Radius Plots Research Articles

Influence of wildfires severity on tree composition and structure in Aberdare Afromontane Forest Ranges, Kenya

Wildfires strongly impacts on the forest ecosystems, with poorly understood consequences on the composition, diversity and structure within Afromontane forests of Eastern Africa. The impacts of wildfire on vegetation were investigated one year after the fire occurrence season. The burn severity was evaluated using Sentinel-2 satellite derived spectral index known as dNBR (difference Normalized Burn Ratio). This was used to delineate wildfire into low and high severity classes. We investigated the effects of wildfires using 36 plots of 15m radius distributed in high and low burn severities while others were laid in unburnt areas. Our findings indicated that tree height, basal area and density were significantly different along severity classes (p = 0.003, p=0.007 and p<0.000 respectively). However, diameter at breast Height was not significant along severity classes (p=0.185). The most ecologically important species based on Important Value Index (IVI) within the fire affected areas were Juniperus procera, Nuxia congesta, Olea europaea subsp. cuspidata, Protea kilimandscharicum and Scurtia myrtina. Among the five dominant tree species, the density of Protea kilimandscharicum and Olea europaea subsp. cuspidata were significant along the fire severities (p<0.05). Interaction of vegetation zones and wildfire severity indicated that only height was significant (p= 0.000) while all the other tree variables and species diversity index were insignificant; DBH (p=0.053), basal area (p=0.606), tree density (p=0.389), Shannon Weiner diversity index (p=0.843), Simpson dominance index (p=0.490) and Pielou's evenness index (p=0.248). Whereas this study was on a short-term post-fire effects on vegetation, it has shown remarkable findings which can guide restoration and management of fire affected landscapes. The study recommends evaluation of long-term regeneration and recovery to guide integrated fire management within Afromontane Forest Ecosystems.

A method for updating variable radius plot surveys

Variable radius plot surveys can require updated estimates when the quality of previous estimates have declined over time. We developed a statistical estimator for this purpose that is the product of two estimators, one estimator is for the updated volume-to-basal-area ratio and the other estimator is for the updated basal area. Our estimator relies only on the surveyor identifying previously measured trees and does not require the identification of ingrowth, which simplifies its application. We also propose a variance estimator that relies on the bootstrap method. We investigate the point and variance estimators under repeated sampling of stem-mapped populations that include five measurements over a period of approximately 20 years. Based on 144 sampling scenarios, our estimator demonstrated relative biases ranging between −0.3% and 0.8%. The bootstrap variance estimator tended to be deflated, with relative absolute biases ranging between −8% and 4%. When revisiting one third of the initially installed plots, our estimator obtained relative root mean square errors within 1.6% of an independent resurvey effort that does not use the prior survey. This implies that our estimator can substantially reduce field work while producing surveys of approximately the same quality when updating prior surveys.

Stand-level sampling designs for bark stripping caused by red deer (Cervus elaphus L.): simulation studies based on nine fully censused stands

AbstractPrecise assessment of bark stripping damage is of high economic importance, since bark stripping makes wood unusable for saw timber and it is important for compensation payments for game damage. Bark stripping is clustered and decreases with increasing tree diameter, so that common forest inventories, optimized for assessing timber production variables such as standing timber volume, do not provide adequately precise estimates of bark stripping damage. In this study we analysed different sampling designs (random sampling, systematic sampling), tree selection methods (fixed radius plot, angle count sampling) and number of plots and plot sizes (plot radius: 2–20 m; basal area factor: 1–6m2/ha) for bark stripping assessment. The analysis is based on simulation studies in 9 fully censused stands (9026 trees). Simulations were done for actually assessed damage and randomly distributed damage and each scenario was repeated 100 times with different random points or different random grid locations. Systematic sampling was considerably more precise than random sampling in both scenarios. Sampling intensities to attain a standard error of 10% ranged between 12 and 18% dependent on the plot size. For a given sampling intensity, precision increased with decreasing plot size or increasing basal area factor. This implies, however, a large number of plots to be measured, which is expensive, when travel costs are high. Differences between tree selection by fixed radius plots or angle count sampling were minor. For bark stripping damage, we recommend sampling with fixed radius plots with a radius of 4–6 m and the measurement of approximately 230 or 150 plots, respectively.

