Thus, for long-term land management, the sustainability of mengrove plants must be maintained.

Driving factors of tree biomass and soil carbon pool in xerophytic forests of northeastern Argentina

BackgroundThe conversion of forests into agricultural lands can be a threat because the forests carbon stored could be a source of emissions. The capacity to improve the predictions on the consequences of land use change depends on the identification of factors that influence carbon pools. We investigated the key driving factors of tree biomass and soil carbon pools in xerophytic forests in northeastern Argentina. Based on analyses of forest structure variables and abiotic factors (topography and soil properties) from 18 mature forests, we evaluated carbon pools using uni- and multivariate (redundancy analysis) methods.ResultsThe total carbon pool was estimated at 102.4 ± 24.0 Mg ha−1. Soil organic carbon storage is the single largest carbon pool relative to tree biomass, representing 73.1% of total carbon. Tree canopy cover and basal area were positively correlated with biomass carbon pool (r = 0.77 and r = 0.73, p < 0.001, respectively), proving to be significant drivers of carbon storage in this compartment. Slope, soil clay content and cation-exchange capacity had a better explanation for the variability in soil carbon pools, and all showed significant positive correlations with soil carbon pools (r = 0.64, 0.60 and 0.50; p < 0.05, respectively). The vertisols showed a 27.8% higher soil carbon stock than alfisols.ConclusionsThe relevance of our study stems from a dearth of information on carbon pools and their drivers in xerophytic forests, and in particular, the importance of this ecosystems’ type for Argentina, because they cover 81.9% of native forest area. Basal area and tree canopy cover exert a strong effect on the carbon pool in tree biomass but not in the soil. The results suggests that there is a potentially major SOC accumulation in forests located in slightly sloping areas and soils with higher topsoil clay content, such as vertisols. This could provide an important reference for implementing forestry carbon sink projects.

Restored forested wetland surprisingly resistant to experimental salinization.

Salinization of coastal freshwater wetlands is an increasingly common and widespread phenomenon resulting from climate change. The ecosystem consequences of added salinity are poorly constrained and highly variable across prior observational and experimental studies. We added 1.8 metric tons of marine salts to replicated 200 m2 plots within a restored forested wetland in Eastern North Carolina over the course of four years. Based on prior small-scale experiments at this site, we predicted that salinization would lead to slower tree growth and suppressed soil carbon cycling. Results from this large-scale field experiment were subtle and inconsistent over space and time. By the fourth year of the experiment, we observed the predicted suppression of soil respiration and a reduction of water extractable carbon from soils receiving salt treatments. However, we found no cumulative effects of four years of salinization on total soil carbon stocks, tree growth, or root biomass. We observed substantial variation in soil solution chemistry (notably, pH and base saturation) across replicated treatment blocks; the effective salt levels, ionic composition, and pH varied following treatment depending upon pre-existing differences in edaphic factors. Our multi-year monitoring also revealed an underlying trend of wetland acidification across the entire site, a suspected effect of ecosystem recovery following wetland restoration on former agricultural land. The overwhelming resistance to our salt treatments could be attributed to the vigor of a relatively young, healthy wetland ecosystem. The heterogeneous responses to salt that we observed over space and time merits further investigation into the environmental factors that control carbon cycling in wetlands. This work highlights the importance of multi-year, large-scale field experiments for investigating ecosystem responses to global environmental change.

Temporal variation in the soil properties and rice yield of organic rice farming in the tropical monsoon region, Indonesia

One of the organic farming goals is improving soil properties to support sustainable rice production. This study investigated the soil properties and rice yields under temporal variation of organic rice fields. Soil sampling was conducted in organic rice fields with three temporal variations, namely 0, 4, 7, and 10 years in a tropical monsoon region in Central Java, Indonesia. Variables observed included soil organic carbon, soil carbon stock, soil microbes population, dissolved organic carbon, soil liquid limit, soil sticky limit, soil plasticity limit, soil color changing limit, soil friability, soil porosity, soil total nitrogen, soil total phosphorus, soil available sulfur, exchangeable calcium, cation exchange capacity, total potassium, bulk density, base saturation, exchangeable sodium, exchangeable potassium, and rice yield. This study confirms that soil organic carbon increased by 51.63% within 10 years (from 1.84% to 2.79%). Organic farming also improved all the physical, chemical, and biological soil properties, by the increase of soil organic carbon. However, soil organic carbon is mostly determined by soil cation exchange capacity, soil total phosphorus, and soil porosity. The mechanism of rice yield increase in organic rice farming is not affected by soil organic carbon directly but through the synergic increase in soil total nitrogen. The 1% increase of soil organic carbon increases 0.065% of soil total nitrogen hence rice yield increases by 1.66 tons ha&lt;sup&gt;-1&lt;/sup&gt;. This study supports sustainable agriculture by providing evidence of improved soil properties under organic farming.

