Carbon Content Research Articles

Cone and fruit impacts on understory flammability depend on traits and forest floor coverage

BackgroundUnderstory flammability is affected by abscised plant tissue. Extensive research has shown how interspecific differences in leaf litter traits affect flammability; however, leaves represent only one component of the litter layer. Cones and fruit are also common constituents of the forest floor, yet surprisingly little is known about how flammability is affected by their presence. In this study, we ask how flammability is affected by cones and fruit trait differences, coverage differences, and varying species and coverage combinations. To address these questions, we compared cone and fruit morphological and chemical traits among longleaf pine, loblolly pine, shortleaf pine, sweetgum, post oak, and water oak. We also used burn trials to compare fire behavior of single and mixed-species treatments at three coverage levels (10% of plot area (low), 30% (medium), and 50% (high)) integrated within a common mixed-litter layer under field conditions in central Alabama, USA.ResultsLike other plant tissues, cone/fruit dry matter, carbon, and lignin content promote fuel consumption and flame height, while nitrogen suppresses flammability. Single-species treatments produced distinct patterns in fire behavior, with longleaf pine cones consistently showing higher percent fuel consumption, flame height, and maximum smoldering temperature than sweetgum capsular heads. Mixed-species treatment results were less consistent; however, at high coverage, a representative upland three-way mixture (longleaf pine + sweetgum + post oak) showed significantly greater fuel consumption and flame height relative to a bottomland three-way mixture (loblolly pine + sweetgum + water oak) at high coverage. Medium cone/fruit coverage maximized flammability in most single and multi-species treatments and produced non-additive fuel consumption in mixtures containing longleaf pine and sweetgum.ConclusionOur results confirm that individual species’ cone and fruit flammability often parallels that of litter. Fire behavior in mixture is generally driven by the most flammable constituent species, but this result changes with cone and fruit coverage. Collectively, these results indicate that cones/fruit identity and coverage play an important role in understory flammability and should be integrated into fire behavior modeling efforts in monocultures and mixtures.

Evaluation of Recoverable Hydrocarbon Reserves and Area Selection Methods for In Situ Conversion of Shale

It is well known that the existing horizontal-well-drilling and hydraulic fracturing technology used to achieve large-scale, cost-effective production from immature to low–moderate-maturity continental shale in China, where the organic matter mainly exists in solid form, is fairly ineffective. To overcome the obstacles, in situ conversion technology seems feasible, while implementing it in the target layer along with estimating the amount of expected recoverable hydrocarbon in such shale formations seems difficult. This is because there are no guidelines for choosing the most appropriate method and selecting relevant key parameters for this purpose. Hence, based on thermal simulation experiments during the in situ conversion of crude oil from the Triassic Chang 73 Formation in the Ordos Basin and the Cretaceous Nenjiang Formation in the Songliao Basin, this deficiency in knowledge was addressed. First, relationships between the in situ-converted total organic carbon (TOC) content and the vitrinite reflectance (Ro) of the shales and between the residual oil volume and the hydrocarbon yield were established. Second, the yields of residual oil and in situ-converted hydrocarbon were measured, revealing their sensitivity to fluid pressure and crude oil density. In addition, a model was proposed to estimate the amount of in situ-converted hydrocarbon based on TOC, hydrocarbon generation potential, Ro, residual oil volume, fluid pressure, and crude oil density. Finally, a method was established to determine key parameters of the final hydrocarbon yield from immature to low–moderate-maturity organic material during in situ conversion in shales. Following the procedure outlined in this paper, the estimated recoverable in situ-converted oil in the shales of the Nenjiang Formation in the Songliao Basin was estimated to be approximately 292 × 108 tons, along with 18.5 × 1012 cubic meters of natural gas, in an area of approximately 8 × 104 square kilometers. Collectively, the method developed in this study is independent of the organic matter type and other geological and/or petrophysical properties of the formation and can be applied to other areas globally where there are no available in situ conversion thermal simulation experimental data.

