Total Stock Research Articles

The implications of biomass and carbon sequestration of exclosure for climate change mitigation in arid areas, Sekota district, northern Ethiopia

Climate dynamics management plays a crucial role in safeguarding the environment from a global to local scale. Land degradation poses a significant threat to the livelihoods of millions of people living in drylands. Arid regions are particularly vulnerable when it comes to finding suitable habitats for ecological processes. Various global initiatives have been developed to restore degraded drylands. In addition, exclosures have important implications in arid areas for regulating environmental services. However, there is a lack of systematic studies on the biomass improvement and climate change mitigation effects of exclosures. A study was carried out in the Sekota district of northern Ethiopia to evaluate the impact of exclosures on biomass production and carbon stock. Three sites—Gateno, Jinqaba, and Mildam—were chosen for the pilot study. Data was collected from 27 quadrats, with different sizes used for sampling saplings, seedlings, litter, and soil. Soil samples were taken at depths of 0–20 cm and 0–40 cm. The data was analyzed using Excel and R Studio, and a linear mixed-effect model was used to determine the differences between land uses. The results indicated significant variations in above-ground biomass carbon, soil organic carbon, and total carbon stock between the two land uses. Furthermore, the observational perspective of exclosures in the Sekota district reveals a sustainable and suitable environment for interested parties. Exclosures prove to be effective in the restoration of degraded lands, as well as in enhancing biomass accumulation and carbon sequestration.

Biomass and Carbon Stock Capacity of Robinia pseudoacacia Plantations at Different Densities on the Loess Plateau

Forests make an important contribution to the global carbon cycle and climate regulation. Caijiachuan watershed false acacia (Robinia pseudoacacia Linn.) plantation forests have been created for 30 years, but a series of problems have arisen due to the irrationality of the density involved at that time. To precisely assess the contribution of R. pseudoacacia plantations with different densities to this cycle, we measured the diameter at breast height (DBH), tree height (H), biomass, and carbon stocks in trees, shrubs, herbs, litter, and soil across different density ranges, denoted as D1 = 900–1400, D2 = 1401–1900, D3 = 1901–2400, D4 = 2401–2900, and D5 = 2901–3400 trees ha−1. In order to achieve the purpose of accurately estimating the biomass, carbon stocks and the contribution rate of each part in different densities of R. pseudoacacia plantations were measured. The results are as follows: (1) Both DBH and H decreased with increasing density, and field surveys were much more difficult and less accurate for H than DBH. Based on the two allometric growth models, it was found that the determination coefficient of the biomass model that incorporated both H and DBH (0.90) closely resembled that of the model using only DBH (0.89), with an error margin of only 0.04%. (2) At the sample scale, stand density significantly affected R. pseudoacacia stem biomass and total biomass. At the individual plant scale, stand density significantly affected R. pseudoacacia organ biomass. Increasing stand densities promoted the accumulation of vegetation biomass within the sample plot but did not improve the growth of individual R. pseudoacacia trees. The stem biomass constituted the majority of the total R. pseudoacacia biomass (58.25%–60.62%); the total R. pseudoacacia biomass represented a significant portion of the vegetation biomass (93.02%–97.37%). (3) The total carbon stock in the sample plots tended to increase with increasing stand density, indicating a positive correlation between density and the carbon stock of the whole plantation forest ecosystem. Hence, in future R. pseudoacacia plantations, appropriate densities should be selected based on specific objectives. For wood utilization, a planting density of 900–1400 trees ha−1 should be controlled. For carbon fixation, an initial planting density of 2900–3400 trees ha−1 should be selected for R. pseudoacacia. This study provides theoretical support for local forest management and how to better sequester carbon.

