Tree Biomass Research Articles

Strategy on rapid selection of woody species for phytoremediation in soils contaminated with copper, lead and zinc in Shanghai

The use of woody species for the remediation of heavy metal-contaminated soils is an environmentally friendly and economically viable strategy. This study investigates the phytoextraction abilities of 15 woody species for copper, lead and zinc in contaminated soil. The results indicated that all species showed phytoextraction ability, with metal concentrations varying from 5.59 to 27.45 mg·kg−1 for Cu, 2.79 to 16.75 mg·kg−1 for Pb and 22.13 to 185.72 mg·kg−1 for Zn in the stem tissues depending on the species. Pterocarya stenoptera, Paulownia fortunei and Salix matsudana were identified as the top performers in terms of overall phytoextraction capacity. Notably, their capacity to transport zinc exceeded that of copper and lead. The enrichment of copper, lead and zinc in the soil showed a synergistic effect in the presence of heavy metal. The distribution of heavy metals within plant tissues was affected by water content and the inherent toxicity of metals. The study highlights that the accumulation of tree biomass and water content in the stem play a significant role in determining the amount of heavy metals phytoextracted. This insight offers a quick method for the rapid selection of woody species for phytoremediation in urban soils contaminated with heavy metals.

Tree species diversity and spatial distribution of carbon stock in forests under different management regimes in Nepal's Western Terai Arc Landscape

Reliable tree species diversity and carbon stock data are crucial for establishing a baseline and aiding monitoring and management decision-making to ensure ecosystem functions and services, including carbon management. However, such data are not available for many primary forests, especially in developing countries like Nepal. For this study, we generated primary baseline data on tree species diversity, biomass, and carbon stock for forests under different management regimes in one of the critical landscapes of western Nepal. We sampled 94 clusters of concentric circular sample plots placed systematically at the nodes of 3 km by 3 km square grids in biological corridors (managed by community forest user groups) and a national park's buffer zones (managed by buffer zone user groups) to study the tree species composition and estimate the carbon stock. The number of tree species and botanical families reported in different sites did not differ significantly. The basal area was found to be highest in Brahmadev Corridor where tree density per unit area was also highest. Our study sites showed a basal area ranging from 26.42 to 40.65 m2/ha, which is higher than previously reported from similar forests. The total biomass (302.12 to 496 tons/ha) and carbon stock (142 to 233.12 tons/ha), both being highest in Brahmadev Corridor, were within the range of comparable data and national averages. The number of stems in all sites showed the reverse J-shaped pattern, indicating a stable population and good species recruitment. The buffer zones had a large proportion of forest area with the highest carbon stock classes of 300–400 tons/ha. The basal area and diameter at breast height showed a significant positive correlation with carbon stock, indicating that the basal area is a key determinant of carbon stock. Our study provides disaggregated information on tree species diversity, the quality of forests in terms of stem density and size-class distribution, and carbon stock and its distribution in different carbon stock classes in two forest management regimes. In this sense, our study is the first of its kind in providing important insights into forest and carbon management because areas with different carbon stocks need different management prescriptions.

Effects of soil compaction on above- and belowground interactions during the early stage of forest development

Forested green spaces in urban and peri-urban areas are expected to serve multiple roles, including providing ecosystem services and maintaining species diversity and soil health, both of which are particularly important for human health. However, soil compaction is a major cause of soil degradation in urban areas and brownfields (abandoned, previously developed land). We examined the effects of compaction on soil physicochemical properties, tree species richness, tree basal area, and the functional diversity of microbial communities in an immature volcanic soil through a long-term (14-year) field experiment. Our experimental results showed that soil compaction reduced not only both tree species richness and biomass but also the multifunctionality of soil microbial communities. Furthermore, tree species richness was significantly positively related to soil microbial decomposition activity. These findings provide evidence of above- and belowground interactions and underscore their importance in the design of urban forests using ecosystem-based solutions.

