Empirical evidence of the impact of commercial charcoal production on Woodland in the Forest-Savannah transition zone, Ghana

Charcoal production, is one of the major drivers of land-cover change in Ghana. The trade has in recent time increased in the Central Gonja District of northern Ghana known to be one of the major food baskets of the country. This study assessed the impact of charcoal production on soil properties in the Central Gonja District of Ghana. Composite and core samples (60 samples) from ten (10) randomly selected sites were taken from 0-30 and 30-60 cm depths at the charcoal production site (CPS) and its adjacent field soils, which served as the control (CS). The samples were analyzed for soil texture, exchangeable bases, organic matter, percent carbon, total nitrogen, saturated hydraulic conductivity and electrical conductivity. The results showed that charcoal production site (CPS) had significantly (p < 0.01) higher content of sand, potassium, hydraulic conductivity and electrical conductivity than the control site (CS) within 0 – 30cm depth. Magnesium, calcium, sodium and percent carbon content decreased by 45.7, 2.7, 15.4 and 46.7% respectively in CPS when compared to CS within the top soil 0 -30cm. Hydraulic conductivity significantly (p < 0.01) increased from 0.5±0.3 (CS) to 1.8±1.0 h -1 (CPS), which is an increase of about 72 % in CPS due to soil heating. Soil organic matter in CPS decreases by 44% when compared with the CP site. There is a need for further research on the impact of charcoal production on soil nutrient, hydrology and crop production.

Tree-ring data has been widely used to inform about tree growth responses to drought at the individual scale, but less is known about how tree growth sensitivity to drought scales up driving changes in forest dynamics. Here, we related tree-ring growth chronologies and stand-level forest changes in basal area from two independent data sets to test if tree-ring responses to drought match stand forest dynamics (stand basal area growth, ingrowth, and mortality). We assessed if tree growth and changes in forest basal area covary as a function of spatial scale and tree taxa (gymnosperm or angiosperm). To this end, we compared a tree-ring network with stand data from the Spanish National Forest Inventory. We focused on the cumulative impact of drought on tree growth and demography in the period 1981-2005. Drought years were identified by the Standardized Precipitation Evapotranspiration Index, and their impacts on tree growth by quantifying tree-ring width reductions. We hypothesized that forests with greater drought impacts on tree growth will also show reduced stand basal area growth and ingrowth and enhanced mortality. This is expected to occur in forests dominated by gymnosperms on drought-prone regions. Cumulative growth reductions during dry years were higher in forests dominated by gymnosperms and presented a greater magnitude and spatial autocorrelation than for angiosperms. Cumulative drought-induced tree growth reductions and changes in forest basal area were related, but initial stand density and basal area were the main factors driving changes in basal area. In drought-prone gymnosperm forests, we observed that sites with greater growth reductions had lower stand basal area growth and greater mortality. Consequently, stand basal area, forest growth, and ingrowth in regions with large drought impacts was significantly lower than in regions less impacted by drought. Tree growth sensitivity to drought can be used as a predictor of gymnosperm demographic rates in terms of stand basal area growth and ingrowth at regional scales, but further studies may try to disentangle how initial stand density modulates such relationships. Drought-induced growth reductions and their cumulative impacts have strong potential to be used as early-warning indicators of regional forest vulnerability.