Quantifying Dissolved Organic Compound Efflux from Drained Peatlands in Hemiboreal Latvia

This study evaluated the impact of different land use types on groundwater dissolved organic carbon (DOC) concentrations and annual DOC efflux from drained peatlands to catchment runoff, providing insights into the mechanisms of carbon stock changes in peatland soils. We measured groundwater chemical properties and various environmental variables, and calculated daily runoff and evapotranspiration for 2021 to estimate monthly and annual DOC efflux and analyzed main affecting factors in different peatland land use types. The highest DOC concentrations in groundwater were found in Scots pine forests and active peat extraction sites, with values of 113.7 mg L−1 and 109.7 mg L−1, respectively, and the lowest in silver birch forests and croplands, at 51.9 mg L−1 and 18.6 mg L−1, respectively. There were statistically significant correlations, including a strong negative correlation between DOC concentrations and several groundwater chemical properties, such as pH, electrical conductivity (EC), Ca, Mg, and K concentrations. The concentrations of DOC in the groundwater of drained peatland showed significant variation between different land use types. The highest annual DOC efflux was observed in active peat extraction sites, at 513.1 kg ha−1 y−1, while the lowest was in grasslands, at 61.9 kg ha−1 y−1, where Ca and Mg concentrations, as well as EC, were the highest. Continuous monitoring of these concentration patterns is essential.

Long-Term Organic Cultivation in Greenhouses Enhances Vegetable Yield and Soil Carbon Accumulation through the Promotion of Soil Aggregation

The long-term use of fertilizers and pesticides in conventional cultivation has resulted in a decrease in soil productivity and vegetable yields in greenhouses. However, there is little research exploring the changes in soil organic carbon and the microbial community mediated by soil aggregates, or their impacts on soil productivity. This study investigated the properties of soil aggregates, including the levels of organic carbon fractions, microbial community, and enzyme activity with the three aggregate classes: microaggregates (<0.25 mm), small macroaggregates (2–0.25 mm) and large macroaggregates (>2 mm) under conventional cultivation (CC), integrated cultivation (IC), and organic cultivation (OC) in greenhouses. The results showed that (1) OC and IC promoted the formation of small macroaggregates and enhanced aggregate stability compared to CC; (2) SOC in the three size fractions of OC increased by 92.06–98.99% compared to CC; EOC increased by 98.47–117.59%; POC increased by 138.59–208.70%; MBC increased by 104.71–230.61%; and DOC increased by 21.93–40.90%, respectively; (3) organic cultivation significantly increased enzyme activity in all three particle-size aggregates and increased the relative abundance of bacteria in microaggregates as well as the relative abundance of fungi in small macroaggregates. Structural equation model (SEM) analysis revealed that organic farming practices fostered the development of smaller macroaggregates, elevated microbial and enzyme activities within soil aggregates, and facilitated the conversion of soil nutrients and carbon sequestration. Therefore, long-term organic cultivation increases soil carbon content and vegetable yield in greenhouses by increasing the proportion of small aggregates. In conclusion, long-term organic cultivation in greenhouses improves soil structure, increase soil fertility and vegetable yield, and has a positive impact on the environment. Organic cultivation increases soil fertility and contributes to maintaining ecological balance and protecting the environment in greenhouses.

Nano Biochar: Properties, Preparation, Key Features and its Impact on Soil and Crop Ecosystem

Nano biochar, a carbon-rich material, is increasingly recognized for its pivotal role in sustainable agriculture and environmental management. It is produced through the pyrolysis of biomass under controlled conditions, converting organic matter into a stable form of carbon. This process effectively sequesters carbon and mitigates greenhouse gas emissions while yielding a valuable soil amendment. In agriculture, biochar offers multifaceted benefits. Its porous structure enhances soil fertility and water retention, fostering optimal conditions for plant growth. By serving as a reservoir for nutrients, biochar promotes their slow release, reducing the risk of leaching and nutrient runoff. Moreover, its neutral pH and high organic carbon content contribute to soil health and microbial activity. Some key features of nano biochar are enhancing surface area and porosity, improved soil fertility, nutrient retention and recycling, slow-release fertilizer, enhanced microbial population, carbon sequestration etc. Furthermore, biochar aids in waste management by utilizing agricultural residues as feedstock. However, despite its promising advantages, biochar application requires careful consideration. Variations in feedstock and production methods can influence its efficacy and environmental impact. Moreover, its long-term effects on soil health and crop productivity warrant further research and field trials. It presents a sustainable solution for enhancing agricultural productivity, mitigating climate change, and managing organic waste. However, its optimal utilization necessitates comprehensive understanding, integrated management practices, and ongoing scientific inquiry.