Above-ground bole biomass and carbon stock of recreational trees at Agodi Gardens, Oyo State, Nigeria

This study used allometric equations to evaluate the biomass and carbon stock of recreational trees at Agodi Gardens in Ibadan Metropolis. Stratified sampling technique was used to delineate 15 plots (25m x 25m). Six allometric equations were selected to estimate Aboveground Biomass (AB) of the tree species. Models selected were assessed based on highest adjusted coefficient of determination (AdjR2), significant F-ratio (P<0.05) and least Root Means Square Error (RSME). A total of 220 trees belonging to 18 species were encountered. The dominant Diameter at Breast Height (DBH) and Height (Ht) were 62.8cm and 39.1m, respectively for Alstonia bonnei and Elaeis guineensis. The mean AB/ha was 2.8006Kgha-1 and the highest carbon stock of 3.332147 x 10-4 was recorded for Khaya ivorensis. Equation C= 2.6 x 10-7+ln (AB) + lnDBH²+lnHt (AdjR²=99%), gave the best fit to estimate carbon stock in the study area. The study found a significant relationship between AB, DBH and Ht, with a high correlation between DBH and Ht (P-value=0.00). Hence, as the DBH increases, the Ht increases with an increase in AB. Most trees had low slenderness coefficients (<70). The developed allometric model improved the prediction of aboveground stem biomass and carbon stock, making it useful for future research.

Exploring influential factors on biomass and diversity of ancient trees in human-dominated regions: A case study in Guangdong Province, China

Ancient trees, which are vital for biodiversity and cultural heritage, maintain species richness, ecosystem resilience, and societal interconnectedness. However, escalating global climate change and human activities have led to widespread declines in ancient tree diversity and habitat degradation. Hence, understanding ancient tree dynamics is vital for precise conservation strategies, fostering harmony between society and ecology. This study addresses the gap in understanding the factors influencing ancient tree biomass and diversity in human-dominated areas. This study first collected biomass equations for ancient tree species. The biomass of ancient trees within human-influenced regions of Guangdong Province was subsequently computed in detail. Finally, by employing a structural equation model, we sought to quantitatively elucidate the influence of natural variables (encompassing geography, topography, soil composition, and climatic conditions) alongside anthropogenic variables (including population density, per capita GDP, the human footprint, ancient villages, and religious sites) on both the biomass and species richness of ancient trees. The species with the highest total biomass included Ficus microcarpa L.f. (2.45 × 105 t), Ficus concinna (Miq.) Miq. (4.07 × 104 t), and Litchi chinensis Sonn. (3.16 × 104 t). Moreover, the biomass presented a pronounced phylogenetic signal and evolutionary conservation. According to the results of the structural equation model, across the entire study area, soil characteristics emerged as the most influential predictor among the natural factors (β = −0.14), whereas population density stood out as the foremost predictor among the anthropogenic factors (β = 0.23). Notably, both climatic conditions and anthropogenic factors contributed positively to an increase in ancient tree biomass (β = 0.02) (β = 0.07), albeit concurrently leading to a decrease in species richness (β = −0.05) (β = −0.08). In regions characterized by high levels of disturbance, anthropogenic factors indirectly increase biomass by increasing the abundance of large-diameter ancient trees (β = 0.28) while concurrently decreasing species richness (β = −0.11). Conversely, in areas with low levels of disturbance, anthropogenic influences also indirectly increase biomass (β = 0.19) by fostering the growth of large-diameter ancient trees while simultaneously promoting species richness (β = 0.01). This study investigated biomass and diversity factors in ancient trees within human-dominated regions of Guangdong Province. This study provides insights into ecosystem determinants, informing conservation strategies and contributing to biodiversity preservation amid societal and environmental dynamics.

Primary productivity regulates rhizosphere soil organic carbon: Evidence from a chronosequence of subtropical Chinese fir (Cunninghamia lanceolata) plantation

Tree plantations worldwide are a large terrestrial carbon sink. Previous studies on the carbon sequestration capacity of plantations mainly focused on tree biomass carbon sequestration, but the importance of soil organic carbon (SOC) was relatively unclear. Living root carbon inputs influence SOC via plant-microbe interactions in the rhizosphere and play an essential role in nutrient cycling. Here, we compared SOC, including its fractions, microbial properties, and major nutrients in rhizosphere and bulk soils, and examined their relationships to net primary productivity (NPP) across three developmental stages of Chinese fir (Cunninghamia lanceolata) plantations (6, 18, and 42 years old) in subtropical China. Although NPP differed among the three plantations, SOC concentration in bulk soils did not vary significantly among them. However, SOC concentration and labile C pool I and recalcitrant C pool in rhizosphere soils were significantly (p < 0.05) higher in the young (6-year) and mature (42-year) plantations, both of which had lower (p < 0.05) NPP (−37.71 % and − 42.67 %) compared to the middle-aged (18-year) plantation, suggesting a decoupling of NPP from rhizosphere SOC in the plantations. The decoupling of NPP from rhizosphere SOC concentrations may be driven by nitrogen (N) and phosphorus (P) tree growth requirements, belowground C allocation, and resultant microbial activity in this highly weathered subtropical soil. Our study provides field-based evidence suggesting that rhizosphere SOC changes are primarily regulated by net primary production in subtropical forest plantations. We propose that accurate predictions of SOC dynamics in forest plantations require an improved understanding of rhizosphere processes during plantation development.