Enhanced Nitrogen Fertilizer Input Alters Soil Carbon Dynamics in Moso Bamboo Forests, Impacting Particulate Organic and Mineral-Associated Carbon Pools

The application of nitrogen fertilizer is crucial in the cultivation of bamboo forests, and comprehending the alterations in soil organic carbon (SOC) due to nitrogen application is essential for monitoring soil quality. Predicting the dynamics of soil carbon stock involves analyzing two components: particulate organic carbon (POC) and mineral-associated organic carbon (MAOC). This study aimed to investigate the impact of high nitrogen inputs on SOC stock in Moso bamboo forests located in southwestern China. The research focused on analyzing changes in soil chemical properties, SOC content, and its components (POC and MAOC), as well as microbial biomass in the surface layer (0–10 cm) under different nitrogen applications (0, 242, 484, and 726 kg N ha−1 yr−1). The results indicate that nitrogen application significantly reduced the SOC content, while concurrently causing a significant increase in POC content and a decrease in MAOC content within the Moso bamboo forest (p &lt; 0.05). The HM treatment notably increased the NO3−-N content to 2.15 mg/kg and decreased the NH4+-N content to 11.29 mg/kg, although it did not significantly influence the microbial biomass carbon (MBC) and nitrogen (MBN). The LN and MN treatments significantly reduced the MBC and MBN contents (71.6% and 70.8%, 62.5% and 56.8%). Nitrogen application significantly increased the Na+ concentration, with a peak observed under the LN treatment (135.94 mg/kg, p &lt; 0.05). The MN treatment significantly increased the concentrations of Fe3+ and Al3+ (p &lt; 0.05), whereas nitrogen application did not significantly affect Ca2+, Mg2+ concentration, and cation exchange capacity (p &gt; 0.05). Correlation and redundancy analyses (RDAs) revealed that the increase in annual litterfall did not significantly correlate with the rise in POC, and changes in extractable cations were not significantly correlated with the decrease in MAOC. Soil nitrogen availability, MBC, and MBN were identified as the primary factors affecting POC and MAOC content. In conclusion, the application of nitrogen has a detrimental impact on the soil organic carbon (SOC) of Moso bamboo forests. Consequently, it is imperative to regulate fertilization levels in order to preserve soil quality when managing these forests. Our research offers a theoretical foundation for comprehending and forecasting alterations in soil carbon stocks within bamboo forest ecosystems, thereby bolstering the sustainable management of Moso bamboo forests.

Changes in Soil Organic Carbon Stocks Due to Land Use Changes in the Extended São Francisco River Basin

As the largest carbon reservoir in terrestrial ecosystems, soils play a critical role in food production, mitigation and adaption to climate change, and sustainability of agroecosystems. In this context, the aim of this study is to estimate variations in soil carbon stocks resulting from land use and management changes in different biomes that compose the Bacia Estendida do Rio São Francisco (BESF - Extended São Francisco River Basin), between 1985 and 2017. For this, remote sensing data and information from the IBGE agriculture and livestock census were used, in addition to emission factors to estimate soil organic carbon (SOC) changes. The results indicate that BESF had about 5.70 million ha degraded in the analyzed period, in addition to an increase of 0.72 Tg C year-1 in SOC stocks. The sub-medium São Francisco River basin recorded the highest SOC gain, with an increase of 0.54 Tg C ha-1; on the other hand, the sub-medium São Francisco River sub-basin had the greatest SOC losses, with an estimated reduction of 0.07 Tg C year-1. In short, this study provides important evidence on changes in SOC stocks in the region, emphasizing the importance of native vegetation conversion to agriculture and livestock systems under sustainable soil management for mitigating greenhouse gas emissions and maintaining soil quality.

