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CHARACTERIZING AND SEPARATING THE LIGNOCELLULOSIC FIBERS FROM THE AÇAÍ PULPING WASTE: TOWARDS KRAFT PULPING

Dhimitrius Neves Paraguassú Smith de Oliveira — 2024-07-03

Background: Over 80% of the açaí fruit is a valuable lignocellulosic waste. Kraft pulping is an alternative for future industrialization to convert açaí waste fibers into paper, but it demands high amounts of undamaged fibers. Therefore, this work aimed to characterize the açaí waste fiber, and to test three fiber extraction methods from the seed’s surface, one manual and two mechanical, focusing on the papermaking industry.

Results: Açaí waste fibers have ≈ 50 % of cellulose with lower contents of extractives (≈ 4.7 %) and non-cellulosic structural components (≈ 43.3 %). Microscopic açaí fibers are bundles that dissociate into short fiber cells (388 µm). Their pulp-paper quality biometry indexes were aspect ratio (31.8-41.2), wall fraction (52.8 %), flexibility coefficient (47.2 %), boiler index (0.6), Runkel index (1.2), and Mulstep index (0.8). The manual removal preserved the fibers but had the lowest efficiency (0.1 g/min). The food processor balanced intermediate preservation of the fibers and efficiency (0.5 g/min). Despite the highest efficiency (3.4 g/min), the hammer mill method damaged the fiber morphology and increased the levels of extractives (> 3%) and hemicelluloses (> 10%).

Conclusion: Açaí waste macroscopic fibers are dissociable into short fibers and have a favorable chemistry for kraft pulping and developing cellulose products. The fiber biometry is not ideal, but not limiting, demanding adjustments in the future kraft pulping parameters. The extraction of the fiber by the food processor is recommended, which is transferrable to the local communities, assuring an integrated bioeconomy of the açaí waste.

DUAL-POLARIZATION VEGETATION INDICES FOR THE SENTINEL-1 SAR SENSOR AND ITS CORRELATION TO FOREST BIOMASS FROM ATLANTIC FOREST FRAGMENTS

Erli Pinto dos Santos — 2024-08-04

Background: Vegetation indices have recently been proposed for remote sensing SAR (synthetic aperture radar) sensor measurements to monitor vegetation. However, they still lack validation studies on different vegetation types for their correct application. Thus, the objective of this study was to test the applicability of the Dual-polarization SAR Vegetation Index (DPSVI) and the modified DPSVI (DPSVIm) as indicators of aboveground biomass (AGB) from dense forest fragments.

Results: Three forest fragments, comprising 54 forest plots with AGB ranging from 12 up to 220 Mg ha-1, were studied. These forest fragments belong to the Brazilian Atlantic Forest biome, and were located within the Doce river hydrographic basin in the state of Minas Gerais, Brazil. AGB was compared with the DPSVI and DPSVIm indices, computed from dual-polarization Sentinel-1 images, using Spearman’s rank correlation test through two approaches. In the first approach (A1), correlation tests were performed using all forest plots; in the second approach (A2), samples were taken from plots on flat to undulating terrain slopes. The correlation of AGB with DPSVI presented no significant correlation (p-value >> 0.05). In contrast, for DPSVIm, the correlation with AGB was significant and positive, with coefficients ranging from 0.4 in approach A1 to 0.7 in approach A2.

Conclusion: While the DPSVI index did not show a correlation with the AGB of the studied forests, even though it is a C-band index, the DPSVIm was found to be a good indicator of the amount of AGB in forests and therefore has potential for applications in future studies, particularly in areas with reasonable slope or flat terrain.

A GENERALIZED MIXED-EFFECTS HEIGHT-DIAMETER MODEL FOR INTENSIVELY MANAGED Pinus taeda STANDS IN SOUTHERN BRAZIL

Ximena Mendes de Oliveira — 2024-10-08

Background: The insertion of stand variables allows for generalized mixed-effects height-diameter model, and the inclusion of random effects aids in model flexibility and application to new databases through calibration. This study aimed to develop a generalized mixed-effects model capable of accurately predicting the total height of Pinus taeda trees, subjected to different management regimes and at different ages.