Trends in planted native tree biomass established in a tropical Andes city water basins

Studying tree growth processes helps us evaluate the success of restoration efforts in recovering ecosystem processes such as carbon accumulation. Here, we study aboveground biomass dynamics in four common‐endemic tree species from the tropical Andes (Quercus humboldtii, Retrophyllum rospigliosii, Citharexylum subflavescens, and Croton magdalenensis), established in the main water supply basins of Medellín, Colombia. We use measurements from 19 permanent plots from five censuses between 2010 and 2023 to develop biomass equations as a function of t for each species (B = f[t]) by combining tree growth models of diameter (D) as a function of time (t) and pre‐existing allometric equations of biomass (B) developed in the same site as a function of D and wood density (ρ). We found that, because of initially higher growth rates characteristic of species belonging to the fast‐growing end of the fast‐slow growth economic spectrum, C. magdalenensis and C. subflavescens were the species with higher biomass accumulation at 13 years (142 and 132 kg, respectively). However, the potential of the slow‐growing species (Q. humboldtii and R. rospigliosii) for carbon sequestration initiatives in the long term was highlighted. To our knowledge, this is the first study in the region examining the dynamics of aboveground biomass in Andean restoration programs. It combines growth models and allometric equations, which can be useful for measuring the success of the implementation of ecological restoration programs and evaluating the need to apply adaptive management strategies.

Measuring the extent of trees outside of forests: a nature-based solution for net zero emissions in South Asia

Abstract To reduce emissions of carbon and other greenhouse gases on a pathway that does not overshoot and keeps global average temperature increase to below the 1.5 oC target stipulated by the Paris Agreement, it shall be necessary to rely on nature-based solutions with atmospheric removals. Without activities that create removals from carbon sequestration it will not be possible to balance residual emissions. Policies that focus solely on reducing deforestation will only lower future emissions. On the other hand, activities that include regeneration or regrowth of tree biomass can be used to create net-zero emissions through carbon sequestration and atmospheric removals now. New methods demonstrated here using high resolution remote sensing and deep machine learning enable analyses of carbon stocks of individual trees outside of forests (TOF). Allometric scaling models based on tree crowns at very high spatial resolution (&lt;0.5 m) can map carbon stocks across large landscapes with millions of trees outside of forests. In addition to carbon removals, these landscapes are also important to livelihoods for millions of rural farmers and most TOF activities have the capacity to bring more countries into climate mitigation while also providing adaptation benefits. Here were present a multi-resolution, multi-sensor method that provides a way to measure carbon at the individual tree level in TOF landscapes in India. The results of this analysis show the effectiveness of mapping trees outside of forest across a range of satellite data resolution from 0.5 m to 10 m and for measuring carbon across large landscapes at the individual tree scale.

Resource availability enhances positive tree functional diversity effects on carbon and nitrogen accrual in natural forests

Forests harbor extensive biodiversity and act as a strong global carbon and nitrogen sink. Although enhancing tree diversity has been shown to mitigate climate change by sequestering more carbon and nitrogen in biomass and soils in manipulative experiments, it is still unknown how varying environmental gradients, such as gradients in resource availability, mediate the effects of tree diversity on carbon and nitrogen accrual in natural forests. Here, we use Canada’s National Forest Inventory data to explore how the relationships between tree diversity and the accumulation of carbon and nitrogen in tree biomass and soils vary with resource availability and environmental stressors in natural forests. We find that the positive relationship between tree functional diversity (rather than species richness) and the accumulation of carbon in tree biomass strengthens with increasing light and soil nutrient availability. Moreover, the positive relationship between tree functional diversity and the accumulation of carbon and nitrogen in both organic and mineral soil horizons is more pronounced at sites with greater water and nutrient availabilities. Our results highlight that conserving and promoting functionally diverse forests in resource-rich environments could play a greater role than in resource-poor environments in enhancing carbon and nitrogen sequestration in Canada’s forests.