Inconsistent elevational patterns of soil microbial biomass, diversity, and community structure on four elevational transects from subtropical forests

The use of elevational gradients as proxies for time in predicting soil microbial responses to imminent climate changes is common, yet reliance on single-transect studies has raised concerns about the method's validity due to the lack of replication. Addressing this gap, our study evaluates the effects of elevation on soil microbial communities within subtropical forests, using four closely situated transects with consistent climatic and vegetative characteristics. Through phospholipid fatty acid analysis and Illumina MiSeq sequencing, we investigate variations in microbial biomass and the composition of communities at different elevations. Our results show that the ways microbial communities, both bacteria and fungi, respond to changes in elevation, particularly in aspects of biomass and diversity, vary significantly across different transects. Environmental factors, like soil pH, soil organic carbon concentration, and climatic factors, distinctly affect the attributes of these microbial communities through diverse mechanisms. These results underscore the need for multi-transect studies to accurately measure soil microbial responses to elevation and climate changes, challenging the predictive reliability of studies based on a single transect.

Calculation of production balances and costs in ladle furnace refining process with addition of scrap steel

As increasing the scrap steel ratio has become an important approach for energy conservation and emission reduction in the steel industry, the technology of multi-point scrap addition has emerged. Ladle furnace (LF) refining is a feasible step for scrap steel utilisation, which is often overlooked and relied solely on empirical adjustment, resulting in difficulty of precise control. It is necessary to conduct in-depth research on this process using scientific methods and explore the impact of scrap steel addition on other materials. A comprehensive calculation model was established by scientifically investigating material and thermal balances in the LF process in this article, and the impact of initial steel and scrap compositions, temperature, mass and price of scrap on production costs were analysed and compared based on the model. The results showed that as the carbon and silicon content in the initial steel increase by every 0.01% could on average reduce the production cost per ton of steel by 4.013 CNY and 0.8473 CNY, respectively, and increases by 0.123 CNY as the sulphur content increase every 0.001%. The impact of scrap composition on costs is similar to that of the initial molten steel. Increasing the carbon and sulphur content in scrap by every 0.01% will on average increase costs by 0.0765 CNY and 0.01 CNY, respectively. When the price difference between scrap and the crude steel price is within 450–500 CNY/t, increasing scrap addition will create more profit. The relative reduction in smelting time is 7.97 s as the scrap temperature increases every 50°C. The present study holds academic and industrial significance in improving LF efficiency and promoting the LF process towards a more sustainable direction.

Synthesis, Characterization, and Control Release of Zinc Layered Nitrate Intercalated with Beta-Napthoxyacetic Acid (BNOA) Nanocomposite

In this research, the synthesis of the host using zinc nitrate-hexahydrate as a precursor to form zinc layered nitrate (ZLN) and the guest anion which is beta-napthoxyacetic acid (BNOA) will be intercalated with the ZLN to produce nanocomposites called ZLN/beta-napthoxyacetic acid (ZLNB). The method used for the synthesis of the host was self-assembly and ion exchange. The nanocomposites were confirmed with the basal spacing increases from 9.8 to 28.2 Å by using powder X-ray diffraction (PXRD). Therefore, proved the bigger basal spacing compared to the layered double hydroxide of MgAl and ZnAl. The appearance of the FTIR shift band at 1603 cm−1 of C=C aromatic ring indicates that the anions have been successfully incorporated into the interlayers of ZLNB. Moreover, the loading percentage estimated by the carbon content from the ZLNB determined by CHNS analyzer was 41.8% (w/w). The morphology analysis confirmed the plate-like structure for ZLN into flaky-like with irregular, porous and unambiguous structure for ZLNB by field emission scanning electron microscopy (FESEM). The controlled release property showed that the release of BNOA in the various aqueous solutions is in the order of Na3PO4 > Na2SO4 > NaCl and fitted into pseudo-second-order kinetic models.