AGB estimation using Sentinel-2 and Sentinel-1 datasets.

Climate change is one of the greatest threats recently, of which developing countries are facing most of the brunt. In the fight against climate change, forests can play an important role, since they hold a substantial amount of terrestrial carbon and can therefore affect the global carbon cycle. Deforestation, however, is a significant challenge. There are financial incentives that can help in halting deforestation by compensating developing countries for their efforts. They require however assessments which makes it essential for developing countries to regularly monitor their stocking. Based on the aforementioned, forest carbon stock assessment was conducted in Margalla Hills National Park i.e., Sub-tropical Chir Pine Forest (SCPF) and Sub-tropical Broadleaved Evergreen Forest (SBEF), in Pakistan combining field inventory with a remote-sensing-based approach using machine learning algorithms. Circular plots of a 20m radius were used for recording the data and Sentinel-2 (S2) and Sentinel-1 (S1) satellite data were used for estimating the Aboveground Biomass (AGB). The performances of Random Forests (RF) and Support Vector Machine (SVM) were explored. The AGB was higher for the SCPF. The RF performed better for SCPF, but SVM was better for SBEF. The free available satellite data in the form of S2 and S1 data offers an advantage for AGB estimations. The combination of S2 and S1 for future AGB studies in Pakistan is also recommended.

Dynamics of Odonata in an Agroecosystem: Effects of Paddy Cultivation Phases on the Diversity of Dragonflies and Damselflies

Wetlands represent a major part of biodiversity and provide habitat to many species which cannot succeed in other ecosystems. Man-made wetlands like Paddy fields represent a greater percentage of wetland ecosystems in Sri Lanka. However, there are only a few studies that observed the Odonata diversity in man-made wetland ecosystems in Sri Lanka. Therefore, this study was conducted to observe the effect of cultivation phases of a paddy-field ecosystem on the diversity of Odonata. The paddy culture period chosen for the study was started in June 2022 and ended in September 2022 and the study covered the Seeding, Tillering, Booting, Flowering, and Harvesting phases. Fixed-radius point count method was used for the data collection purpose and ten circular plots of 5m radius were laid maintaining a 50 m distance between two plots in the study area which had a total area of 785m2. At all five successive stages of the cultivation cycle, the number of Odonata species and their abundance were recorded once a week in each plot. Data was recorded each day from 8.00 am to 10.00 am and from 3.00 pm to 5.00 pm. Odonata diversity was calculated separately at each of the stages of the paddy cultivation cycle using Simpson‘s index (D) and Shannon- wiener index (H‘). According to results, 592 individuals were recorded belonging to 14 species of Odonata in 02 families. Among the total recorded species, 64% of species belonged to the family Libellulidae. Sri Lankan Orange-faced Sprite (Pseudagrion rubriceps ceylonicum) was the only endemic Odonata species that were recorded during the study. The overall H‘ and D diversity indexes were 1.71 and 0.75, respectively. Values of H‘ and D diversity indexes for these five stages (Seeding, Tillering, Booting, Flowering, and Harvesting) were 1.36 &amp; 0.65, 1.59 &amp; 0.72, 1.72 &amp; 0.76, 1.81 &amp; 0.79 and 1.59 &amp; 0.78, respectively. The study revealed that among the index values of each cultivation phase, the flowering stage had the highest diversity, while the seeding phase showed the lowest diversity. Therefore, it is evident that the transformation of land use/habitat in different stages plays a major role in the diversity of Odonata. and this study can be used to depict the impacts on biodiversity due to the degradation of wetlands. &#x0D; Keywords: Odonata, Paddy cultivation phases, Biodiversity, Man-made wetland

Potential Of 10 Types of Eucalyptus Clones in The Concession Area Pt Tpl Tbk Simalungun Indonesia (Wood Potency Of 10 Eucalypt Clone in Tpl Ltd Forest Consession, Simalungun of Indonesia)