Results: Experimental data between 4 and 27 years of age collected from stands of Pinus taeda located in the State of Santa Catarina were used. The experiment covers a combination of different planting densities and thinning intensities. The Lasso method was used to select the model’s independent variables, and mixed modeling was implemented, with calibration using BLUP (best linear unbiased predictor). Dominant height and quadratic mean diameter were selected in different formulations by the Lasso method to compose the predictor variables of the model, along with diameter at 1.3 m (dbh). Random effects were entered into the intercept and inverse of dbh terms of the model.

Conclusion: The results show that the generalized model developed presents flexibility and can be applied to Pinus taeda stands in southern Brazil using the calibration of random effects, when necessary, by collecting a small sample of plot data.

SILICATES AS ALTERNATIVE PRETREATMENT FOR CELLULOSE PULP TO OBTAIN NANOFIBRILS FOR APPLICATION IN BIODEGRADABLE PACKAGING: A TECHNICAL REVIEW

Adriano Reis Prazeres Mascarenhas — 2024-08-04

Background: The production of cellulose microfibrils/nanofibrils (CMF/CNF) has attracted increasing attention in recent decades due to their excellent barrier, mechanical, and surface chemistry properties. However, large-scale industrial production of CMF/CNF has been a major challenge due to their high energy consumption, limiting their application. In this context, in recent years many studies have focused on developing pre-treatments designed to facilitate the fibrillation of CMF/CNF by reducing energy consumption during their production. This review highlights the latest advances in the use of silicates as chemical pre-treatments for CMF/CNF production, covering the main aspects related to the effects of chemical modification on the production and the properties of materials for application in biodegradable packaging.

Results: Energy consumption reductions of up to 30% were achieved by pretreating cellulose pulps using silicates. In addition, the pre-treatments resulted in smaller CMF/CNF diameters and greater individualization of the nanofibrils. Studies evaluating the thermal stability, hydrophobicity, mechanical properties, and porosity of CMF/CNF pre-treated with silicates have reported promising results. The application of CMF/CNF pretreated with calcium and magnesium silicates in cardboard coating resulted in packaging with low water vapor permeability and high ductility.

Conclusion: Silicates interact well with cellulose surfaces, making them a promising material for the chemical pre-treatment of CMF/CNF. Furthermore, the modification by silicates could be an interesting strategy for expanding the use of CMF/CNF in the development of new products.

USE OF NEAR INFRARED SPECTROSCOPY FOR ESTIMATING MOISTURE CONTENT IN BRAZILIAN CHERRY (Eugenia uniflora L.) SEEDS SUBMITTED TO DEHYDRATION

Michele Cerqueira da Silva Alves — 2024-09-27

Background: The determination of seed moisture content is of utmost importance for the evaluation of its quality. Near-infrared (NIR) spectroscopy has been successfully applied to estimate properties of biological materials. However, studies using this technique on forest seeds are still scarce. Thus, the aim of this study was to explore the potential of NIR spectroscopy for estimating the moisture
content of E. uniflora seeds. NIR spectra were obtained using optical fiber from 100 individual seeds that were dehydrated in silica gel for 2, 7, 14, and 21 days. Subsequently, the seeds were subjected to the moisture test by the oven method, and had moisture contents of 52.4%, 41.7%, 33.1%, 21.8%, and 18.1%, respectively.

Results: Principal component analysis (PCA) of the spectral signatures explained 100% of the data variability. The moisture content was associated with the spectra by partial least squares regression (PLS-R) and the predictive model presented a coefficient of determination in cross-validation (R²cv) of 0.88 and the root mean square error of cross-validation (RMSEcv) was 5.43%.

