Clear-cutting Research Articles

Содержание тяжёлых металлов в донных отложениях малых рек Республики Коми в условиях сплошных рубок

The accumulation of heavy metals was studied in 24 watercourses of the Komi Republic, disturbed by logging of various ages. Heavy metals were determined by X-ray fluorescence spectroscopy. The accumulation of heavy metals in the sediments of small rivers of the Komi Republic is associated with the degree of disturbance of the catchment basins by clear forest cuts. Geochemical changes in rivers with disturbed catchments are manifested in an increase in the content of strontium, lead, arsenic, zinc, nickel, cobalt, chromium, iron and titanium, and a decrease in the content of manganese.

Effects of Wildfire and Logging on Soil CO2 Efflux in Scots Pine Forests of Siberia

Wildfires and logging play an important role in regulating soil carbon fluxes in forest ecosystems. In Siberia, large areas are disturbed by fires and logging annually. Climate change and increasing anthropogenic pressure have resulted in the expansion of disturbed areas in recent decades. However, few studies have focused on the effects of these disturbances on soil CO2 efflux in the vast Siberian areas. The objective of our research was to evaluate differences in CO2 efflux from soils to the atmosphere between undisturbed sites and sites affected by wildfire and logging in Scots pine forests of southern Siberia. We examined 35 plots (undisturbed forest, burned forest, logged plots, and logged and burned plots) on six study sites in the Angara region and four sites in the Zabaikal region. Soil CO2 efflux was measured using an LI-800 infrared gas analyzer. We found that both fire and logging significantly reduced soil efflux in the first years after a disturbance due to a reduction in vegetation biomass and consumption of the forest floor. We found a substantially lower CO2 efflux in forests burned by high-severity fires (74% less compared to undisturbed forests) than in forests burned by moderate-severity (60% less) and low-severity (37% less) fires. Clearcut logging resulted in 6–60% lower soil CO2 efflux at most study sites, while multiple disturbances (logging and fire) had 48–94% lower efflux. The soil efflux rate increased exponentially with increasing soil temperature in undisturbed Scots pine forests (p < 0.001) and on logged plots (p < 0.03), while an inverse relationship to soil temperature was observed in burned forests (p < 0.03). We also found a positive relationship (R = 0.60–0.83, p < 0.001) between ground cover depth and soil CO2 efflux across all the plots studied. Our results demonstrate the importance of disturbance factors in the assessment of regional and global carbon fluxes. The drastic changes in CO2 flux rates following fire and logging should be incorporated into carbon balance models to improve their reliability in a changing environment.

The Risk of Virus Emergence in South America: A Subtle Balance Between Increasingly Favorable Conditions and a Protective Environment.

South American ecosystems host astonishing biodiversity, with potentially great richness in viruses. However, these ecosystems have not yet been the source of any widespread, epidemic viruses. Here we explore a set of putative causes that may explain this apparent paradox. We discuss that human presence in South America is recent, beginning around 14,000years ago; that few domestications of native species have occurred; and that successive immigration events associated with Old World virus introductions reduced the likelihood of spillovers and adaptation of local viruses into humans. Also, the diversity and ecological characteristics of vertebrate hosts might serve as protective factors. Moreover, although forest areas remained well preserved until recently, current brutal, sudden, and large-scale clear cuts through the forest have resulted in nearly no ecotones, which are essential for creating an adaptive gradient of microbes, hosts, and vectors. This may be temporarily preventing virus emergence. Nevertheless, the mid-term effect of such drastic changes in habitats and landscapes, coupled with explosive urbanization and climate changes, must not be overlooked by health authorities.