&lt;span lang="EN-US"&gt;A researched 10 clones of Eucalypts were done in Toba Pulp Forest in 2 sectors of Aek Nauli and Tele as the representative plots. The aim of this research is to know the prospective species in wood producing to be plant at the second period. Research method of inventory of stand by circle radius plot of 11.28 m (0.04 ha) with 3 replications summarized plot broaded about 1.2 ha. The results of the research shown the relation of trees number to average of diameter as mathematical linear regression Dp = 4.218 + 0.007 Np with correlation coefficient (r) is 0.579 and determination coefficient (r2) is 0.336; The relation of trees number to average of Height as a mathematical linear Hp (m) = 4.218 + 0.007 Np (btg) with correlation coefficient (r) is 0.579 and determination coefficient (r2) is 0.336; The relation of trees number to average of bole area (BDp) as a mathematical linear regression BDp (m2) = 16.961 – 0.003 Np (stand) with correlation coefficient (r) is 0.294 and determination coefficient (r2) is 0.087 and The relation are of trees number (Np), averaged of diameter (Dp) and averaged of height (Hp) in to the woods volume (Vp) as a mathematical linear Vp (m3) = - 450.636 + 0.157 Np + 32.409 Dp – 2.199 Hp with correlation coefficient (r) is 0.933 and (r2) determination coefficient is 0.871. Based on the wood analysis volume analysis can be resumed that 3 IND eucalypts clones are recommended for planting the next period, namely IND 61, IND 60 and IND 11. 087 and the relation are of trees number (Np), averaged of diameter (Dp) and averaged of height (Hp) in to the woods volume (Vp) as a mathematic linear Vp (m3) = - 450.636 + 0.157 Np + 32.409 Dp – 2.199 Hp with correlation coefficient (r) is 0.933 and (r2) determination coefficient is 0.871. Based on the wood analysis volume analysis can be resumed that 3 IND eucalypts clones are recommended for planting the next period, namely IND 61, IND 60 and IND 11. 087 and the relation are of trees number (Np), averaged of diameter (Dp) and averaged of height (Hp) in to the woods volume (Vp) as a mathematic linear Vp (m3) = - 450.636 + 0.157 Np + 32.409 Dp – 2.199 Hp with correlation coefficient (r) is 0.933 and (r2) determination coefficient is 0.871. Based on the wood analysis volume analysis can be resumed that 3 IND eucalypts clones are recommended for planting the next period, namely IND 61, IND 60 and IND 11.&lt;/span&gt;

NATURAL FACTORS AFFECTING THE DENSITY OF REGENERATION IN SUBTROPICAL CHIR PINE FOREST OF MALAKAND REGION, KHYBER-PAKHTUNKHWA, PAKISTAN

Chir pine botanically called Pinus roxburghii of family Pinaceae, found in sub-tropical chir pine zone providing valuable services to the locals. The anthropogenic disturbances in sub-tropical Chir pine forest are mostly affecting natural regeneration in coniferous forest of Pakistan. However, natural factors like slope, aspect, elevation, sunshade etc. also responsible for low density of natural regeneration in these forests. Therefore, we formulated a study to investigate the effect of slope and aspect on natural regeneration of chir pine forest in Malakand region in Khyber Pakhutnkhwah. Regeneration was studied on three different slopes (steep slopes of 27° and above, the moderate slope of 18- 27° and gentle slope 18° and below and northern and southern aspect. A total of 45 random samples were thoroughly studied in the form of circular plots of radius 8.4 meters, 15 from each category of slope in each study area. Similarly, 20 plots on southern and 20 northern aspect were also selected randlomly in each study area. Analsysis was carried out through two way analysis of variance for slopes and two sample independent t- test for aspect through SPSS and significance difference among slope was determined through tukey test. The result showed that moderate slope and southern aspect was the best for optimum natural regeneration. The less number of regeneration on gentle slope corresponds to heavy anthropogenic activities, grazing pressure and inadequate mother trees. The study recommend to focus efforts of regeneration protectoin mainly on moderate slope, prohibit individuals from collecting seeds, and raise public understanding of natural regeneration.