Conclusion: The statistics associated with the models indicate that NIR spectroscopy has potential for estimating the moisture content of E. uniflora seeds.

SPATIOTEMPORAL DYNAMIC OF OAK FOREST GREENNESS IN RESPONSE TO CLIMATE CHANGE DERIVED DROUGHT

Maryam Daghestani — 2024-05-20

BACKGROUND: Climate change, which has mainly manifested in Iran in the form of intensifying periods of drought, can have profound effects on the valuable forest ecosystems of Zagros in the west of Iran. In this study, the drought trend in the period from 2000 to 2020 was investigated on the spatiotemporal dynamics of greenness of Zagros oak forests in Kohgiluyeh and Boyer Ahmad province in the west of Iran. SPI, PDSI, NDVI and EVI with modeling their relationship based on GWR was used. Also, based on two climate change scenarios RCP2.6 and RCP8.5, the simulation of drought conditions and changes in forest greenness until 2050 were studied.

RESULTS: The results showed that the peak greenness of the oak forests has a significant sensitivity to changes in rainfall and drought at the end of the cold period of the year and in the spring season. The negative phases of the drought have been completely consistent with the periods of greenness loss. Also, both the greenness and the area of the oak forests have decreased. The EVI index showed
the highest sensitivity to the PDSI, and the developed model based on these two indices had a spatial explanation coefficient between 40 and 70%.

CONCLUSION: The implementation of the developed model under two scenarios showed that the forest greenness will face a decrease of about 25% in the RCP8.5 scenario and about 15% in the RCP2.6 scenario until 2050. The relationship between drought and forest decline was proven in this study.

Advances and perspectives in the propagation and conservation of mangabeira (Hancornia speciosa Gomes) – review on a tropical fruit tree with socioeconomic importance

Augusto Vinicius de Souza Nascimento — 2024-04-22

Background: Hancornia speciosa is a species known for its medicinal and food properties. Being a native plant of various regions in Brazil, some aspects of its production system are still not well-defined. Among them, large-scale asexual propagation stands out, hindering commercial orchards' establishment using materials with superior characteristics. In this context, this article aimed to investigate the scientific production related to the propagation and conservation of the mangabeira tree, using a mixed methodology of bibliometric analysis and literature review. The Scopus and Web of Science databases were consulted, and the VOSviewer software was employed to map the cooperation network among authors, institutions, and keywords.

Results: The study included 71 articles and found a significant increase in scientific production on the propagation and conservation of the mangabeira tree since 2009. Most studies focused on seed technology, seedling production, in vitro propagation and conservation, and cryopreservation.

Conclusion: It is concluded that the mangabeira tree has great potential for developing new propagation protocols, emphasizing techniques that allow for the clonal propagation of the species, such as grafting, rooting of cuttings, and micropropagation. It is expected, therefore, that future research will continue to improve the in vitro and ex vitro propagation of the mangabeira tree, contributing to the expansion of commercial orchards of this fruit tree.

VALORIZATION OF Paulownia tomentosa WOOD WASTES TO PRODUCE CELLULOSE NANOCRYSTALS

Carline Andréa Welter — 2024-08-04

Background: Paulownia tomentosa wood has chemical properties that satisfy the requirements for good raw material to obtain cellulose-based products, such as nanocellulose. Cellulose nanocrystals (CNC) are derived from naturally occurring cellulosic fibers, constituted of cellulose chains with an organizational setting that results in rigid rod-shaped crystals. This study assessed the wood wastes from Paulownia tomentosa Steud. as raw material for producing cellulose nanocrystals (CNC) using alkaline and delignification treatments, followed by a hydrolysis process with sulfuric acid at the 52% and 58% concentrations. The isolation of CNC from Paulownia tomentosa wood wastes was confirmed through different spectroscopic analyses.