Estimating the accuracy of smartphone app-based removal estimates against actual wood-harvesting data from clear cuttings

Estimating the accuracy of smartphone app-based removal estimates against actual wood-harvesting data from clear cuttings

Fruiting of Cronartium and Coleosporium rust fungi on Melampyrum spp. in Scots pine stands under various forest management applications in northern Finland

Cronartium pini is the causal agent of Scots pine blister rust in northern Europe. New silvicultural methods have recently been launched to manage Pinus sylvestris stands in Finland. Continuous-cover-forest management (CCF) is an approved alternative method for the traditional rotation-forest management (RF). The aim of this study was to compare fruiting and disease incidence of C. pini in forest stands managed applying the CCF and RF approaches. The incidence of C. pini-caused disease was assessed on P. sylvestris before, and on alternate herbaceous plant hosts Melampyrum pratense and M. sylvaticum one year after the CCF or RF application procedures and compared between several forest management types such as seed-tree cutting (STC), clearcutting (CC), gap cutting (GC), selection cutting (SC) and uncut control in seven study sites. Fruiting of the needle rust fungus, Coleosporium tussilaginis f. sp. melampyri, was also investigated. In 2020–2021, the number of P. sylvestris trees with symptoms of C. pini was low in all management types, and disease incidence varied from 0% to 2.8% among the management types. There was no statistically significant difference in the frequency of symptomatic pines between the management types and study sites at the beginning of the silvicultural management operations. Ten M. sylvaticum and/or M. pratense from five sample plots were collected in each managed stand. The incidence of symptomatic leaves of C. pini on M. sylvaticum varied from 0.6% to 7.7% among the management types and on M. pratense from 0% to 1.2% one year after the management applications. Coleosporium needle rust was more common than C. pini on Melampyrum spp. The percentage of leaves with C. tussilaginis f. sp. melampyri telia varied from 7.9% to 55.4% on M. pratense and from 0.6% to 24.8% on M. sylvaticum among the management types. The frequency of C. pini telia on M. pratense did not differ between the management types. The frequency of C. tussilaginis f. sp. melampyri telia on M. pratense did not differ between study sites, but it was significantly higher in unmanaged control stands compared to CC- or STC-managed stands a year after the management application. This indicated that the rust fungus fruited on Melampyrum more abundantly in forest stands that had the highest tree density prior to its fruiting. The results provide basic information of rust incidence in forest stands shortly after their management. The long-term effect of the different forest management types on rust incidence both on pines and alternate hosts will be assessed periodically years later. Keywords: alternate hosts; Melampyrum pretense; Melampyrum sylvaticum; Pinus sylvestris; rust diseases; Scots pine blister rust

IN VIVO ACCURACY OF A NEW ROBOTICALLY ASSISTED SYSTEM FOR TOTAL KNEE ARTHROPLASTY: A PROSPECTIVE COHORT STUDY

IntroductionRecent technological advancements have led to the introduction of robotic-assisted total knee arthroplasty to improve the accuracy and precision of bony resections and implant position. However, the in vivo accuracy is not widely reported. The primary objective of this study is to determine the accuracy and precision of a cut block positioning robotic arm.MethodSeventy-seven patients underwent total knee arthroplasty with various workflows and alignment targets by three arthroplasty-trained surgeons with previous experience using the ROSA® Knee System. Accuracy and precision were determined by measuring the difference between various workflow time points, including the final pre-operative plan, validated resection angle, and post-operative radiographs. The mean difference between the measurements determined accuracy, and the standard deviation represented precision.ResultsThe accuracy and precision for all angles comparing the final planned resection and validated resection angles was 0.90° ± 0.76°. The proportion within 3° ranged from 97.9% to 100%. The accuracy and precision for all angles comparing the final intra- operative plan and post-operative radiographs was 1.95 ± 1.48°. The proportion of patients within 3° was 93.2%, 95.3%, 96.6%, and 71.4% for the distal femur, proximal tibia, femoral flexion, and tibial slope angles when the final intra-operative plan was compared to post-operative radiographs. No patients had a postoperative complication requiring revision at the final follow-up.ConclusionsThis study demonstrates that the ROSA Knee System has accurate and precise coronal plane resections with few outliers. However, the tibial slope demonstrated decreased accuracy and precision were measured on post-operative short-leg lateral radiographs with this platform.