Impact of corporate governance on tax avoidance

In light of the pivotal role that taxes play as a primary source of income, particularly within developing economies, this study aims to examine the influence of various corporate governance (CG) mechanisms on tax avoidance. We employ three proxies to measure tax avoidance or tax management within companies listed on the Tehran Stock Exchange (TSE). The CG mechanisms under scrutiny encompass board size and independence, CEO duality, auditor type, common stock ratio of at least 5% to total stock, managers' common stock holdings about total stock, gender diversity, manager ownership value, board meeting frequency, CEO stock ownership percentage, institutional shareholders' stock holdings, audit committee membership, and financial specialization. This research investigates 192 companies listed on the TSE, utilizing data available on the TSE website from 2011 to 2021. Our findings indicate that while several CG mechanisms, such as board size and independence, audit firm size, gender diversity, institutional ownership, and the specialization of audit committee members, serve to reduce tax avoidance, CEO duality exacerbates it. Moreover, profitability, financial leverage, and capital significantly inhibit tax avoidance. In contrast, the return on assets (ROA), economic growth, and inflation have a pronounced positive association with tax avoidance. A notable constraint of this study lies in its exclusive focus on publicly listed firms, driven by the availability of relevant information. This study offers valuable insights into the three dimensions of tax avoidance and their interaction with CG mechanisms, with implications for performance monitoring.

The low-volatility effect in African frontier equity markets

ABSTRACT This study investigated the extent to which the low-risk anomaly is present in a pooled sample of nine African frontier equity markets from March 2004 to July 2023. Portfolio-level analysis was used to investigate the total stock returns of equally weighted quintile portfolios sorted on historical volatility. The presence of a monotonic relationship between historical volatility and subsequent returns was evaluated using monotonicity tests, controlling for possible mediating variables. The results revealed evidence of a statistically significant low-volatility premium, except during bull markets. These findings imply that investors can expect to earn higher returns by allocating to stocks with lower historical volatility, but only during bear markets. These results hold for realistic portfolio construction constraints, such as (il)liquidity and high transaction costs.

Mapping manufactured capital in mainland China with harmonized night‐time light images between 1992 and 2018

AbstractThe manufactured capital, usually denoted as material stocks from an industrial ecology perspective, has thus far received wide attention in sustainability and circularity science. Sustainable resource management should be rooted in detailed knowledge of manufactured capital accumulation in society at a high spatial resolution. Previous studies demonstrated that night‐time light (NTL) data provide a great opportunity for monitoring material stocks dynamics at a higher spatial resolution on the regional and global scale. However, the potential of historical–geographical refined material stocks has not been fully analyzed and explored because of the inconsistency of NTL images detected by the different satellites. In this study, based on a new set of material stocks data in China and harmonized NTL images (1992–2018), we map the national stocks of 13 bulk materials (including cement, gravel, wood, brick, sand, asphalt, glass, lime, plastic, rubber, copper, aluminum, and steel) at a 1 × 1 km resolution from 1992 to 2018. The results find that the total material stocks increased from 190,000 to 460,000 t/km2 between 1992 and 2018. Among the five end‐use sectors, buildings have the highest density of 430,000 t/km2, while domestic appliances have the lowest density of 140 t/km2. Four manufactured capital clusters, including the Yangtze River Delta, Pearl River Delta, Beijing–Tianjin–Hebei, and Chengdu–Chongqing agglomerations, possess 38% of the national total stocks in 2018, revealing an unbalanced distributed pattern of manufactured capital across China. Our results provide valuable support for policymakers and business decision‐makers on efficient resource management and urban mining.

Calculating the system-wide supply impacts of social housing estate renewal: new measures and methods

Estate renewal has come to be touted as a means of improving social housing supply both qualitatively and quantitatively, replacing ageing and under-maintained dwellings and increasing the total stock of social housing. In this paper, we examine the latter claim. We develop novel measures and methods for calculating the social housing supply impacts of estate renewal, taking account of the reduction in supply caused by tenant relocations and dwelling demolitions prior to the delivery of new social housing. Using administrative data on tenant relocations and dwelling completions for three projects in Sydney, we calculate the social housing accommodation deficit caused by the renewal process, subsequently, the time required for each project to deliver more nights of accommodation than this deficit. These measures illuminate the significant impacts of estate renewal on the social housing system and problematize its justification based on gross or net social housing supply. They constitute a valuable method for examining estate renewal, wherever it may occur.