Soil functions as the active force managing diverse biogeochemical processes in tropical forest ecosystems, including storing and recycling nutrients and decomposing organic matter. Anthropogenic activities, mainly deforestation on charcoal production, have substantially disrupted these processes, leading to notable changes in microbial activities, enzyme functions, and the availability and soil nutrient status of the derived savannah in southwestern Nigeria. While there is increasing recognition of charcoal’s impact on soil properties, there remains a noticeable research gap in understanding its specific effects on some associated soil microbial properties, soil enzymes, and micronutrients in charcoal production sites. Our investigation assesses soil nutrition, microbial composition, and some selected associated P and S enzymes under charcoal production sites of derived Savanna, Nigeria. Soil samples were systematically collected at 0–15 cm, 15–30 cm, and 30–45 cm in locations associated with charcoal production (CPS) and non-production sites (NPS). The objective was to assess the microbial biomass content in phosphorus and activity levels of microorganisms in soil, focusing on their production of phosphorus and sulfur enzymes, and to examine the overall nutrient release in these diverse environments. The findings revealed Biomass phosphorus (Bp), Phosphatase (Pho), Thiosulfate dehydrogenase (Tsd), Dimethyl sulfoxide reductase (Dsr), and micronutrients (Mn, Zn, Cu, Co, Fe) were significantly higher in CPS than in NPS. Phytase (Phy) followed a consistent trend at both sites with significant differences among means. Except for copper (Cu), the cobalt (Co), iron (Fe), manganese (Mn), and zinc (Zn) concentrations declined as the soil depth increased in the CPS and NPS across the three locations. This indicates that charcoal production sites in the derived savannah forest of southwestern Nigeria significantly impact soil properties and microbial activities. The higher Bp, Pho, Tsd, and Dsr levels in CPS suggest increased microbial activity and nutrient availability compared to NPS. Additionally, the variation in micronutrient concentrations with soil depth indicates differences in nutrient distribution and availability between the two sites. These findings underscore the importance of further ecosystems to understand the effects of charcoal production on soil ecosystems and to fully develop sustainable management practices that mitigate these impacts.

Commercial charcoal production is gradually becoming one of the major sources of sustenance and currently plays a major role in promoting entrepreneurial development in Borgu Local Government Area of Niger State. The study was carried out to assess charcoal production and its impact on deforestation and environment in the study area. Data for the study were generated from a structured questionnaire administered to charcoal producers in the study area. Data obtained revealed that majority (83%) were male with 56% within the age class of 21-40, majority (67%) were married and about (51%) attained primary education. Majority of the producers (82%) used traditional earth mound kiln method for charcoal production and about 56% of the producers obtained their raw material from free area. Most preferred tree species for charcoal production was Prosopis africana and accounted for 61%. Loss of biodiversity ranked 1st as regards impact of charcoal production on deforestation and environment in the study area, closely followed by forest degradation and soil degradation respectively. This study will enable forestry policy makers, charcoal producers, and farmers in the study area to be better informed about the implications of charcoal production on deforestation and environment and seek innovative means and ways to combat its menace.

Charcoal production for urban energy consumption is a main driver of forest degradation in sub Saharan Africa. Urban growth projections for the continent suggest that the relevance of this process will increase in the coming decades. Forest degradation associated to charcoal production is difficult to monitor and commonly overlooked and underrepresented in forest cover change and carbon emission estimates. We use a multitemporal dataset of very high-resolution remote sensing images to map kiln locations in a representative study area of tropical woodlands in central Mozambique. The resulting maps provided a characterization of the spatial extent and temporal dynamics of charcoal production. Using an indirect approach we combine kiln maps and field information on charcoal making to describe the magnitude and intensity of forest degradation linked to charcoal production, including aboveground biomass and carbon emissions. Our findings reveal that forest degradation associated to charcoal production in the study area is largely independent from deforestation driven by agricultural expansion and that its impact on forest cover change is in the same order of magnitude as deforestation. Our work illustrates the feasibility of using estimates of urban charcoal consumption to establish a link between urban energy demands and forest degradation. This kind of approach has potential to reduce uncertainties in forest cover change and carbon emission assessments in sub-Saharan Africa.