Influence of Clear Felling on СО2 Emission from Surface of Podzolic Soil of Coniferous–Deciduous Forest (Middle Taiga, Komi Republic)

Influence of Clear Felling on СО2 Emission from Surface of Podzolic Soil of Coniferous–Deciduous Forest (Middle Taiga, Komi Republic)

Response of the Soil Organic Matter to Clear-cutting in the Face of Climate Change – a Report from the East Sudety Mountains, South-West Poland

Abstract Clear-cutting induces biogeochemical, ecological, and hydrological changes in the soil environment, especially in the conditions of climate change effect. This type of management affects soil carbon sequestration. In this paper, we generalize the effect of clear-cutting in mountainous mixed coniferous forests on the direction of organic matter transformation and the properties of humic substances. Soil samples of dystric Cambisols were taken two and ten years after clear-cutting (CC). Soil profiles located at the same elevation under forest cover without any harvesting were used as references. The contents of total organic carbon, total nitrogen, qualitative and quantitative characteristics of humic substances, as well as the mineralogical composition and the clay-associated C fraction, were analysed. Under mountainous conditions, clear-cutting in the mixed coniferous forest enhanced organic matter decomposition and decreased the low-molecular weight humic fraction. It also caused the accumulation of more stable humic acids, particularly in the upper soil horizons, and resulted in accumulation of humic substances with higher contents of C and O and lower H content in the first years after CC. Clear-cutting in the first two years reduced the aliphacity of humic acids in the topsoil. Ten years after harvesting, a significant increase in aliphacity in the Oa horizon confirmed organic matter recovery. Mixed coniferous forests are more resistant to biotic and abiotic disturbances, which is particularly important in the face of violent weather phenomena related to climate change. Thus, forest management plans should consider the conversion of spruce monocultures to mixed coniferous forests.

Сохранение видового разнообразия растений при лесопользовании в ключевых биотопах Вологодской области

A reduction in the number of biological species can cause a loss of the integrity of the biosphere and its ability to maintain the most important characteristics of the natural environment. Therefore, scientific research and the development of practical recommendations in the field of conservation of biological diversity in forest management are currently of particular relevance. Measures to preserve biodiversity in forest management are reflected in the rules of timber harvesting, forestry regulations of forestries and forest development projects. The conservation of biological diversity in the course of logging operations is provided by allocating key biotopes – forest plots of a certain area, especially significant as habitats for rare species of animals and plants. The analysis of the Red Book of the Vologda Region showed that 29 % of rare species are confined to forest areas along watercourses. The study has been conducted at stationary sites within the boundaries of the Vologda Forestry of the Vologda Region (the Southern taiga area of the European part of the Russian Federation), represented by clear cuttings of 2018–2019 with the preserved key biotopes – forest areas along temporary water bodies. The average values for the plantations have been obtained on the basis of the materials from allotment and taxation of the cutting areas before felling. The work has been based on silvicultural and taxation, as well as ecological and biological methods of field evaluation and desk assessment. During the field studies (2023) in the key biotopes, a tally has been carried out by tree species, their diameters at chest height and categories of sanitary condition, with the determination of the average taxation indicators of the stands. The soils and the botanical composition of the live ground cover have been described. The species diversity and abundance of plant species in the key biotopes, as well as in the adjacent areas – in the cuttings and in the stands – have been determined. A higher number of species of taiga flora and the presence of rare plant species in the key biotopes, in contrast to the cuttings, have been established, which indicates the need to preserve the key biotopes during logging operations. Within the boundaries of the key biotopes studied, the average number of plant species in the buffer zone exceeds the number of species in the core of the biotope, the differences are statistically significant. Therefore, in the process of allotment of cutting areas, in addition to the allocation of the central part, or the core of the biotope, it is necessary to preserve a buffer zone as the area with the largest number of species.