Enhanced photocatalyst with TiO2-anchored iron tailings structure for highly efficient degradation of doxycycline hydrochloride

The low utilization of sunlight and fast recombination of photogenerated electron-hole pairs (e−/h+) are the main reasons preventing the wide application of titanium dioxide (TiO2) in photocatalysis. A novel hybrid composite of TiO2/iron tailings (TITs) was synthesized in this study via a facile method as a photocatalyst for the degradation of doxycycline hydrochloride (DOX). The design beneficially enhances the light absorption capacity because the TITs composite photocatalyst has a narrower band gap (2.77 eV), larger light absorption edge (448 nm), and restrains recombination of photogenerated e−/h+, which is attributed to the TITs composite photocatalyst having a lower photoluminescence (PL) strength, a higher transient photo-current response, and a smaller Nyquist plot radius, as compared with pure TiO2. The DOX removal efficiency by TITs during photocatalytic degradation was 98.37% within 120 min under a Xe lamp and 76.73% within 180 min under sunlight, which were 1.23- and 1.46-fold higher than that of pure TiO2, respectively. The DOX removal rate increased by 3.8-fold after swine wastewater was diluted 20 times. This study provides an economical method for the clean recycling of iron tailings and identifies cheap raw materials for the preparation of photocatalytic materials, reducing the cost of photocatalytic materials applied to wastewater treatment, which is helpful for promoting the practical application of TiO2-based photocatalysts.

Physical properties of a quintessence anisotropic stellar model in f(Q) gravity and the mass–radius relation

In this article, we present a new family of solutions to the Einstein field equations of an uncharged spherically symmetric anisotropic matter distribution in the context of f(Q) gravity by choosing f(Q)=Q+aQ^2, a being the coupling constant. Along with the fundamental quintessence dark energy defined by the equation of state parameter -1<omega _q<-frac{1}{3}, we have generated the field equations in modified gravity. Using the linear relationship between radial pressure and energy density along with the Krori–Barua (KB) metric potential, we are able to solve the field equations. Next, we discuss the smooth matching between the exterior Schwarzschild spacetime and the interior spherically symmetric spacetime. We have presented a thorough physical analysis of several factors analytically and graphically to show the physical viability of our suggested model. For the compact star SAXJ 1808.4-3658, our entire graphical analysis was carried out in the context of our solutions for various values of the coupling constant connection to the f(Q) gravity. The influence of coupling constant “a” on different model parameters has been numerically determined and is presented in tabular form. We checked the radial and tangential sound speeds, the stability factor, the adiabatic index, etc. to determine whether our model was stable. It is evident from our analysis that the model is potentially stable when coupling constant a in [0,,5]. The maximum allowable mass and radius from our present model have been obtained through the mass–radius (M-R) plot for different values of a.

Small shrubby patches increase bird taxonomic and functional richness of wood-pastures

AbstractWood-pastures are semi-natural systems that combine a grazed grassland with a tree layer. Shrubs are often controlled, mostly to improve grazing potential, resulting in a reduction of the available ecological niches. From a conservation perspective, it is thus important to identify management practices that counter this reduction. Our overall objective was to determine the value of small shrubby patches to increase the richness of wood-pasture bird communities. As study model we used Mediterranean oak wood-pastures in southern Portugal, locally known as montados. Birds and environmental variables were sampled in 50 m radius plots of wood-pasture with and without small shrubby patches (128–3748 m2, covering less than 0.5% of the study area), in winter (n = 54) and spring (n = 65). Species assemblages’ composition changed between seasons, but in both seasons the assemblages in plots with and without patches were statistically different. Seven species were statistically associated to the presence of patches, in winter and spring, increasing the richness of the respective assemblages. A comparison of the functional composition of communities of patches and matrix revealed that patches increased richness of landscapes by boosting the presence of species with functional traits uncommon in the ecologically simplified matrix. Their presence is promoted by resources added by the patches (e.g. nesting sites, protection, food), but the ranges of individual birds in general extended well beyond the patches. This study demonstrated that the presence of few and small shrubby patches can significantly enrich the bird communities of wood-pastures, both taxonomically and functionally, indicating that promoting them is a cost-effective management measure for these valuable systems.

A rapid approach for ecological assessments in Carolina Bay wetlands that were previously converted to agriculture