Volumetric Add-On Retrofit Strategy with Multi-Benefit Approach toward Nearly Zero Energy Buildings Target

Around 35% of the total housing stock of the European Union is more than half a century old. The shortage of funds for new construction, combined with rapidly changing economic, social, and technological factors, has led to significant obsolescence. Additionally, this situation makes it difficult to satisfy the owners’ energy, functional, and socio-economic needs. This research aims to develop an innovative retrofit approach that brings multiple benefits to assessing retrofit designs for social housing, with specific emphasis on volumetric envelope additions toward the nearly zero energy buildings target (nZEBs). To achieve the purpose of this study, the research through design methodology was chosen. The research methodology consisted of two phases: design and simulation. First, the design phase focused on re-designing and retrofitting social housing to address various aspects of the functional requirements in developing rational solutions. Second, the simulation phase focused on computational modeling and analysis of energy performance to assess the nZEBs target. The results show that the use of high-efficiency Heating, Ventilation, and Air Conditioning (HVAC) systems and improved material envelopes cut electricity consumption use by 43% and primary energy use by 40% compared to the base case. Photovoltaics (PV) production can meet the total electricity demand for six months. This approach can encourage residents and tenants to actively participate in the retrofit process and increase the real estate value of buildings through improvements in energy efficiency and housing function.

The Tendency of Livestock Growth in Ethiopia: A Review

Ethiopia ranks first in Africa and 5th in the globe in its livestock population. The livestock subsector is immensely contributing about 60-70 % to the population’s livelihood and about 80% of the farmers use animal traction to plough their croplands. This study involved gathering livestock-based data from the Central Statistical Agency (CSA) for the years 2004/05 to 2018/19. Additionally, information on livestock holders was systematically organized and analyzed to track progress over the years. Quantifiable values indicating increases were presented in tables and figures. The relationship between cattle numbers and livestock owners’ growth trends was tested using the Pearson correlation. The findings were further supported or challenged through a comprehensive literature review. The data show that the cattle population grew by 57% in 2018/19 than the number it was at the end of 2004/05 and the number of cattle owners increased by about 53 %. Likewise, the total number of sheep population grew by 82.69 % and their holders by 53%, the total goat heads grew by 162.2% and the camel population by 284%. From the total stock of cattle, 97.92% and 99.72% of sheep and all the goats and camels were identified as indigenous, respectively. The study found a significant and strong correlation (p less than 0.01) between the number of animals used for production and the number of holders. This suggests that the growth in livestock population is primarily due to an increased number of livestock owners, rather than an increase in the number of animals per holder. The work identifies bottlenecks in livestock development and provides insights into growth trends and underlying causes. It highlights opportunities for policy interventions to enhance sustainable livestock production. Further research is recommended on addressing feed and water shortages and evaluating policy and institutional setup effectiveness.

Assessment of Species Composition, Diversity and Carbon Stock in a Community Managed Forest of Udaypur District of Nepal

Species composition, diversity, and carbon sock of forests are all critical factors that affect the ability of forests to provide various important ecosystem services. However, there is a notable dearth of research regarding these factors in the community forests of Udaypur district. Therefore, this research was undertaken to assess species composition, and biodiversity and quantify the carbon stock potential of the Sringar community forest (CF) of the Udaypur district of Eastern Nepal. A total of 57 circular plots of 500m2 were inventoried using a systematic random sampling method with 0.5 % sampling intensity. In the CF, 17 tree species from 15 genera and 11 families were identified. The dominant tree species, Shorea robusta observed with a maximum importance value index (IVI) (176.15). According to our study, the total biomass and carbon stock in Sringar CF were 276.98 ton ha-1 and 138.18 ton ha-1, respectively. Accurate estimation of soil carbon stocks is crucial for long-term forest management and climate change mitigation, and the integration of advanced monitoring techniques and predictive models to enhance accuracy and account for future climate projections is needed.

Profitability in Public Housing Companies: A Longitudinal and Regional Analysis Using Swedish Panel Data

Public Housing Companies (PHCs) play an important role in the Swedish housing market, with approximately 300 companies managing circa 802,000 dwellings. The public housing sector thereby represents almost 20 percent of the total housing stock in Sweden and half of the apartments that are available for rental. The purpose of this paper is to analyze the most important factors behind the profitability in Swedish PHCs between 2010 and 2019. The effects of internal growth, age, and capital structure in the PHCs are analyzed together with the effect of the growth of the local market, as well as local rent levels. Financial information for circa 300 PHCs in Sweden was gathered from annual reports published between 2010 to 2019. The financial information was analyzed using panel data analysis methods with several explanatory variables to explain the financial performance of the PHCs. The results from the analysis indicate a highly significant and positive relationship between the annual change in population, age, and profitability in the PHC. A highly significant and negative relationship was found between the PHC internal growth, capital structure, and profitability. The results showed no significant relationship between changes in income, rent levels, and profitability in Swedish PHC.