Vegetation at the former open-pit Ningyo-toge mine, 36 years after closure treatment: Impact of soil cover on woody plant establishment and dominance of the perennial herb Miscanthus sinensis

Soil cover is a prevailing method used at mine sites to ensure the safety of hazardous materials and restore ecological functions when the base materials are unfavorable for plant growth. The former open-pit Ningyo-toge Mine was backfilled with overburden and neutralized smelting residues and covered with soil in 1987. After 36 years, the vegetation remained dominated by the perennial herb Miscanthus sinensis, and woody plant establishment did not progress successfully. This study investigated the factors that inhibited woody plant establishment at the site. The soil profile survey revealed that the soil cover formed Bg horizons (pseudogley soil) with cloudy mottling, representative of poorly drained soil. In the Bg horizon, woody plant roots of Pinus densiflora and Weigela hortensis exhibited growth inhibition. Elemental analysis revealed that in the Bg horizon the roots of P. densiflora and W. hortensis accumulated high Fe concentrations exceeding 10,000 mg/kg DW at critical levels. Our results suggested that woody plant roots in the Bg horizon may have suffered from chronic oxygen deficiency accompanied by excessive Fe stress in the soil cover. Topsoil water content (<50 mm) and microtopographic features were not critical factors disrupting woody plant establishment because some individuals were growing in areas with high soil water content, exceeding 60%. Considering that woody plant roots were developed primarily in the shallow A horizon, A horizon formation by M. sinensis is a key step in initiating woody plant establishment by improving the soil structure and physiochemical characteristics of the soil cover, such as carbon content, exchangeable nutrients, and air-filled porosity. For successful mine pollution control and vegetation recovery, implementing an appropriate topsoil system, such as native forest soil, loosely graded and minor infiltration layer above the overburden would be necessary.

Broadening of the carbon window and the appearance of core-rim carbides in WC-Fe/Ni cemented carbides

Among several separate challenges, the major one for replacing cobalt in cemented carbides is the difficulty to obtain alternative binder materials with a C-window broad enough to be robustly processed under conventional industrial control on the C content. The C-window is defined as the C content range for which phases that are detrimental to the mechanical properties are avoided. The present paper has two main objectives: first, to show that the processing C-window of Fe-Ni based systems is in fact wider than what thermodynamic equilibrium calculations predict, and that its width can be controlled moderately by tweaking the initial WC grain size and the cooling rate used in the material’s processing. Secondly, in case those detrimental phases are not avoided, this work gives insight on how to make their appearance less detrimental for the mechanical properties. The morphology, volume fraction and particle size distribution of the detrimental phases, specifically η6-carbides at low C contents, are investigated to explore desirable combination of hardness and toughness of alternative binder cemented carbides. During this study it was also discovered that in samples with carbon contents below the low-C limit of the C window a carbide with hexagonal lattice known as κ, not commonly seen in cemented carbides, appeared and formed the core of a core-rim structure together with the more common η6-phase. It is believed that the κ-carbide form due to local high concentrations of tungsten during solid state sintering and that it has an impact on the precipitation characteristics of the η6-phase.

Preparation of ultrafine WC-Co powder via fluidized bed

In this paper, the effects of reaction parameters on the deep-reduction and carbonization process of WO2-Co to WC-Co were studied. The results indicate that oxygen loss rate of WO2 is positively correlated with temperature and methane partial pressure. The partial pressure of methane has no significant effect on the formation rate of WC. The carbon content and particle size of the product increase with the increase of CH4 partial pressure. By synergistically regulating the reaction temperature to 950 °C, methane partial pressure to 1.25%, and reaction time to 60 min, ultrafine WC-Co powder without η phase can be obtained. The particle size of the composite powder is 128 nm, with total carbon content of 6.16%, free carbon content of 0.4%, and residual oxygen content of 0.05%, respectively. The growth rate relationship of tungsten carbide is as follows:

High Carbon content Microporous Activated Carbon from Thin Walnut Shells: Optimization, Physico-Chemical Analysis and Structural Profiling"