Broadcast burning has persistent, but subtle, effects on understory composition and structure: Results of a long-term study in western Cascade forests

Approaches to forest management have changed markedly in the Pacific Northwest in recent decades, yet legacies of past management persist on the landscape. Following clearcut logging, woody residues were typically burned to reduce future fire hazard, create planting spots, facilitate natural recruitment, and retard growth of competing vegetation. We asked whether legacies of broadcast burning persist in the forest understory during the early stages of stand closure, how they manifest structurally or compositionally, whether they are altered by subsequent management (pre-commercial thinning), and how they vary with gradients in the physical environment or stand structure. We used data from 44 pairs of burned and unburned plots sampled 37–42 years after clearcut logging of mature and old-growth forests in western Oregon and Washington. Burning had persistent, but mostly subtle effects on community structure and composition. Burned plots had greater cover of early-seral species and lower cover of woody forest species. Among the latter, tall shrubs showed consistently negative responses to burning. Smaller-statured woody and herbaceous species were more variable in their responses, reflecting a greater diversity of regenerative traits. For some understory attributes, effects of burning were contingent on thinning history. For example, burning enhanced species richness and reduced species evenness, but only in unthinned sites. Conversely, burning increased the spatial variability of tall shrub cover, but only in thinned sites. In some instances, thinning compounded the effects of burning, resulting in a four-fold increase in cover of early-seral herbs and a 50% reduction in cover of forest tall shrubs relative to plots that received neither treatment. For most understory attributes, regional variation in the magnitude of the burn effect was not easily explained by burn severity, site environment, or stand structure. Collectively, our results highlight the persistent, but highly variable, effects of broadcast burning on the post-harvest development of the forest understory. They suggest that, where it is feasible, controlled burning can be used in regeneration-harvest units to achieve a variety of management objectives, with minimal effect on the forest understory.

Application of the strip clear-cutting system in a running bamboo (Phyllostachys glauca McClure) forest: feasibility and sustainability assessments.

As a renewable forest resource, bamboo plays a role in sustainable forest development. However, traditional cutting systems, selection cutting (SeC) and clear-cutting (ClC), result in an unsustainable production of bamboo forests due to labor-consuming or bamboo degradation. Recently, a strip clear-cutting (StC) was theoretically proposed to promote the sustainability of bamboo production, while little is known about its application consequence. Based on a 6-year experiment, we applied the strip clear-cutting system in a typical running bamboo (Phyllostachys glauca McClure) forest to assess its feasibility and sustainability. Using SeC and ClC as controls, we set three treatments with different strip widths (5 m, 10 m, and 20 m) for strip clear-cutting, simplified as StC-5, StC-10, and StC-20, respectively. Then, we investigated leaf physiological traits, bamboo size and productivity, population features, and economic benefits for all treatments. The stands managed by StC had high eco-physiological activities, such as net photosynthetic rate (P n), photosynthetic nitrogen use efficiency (PNUE), and photosynthetic phosphorus use efficiency (PPUE), and thus grew well, achieved a large diameter at breast height (DBH), and were tall. The stand biomass of StC (8.78 t hm-2 year-1) was 1.19-fold and 1.49-fold greater than that of SeC and ClC, respectively, and StC-10 and StC-20 were significantly higher than SeC or ClC (p< 0.05). The income and profit increased with the increase in stand density and biomass, and StC-20 and StC-10 were significantly higher than SeC or ClC (p< 0.05). Using principal components analysis and subordinate function analysis, we constructed a composite index to indicate the sustainability of bamboo forests. For the sustainability assessment, StC-10 had the highest productive sustainability (0.59 ± 0.06) and the second highest economic sustainability (0.59 ± 0.11) in all cutting treatments. StC-10 had the maximum overall sustainability, with a value of 0.53 ± 0.02, which was significantly higher than that of ClC (p< 0.05). The results verified that StC for Phyllostachys glauca forests is feasible and sustainable as its sustainability index outweighs those of traditional cutting systems (SeC and ClC), and 10 m is the optimum distance for the strip width of StC. Our findings provide a new cutting system for managing other running bamboo forests sustainably.