Reducing tree volume overestimation in quantitative structure models using modeled branch topology and direct twig measurements

Abstract Quantitative Structure Models (QSMs) are fit to tree point clouds to represent the topology of trees as a network of cylinders. QSMs allow for the calculation of metrics difficult to measure without destructive sampling, including total tree volume. Current limitations in terrestrial laser scanning technology make small branches difficult to accurately resolve, causing overestimation of small branch volume in QSMs, which can translate into overestimating tree biomass. We present a new method called Real Twig to correct overestimated small branch and twig cylinders in QSMs. Real Twig differs from current methods by using twig diameters measured directly from corresponding tree species to model a unique taper for every path in the QSM, using the QSM’s inherent branching topology, but without relying on predefined mathematical or allometric relationships. To test Real Twig, we generated QSMs for different sets of trees that had detailed dry mass and density measurements obtained via felling after scanning. QSM-based biomass estimates were obtained by multiplying the tree’s QSM-based volume estimate by the tree’s specific basic density value. We trained our method with high-quality data consisting of five northern red oak (Quercus rubra L.) and five red maple (Acer rubrum L.) trees, using two different versions of TreeQSM, a widely used algorithm for generating QSMs. We further tested our method on three publicly available datasets, including managed forests and large tropical trees, collected with both phase-shift or time-of-flight sensors. QSMs corrected with our Real Twig method showed a very large improvement in tree biomass estimation, with a relative mean error of −1.2%, a relative root mean square error of 10.5%, and a concordance correlation coefficient of 0.999, compared to a relative mean error 76.8%, a relative root mean square error of 48.7%, and a concordance correlation coefficient of 0.982, when using the standard outputs of TreeQSM.

Development of spatial models and maps for tree species diversity and biomass in a miombo ecosystem, western Tanzania

Development of spatial models and maps for tree species diversity and biomass in a miombo ecosystem, western Tanzania

Forest structure explains spatial heterogeneity of decadal carbon dynamics in a cool-temperate forest

Abstract Accurate evaluation of forest biomass distribution and its long-term change over wide areas is required for effective forest carbon management and prediction of landscape-scale forest dynamics. We evaluated a landscape-scale (225 km2) decadal forest carbon budget at a 1 ha spatial resolution in a cool-temperate forest, by repeating airborne laser observations 10 years apart and partitioning net forest biomass change (FBC) into growth and mortality. Using &gt;10 000 samples, we revealed that naturally regenerated forests have large spatial heterogeneity in net biomass change, and 3/4 of the photosynthetically acquired carbon stock moved to necromass even without anthropogenic disturbances. Actual carbon residence time as living tree biomass was estimated by dividing biomass by growth or mortality rates. The residence time was 107 and 106 years, respectively with large spatial variation among stands (48 and 42 years, respectively, as the difference between 25 and 75 percentile), although studied forest stands have small variation in the forest functional type in a landscape-scale. The best predictors of subsequent decadal biomass changes were two forest structural factors, mean canopy height and canopy height variation in addition to one environmental factor, elevation. Considering the long lifetime of trees, these structural factors may be an indicator of forest soundness rather than a cause of forest growth or mortality. However, in any cases, these structural factors can be powerful predictors of subsequent FBC.

Understory plant biodiversity is inversely related to carbon storage in a high carbon ecosystem.

Given that terrestrial ecosystems globally are facing the loss of biodiversity from land use conversion, invasive species, and climate change, effective management requires a better understanding of the drivers and correlates of biodiversity. Increasingly, biodiversity is co-managed with aboveground carbon storage because high biodiversity in animal species is observed to correlate with high aboveground carbon storage. Most previous investigations into the relationship of biodiversity and carbon co-management do not focus on the biodiversity of the species rich plant kingdom, which may have tradeoffs with carbon storage. To examine the relationships of plant species richness with aboveground tree biomass carbon storage, we used a series of generalized linear models with understory plant species richness and diversity data from the USDA Forest Service Forest Inventory and Analysis dataset and high-resolution modeled carbon maps for the Tongass National Forest. Functional trait data from the TRY database was used to understand the potential mechanisms that drive the response of understory plants. Understory species richness and community weighted mean leaf dry matter content decreased along an increasing gradient of tree biomass carbon storage, but understory diversity, community weighted mean specific leaf area, and plant height at maturity did not. Leaf dry matter content had little variance at the community level. The decline of understory plant species richness but not diversity to increases in aboveground biomass carbon storage suggests that rare species are excluded in aboveground biomass carbon dense areas. These decreases in understory species richness reflect a tradeoff between the understory plant community and aboveground carbon storage. The mechanisms that are associated with observed plant communities along a gradient of biomass carbon storage in this forest suggest that slower-growing plant strategies are less effective in the presence of high biomass carbon dense trees in the overstory.