Results: The suspensions of nanocrystalline cellulose CNC-52 and CNC-58 showed yields of 8.34% and 7.62%, respectively. The particle size distribution of the suspensions, determined by the AFM technique, presented an average of L = 180.01 nm and W = 20.46 nm in CNC-52 and L = 128.06 nm and W = 10.18 nm in CNC-58. Moreover, the FTIR and XRD results demonstrated that there was no difference in the structure of the crystalline network and the chemical composition between cellulose (Kiri-CB) and the CNC.

Conclusion: The results obtained from this study allowed to conclude that it is possible to employ the Paulownia tomentosa wood waste as a source of cellulose for extracting CNC by hydrolysis, adjusting the sulfuric acid concentration to 58% and maintaining it at 45 °C for 60 min.

ARBUSCULAR MYCORRHIZAL FUNGI AND WATER STRESS ON THE PHYSIOLOGY AND QUALITY OF Parkia platycephalic benth

Dayara Lins Porto — 2024-10-01

Background: The water deficit characteristic of semi-arid regions can cause negative changes in plant physiology. Arbuscular mycorrhizal fungi can meet water needs by associating with plant roots, improving seedling quality. The physiological parameters and the quality of the seedlings of Parkia platycephala Benth. were evaluated as a result of the association of isolated strains of Gigaspora rosea, Gigaspora margarita, Acaulospora koskei, Acaulospora morrowiae, intercalated strains (a mixture of the four strains mentioned above) and a control (without inoculation) under two conditions of water regime (with and without stress).

Results: Artificial inoculation of AMF is a promising management technique in the production of P. platycephala Benth seedlings for improving the physiological state, increasing seedling quality, and drought resilience. Under restriction water restriction conditions, the seedlings showed lower values of net CO2 assimilation, leaf transpiration, stomatal conductance, and higher values of internal CO2 concentration. Under these conditions, the G. rosea strain stood out with the lowest rate of net CO2 assimilation (A), leaf transpiration (E), and stomatal conductance (gs) with increases of 34, 49, and 70 %, respectively, compared to the control.

Conclusion: Stomatal closure is a strategy used by Parkia platycephala Benth. seedlings to prevent excessive water loss, and the Gigaspora rosea strain is responsible for mediating the best physiological conditions and better quality seedlings.

Production and analysis of the physical and mechanical of particleboards panels produced with Acrocomia aculeata endocarp

Luisa de Oliveira Menali — 2024-04-19

Background: The macauba (Acrocomia aculeata (Jacq.) Lodd. ex Mart.) is a palm tree native to tropical regions and occurs in much of the Brazilian territory. Current studies are focused on the extraction and exploitation of vegetable oil from this fruit. However, there are few studies on the residue, the endocarp, which represents approximately 25% of the total mass of the fruit. Studies that search for solutions for using residue, thus adding value, and generating environmentally friendly products, are of fundamental importance. Thus, this research aimed to evaluate the physical and mechanical properties of reconstituted wood panels produced with different proportions of macauba endocarp particles to replace pine wood particles, in addition to characterize the physical and chemical properties of macauba endocarp. The chemical characterization tests were performed according to applicable standards. The basic density was determined according to the NBR 11941 standard. Thermogravimetric analysis (TGA), X-ray diffractometry (XRD) and Fourier transform infrared spectroscopy (FTIR) were also performed. The particleboards panels were produced with a nominal density of 0.70g/cm³ and dimensions of 25x25x1.5cm. Five different treatments were evaluated with variations in the proportion of macauba endocarp particles in the core of the panel. For particle agglutination, phenol-formaldehyde adhesive was used at a proportion of 9% for the core and 12% for the faces, based on the dry mass of each panel. Scanning electron microscopy (SEM) was used to analyze the panel surfaces.