Dieback of managed spruce stands in western Germany promotes beetle diversity

Biodiversity loss is a significant problem at a global scale and may be amplified by climate change. In recent years, coniferous forests have had substantial dieback across Europe due to drought and subsequent bark-beetle outbreaks. As many studies on the consequences of disturbance and subsequent management have focused on natural stands, management implications for managed spruce stands are not well understood, even though such stands are widespread throughout Europe. In this study, beetle taxonomy, conservation value, and community composition are compared among spruce plantations and four post-disturbance management approaches: standing deadwood, lying deadwood, clear cuts, and long-term succession. Diversity and community composition differed significantly among management categories, while different beetle families responded similarly. Intact spruce stands harbored the lowest beetle diversity while the highest taxonomic diversity and conservation value was on clear cuts and stands with lying or standing deadwood. The proportion of forest specialists was highest in successional forests. In summary, different forest management categories harbored distinct beetle communities at the family-, species-, and ecological guild levels. Therefore, post-disturbance management should consider the landscape scale and include different management types. This enhances landscape heterogeneity and thus overall biodiversity but could also mitigate negative impacts of natural disturbances on ecosystem services.

An optimization model for detailed scheduling of heterogeneous fleet of log trucks considering synchronization

ABSTRACT Log transportation accounts for a significant portion of the total delivered cost of logs due to the considerable number of truckloads between origins and destinations. Hence, an efficient transportation plan at the operational level can generate cost savings for forest companies. In this paper, a mixed integer linear programming model is developed for daily routing and scheduling of heterogeneous trucks considering synchronization constraints. Continuous time representation is used for modeling the problem to generate accurate schedules and to synchronize the trucks and loaders at cut blocks and sort yards. Compatibility requirements, overtime, and decisions related to the trucking contractors are incorporated in the model. The outputs of the model include the number of trucks utilized by each contractor, the arrival times and waiting times of trucks at each location, the detailed schedule of loaders, and the amount of overtime assigned to the drivers. To validate the model, it is applied to test problems from a case of a Canadian forest company, where transportation activities are contracted out. Results show it is more economical to pay overtime than dispatching additional trucks to carry logs. Additionally, variable costs and maximum driving time have the most impact on the total transportation cost.

Dinâmica estrutural em uma floresta tropical sazonalmente seca sob diferentes sistemas silviculturais

ABSTRACT Considering the importance of evaluating the compatibility between the exploration system usually used in the Caatinga and the vegetation regeneration process, this study aimed to evaluate the feasibility of recovering structural parameters in an experimental unit subjected to different management systems aged 9, 12, 16, 20 and 26 years post-exploitation. The area was subjected to clearcutting (CC) regimes and three types of selective cuttings (SC1 – selective cutting 1, cut of trees with diameter at the base – DAB &lt; 15 cm; SC2 – selective cutting 2, cut of trees with DAB &gt; 10 cm; and SC3 – selective cutting 3, cut of trees with DAB between 5 and 10 cm). In permanent plots of 20 m × 20 m, individuals with a circumference at breast height (CBH) ≥ 6 cm and a total height greater than 1.0 m were measured. Over the years of monitoring, the CC presented the lowest values of density, dominance, and volume, not obtaining a recovery in basal area and volume even after 26 years of regeneration. Treatments SC2 and SC3 stood out regarding recovery of the original woody biomass stock, presenting values higher than the original ones and indicating that the initial data did not correspond to the site's maximum potential. The forest dynamics pointed to the insufficiency of the 15-year clearcutting cycle in terms of recovering this region forest composition and structure.