Afforestation improves soil organic carbon and total nitrogen stocks mainly through increasing > 2 mm aggregate fractions and stimulating carbon and nitrogen transformations within aggregates in subtropical karst region

Vegetation restoration can significantly increase soil organic carbon (SOC) and total nitrogen (TN) stocks, however, the response of SOC and TN stocks, as well as their distribution, transformation, and stability within aggregates, to afforestation in fragile karst ecosystems remains unclear. In this study, soil samples were collected from orchards, 10-, 20-, and 40-year Dodonaea viscosa plantations after afforestation following orchard abandonment in a karst rocky desertification area. A natural succession shrubland soil served as the control. Aggregate size distribution, SOC and TN contents, and δ13C and δ15N values in bulk soils and aggregate fractions were determined. The results showed that 0.25–2 mm aggregates were the main contributors to SOC and TN stocks, amounting to 47.7 %-55.6 % and 43.0 %-51.7 %, respectively. Compared to orchards, D. viscosa afforestation significantly increased SOC and TN stocks by 160 %-393 % and 184 %-416 %, respectively, more obviously with prolonged afforestation. This effect was mainly attributed to the increases in > 2 mm aggregate fractions and their associated SOC and TN contents. In addition, δ13C and δ15N values decreased with decreasing aggregate size in afforested and shrubland soils. The C flow pathways followed the trend from < 0.053 mm to 4–8 mm following afforestation, but this was not the case for orchard soils exhibiting pathways from 2-4 mm to < 0.053 mm progressively. These results indicated that large aggregates showed a faster turnover rate and contributed to higher SOC and TN contents following afforestation. The significant and positive relationships between SOC and TN contents and magnesium, aluminium and iron oxides suggested the stimulatory effect on SOC and TN accumulation. Noticeably, although SOC and TN stocks in bulk soils following 40-year afforestation reached the level of shrubland, the proportion of > 2 mm aggregates and the geometric mean diameter remained significantly lower than those of shrubland soils. Soil aggregate stability following D. viscosa afforestation may take longer to reach natural restoration levels.

FORESTRY AND STAND MENSURATION CHARACTERISTICS OF OAK STANDS IN RECREATIONAL AND HEALTH FORESTS OF THE LEFT-BANK STEPPE

The study of forestry and stand mensuration characteristics of oak stands in the recreational and health forests of the Left-Bank Steppe was carried out based on forest management materials. The distribution of oak stands in recreational and recreational forests of the region by location, origin, forest types, age groups and classes, health status classes, and relative completeness was analyzed. Indicators of the use of forest site capacity by modal oak stands within forest areas of green zones around settlements (forestry part of forests of green zones) were calculated. It was found that oak groves in the recreational and recreational forests of the Left-Bank Steppe occupy an area of more than 73 thousand hectares or 39% of the total area of recreational and recreational forests of the Left-Bank of Ukraine. Artificial oak plantations predominate, the share of which is 52.9%. Sprouted oak stands occupy 42.5% of the area, and natural seeded stands occupy 4.6%. The largest reserve (195 m3·ha–1) is characterized by natural seed stands. Forests in the conditions of dry birch and sapwood predominate — 25,9 thousand hectares, which is 35.4% of the total area of oak stands in study region. In terms of area and stock, medieval plantations prevail, the share of which is 60.7% of the total area and 56.6% of their total stock. The predominance of oak stands growing according to the II and III site classes (62.7%) and characterized by a relative completeness of 0.7–0.8 (63.7%) was noted. It was established that the relative completeness of oak stands, starting from the VII age class, gradually decreases. The rate of use of forest plant potential by oak trees within the forests of green zones around settlements (forestry part) compared to local highly productive stands amounts to 76%. Losses of wood due to the insufficient degree of use of land fertility were estimated at 916.7 thousand m3.