Results:The endocarp of Acrocomia aculeata has low extractive content, high lignin content and high densification, 1.23g/cm³, when compared to Pinus oocarpa wood, 0.43g/cm³. All panels were classified as low density according to CS 236-66 and had an average apparent density between treatments of 0.586g/cm³. A greater dimensional stability and a decrease in the static bending properties of the panels was observed as the proportion of macauba endocarp particles increased. The internal bonding of the panels showed a positive result with the increase in the use of particles of the residue.

Conclusion: The panels produced have potential for use for non-structural purposes.

THE DISPERSIBILITY OF CELLULOSE I AND CELLULOSE II BY TEMPO-MEDIATED OXIDATION

Nursyamimi Ahmad Ghazali — 2024-04-22

Background: The restricted dispersibility of cellulose in water has grown to be a significant problem which is a key step in making cellulose soluble in water and common solvent. To overcome the obstacle, cellulose structure is being modified to improve the surface properties and the utilization of the cellulose itself. In this study, cellulose I and cellulose II were examined after treated with water-soluble 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO). The hydrogen bond between chains and the crystallinity of the cotton linter (cellulose I) was first broken by NaOH/urea treatment. Then, cellulose I and NaOH/urea-treated cellulose (cellulose II) were oxidized with sodium chlorite, sodium bromide, and TEMPO in a catalytic amount.

Results: The success of oxidation is revealed when both cellulose I and II treated with TEMPO had preferentially converted the hydroxyl groups to carboxylate groups through Fourier Transform Infrared Spectrometer (FTIR). Besides, through X-ray diffraction analysis, cellulose I and II exhibited a decreased in the crystallinity. All samples were examined by thermogravimetric analysis, dispersion analysis, and field emission scanning electron microscopy.

Conclusion: The result showed, cellulose has been successfully modified using TEMPO-mediated oxidation with improved dispersion properties. The scattered structure revealed through morphology analysis proved that cellulose treated with TEMPO had resulted in a more dispersed and separated cellulose fibre structure. High cellulose dispersion ability will allow the manufacturing process of hydrogel, film and fibre to be much easier and faster. This is necessary for creating novel, environmentally friendly materials for various applications across numerous industries and future research anticipated to increase.

APPARENT DENSITY OF EUCALYPTUS WOOD EVALUATED BY DIGITAL X-RAY IMAGES AFTER STORAGE IN THE FIELD DURING 365 DAYS

Rayana Augusta Grandal Savino Barbosa — 2024-07-09

Background: The use of X-rays non-destructive technique in color scale in 2D and 3D needs further studies to understand variations in the apparent density of wood stored under natural conditions. The objective of this study was to evaluate, by digital X-ray images and to test the rainbow scale in digital X-ray images in 2D and 3D, the apparent density of eucalyptus wood after storage in the field during 365 days. Trees of two diametric classes were randomly distributed at three heights in a pile in direct contact with the soil. The apparent density of the wood and its diametric profiles in the radial direction were determined using digital X-ray images in gray scale, and converted to a rainbow scale and the density variations plotted on a 3D surface.

Results: The wood density decreased as the storage period increased. The density of the samples at 0 days of storage evaluated with the 3D images was homogeneous, while an intense attack by xylophagous organisms due to the exposure to the environmental conditions was observed in those collected at 365 days of storage.

Conclusion: The rainbow scale color from X-ray images facilitated to visualize and to interpret the variation of apparent density distribution of the wood.

PRODUCTION AND CHARACTERIZATION OF WOOD BIOCHAR FROM ENERGETIC FORESTS BY PYROLYSIS IN A HORIZONTAL SCREW REACTOR

Everton Hillig — 2024-09-27

Background: Acacia mearnsii and Eucalyptus dunnii are species planted mainly for tannin and cellulose production. However, its woods have characteristics favorable to their use for energy generation, being commercialized in the form of firewood, chips or charcoal too. Biochar is a stable form of carbon that can be obtained by converting small particles of wood in the pyrolysis process and that can be used as solid fuel, among other applications as a soil conditioner. In this study, the properties of biochar produced in a horizontal reactor using wood of these species and under milder temperatures were evaluated.