Restoring wetlands is expensive, and methods for evaluating restoration condition are needed. This study developed chronosequences for use in ecological assessments (EAs) of restoration projects for Carolina Bay wetlands (CBWs) in the Southeastern US that were previously used for agriculture. An empirical method was also developed to estimate saturation levels to be used with the chronosequences. Data were collected from nine restored CBWs whose restoration ages ranged from 0 to 23 years. Plots were sorted into four Hydrologic Groups: 0–13 (Group 1), 14–50 (Group 2), 51–100 (Group 3), and 101+ (Group 4) consecutive days of saturation within 30 cm of the soil surface during the growing season. Litter thickness, tree basal area, and potential tree height were measured within a variable radius plot using a 10-factor prism across all Hydrologic Groups. Litter thickness and tree height reached an equilibrium at 15 years since restoration once crown closure occurred at the sites. In Groups 1 and 2, tree basal area reached an equilibrium at 15 years, and in Groups 3 and 4 it increased linearly to 23 and 21 years. Regression equations were developed (R2 = 0.57–0.73) to estimate saturation duration based on hydrology indicators, litter thickness, potential tree height, and soil type. These results showed that chronosequences and saturation duration would be useful for proposing performance standards in restored CBWs at time periods ranging from 5 to 23 years.

Woody species diversity, composition, structure and carbon storage of a dry evergreen montane forest of Essimingor Nature Forest Reserve in Tanzania

Abstract. Mwakalukwa EE, Mwakisu A, Maliondo SMS. 2023. Woody species diversity, composition, structure and carbon storage of a dry evergreen montane forest of Essimingor Nature Forest Reserve in Tanzania. Intl J Trop Drylands 7: 26-36. The biodiversity status of flora and fauna of many forests found on small protruding and isolated hills in most parts of dry areas in Tanzania is largely less studied. Their contribution to climate mitigation options also remains largely unknown. This study assessed the woody species diversity, composition, structure and carbon stocks potential of a dry evergreen montane forest of Essimingor Nature Forest Reserve in Tanzania. The vegetation data were collected from 23 concentric sample plots of 5m, 15m, and 20m radius laid systematically across the entire forest area of 6,100 ha. A total of 54 trees and shrubs species belonging to 29 families were identified. Diversity indices indicated the forest to have a high diversity of woody species. The most important species were Cassipourea malosana, Diospyros abyssinica and Drypetes natalensis. Stand structure comprised 288±173 stems ha-1, basal area of 11.47±7.23 m2ha-1 and standing volume of 27.3±16.3 m3ha-1. The mean above-ground and below-ground carbon stocks were 56.93±34.60 Mg C ha-1 and 34.71±19.72 Mg C ha-1, respectively. The observed high species diversity and carbon density signify the importance of conservation efforts bestowed in this reserve. Quantification of other carbon pools for estimation of the total carbon stock potential of this forest is recommended.

Diboronic-Acid-Based Electrochemical Sensor for Enzyme-Free Selective and Sensitive Glucose Detection.

A diboronic acid anthracene-based fluorescent system for detecting blood glucose could be used for 180 days. However, there has not yet been a boronic acid immobilized electrode to selectively detect glucose in a signal-increased way. Considering malfunctions of sensors at high sugar levels, the electrochemical signal should be increased proportionally to the glucose concentration. Therefore, we synthesized a new diboronic acid derivative and fabricated the derivative-immobilized electrodes for the selective detection of glucose. We performed cyclic voltammetry and electrochemical impedance spectroscopy with an Fe(CN)63-/4- redox pair for detecting glucose in the range of 0-500 mg/dL. The analysis revealed increased electron-transfer kinetics such as increased peak current and decreased semicircle radius of Nyquist plots as the glucose concentration increased. The cyclic voltammetry and impedance spectroscopy showed that the linear detection range of glucose was 40 to 500 mg/dL with limits of detection of 31.2 mg/dL and 21.5 mg/dL, respectively. We applied the fabricated electrode to detect glucose in artificial sweat and obtained 90% of the performance of the electrodes in PBS. Cyclic voltammetry measurements of other sugars such as galactose, fructose, and mannitol also showed linear increased peak currents proportional to the concentrations of the tested sugars. However, the slopes of the sugars were lower than that of glucose, indicating selectivity for glucose. These results proved the newly synthesized diboronic acid is a promising synthetic receptor for developing a long-term usable electrochemical sensor system.

Habitat selection by Asiatic black bear (Ursus thibetanus) in Siran and Kaghan Valleys, Pakistan.