This paper examines the sustainability of charcoal production that maximizes social welfare based on optimal control techniques visa-vis the activities of profit maximizing charcoal producing firms in South Sahara Africa. I set up a theoretical model involving the socially optimal charcoal production that will maximize the socially optimal discounted sum of net benefit of Charcoal production for both the private profit maximization firm and that which will yield sustainability. After solving for the optimal choices for both functions it reveals that there is indeed divergence between these two entities simply because environmental degradation and deforestation (externalities) associated with charcoal production are not internalized into the production function of the profit maximizing charcoal producing firms. These externalities would lead to unsustainability of the forest environment and subsequently deforestation. Fiscal policy measures and public ownerships are recommended to deal with externalities that are inherent in charcoal production so as to improve sustainability while ensuring charcoal continues to provide livelihood benefits for the numerous people that live in the charcoal producing belt.

Enzyme activities and metabolic profiles of soil microorganisms at KILN sites in Quercus spp. temperate forests of central Mexico

Rapid mapping and impact estimation of illegal charcoal production in southern Somalia based on WorldView-1 imagery

Drought and grazing patch dynamics under different grazing management

Forests play a crucial role in the EU's strategy for decarbonisation and in achieving neutrality targets, primarily through their capacity for carbon sequestration (carbon stock change) and storage (carbon stock) in above-ground biomass, dead organic matter, and soil organic matter. Alongside reforestation, sustainable forest management practices can further enhance the role of forests in decarbonisation. Our focus is on the Arge&amp;#537;-Vedea basin in Romania, a region stretching from the Carpathian Mountains to the Danube River. We analyse systematic sample plots across an area covering 300,000 hectares of forest. We studied the relationship between stand attributes (basal area, diameter at breast height, age, species) and carbon stock changes in various carbon pools, evaluated also under different forest management practices context. Correlation analysis reveals a negative correlation between basal area and carbon stock changes in living trees and litter, which suggests that an increased basal area leads to reduced carbon stock changes (r = -0.15). Older stands tend to have lower net living tree carbon changes due to reduced growth and increased disturbance. Similarly, we found that soil carbon stock generally increases with the age of stands and decreases following disturbance, such as the harvesting of older stands (i.e., on average, by 10%). The effects of various forest management practices (no intervention, clear-cuts, shelterwood, thinning, and stands affected by natural disturbance) on different carbon pools are distinct. While all interventions generally decrease carbon stock in above-ground biomass, thinning operations result in a minor increase, especially in the lower-density stands, but still five times less than non-intervention stands (+13 tC/ha) with a decrease in deadwood carbon, indicating the role of selective removal in forest health maintenance. In contrast, in no intervention management increases living tree carbon, underscoring the benefits of natural forest dynamics. Stands in the initial development stage exhibit the highest carbon sequestration capacity (+11 tC/ha), while stands in the understory initialization stage show a decrease in tree biomass (-11 tC/ha) due to the harvesting operations. Natural disturbances significantly impact the deadwood pool, tripling the carbon stock change compared to shelterwood-managed stands. Stands, where thinning is performed, are the only ones showing decreased deadwood carbon stock change. Similarly, the litter pool decreases in stands undergoing thinning and clear-cutting. Regarding the regeneration pool, stands affected by clear-cuts and natural disturbance (in a five-year period) showed the highest decrease in carbon stock change (-0.03 tC/ha). This research reveals key insights into the variations in carbon stock caused by different management practices and the age progression of forest stands. This information is crucial for accurately modelling the carbon dynamics within forest ecosystems.

The need for energy sources that are both efficient and cheap, while simultaneously being environmentally sustainable, emphasizes the shift from one form of energy to an alternative source. This review has examined the transition from charcoal to briquette production in India. It uses various published works from reputable sources to deduce information on the impact of charcoal production, transition to biomass, briquette technologies, briquette feedstock, production, and its environmental and economic benefits. Challenges in the transition, government policies, and intervention in briquette production are also reviewed. The review revealed the devastating effects charcoal production has on the environment which exacerbates forest depletion, air pollution, soil erosion, species extinction, and climate change. At the same time, briquette production influenced rural livelihood and provided more efficient and cleaner energy due to its calorific value, low emission, and reduced pollution. The biomass feedstock comprises various materials such as rice husks, groundnut shells, sugarcane bagasse, corn husks, sawdust, cow manure, pine timber, bamboo particles, plastic refuse, and forestry byproducts. The review investigates the myriad technological methodologies employed in the production of briquettes. Various methods are used in briquette production such as compressing the biomass into multiple shapes and sizes. It explores challenges such as cost in initial setup, lack of awareness, seasonal variation in biomass availability, and lack of storage and supply chain. The study recommends that further research and policy interventions be made to enhance the adoption of briquette, provide efficient and affordable technology to rural communities, and expand markets for briquette industries.