Harvesting efficiency and understory damage with different cutting methods on two storied stands of silver birch and Norway spruce

Uneven-aged forests set certain challenges for cut-to-length harvesting work. It is a challenge to cost-effectively remove larger trees while leaving a healthy understory for regrowth. The study’s aim was to evaluate productivity and costs of harvesting two-storied Silver birch (Betula pendula Roth) and Norway spruce (Picea abies (L.) H. Karst.) stands by creating time consumption models for cutting, and using existing models for forwarding. Damage to the remaining understory spruce was also examined. Four different harvesting methods were used: 1) all dominant birches were cut; 2) half of them thinned and understory was preserved; compared to 3) normal thinning of birch stand without understory; and 4) clear cutting of two-storied stand. Results showed the time needed for birch cutting was 26–30% lower when the understory was not preserved. Pulpwood harvesting of small sized spruces that prevent birch cutting was expensive, especially because of forwarding of small amounts with low timber density on the strip roads. Generally, when taking the cutting and forwarding into account, the unit cost at clear cuttings was lowest, due to lesser limitations on work. It was noted that with increasing removal from 100 to 300 m3 ha–1, the relative share of initial undamaged spruces after the harvest decreased from 65 to 50% when the aim was to preserve them. During summertime harvesting, the amount of stem damage was bigger than during winter. In conclusion, two-storied stands are possible to transit to spruce stands by accepting some losses in harvesting productivity and damages on remaining trees.

Road Surface Identification, Roads (Tanah Tinggi – Jati Perumnas) Ternate City Using The PCI Method

The section (Highway of Tanah Tinggi – Jati Perumnas) is a primary local road as a road that connects the sub-districts of Central Ternate city and South Ternate city. the Tanah Tinggi – Jati Perumnas highway is a road that has a high traffic density on weekdays and weekends. As a main road, it is important to know the surface condition of this road. To find out the condition of the road surface, identification was carried out using the Pavement Condition Index (PCI). The identification results show that the Jalan Raya Tanah Tinggi – Perumnas Jati section in segment 5 (sta 200 to sta 250) obtained a total score of 23 with a reduction correction value of 24 resulting in a PCI score of 76 (very good), where the damage that occurred was: Bleeding, Polished Aggregate, Patching & util Cut Patching, Block Cracking, Long & Trans Cracking.

Long-term dynamics of forests with Pinus sibirica in the upper reaches of the River Kolva (Northern Pre-Urals, Russia) from 1938 to 2023

Forest ecosystems have been impacted by human activity over several millennia in a variety of ways. Previous land use activity has not only changed the ratio of various terrestrial ecosystems, but also influenced the distribution of tree species. The insight into the forest species composition, dynamics and revealing how it differs from the modern one should be of decisive importance for the identification and conservation of the most valuable forests, as well as the restoration of ones previously disturbed. The density and distribution of some species continues to decline rapidly due to the anthropogenic activity. This problem is most urgent in boreal forests, formed by a limited set of tree species. Studies of the long-lived tree species dynamics and their ability to restore after various types of disturbances deserve special attention. Based on analysis of forest management materials from 1938 and 2023, this paper was aimed to analyse the dynamics of forests with the participation of Pinus sibirica in the Northern Pre-Urals (Permsky Krai, Russia), on the western border of the species' natural range. In 1938, the forests with Pinus sibirica occupied 16.6% of all forests in the research area. In 1938, most forests with Pinus sibirica (64%) were forests, in which P. sibirica was represented by only 1–5% of the stock. Pinus sibirica-dominated forests were almost absent, with only one site with 60% dominance of P. sibirica, and five sites with 40% dominance of P. sibirica. Over the next 85 years, the area of forests with Pinus sibirica participation in the research area has decreased by 2.5 times due to the impact of clear cuttings and forest fires. By 2023, the ratio of forest areas with various proportions of Pinus sibirica participation had changed considerably. The highest changes were found in forests with Pinus sibirica participation of 1%, 5% and 20% of the stock. Analysis of the typological structure of forests showed that at present Pinus sibirica has survived only in natural dark-coniferous forests, which have not been affected previously by forestry activities and fires. Due to the exceptionally slow regeneration following fires and logging activities, Pinus sibirica is absent in the forests formed over the studied period. The current federal legal restrictions prove ineffective as they target the preservation of forest stands containing over 30% of Pinus sibirica, while the majority of forests in the study area contain less proportion of this species. We believe that it is necessary to develop uniform measures to preserve existing and restore the lost Pinus sibirica populations in the Komi Republic and the Permsky Krai, including the prohibitions on the logging of forests with any proportion of Pinus sibirica as well as the creation of P. sibirica forest plantations.