Changing the land use from degraded pasture into integrated farming systems enhance soil carbon stocks in the Cerrado biome

Integrated agricultural production systems can increase soil organic carbon stocks over time and contribute to the mitigation of climate change. The present study aimed to evaluate soil carbon stocks, accumulation rates (TOC), total nitrogen (TN), and the quality of soil organic matter (SOM) after the transition of a low-productivity pasture into agrosilvopastoral systems in the Cerrado biome. We evaluated an 11-year-old experiment, and the treatments studied were: Eucalyptus + buffel grass; Eucalyptus + cowpea; Eucalyptus + pigeon pea; eucalyptus + buffel grass + cowpea; Eucalyptus + buffel grass + pigeon pea; Eucalyptus in monoculture (with a 20 × 3 m tree arrangement and no cultivation between rows but with a history of forage and grain crop production); and a low-productivity pasture as additional treatment and reference to the soil condition previously the land-use change. In this study, TOC and TN stocks and accumulation, labile (LC) and non-labile carbon (NLC), and SOM humic fractions were evaluated at 0-10, 10-20, 20-40, and 0-40 cm depth layers. Integrated farming systems have increased TOC and TN, NLC, carbon contents and stocks in SOM chemical fractions in all depths and TOC and TN accumulation of 5.22 Mg ha-1 year-1 and 0.23 Mg ha-1 year-1, respectively, at the 0-40 cm depth layer. The integration of Eucalyptus with legumes or buffel grass increased the LC content in the surface layer of the soil. The transition from low-productivity pasture into integrated farming systems can promote the recovery of SOM and soil quality. Hence, our results suggest that agrosilvopastoral systems can be used as sustainable farming systems in the Cerrado biome.

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.

POTENTIAL OF CARBON SINK IN MANGROVE SUBSTRATES IN LEMBAR BAY, WEST LOMBOK, INDONESIA

Mangroves are one of the coastal vegetation that can mitigate carbon (carbon sink and carbon storage). This study aimed to determine the potential for soil carbon stock found under stands of mangroves in Lembar Bay, West Lombok, and West Nusa Tenggara. The research began with the identification of the species and then proceeded toa sampling of the soil, which was then analyzed using the Walkley and Black method. The results showed that there were ten species of mangroves, namely, Rhizophora stylosa, Avicennia lanata, Avicennia marina, Bruguiera gymnorrhiza, Ceriops decandra, Excoecaria agallocha, Lumnitzera racemosa, Scyphiphora hydrophyllacea, Thespesia populnea, and Xylocarpus maluccensis. The highest soil carbon content percentage was found in the lower soil of the A. lanata (1.43 %C) mangrove, and the lowest was found in the lower-stand soil of E. agallocha (0.21 %C). Meanwhile, the carbon sinks per meter were 0.002-0.066 gC/m2, with an average of 0.020±0.020 gC/m2. The estimated total soil carbon sink in 10 mangrove stands was 0.20-6.60 tons C/ha, with an average of 2.18±2.010 tons C/ha. The average total estimated soil carbon stock found in 20.49 ha of the mangrove area studied was 44.67 tonsC, which is equivalent to 263.69 tonsC in a mangrove area of ​​120.96 ha in Lembar Bay.

Effects of Drainage on Carbon Stock in Hemiboreal Forests: Insights from a 54-Year Study

In the Northern Hemisphere, forests play an important role in carbon storage. During the past few decades in the eastern Baltic and Nordic regions, forest drainage has been a common occurrence, which also has an effect on carbon stock. Most of the studies on this issue were carried out in boreal zones and were focused on short-term effects. Thus, our aim was to evaluate the long-term (after 54 years) effect of drainage on carbon stock (CS) changes in organic soil (Fibric histosols) in hemiboreal forests. Three forest types were selected in drained (Myrtillosa turf. mel (Mmel)) and undrained (Caricoso–phragmitosa (CP) and Sphagnosa (Sph)) parts of the same area. Surface level changes, soil penetration resistance, and soil and tree biomass carbon stock were assessed to evaluate the drainage effect. Drainage caused an average surface level drop of 25 cm, but did not deplete the soil carbon pool, resulting in significantly and substantially higher (2 to 6 times) tree biomass carbon stock. The drainage of organic soils in managed wet forests leads to an increased long-term contribution to climate change mitigation, thus such areas should be established or maintained in conjunction with areas that maximize other ecosystem services to ensure the sustainability of forest landscapes.