Asiatic black bear is present in variety of habitats like broad-leaves and coniferous forests, extending form sea level to 4300m elevation and change their habitat for food purpose seasonally. The present study was conducted at Kaghan and Siran Valleys, District Mansehra, Khyber Pakhtunkhwa, Pakistan to assess habitat of black bear. Line transect method was used for observation of bear signs. Twelve meter circular radius plots were selected for the concern vegetation's i.e. (trees, shrubs and herbs) and three to six plots were placed in each transect. At the result of sign survey, thirteen different categories of bear signs were recorded and encounter rate was calculated for each sign. A total of 1858 signs were observed during field surveys. Total (81%) coniferous species were recoded among trees, with the highest appearance of Pinus wallichiana (34.22%) and Spruce spp (27.76%), similarly broad leaves trees (18.56%) were also recoded from habitat plots. Most of the signs were encountered in bushy areas, whereas high number of Viburnum Spp (60.29%) was present. It is indicated that black bear prefers blend of Coniferous Trees, Viburnum and Ferns Species; probably because these plants provide enough food, protection, and meticulous shelter because more than 80% of habitat composed of these three species. Currently habitat destruction and increase in human population are the up-growing issues for wild animals (especially Asiatic black bear), which is highly sensitive to such problems. High levels of conservation efforts are recommended for the protection of black bear habitat and to avoid human interference in their territory.

TreeMap 2016 Dataset Generates CONUS-Wide Maps of Forest Characteristics Including Live Basal Area, Aboveground Carbon, and Number of Trees per Acre

Abstract The TreeMap 2016 dataset provides detailed spatial information on forest characteristics including number of live and dead trees, biomass, and carbon across the entire forested extent of the continental United States at 30 × 30m resolution, enabling analyses at finer scales where forest inventory is inadequate. We used a random forests machine learning algorithm to assign the most similar Forest Inventory Analysis (FIA) plot to each pixel of gridded LANDFIRE input data. The TreeMap 2016 methodology includes disturbance as a response variable, resulting in increased accuracy in mapping disturbed areas. Within-class accuracy was over 90% for forest cover, height, vegetation group, and disturbance code when compared to LANDFIRE maps. At least one pixel within the radius of validation plots matched the class of predicted values in 57.5% of cases for forest cover, 80.0% for height, 80.0% for tree species with highest basal area, and 87.4% for disturbance. A new feature of the dataset is that it includes linkages to select FIA data in an attribute table included with the TreeMap raster, allowing users to map summaries of 21 variables in a GIS. TreeMap estimates compared favorably with those from FIA at the state level for number of live and dead trees and carbon stored in live and dead trees. Study Implications: TreeMap 2016 provides a 30 × 30 m resolution gridded map of the forests of the continental United States. Attributes of each grid cell include a suite of forest characteristics including biomass, carbon, forest type, and number of live and dead trees. Users can readily produce maps and summaries of these characteristics in a GIS. The TreeMap also includes a database containing, for each pixel, a list of trees with the species, diameter, and height of each tree. TreeMap is being used in the private sector for carbon estimation and by land managers in the National Forest system to investigate questions pertaining to fuel treatments and forest productivity as well as Forest Plan revisions.

Structural characteristics of black spruce (Picea mariana) infested with eastern spruce dwarf mistletoe (Arceuthobium pusillum), Minnesota, USA

Disturbances are important processes within forested ecosystems, influencing stand dynamics, species composition, and ecosystem services, with effects across multiple spatial scales. Interacting effects across scales can influence the suitability and results of management actions, necessitating a thorough understanding of disturbances at multiple scales. Eastern spruce dwarf mistletoe (Arceuthobium pusillum Peck, hereafter ESDM) is a native disturbance agent of lowland black spruce (Picea marina (Mill.) B.S.P.) in Minnesota, USA. ESDM results in mortality at the individual tree scale but is commonly managed through stand-level silvicultural treatments; ESDM can also influence landscape-scale forest composition. Despite its role as a mortality agent of black spruce, little is known about the relationship between structure and infestation at scales finer than the stand. Here, our objective was to quantify the relationship between ESDM infestation and structure at the stand, plot, and neighborhood scales. Twenty-five black spruce stands, 12 infested and 13 uninfested, were sampled using fixed radius plots; variables collected relate to ESDM infestation severity, forest structure, and forest composition. The relationship between forest structure and ESDM infestation presence was analyzed at the stand, plot, individual tree, and neighborhood (a hybrid scale focused on individual trees but including variables measured in the plot in which the tree is located) scales. Infested plots and neighborhoods had significantly lower trees per hectare and higher species richness and Shannon’s Diversity than uninfested plots and neighborhoods; these differences were not significant the stand scale. At the stand scale, stand structure and composition variables, including trees per hectare and species diversity metrics, shift with ESDM severity. However, at the tree level, the presence or absence of ESDM is more strongly related to structure than is severity.. When incorporating ESDM infestations in management planning and decision making, considering the appropriate scale is important. By documenting the effects of ESDM at multiple scales, we can deepen our understanding of stand dynamics and succession in lowland black spruce and use this information to develop new, ecologically based management approaches in these forests that more closely reflect the local disturbance regimes.