High carbon content-activated carbon with high micro-porosity was prepared from thin walnut shell by pyrolysis process with chemical activation (using KOH), exhibiting the promising potential to be a very good adsorbent. The aim of the study was to evaluate the effect of activation temperature, holding time and impregnation ratio on moisture content, total carbon content, ash content, BET surface area, adsorption capacity, total pore volume and iodine absorption value. Design expert predicted 5500C activation temperature, 2.5h holding time and 1:1 impregnation ratio as optimum conditions for development of activated carbon. The developed activated carbon was compared with market sample activated carbon for physico-chemical properties and surface characteristics. The developed activated carbon was characterized by high carbon content (80.06%), BET surface area (735.36 m2/g), iodine absorption value (783.64mg/g), adsorption capacity (201.31mg/g), low ash content (5.01%) and total pore volume (0.29). XRD patterns of activated carbon developed from thin walnut shell confirmed its highly amorphous structure. FTIR analysis indicated similarities in peaks at different wave numbers with no significant differences in both samples. SEM-EDX analysis revealed highly porous structure with high carbon, potassium elemental composition of developed activated carbon as compared to market sample.

Investigation of the effect of antioxidant on carbon deposition of compression ignition engine for carbon emissions reduction

The study aimed to assess carbon deposition tendencies in mustard biodiesel with varying oxidation levels by examining residual carbon and existent gum content. Gas chromatography–mass spectrometry (GC-MS) and infrared spectrometry were used to analyze the chemical components of residual carbon and existent gum in mustard biodiesel and an antioxidant before and after oxidation. The research investigated carbon deposition on the exhaust valve of a compression ignition engine using mustard biodiesel blended with clove oil as an antioxidant. The engine ran for 100 h on each fuel sample: diesel (D100), biodiesel blended fuel (B30), and clove oil (3000 ppm). After completing 100 h on each sample, engine exhaust was analyzed for carbon deposition using Scanning Electron Microscopy (SEM) and Energy Dispersive Microscopy (EDX).The findings revealed increased carbon deposition when using biodiesel blended fuel compared to diesel fuel. However, the addition of an antioxidant to the biodiesel blend resulted in reduced carbon deposition. This suggests that the use of antioxidants effectively mitigated carbon buildup in the engine’s exhaust when using biodiesel blends. The aim of this study is to enhance engine performance, increase engine life, and reduce pollution in the environment.

Dynamics of Water-Soluble Carbon and Nitrogen Content in Soils in the First Years after Clearcutting

Dynamics of Water-Soluble Carbon and Nitrogen Content in Soils in the First Years after Clearcutting

Comparative analysis of hydrogen-rich syngas production from various feedstocks using bubbling fluidized bed

Any carbon-based materials, including any trash that contains carbon, may be converted into sustainable energy through the thermochemical process known as gasification. The bubbling fluidized bed (BFB) is used for sewage sludge (SS), plastic waste (PW), and refuse-derived fuel (RDF) gasification. The sensitivity analysis of gasification processes is examined. The maximum H2 selectivity in RDF gasification is 70%, followed by SS (65%) and PW (62%) at S/B=2. PW gasification, although producing more H2, generates more CO and CO2 than RDF and SS because to its high carbon content. At 700°C–800°C, three feedstocks have good H2 selectivity. RDF gasification has the best selectivity of all component products over the temperature range. The H2/CO molar ratio range (1–2) for chemical synthesis suggests steam to biomass (S/B) values of 1.2–2.6 for RDF and SS. As S/B value increases, CO/CO2 molar ratio increases, which compresses CO2 for CO production, improving syngas quality, notably for power generation. In PW gasification, the H2/CO ratio (≤2) is expected at >750°C. Pressure only effects H2/CO and CO/CO2, in PW gasification. The evaluation of lower heating value (LHV) and cold gas efficiency (CGE) involves exploring a range of selected parameters. Elevated reaction temperatures positively influence both LHV and CGE; however, this is not the case for S/B ratio and reaction pressure. Among the gasification processes, PW gasification exhibits the highest LHV, while SS gasification demonstrates the highest CGE. Besides, the gasification efficiency (ƞG) is found about 35~41% at the S/B=2, which is lower than the efficiency in terms of CGE (57.6%) due to the energy consumption increase as the temperature increased. O2/S increases negatively affect product composition but allow parameter indicator value adjustment to parameter indicator of the desired syngas product quality.