One Health Approach Utilizing Mycelium to Prevent Wildfires in Southeast Ontario

The prevalence and intensity of wildfires have increased dramatically in Ontario, Canada since 2022. This has been exacerbated by climate change, clearcut logging, and poorly extinguished campfires. While previous interventions have targeted the downstream effects of wildfires such as deforestation, there have been no interventions that utilize a One Health approach to equally consider the health of humans, non-human animals, and the environment. This paper proposes a novel and cost-effective initiative utilizing cultivated mycelium from degraded slash piles, harvested and transformed into an organic fire-retardant spray for application on nearby trees. The proposed initiative aims to reduce the risk of wildfire ignition from at-risk trees in Lyndhurst, Ontario to protect the lives of humans and non-human animals as well as the integrity of properties and wildlife habitats, simultaneously contributing to the restoration of forest health as a crucial carbon sink. This may mitigate the effects of climate change and improve air quality, acting as a protective measure for human, non-human animal, and environmental health.

Not-so-random forests: Comparing voting and decision tree ensembles for characterizing partial harvest events

Ensemble-based change detection can improve map accuracies by combining information from multiple datasets. There is a growing literature investigating ensemble inputs and applications for forest disturbance detection and mapping. However, few studies have evaluated ensemble methods other than Random Forest classifiers, which rely on uninterpretable “black box” algorithms with hundreds of parameters. Additionally, most ensemble-based disturbance maps do not utilize independently and systematically collected field-based forest inventory measurements. Here, we compared three approaches for combining change detection results generated from multi-spectral Landsat time series with forest inventory measurements to map forest harvest events at an annual time step. We found that seven-parameter degenerate decision tree ensembles performed at least as well as 500-tree Random Forest ensembles trained and tested on the same LandTrendr segmentation results and both supervised decision tree methods consistently outperformed the top-performing voting approach (majority). Comparisons with an existing national forest disturbance dataset indicated notable improvements in accuracy that demonstrate the value of developing locally calibrated, process-specific disturbance datasets like the harvest event maps developed in this study. Furthermore, by using multi-date forest inventory measurements, we are able to establish a lower bound of 30% basal area removal on detectable harvests, providing biophysical context for our harvest event maps. Our results suggest that simple interpretable decision trees applied to multi-spectral temporal segmentation outputs can be as effective as more complex machine learning approaches for characterizing forest harvest events ranging from partial clearing to clear cuts, with important implications for locally accurate mapping of forest harvests and other types of disturbances.

Thermal comfort in a building constructed of FOAM concrete made in Burkina Faso

Thermal comfort is a feeling of well-being in a given environment. In the context of sustainable development, new regulations on thermal insulation in the building sector are leading researchers to design new materials for energy-saving systems and ensuring comfort in the habitat. We highlight the effects induced by the use of Pr. Blanchard's foamed concrete (FC) in construction in order to reduce energy consumption and ensure hygrothermal comfort in the home. This article numerically studies the thermal comfort for buildings constructed with materials such as foamed concrete, cinder block, compressed earth brick (CEB), adobe and cut laterite block (CLB). The comparison of the hygrothermal behavior (temperature and relative humidity) of premises made of different materials was carried out with three typical climates (January: dry and cold period, April: dry and hot period and August: humid period and mild temperature) under climatic conditions of Ouagadougou in Burkina Faso. The results showed that for the months of January, April and August the temperatures of the foamed concrete room (FC-930, thickness: th=17.5 cm) having respectively values of 296 K, 304 K, and 298 K is always lower to other materials. The relative humidity of the foamed concrete cell (FC-930, th=17.5 cm) in the months of January, April and August has values of 19%, 31 % and 63.7 % respectively which are also higher than those of the cells built with several local materials. Thus, a building constructed with foamed concrete has better thermal comfort than those made of concrete block, CEB, adobe and CLB.