COMPARISON OF VARIED FOREST INVENTORY METHODS AND OPERATING PROCEDURES FOR ESTIMATING ABOVE-GROUND BIOMASS IN MALAWI’S MIOMBO WOODLANDS

This study assessed forest inventory methods and standard operating procedures (SOPs) for estimating above-ground biomass (AGB) and carbon, as employed in the key REDD+ Miombo Forest Reserves of Malawi. Analysis of Variance statistical technique was applied to investigate the following methods and SOPs: (i) allometry, (ii) sample plot configuration, and (iii) dendrometric measurements. Results indicate that the allometric equations parameter significantly (P&lt;0.001) affected the AGB estimations and was the highest contributor (97.95%) of the total variation. Malawi’s specific allometry provided the highest AGB estimate (113.08±1.56 t/ha). In contrast, the Pan-Tropical/generalized allometric models substantially underestimated AGB within the range of 16.7-67.9%. Furthermore, the findings demonstrate that the use of varied sampling plot sizes significantly (P&lt;0.001) affected the estimates of AGB. However, the plot size parameter contributed only 1.65% to the total variation. The 20m radius plot size registered the highest AGB (75.31±0.77 t/ha) compared to the 17.84m radius plot (66.12±1.61 t/ha). This signifies that the plot size of 17.84m radius underestimated the AGB by 12.2%. However, results on dendrometric measurements showed no significant (P&gt;0.05) differences in the AGB estimates between the use of diameter tape (D-tape) and calliper in measuring dbh of individual trees despite the former yielding higher estimates of AGB (74.65±0.93 t/ha) than the latter (72.53±0.98 t/ha). This demonstrates that the use of calliper in measuring dbh underestimated AGB t/ha by only 2.8% compared to the use of D-tape. Therefore, the study recommends; employment of local allometry, adoption of a circular sampling design of 20m radius, and consistent use of D-tape in measuring dbh for AGB in Malawi’s Miombo Woodlands. In conclusion, incorporation of these changes is envisaged to facilitate quick realisation of Malawi’s REDD+ carbon payments, smooth running of the National Forest Inventory system, robust implementation and global recognition of the REDD+ efforts.

Identification of Generalized Peptide Regions for Designing Vaccine Effective for All Significant Mutated Strains of SARS-CoV-2.

Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 infection has become a worldwide pandemic and created an utmost crisis across the globe. To mitigate the crisis, the design of vaccine is the crucial solution. The frequent mutation of the virus demands generalized vaccine candidates, which would be effective for all mutated strains at present and for the strains that would evolve due to further new mutations in the virus. The objective of this study is to identify more frequently occurring mutated variants of SARS-CoV-2 and to suggest peptide vaccine candidates effective against the viral strains considered. In this study, we have identified all currently prevailing mutated strains of SARS-CoV-2 through 2D Polar plot and Quotient Radius characterization descriptor. Then, by considering the top eight mutation strains, which are significant due to their frequency of occurrence, peptide regions suitable for vaccine design have been identified with the help of a mathematical model, 2D Polygon Representation, followed by the evaluation of epitope potential, ensuring that there is no case of any autoimmune threat. Lastly, in order to verify whether this entire approach is applicable for vaccine design against any other virus in general, we have made a comparative study between the peptide vaccine candidates prescribed for the Zika virus using the current approach and a list of potential vaccine candidates for the same already established in the past. We have finally suggested three generalized peptide regions which would be suitable as sustainable peptide vaccine candidates against SARS-CoV-2 irrespective of its currently prevailing strains as well any other variant of the same that may appear in the future. We also observed that during the comparative study using the case of E protein of Zika virus, the peptide regions suggested using the new approach that matches with the already established results. The study, therefore, illustrates an approach that would help in developing peptide vaccine against SARS-CoV-2 by suggesting those peptide regions which can be targeted irrespective of any mutated form of this virus. The consistency with which this entire approach was also able to figure out similar vaccine candidates for Zika virus with utmost accuracy proves that this protocol can be extended for peptide vaccine design against any other viruses in the future.