Assessing leaf physiological traits in response to flooding among dominant riparian herbs along the Three Gorges Dam inChina.

Dams worldwide have significantly altered the composition of riparian forests. However, research on the functional traits of dominant herbs experiencing flooding stress due to dam impoundment remains limited. Given the high plasticity of leaf traits and their susceptibility to environmental influences, this study focuses on riparian herbs along the Three Gorges Hydro-Fluctuation Zone (TGHFZ). Specifically, it investigates how six leaf physiological traits of leading herbs-carbon, nitrogen, phosphorus, and their stoichiometric ratios-adapt to periodic flooding in the TGHFZ using cluster analysis, one-way analysis of variance (ANOVA), multiple comparisons, Pearson correlation analysis, and principal component analysis (PCA). We categorized 25 dominant herb species into three plant functional types (PFTs), noting that species from the same family tended to fall into the same PFT. Notably, leaf carbon content (LCC) exhibited no significant differences across various PFTs or altitudes. Within riparian forests, different PFTs employ distinct adaptation strategies: PFT-I herbs invest in structural components to enhance stress resistance; PFT-II, mostly comprising gramineous plants, responds to prolonged flooding by rapid growth above the water; and PFT-III, encompassing nearly all Compositae and annual plants, responds to prolonged flooding with vigorous rhizome growth and seed production. Soil water content (SWC) emerges as the primary environmental factor influencing dominant herb growth in the TGHFZ. By studying the response of leaf physiological traits in dominant plants to artificial flooding, we intend to reveal the survival mechanisms of plants under adverse conditions and lay the foundation for vegetation restoration in the TGHFZ.

Direct air capture using halophilic Cyanobacterium aponinum PCC10605 under illumination of light-emitting diodes in marine environment

Excessive carbon dioxide (CO2) emissions have become a disaster, calling for an effective way to reduce atmospheric CO2 content. Cyanobacteria, also known as blue-green algae, are potent natural carbon sinks with efficient photosynthesis and produce valuable compounds. Herein, we demonstrated the excellent properties of Cyanobacterium aponinum PCC10605 (Capo) in maintaining growth and protein accumulation under salt stress and red light-emitting diodes (LEDs) illumination at 660 nm under direct air capture (DAC) condition. Multi-factor optimization from response surface methodology revealed the best condition of 25 °C, 70 μE light intensity, 17 g/L salt, 16 to 8 h for light to dark period, and 6 mM nitrogen to yield the highest combination of 1.49 g/L biomass and 19.1 % C-phycocyanin (C-PC) content. Capo also thrived in 50 % seawater from Penghu, Taiwan where its DAC capacity was confirmed using an elemental analyzer, showing that 48.2 % carbon content was equivalent to specific capture ratio of 1.75 g-CO2/g-DCW and volumetric efficiency of 2.62 g-CO2/L, respectively. Finally, scaling up cultivation in 2-liter photobioreactor was successfully carried out under red LED illumination. The potential of Capo in reducing atmospheric CO2 level represents an advancement in sustainable biotechnology for climate change mitigation.

Effects of fertilization applications on soil aggregate organic carbon content and assessment of their influencing factors: A meta-analysis

Fertilizer application plays an important role in agricultural soil organic carbon (SOC) and its sustainable management. However, there is a lack of consensus about the mechanisms regarding fertilizer application in the soil on the procedure of carbon sequestration and sink enhancement in the aggregates. In this study, the extent by which various fertilization treatments, fertilization durations, climate conditions, soil texture, and land-use types affected the organic carbon (OC) content of different particle-size aggregates was quantitatively assessed using a meta-analysis of 696 treatment comparisons from 36 published studies. Based on the meta-analysis results, fertilization enhanced the OC contents of macroaggregates and clay and silt particles, particularly through replenishing organic material. Long-term fertilization increased the OC content of macroaggregates (>0.25 mm), while the OC content of the clay and silt particles (<0.053 mm) reached a maximum at 15.4 years of fertilization, after which it reached carbon saturation. Organic fertilizer effectively increased the OC content of small macroaggregates (0.25–2 mm) and microaggregates (0.053–0.25 mm) at lower temperatures and precipitation. Compared with inorganic fertilization, combined organic–inorganic fertilization increased OC contents of all sizes of aggregates in sandy or clay loam soils, but decreased OC contents of microaggregates and clay and silt particles in silt loam soils. All fertilization treatments increased the OC content of all particle-size aggregates in upland soils. In contrast, inorganic fertilization and mixed organic–inorganic fertilization reduced the OC content of microaggregates (0.053–0.25 mm) and clay and silt particles (<0.053 mm) in paddy field soils. In conclusion, the application of organic fertilizers is more conducive to the accumulation of OC in agricultural soil aggregates. Whereas the limiting factors for the accumulation of OC content in soil aggregates vary under different conditions, organic fertilizer inputs should be given more consideration, especially in dryland and coarse-textured soils.