Calibration and validation of the relative differenced Normalized Burn Ratio (RdNBR) to three measures of fire severity in the Sierra Nevada and Klamath Mountains, California, USA

In order to assess long-term community dynamics in tree populations, we investigated trees with a diameter at breast height (DBH) > 5 cm in an 11-ha fragment of submontane tropical forest in southeastern Brazil, at the beginning and end of a seven-year period. We observed a general tendency toward decreasing numbers of trees and toward stability in basal area. The stability in basal area was associated with an equilibrium between the loss of trees and the basal area gain from the horizontal growth of surviving trees, as well as from recruits The abundance of dead trees was significantly higher than was that of recruits. Changes in tree abundance occurred mainly in the lower DBH classes, whereas changes in basal area occurred mainly in the intermediate DBH classes. Among trees with a DBH > 10 cm, the observed rates of mortality and recruitment (2.4% yr-1 and 1.8% yr-1, respectively) were similar to those reported for other tropical forests. When we examined only trees with a DBH > 10 cm, we found the half-life to be 29.5 years, which places the forest fragment studied among the most dynamic of tropical forests. Over the seven-year period evaluated, the tree community lost ten species, with no new records. The most abundant species showed the highest rates of mortality and recruitment. Climax species, whether shade-tolerant or light-demanding, accounted for more species and individuals than did pioneer species, suggesting that the former group has a greater influence on forest dynamics. The results suggest that the tree community studied is in or is approaching a state of dynamic equilibrium, the changes in community structure and composition being attributed to periodic fluctuations.

I studied the dynamic nature of old-growth, eastern U.S. forests by addressing the following questions: (1) How much do stand density, basal area, and size structure vary over time within several old-growth remnants? (2) How do mortality and growth rates vary with stem size? (3) How much does the importance of individual species vary over time and space? (4) At what rate do snags and stumps form and deteriorate? In 1990–1991, I resampled canopy stems within several old-growth remnants in the southern Appalachians, in Hueston Woods State Park, Ohio, and in the Tionesta Scenic and Research Natural Areas, Pennsylvania. I had previously sampled those sites in 1976–1977 using the point-centered quarter method. I remeasured the same trees and measured new trees if the old ones had died or if a new stem closer to the point than the old stem for that quarter had grown to ≥25 cm in diameter at breast height. Density and basal area changes were small. Density changes equaled −0.33%, −0.52%, and 0.00%/yr for the southern Appalachians, Hueston Woods, and Tionesta sites, respectively. Corresponding basal-area changes were 0.03%, −0.22%, and 0.45%/yr. Mortality increased consistently with stem size in all three areas. However, growth rates of smaller stems more than compensated for the higher mortality rates of larger stems, so that overall stem size increased between samples. Most species changed little in relative density or basal area. Overall Fagus showed the largest changes between samples, with a small decrease in the southern Appalachians, a larger decrease in Hueston Woods, and an increase in Tionesta. Trees usually died standing, breaking off at a variety of heights. For example, only 6–27% of trees that died were uprooted, depending on region, whereas 16–31% broke at a height of ≥16 m. Total snag densities were 15–18 snags/ha. In general these stands were marked by slow changes toward fewer, larger stems, even after centuries in which no major disturbances had occurred. However, changes in pathogens, climate, and atmospheric chemistry could change these trends in the future.

Effects of Increased Rainfall on Native Forage Production in Eastern Montana