In-situ construction of β-Bi2O3/Ag2O photocatalyst from deactivated AgBiO3 for tetracycline degradation under visible light

• AgBiO 3 can release massive ROS without external support for the mineralization of tetracycline wastewater. • A novel visible light-driven β-Bi 2 O 3 /Ag 2 O photocatalyst was constructed from deactivated AgBiO 3 for tetracyclines removal. • The changes of phase state and morphology of deactivated AgBiO 3 during calcination were studied in detail. • The possible degradation pathways and enhanced photocatalytic mechanism were illustrated. Silver bismuth (AgBiO 3 , ABO) can release massive reactive oxygen species (ROS) without external support for the mineralization of organic matter. However, with the release of ROS, the catalytic activity of ABO gradually dwindled. Herein, we activated the deactivated ABO (ABO-DA) by simple calcination method to obtain a series of bismuth and silver compounds. With increasing calcination temperature, the components changed to ABO-DA@Ag 2 O, β-Bi 2 O 3 /Ag 2 O, and then α-Bi 2 O 3 /Ag 2 O, respectively. Meanwhile, the morphology changed from nanosheets to porous nanosheets, and then to porous gullies. Comparison with the others, ABO-290 (β-Bi 2 O 3 /Ag 2 O) activated at 290 °C showed the optimum degradation efficiency (78.0% within 2 h) and highest apparent reaction rate constant (3.7 times than ABO-DA) for tetracycline (TC) degradation. That was because that ABO-290 had the lowest recombination probability, minimum Nyquist plot radius and strongest photo response capability. In addition, the possible degradation path of TC by ABO-290 was proposed based on the results of GC–MS and LC-MS. This study not only deepens the comprehension on the deactivation of silver bismuthate catalysts, but also opens a novel perspective for the construction of highly efficient photocatalysts from deactivated catalysts.

Molecular modelling and structure-activity relationship of a natural derivative of o-hydroxybenzoate as a potent inhibitor of dual NSP3 and NSP12 of SARS-CoV-2: in silico study

The nsp3 macrodomain and nsp12 (RdRp) enzymes are strongly implicated in the virulent regulation of the host immune response and viral replication of SARS-CoV-2, making them plausible therapeutic targets for mitigating infectivity. Remdesivir remains the only FDA-approved small-molecule inhibitor of the nsp12 in clinical conditions while none has been approved yet for the nsp3 macrodomain. In this study, 69,067 natural compounds from the IBScreen database were screened for efficacious potentials with mechanistic multitarget-directed inhibitory pharmacology against the dual targets using in silico approaches. Standard and extra precision (SP and XP) Maestro glide docking analyses were employed to evaluate their inhibitory interactions against the enzymes. Four compounds, STOCK1N-45901, 03804, 83408, 08377 consistently showed high XP scores against the respective targets and interacted strongly with pharmacologically essential amino acid and RNA residues, in better terms than the standard, co-crystallized inhibitors, GS-441524 and remdesivir. Further assessments through the predictions of ADMET and mutagenicity distinguished STOCK1N-45901, a natural derivative of o-hydroxybenzoate as the most promising candidate. The ligand maintained a good conformational and thermodynamic stability in complex with the enzymes throughout the trajectories of 100 ns molecular dynamics, indicated by RMSD, RMSF and radius of gyration plots. Its binding free energy, MM-GBSA was recorded as –54.24 and –31.77 kcal/mol against the respective enzyme, while its structure-activity relationships confer high probabilities as active antiviral, anti-inflammatory, antiinfection, antitussive and peroxidase inhibitor. The IBScreen database natural product, STOCK1N-45901 (2,3,4,5,6-pentahydroxyhexyl o-hydroxybenzoate) is thus recommended as a potent inhibitor of dual nsp3 and nsp12 of SARS-CoV-2 for further study. Communicated by Ramaswamy H. Sarma