Pattern of plant biomass and carbon stock along different elevational forests in eastern Nepal

The primary aim of this investigation was to determine the biomass and carbon stock distribution pattern among different forest stands of diverse elevations in the Morang district of East Nepal. It is noteworthy to estimate carbon stock and biomass of relatively least underexplored forests in east Nepal. The data for estimating the biomass and carbon stocks of the five different forest sites, viz. Bhaunne, Raja-Rani, Murchungi, Adheri, and Sagma located between 100-1300m above the mean sea level, were acquired through the measurement of inventory plots selected randomly. Altogether, 50 sample plots were established within five forest stands located on different elevational zone; within each forest site, 10 sample plots of 20m × 20m size, were laid out for the measurement of trees. In the case of shrubs and herbs, nested plots of 5m × 5m and 1m ×1m, respectively were established. Calculation of the biomass of trees and shrubs was facilitated through the application of an allometric equation, while the biomass of herbs was determined by the harvest method. The carbon concentration in the plant materials was estimated using ash content method. The comprehensive analysis of the stand biomass in the Bhaunne, Raja-Rani, Murchungi, Adheri, and Sagma forest sites were: 815.86 Mg ha-1, 414.19 Mg ha-1, 606.81 Mg ha-1, 519.20 Mg ha-1, and 299.96 Mg ha-1, respectively, with minimum at the Sagma site (high-altitude forest) and maximum at the Bhaunne site (low-altitude forest). As per the variation in stand biomass, the carbon stocks in the forest sites also showed the same trend, but the values ranged from 140.19 Mg C ha-1 to 333.63 Mg C ha-1, with the minimum in the Sagma site and the maximum in the Bhaunne site. The application of the Friedman Test revealed statistically significant variation in the tree biomass between the Murchungi and Sagma sites and also in the shrub biomass between the Adheri and Sagma sites. Similarly, noteworthy variations were observed in the herb biomass of the Bhaunne, Raja-Rani, Murchungi, and Adheri sites as compared to that of the Sagma site. The present study contributes to the understanding of forest ecosystems in context to carbon management.

Comparative analysis of foliar galls and ungalled leaves of Alstonia scholaris with a focus on tissue ultrastructure and phytochemistry

Plant-insect interactions where the insect changes the course of host-plant growth by building a new structure called as a “gall” to protect and nourish the growing insect continue to fascinate scientists. Alstonia scholaris, a medicinal plant extensively used in Indian Traditional Medicine has shown to have such interactions with insect Pauropsylla tuberculata Crawford producing numerous galls on the plant leaves. This intricate and poorly understood natural relationship demands further investigation to unravel the distinctions between gall tissue and unaffected leaves. We examined the tissue ultrastructure by scanning electron microscope (SEM) and phytochemistry by thin layer chromatography and liquid chromatography - high resolution mass spectrometry to understand variations between the gall tissues and ungalled leaves of A. scholaris. The data showed dense population of sclereids in the gall tissues in addition to parenchyma cells. The concentration of aluminium, phosphorus and carbon were found to be reduced in the galls while cobalt and oxygen were increased. The SEM images gives insight into the ecological relationship between these species. The phytochemical analysis indicated not only enrichment of alkaloids and terpenoids in the gall tissues but also observed several novel peaks with unreported masses indicating a potential reservoir of bioactive phytochemicals.