Stand Age and Climate Change Effects on Carbon Increments and Stock Dynamics

Carbon assimilation and wood production are influenced by environmental conditions and endogenous factors, such as species auto-ecology, age, and hierarchical position within the forest structure. Disentangling the intricate relationships between those factors is more pressing than ever due to climate change’s pressure. We employed the 3D-CMCC-FEM model to simulate undisturbed forests of different ages under four climate change (plus one no climate change) Representative Concentration Pathways (RCP) scenarios from five Earth system models. In this context, carbon stocks and increment were simulated via total carbon woody stocks and mean annual increment, which depends mainly on climate trends. We find greater differences among different age cohorts under the same scenario than among different climate scenarios under the same age class. Increasing temperature and changes in precipitation patterns led to a decline in above-ground biomass in spruce stands, especially in the older age classes. On the contrary, the results show that beech forests will maintain and even increase C-storage rates under most RCP scenarios. Scots pine forests show an intermediate behavior with a stable stock capacity over time and in different scenarios but with decreasing mean volume annual increment. These results confirm current observations worldwide that indicate a stronger climate-related decline in conifers forests than in broadleaves.

Soil organic carbon stocks and fractions under integrated systems and pasture in the Cerrado of Northeast Brazil

The adoption of integrated systems can reduce the pressure for the conversion of areas under native Cerrado to agricultural lands. However, little is known about how these systems affect total organic carbon pools and stocks in the Cerrado of Northeast Brazil. We aimed to evaluate the dynamics of soil organic carbon (SOC) and C and N stocks in a Cerrado under different cropping systems, in the agricultural frontier of Matopiba, Brazil. The systems were (i) Native Cerrado vegetation (NCF), (ii) integrated crop-livestock-forest system (ICLF), (iii) integrated crop-livestock system under no-tillage (ICL1), (iv) integrated crop-livestock with recent soil tillage (ICL2), and (v) pasture (PA). Soil samples were collected at 0.0–0.10, 0.10–0.20, 0.20–0.30, and 0.30–0.50 m depths to determine the soil C and N stocks, SOC fractions, and the carbon management index (CMI). Total C stocks in the 0.0–0.50 m soil profile were highest in ICL2 (127 Mg ha−1), ICL1 (112 Mg ha−1), and PA (101 Mg ha−1) and lowest in NCF (61 Mg ha−1) and ICLF (67 Mg ha−1). Similarly, total N stocks were highest in ICL1 (6.7 Mg ha−1), PA (6.7 Mg ha−1) and ICL2 (6.5 Mg ha−1), and lowest in NCF (4.7 Mg ha−1) and ICLF (4.8 Mg ha−1). ICL2 and ICL1 presented the greatest amount of humic fractions among the systems. The adoption of conservationist management systems that provide a permanent input of organic residues in the long-term is crucial for SOC stabilization and increases in soil C and N stocks. Integrated crop-livestock systems are the most suitable alternative for sequestering C and N in grain production systems in the Cerrado of Matopiba region.

Downed woody debris varies with climate and harvesting treatment in Douglas-fir forests of British Columbia, Canada

Downed woody debris is important for biodiversity, forest regeneration, and carbon, nutrient, and water cycling, and past studies have examined how the coarse fraction is affected by climate or harvesting. In a field study in Douglas-fir dominated forests, we expand existing knowledge by investigating the interacting effects of climate and harvesting on downed woody debris of all sizes. Across a 900-km long latitudinal gradient in British Columbia, we found that coarse woody debris (CWD, &amp;gt;7.5 cm diameter) in humid climates contained 700% greater carbon stocks, had 500% greater volume, and was more diverse than in arid climates. Pre- and post-harvest, small and fine woody debris comprised a higher proportion of total woody debris carbon stocks in arid than moist climates, especially after clearcutting and seed tree treatments. Harvesting generally decreased total CWD volume, but it was not depleted on any site. Harvesting substantially reduced the volume of large, highly decomposed CWD except at the two most arid sites, and losses of large CWD increased with increasing tree removal. These losses were accompanied by a pulse of fresh, small diameter CWD and SWD which are short-term organic nutrient sources but have less habitat value than larger pieces and contribute to fuel loads. Because CWD was less abundant in arid than humid mature forests, care must be taken on arid sites to avoid its depletion during harvesting, especially clearcutting, where future woody debris inputs will not occur for decades.