Extraction of Anacardium occidentale: a kinetic, thermodynamic, phytochemical identification, and antibacterial study

Cashew tree biomass, Anacardium occidentale, represents an underutilized part of the plant and could have great potential for application in several areas, such as bioengineering, food science, and chemical. The stirred bed process was optimized to produce extracts from Anacardium occidentale stem bark (SBAo) and leaves (LAo) for bactericide purposes. Variables as alcohol content, stirring speed (SS), particle size (PS), solid-to-solvent ratio (S/S), temperature, and extraction time were evaluated. Subsequently, kinetic, thermodynamic and diffusivity fittings of the data were performed using different nonlinear models (Peleg, 2nd order, Elovich, power law, and Fick’s 2nd law) applied to the yield curves. Extracts were characterized by Fourier-transform infrared (FTIR) spectroscopy, total phenolic content (TPC), total flavonoid content (TFC), trolox equivalent antioxidant capacity (TEAC), and ultra-high resolution mass spectrometry (UHRMS) techniques for qualitative and quantitative determination of the phytochemicals. The optimized operating conditions obtained were ethanol in solvent at 70%, PS < 45 μm, 1200 rpm SS, 1/10 S/S ratio, and extraction time of 1 h at 50 ºC. The 2nd order kinetic model was the one that presented the best fits: SBAo (R2 > 0.9893 and RMSE < 3.4293) and LAo (R2 > 0.9985 and RMSE < 3.1117). Both A. occidentale extracts showed high levels of polyphenols and flavonoids, such as anacardic acid. Finally, the optimized extracts showed antibacterial susceptibility, with larger halos against S. aureus, 0.88± 0.07 mm (SBAo) and 0.45 ± 0.03 mm (LAo), in relation to E. coli, 0.80 ± 0.10 mm (SBAo) and 0.69 ± 0.08 mm (LAo).

Tree Species Diversity and Carbon Stock of Tropical and Sub-Tropical Forests of Mizoram, Northeast India

The present study was conducted in tropical and sub-tropical forests of Mizoram, Northeast India. A total of 49 species belonging to 40 genera and 26 families were recorded in the tropical forest (TF). Whereas, in the subtropical forest (STF), 47 species belonging to 42 genera and 28 families were recorded. As per Importance Value Index (IVI), the most dominant species in TF were : Castanopsis tribuloides (47.67), Schima wallichii (40.71), Aporosa octandra (20.96) and Wendlandia budleioides (17.79). Whereas, the species such as Ilex godajam (41.42), Saprosma ternatum (32.74) and Diospyros racemosa (31.34) were the most dominant species in STF. The total tree density and basal area were 1610 individuals ha-1 and 25.016 m2 ha-1 in TF and 1380 individuals ha-1 and 24.20 m2 ha-1 respectively in STF. The diversity indices such as Shannon’s diversity index (H′), Simpson’s dominance index (CD), Margalef richness index (d), and Pielou’s evenness index (J) ranged from 2.93-3.16, 0.91-0.94, 7.82-8.15, 0.76-0.81 in both the forests. The total tree biomass was 178 Mg ha-1 in TF and 144 Mg ha-1 in STF. Similarly, the total carbon stock in TF was 85 Mg C ha-1 and 68 Mg C ha-1 in STF. Such information on these forests can serve as a valuable tool for improving our capacity to enhance biodiversity conservation efforts and management of tropical forests for their sustainable use in the future.