Functional diversity and carbon storage of plant community elevation patterns and carbon accumulation mechanisms in desert shrubland of Yanqi Hola Mountain, China

Exploring the distribution characteristics of plant community functional diversity, functional traits and plant and soil carbon stocks along elevation and the effects of functional diversity and functional traits on carbon stocks is of great significance for revealing the distribution characteristics of plant community functional diversity and carbon stocks in the desert area and understanding the carbon accumulation mechanism. In this study, we took the leaf functional traits of plant community species and the carbon stocks of plants and soils of sample plots in the pre-Hola Mountain desert area as the research objects and explored their altitudinal distribution characteristics and their interrelationships. The results showed that (1) the plant carbon storage capacity of the shrub - herb association was the strongest, and the soil carbon storage capacity of the herb association was the strongest. (2) Functional richness and plant carbon storage capacity tended to increase and then decrease with elevation, while functional evenness and leaf phosphorus content tended to decrease and then increase with elevation. Functional dispersion, leaf water content, chlorophyll content, leaf carbon, nitrogen content, and soil carbon stock all showed a gradual increase with elevation, and the total carbon stock gradually increased with elevation in the middle and low elevation areas (1200–1800 m), and showed a wave-like change in the high elevation areas (1800–2400 m). (3) The accumulation of soil carbon stocks in the study area is mainly dominated by the “mass ratio hypothesis”, while the accumulation of plant carbon stocks is mainly dominated by the “ecological niche complementarity hypothesis”, and plant and soil carbon stocks are mainly affected by the specific leaf area and the content of carbon, nitrogen, and phosphorus in leaves.

Salinity, mineralogy, porosity, and hydrodynamics as drivers of carbon burial in urban mangroves from a megacity

Mangrove ecosystems are an important blue carbon store but exhibit considerable variation in soil carbon stocks globally. Unravelling the conditions controlling carbon stock is critical for assessing current and future carbon budgets. Mangrove soil biogeochemical cycles can strongly influence carbon storage capacities. We thus investigated carbon sequestration and the environmental parameters shaping variability in biogeochemical cycling and carbon storage in sediment samples from four mangrove sites along an estuarine-to-marine gradient in Hong Kong, a megacity. Our results showed that organic matter in Hong Kong mangroves is sourced principally from autochthonous mangrove plants. Total nitrogen was higher in the freshwater-influenced sites and supplied from different sources. Marine-influenced sites had larger sulfur fractionations, reflecting higher marine-sourced sulfate concentrations and indicating a relatively open sulfate system. We estimated an average organic carbon stock of 115 ± 8 Mg C ha−1 in the upper 100 cm soil layer placing Hong Kong mangroves at the lower end of the global spectrum of the soil carbon stock. Carbon accumulation was found to be driven by a combination of higher total organic matter inputs, soil fluxes, and porosity. Notably, despite having the highest mass-specific soil organic carbon contents, Mai Po had the lowest integrated soil organic carbon storage (77 ± 3 Mg C ha−1). This was primarily due to lower sediment density and higher tidal pumping leading to a decrease in carbon retention. Total organic matter input, sediment characteristics, and hydrodynamics were the main factors influencing soil organic carbon storage. Overall, our results suggest that (1) while multiple parameters can enhance soil organic carbon content and increase carbon storage capacities, (2) hydrodynamics and sediment characteristics can increase the potential for leakage of carbon, and (3) high carbon content does not always equal high carbon sequestration and stock.

Assessment of roadside grassland soil carbon characteristics

Carbon is a vital component of soil health and plays a crucial role in supporting plant growth and ecosystem functioning. By understanding the carbon content and characteristics of roadside grassland soil, we can evaluate its fertility and potential for supporting vegetation. Assessing roadside grassland soil carbon characteristics is important for understanding soil fertility, carbon sequestration potential, and the impact of human activities on soil health. The investigation includes elemental analysis of grassland soil and on that base calculation of ratios, soil organic carbon, soil carbon stocks, the carbon dioxide equivalent emissions from SCS soil carbon stocks loss. The samples have more percentage of element hydrogen which contribute to anaerobic conditions in grassland soil include waterlogging or poor drainage, high organic matter content, and compacted soil. The C/N (Carbon to Nitrogen) ratio is low and this is the reason of delayed decomposition and difficulties of nutrient cycling processes within the ecosystem. The soil organic carbon varies between 1 % and 2 %. Soil carbon stock between 304gC and 474 gC may be considered relatively low. The carbon dioxide equivalent emissions from SCS soil carbon stocks loss was between 2 and 3 %. This loss in carbon dioxide equivalent emissions from soil carbon stocks can be considered relatively low and potentially beneficial. Implementing practices that promote carbon sequestration, such as reducing soil disturbance, implementing cover cropping, and adopting sustainable land management practices, can help mitigate soil carbon loss and reduce emissions.