Does Soil Acidification Matter? Nutrient Sustainability of Timber Harvesting in Forests on Selected Soils Developed in Sediments of the Early vs. Late Pleistocene

With this study, our aim was to estimate the nutrient fluxes relevant for assessing nutrient sustainability as accurately as possible and to calculate nutrient balances for alternative forest management scenarios. Furthermore, we tested whether mapping units from existing geologic maps can serve as a basis for forest practitioners to estimate nutrient sustainability or whether more detailed data are needed. Positive fluxes include deposition and weathering, while negative fluxes include losses due to leaching and nutrient removal through timber harvesting in the balance. Weathering and leachate losses were modeled with a geochemical model. The SwissStandSim model was used to simulate the biomass growth under different harvesting and silvicultural strategies, allowing for sustainability to be assessed for each nutrient at a given intensity of use. This assessment was made per rotation period based on two criteria: (i) nutrient supply and (ii) total stocking volume. As a result, it can be noted that the accurate estimation of individual fluxes is essential for assessing the sustainability of forestry practices and that it needs detailed site-specific data. Various influencing factors turned out to be important, particularly the assumed depth of the root zone.

Biomass allocation and carbon storage in the major cereal crops: A meta‐analysis

AbstractCrop biomass is the reservoir of carbon (C), a valuable input to the soil, thus supporting the soil fauna and enhancing soil health. There are limited studies that compared the major cereal crops for C storage for regenerative agriculture and to optimize C sequestration strategies. The objective of this study was to quantify the extent of variation in biomass allocation and C storage between maize (Zea mays L.), sorghum (Sorghum bicolor [L.] Moench), and wheat (Triticum aestivum L.) for crop production, and C sequestration potential. The study used metadata from 40 global studies that reported on the allocation of plant biomass and C between roots and shoots of the major cereal crops. Key statistics were computed to determine the variability between genotypes for total plant biomass (Pb), shoot biomass (Sb), root biomass (Rb), root‐to‐shoot biomass ratio (Rb/Sb), total plant carbon content, shoot carbon content, root carbon content, total plant carbon stock (PCs), shoot carbon stock, root carbon stock, and root‐to‐shoot carbon stock ratio (RCs/SCs). Maize exhibited the highest variability for Pb (with a coefficient of variation [CV] of 31.2% and a mean of 4.2 ± 1.3 Mg ha−1 year−1), followed by wheat (CV of 24.2% and a mean of 1.5 ± 0.4 Mg ha−1 year−1) and sorghum (CV of 16.8% and a mean of 2.0 ± 0.8 Mg ha−1 year−1), respectively. A similar trend was observed for PCs, with maize (CV of 40.1% and mean of 1.6 ± 0.7 Mg ha−1 year−1) showing the highest total plant C stock variability, followed by wheat (24.4% and 0.2 ± 0.1 Mg ha−1 year−1) and sorghum (16.3% and 0.9 ± 0.3 Mg ha−1 year−1), respectively. Maize (with a CV of 24.4% and mean of 0.1 ± 0.03 Mg ha−1 year−1) exhibited the highest variability for Rb/Sb, while wheat (30.92% and 0.2 ± 0.05 Mg ha−1 year−1) exhibited the highest variability for RCs/SCs. Correlation analysis revealed the following significant associations: Pb and mean annual temperature (MAT) (r = −0.47), and Sb and MAT (r = −0.43), and Pb and mean annual precipitation (MAP) (r = −0.34), and Sb and MAP (r = −0.30). Rb had a strong, significant positive correlation with MAT (r = 0.72) and MAP (r = 0.85). The meta‐analysis revealed that maize and sorghum have the highest variability for Pb and plant carbon stocks, while wheat exhibited the highest variability for the below‐ground biomass and carbon stocks. The data aided in crop selection and suggested that the best cultivars could be developed and identified for production and C sequestration potential for cultivation by farmers, land rehabilitation, and climate change mitigation.

Carbon storage in rare ecosystems relative to their encroaching forests in western Lower Michigan.