An Appraisal of the Potential of Sequestering Carbon through Pomegranate Orchards in India

Pomegranate is an important arid and semi-arid fruit crop of Indian origin. Land use change from agriculture to pomegranate orchards not only enhances farmers’ income but also helps in sequestering carbon and provides additional ecosystem services. Assessing carbon stocks and stock changes in fruit orchards is crucial under the United Nations Framework Convention on Climate Change and the Kyoto Protocol. In this context, we conducted a study to estimate carbon stocks in pomegranate orchards in India. We developed an exclusive allometric equation to estimate pomegranate tree biomass and collected extensive samples of trees, litter, weeds, and soil. We grouped pomegranate-growing areas by similarity in variety, soil, and climate, and then calculated the carbon held in these pools. Finally, we computed the carbon sequestered by pomegranates per hectare, providing valuable insights for climate change mitigation efforts. The national-level carbon storage in pomegranate orchards was then computed by multiplying the area occupied by pomegranate in these regions by the amount of carbon sequestered in one ha of land. Nearly 42.49 mt of carbon is sequestered in the pomegranate orchards of the country with 18.42 mt (43.36% of the total CS) stored in tree biomass and 24.1 mt (56.71% of the total CS) stored in soil. This study underscores the important role of pomegranate orchards in India, not only as a lucrative agro-economic venture for farmers but also as a significant contributor to carbon sequestration and overall ecosystem services. Such insights are essential for guiding sustainable land use practices and aligning agricultural efforts with global climate change mitigation strategies.

A local perspective on the links between flora biodiversity and ecosystem services in the Northwest Highlands of Ethiopia

The main concern that this study attempts to address is the reason that the local people sustainably conserve church forests while aggressively exploiting biodiversity in common forests, shrublands, and grasslands. The study assesses the local perspective on the links between flora biodiversity and ecosystem services across a range of management options in the typical watershed of the Northwest highlands of Ethiopia. A mixed study design that included questionnaires, remote sensing, and hermeneutics was used because of the multidisciplinary character of the research. There has been a perceptible decline in flora biodiversity in the open-access shrublands, forests, and grasslands as a result of increased settlement encroachment, unchecked and continuous overgrazing, excessive firewood collection, and the cutting of living and dead tree and shrub biomass. Because of this, it was noticed that the availability of wild edible plants, medicinal plants, trees to produce tools, habitat for wild animals, and lumber production is drastically reduced. Alternatively, the church forests were preserved with responsive caring, which enables the outstanding performance of the majority of ecosystem services (except for collecting firewood and fibers) for the local community with the principles of equality and inclusiveness. Therefore, to restore open-access communal grazing ecosystems and the synergy of many ecosystem services in a given watershed, an effective institutional structure must be developed at the local administration level. To offer a range of ecosystem services and socioeconomic benefits, reforestation and planting of both exotic and native plants with enclosure management established on the values of justice, equality, inclusivity, and well-managed local governance with strict laws, sanctions, and enforcement must be the cornerstones of the management plan.

Effect of altitudes and aspects on carbon sequestration potential of Quercus floribunda forests of Garhwal Himalayas

The forests are major resources for carbon sequestration and help to mitigate the adverse effect of atmospheric carbon and reduce global warming. The present study was conducted to estimate the carbon sequestration potential of the Quercus floribunda forests at two different aspects and three altitudes. Ten quadrates of 10 × 10 m size were laid out in each forest for the estimation of stand density, tree biomass, and soil samples were collected from each quadrate. Q. floribunda was the dominating tree at studied altitudes and aspects with the IVI values of 161.14 and 124.96 in the southern aspect and northern aspects, respectively. the highest values of above-ground biomass density (AGBD), below-ground biomass density (BGBD), total biomass density (TBD), and total carbon density (TCD) was recorded at the upper elevation (2500–2700 m) of southern and northern aspects. In the southern aspect values of AGBD (476.67 < 575.67 Mg/ha), BGBD (124.8 < 148.9 Mg/ha), TBD (601.53 < 724 Mg/ha), TCD (300.83 < 362.03 Mg/ha) were higher than northern aspect. The values of AGBD, BGBD, TBD, and TCD were reported maximum (638 Mg/ha, 163.1 Mg/ha, 800.5 Mg/ha, and 400.35 Mg/ha; respectively) in the upper elevation. Soil organic carbon (SOC), soil organic matter (SOM), and soil organic carbon stock (SOCS) decreased with increasing altitudes and depths which were found higher in the southern aspect. Bulk density (BD) and P increased with altitudes and depth however bulk density was equal (1.29 g cc-1) in both aspects whereas P was also found higher (31.43 kg/ha) in the southern aspect. Highest available nitrogen (398 kg/ha) was recorded in the northern aspect at middle altitude. The available potassium was highest in the northern aspect. At lower altitudes, available potassium ranges between 246–615 kg/ha. Soil pH was found slightly acidic in all the sites ranging from 4.91 to 5.74 in different soil depths. Dehydrogenase activity was ranged between 1.35 and 8.74 µg/g/h from lower to upper soil depth and decreased with an increase in soil depths and increased with altitudes, whereas found highest in the southern aspect. The present study suggested that tree density, tree biomass, carbon sequestration potential, and soil health in Q. floribunda forests were substantially influenced by the altitude as well as the aspect. These findings contribute valuable insights for climate change mitigation and forest management strategies in the study region.