Rising atmospheric carbon dioxide levels are impacting global temperatures, ecological systems, and human societies. Natural carbon sequestration through the conservation of soil and native ecosystems may slow or reduce the amount of CO2 in the atmosphere, and thus slow or mitigate the rate of global warming. Most of the research investigating carbon sequestration in natural systems occurs in forested ecosystems, however rare ecosystems such as coastal plain marshes and wet-mesic sand prairie collectively may serve as significant carbon sinks. Our objectives were to measure and assess the importance of carbon sequestration in three rare ecosystems (oak-pine barrens, coastal plain marsh, and wet-mesic sand prairie) in western Lower Michigan. We measured carbon in standing vegetation, dead organic matter, and soils within each ecosystem and adjacent encroaching forested areas. Driven by tree carbon, total carbon stocks in encroaching areas were greater than in intact rare ecosystems. Soil organic carbon was greater in all intact ecosystems, though only significantly so in coastal plain marsh. Principal components analysis explained 72% of the variation and revealed differences between intact ecosystems and their encroaching areas. Linear models using the ratio of red to green light reflectance successfully predicted SOC in intact coastal plain marsh and wet-mesic sand prairie. Our results infer the importance of these rare ecosystems in sequestering carbon in soils and support the need to establish federal or state management practices for the conservation of these systems.

Carbon Stock Potential of Coconut Plantations in University Campus: A Case Study from Coimbatore, India

The urgent need to mitigate climate change has prompted researchers to explore various avenues for carbon sequestration. One such avenue is the utilization of natural ecosystems like forests and plantations. Coconut plantations in university campuses play a vital role in carbon sequestration in mitigation of climate change. In this case study, we report the potential of coconut plantation from Bharathiar University campus, India. Four plots of 50 m × 50 m were randomly sampled from the coconut plantation in Bharathiar University campus. Carbon stock of the coconut plantation was calculated based on field survey and allometric equations. A total of 171 trees were recorded from the four plots totalling one hectare (ha) area. The total carbon stock determined for the one ha of coconut plantation sampled from Bharathiar University campus was 31.69 tonne/ha and the mean carbon stock per tree was 0.19 ± 0.06 tonne/tree. We have discussed the carbon stock of coconut tree allocation by above-ground and below-ground parts. This case study highlights the importance of coconut plantations in university campuses in support of curbing the atmospheric carbon concentration. We suggest for plantation of coconut trees in university campuses, that can serve not only as carbon sinks but also contribute to fulfilling the sustainable development goals of the nation.

Assessment of Pinus halepensis Forests’ Vulnerability Using the Temporal Dynamics of Carbon Stocks and Fire Traits in Tunisia

Carbon stocks provide information that is essential for analyzing the role of forests in global climate mitigation, yet they are highly vulnerable to wildfires in Mediterranean ecosystems. These carbon stocks’ exposure to fire is usually estimated from specific allometric equations relating tree height and diameter to the overall amount of aboveground carbon storage. Assessments of vulnerability to fire additionally allow for specific fire resistance (bark thickness, crown basal height) and post-fire recovery traits (cone mass for regeneration, and fine branches or leaves mass for flammability) to be accounted for. These traits are usually considered as static, and their temporal dynamic is rarely assessed, thus preventing a full assessment of carbon stocks’ vulnerability and subsequent cascading effects. This study aimed to measure the pools of carbon stocks of individual trees varying between 30 and 96 years old in the Djbel Mansour Aleppo pine (Pinus halepensis) forest in semi-arid central Tunisia in the southern range of its distribution to fit a sigmoid equation of the carbon pools and traits recovery according to age as a vulnerability framework. Allometric equations were then developed to establish the relationships between fire vulnerability traits and dendrometric independent variables (diameter at breast height, height, and live crown length) for further use in regional vulnerability assessments. The total carbon stocks in trees varied from 29.05 Mg C ha−1 to 92.47 Mg C ha−1. The soil organic carbon stock (SOC) at a maximum soil depth of 0–40 cm varied from 31.67 Mg C ha−1 to 115.67 Mg C ha−1 at a soil depth of 0–70 cm. We could identify an increasing resistance related to increasing bark thickness and basal crown height with age, and enhanced regeneration capacity after 25 years of age with increasing cone biomass, converging toward increasing vulnerability and potential cascading effects under shorter interval fires. These results should be considered for rigorous forest carbon sequestration assessment under increasing fire hazards due to climate and social changes in the region.