Forest carbon payments: A multidisciplinary review of policy options for promoting carbon storage in EU member states

Forest carbon sinks can play an important role in mitigating climate change, but currently only a few policies exist globally where economic incentives are created for forest owners to maintain and strengthen sinks. This article aims to facilitate the design and implementation of governmental payment schemes for forest carbon uptake services by presenting a multidisciplinary analysis of the many challenges involved in such schemes and by proposing potential solutions. We assess the consequences, opportunities, and risks of carbon payment schemes from economic, ecological, social, and legal points of view based on existing literature. Our analysis is set in the context of the European Union (EU), but many of the central findings have relevance for a broader geographical area. The main economic challenges of implementing carbon payment schemes relate to potential leakage, the question of additionality, and uncertain forest-owner behavior. The most important ecological considerations include effects on soil carbon dynamics and biodiversity as well as issues of non-permanence and forest resilience. Our exploration of the social acceptance of carbon payments among the general public, key market actors such as forest owners and forest industry, and other stakeholders suggest that both the process of developing the scheme and its details are significant. Further, our legal analysis indicates that central challenges for carbon payment schemes within the EU rise from the requirement to comply with competition and state aid regulations. Finally, we synthesize our findings and suggest a two-step approach for introducing public carbon payments in an EU member state. Initially, the scheme could be launched via De minimis aid or the new aid scheme (GAFSRA). A low carbon price could be applied to moderate market effects, and the payments could be limited to additional carbon storage only. Peatlands, where tradeoffs exist between tree biomass carbon and soil carbon, should initially be excluded from the standard payment scheme, and regulated with command-and-control instruments and measure-based payments instead. In the future, an improved knowledge base and institutional changes may enable schemes that encompass all ecosystem carbon pools on all relevant soil types and create optimal incentives for both forest management and land-use choices by pricing all land-based sinks and emissions. Such schemes could utilize, e.g., cap-and-trade instruments and be complemented by import tariffs to control carbon leakage.

UAV or satellites? How to find the balance between efficiency and accuracy in above ground biomass estimation of artificial young coniferous forest?

The accurate estimation of Above Ground Biomass (AGB) is the basis for plantation forest carbon trading. This study focused on Picea crassifolia artificial plantations, extracting individual tree crown diameters and heights using Unmanned Aerial Vehicles (UAV) data and calculating the individual tree biomass using allometric growth equations. These results were then used to train a satellite image AGB prediction model. In additional, satellite images were resampled to different resolutions to assess the impact of satellite image resolution on model the accuracy. Finally, the model with the highest accuracy among the deep learning algorithms was selected to predicts the AGB within the P. crassifolia plantation forest. The results indicated that the accuracy of single tree crown diameters extracted from P. crassifolia point clouds significantly surpassed those extracted from general point clouds and Crown Height Model (CHM), while the accuracy of the heights extracted from all three sources was similar; RepLKNet outperformed GoogLeNet and ResNet in identifying plantation forest; random forest slightly outperformed XGBoost in the capability of AGB prediction, while the accuracy of the AGB prediction models initially increasd and then decreasd with satellite image resolution, reaching the highest accuracy at a resolution of 50 m. This indicates that the optimal satellite image resolution for estimating the AGB in the study area was affected by scale effects of 50 m. Compared with the combination of satellite data and manual field measurements, the concurrent use of UAVs and satellites offers significant advantages in terms of efficiency and accuracy. UAVs can replace manual sampling for carbon sequestration transactions for plantations.