Results: Temperature of 350°C and the reaction time of 30 minutes promoted an increase in higher calorific value of 33% for A. mearnsii and 51% for E. dunnii, with gravimetric yield of 39% and 32%, respectively. it was found that the 250 and 300 oC was not efficient to carbonize the wood of both species. An increase in specific surface area is observed with increasing carbonization temperature. Bigger increases were produced at temperatures of 350 oC for E. dunnii and 420 oC for A. mearnsii, with increase in porosity. At these temperatures, there was an increase in surface area and a decrease in pore size.

Conclusion: In temperatures of 350°C, the woods of both species provided a good quality biochar with porosity, surface area, pore size and pyrolysis yield suitable for energy use. For soil conditioning use, considering these aspects, suggested to test the appropriate temperatures for each species, between 350 and 420°C.

INFLUENCE OF SPACING BETWEEN TREES ON WOOD AND CHARCOAL QUALITY INDICATORS

Gabriel Soares Lopes Gomes — 2024-04-22

Background: The objective of this study was to evaluate the quality indicators for wood and charcoal
from the Eucalyptus urophylla x Eucalyptus grandis hybrid (Clone GG 100) in different planting
spacings. The study was conducted with the hybrid using the spacings of 2×1, 2×2, 3×2, and 3×3 m.
The chemical properties of wood and charcoal were analyzed, and dry wood mass and energy per
hectare were estimated. The data were subjected to the t test for comparison of means. Moreover,
principal component analysis was conducted to assess the relationships between wood and charcoal
indicators as a function of spacing.
Results: The 2×2 m spacing showed the highest values for dry wood mass, lignin mass, mass of
charcoal, and energy. The wider spacings of 3×2 and 3×3 m resulted in wood and charcoal of
increased quality by showing wood of greater resistance to thermal degradation and charcoal of
higher yield.
Conclusion: Spacing between trees influenced wood quality indicators. The 2×2 m spacing showed
higher estimates of mass and energy per hectare. However, wide spacings with an area greater than
6 m2 are more suitable for charcoal production due to their superior wood properties, especially
basic density and total lignin, which influence gravimetric yields and bulk density.

EFFECTS OF FOREST FRAGMENTATION ON NATURAL POPULATIONS OF Anadenanthera colubrina (Vell.) Brenan: INSIGHTS FOR CONSERVATION AND SUSTAINABLE MANAGEMENT

Karla Daniele Araújo da Silva — 2024-05-14

Background: The objective of this study is to characterize the diversity and genetic structure of A.
colubrina in three Atlantic Forest fragments in the south of Espírito Santo state, using Inter Simple
Sequence Repeats (ISSR) molecular markers. Genomic DNA from 85 trees was analyzed using 12
ISSR primers, generating 147 fragments, of which 109 were polymorphic (74%). Markers were
characterized as moderately informative, with a mean polymorphic informational content of 0.34.
Results: Low genetic diversity was found for the three fragments and in the total sample, based on
Nei’s diversity parameters (H* = 0.26) and Shannon’s index (I* = 0.38). In the dissimilarity analysis,
four groups were observed in the dendrogram with an exclusive clustering trend by location.
The analysis of molecular variance confirmed that most of the genetic variation is found within
populations (73.50%), however, with high genetic differentiation between them (ΦST = 0.26). This
result was supported by the Bayesian approach that indicated genetically structured populations.
Conclusion: The data obtained reveal that forest fragmentation affected the diversity and genetic
structure of A. colubrina and allow expanding knowledge for the development of effective strategies
for the conservation and management of the species.

Molecular and quantitative genetic analysis of the neotropical tree Jacaranda micrantha Cham.

Daniela Sanson — 2024-04-22

Backgrounds: Urban and peri-urban fragments are vital for biodiversity conservation, requiring genetic assessment of tree species in fragmented forests. The aim of this study was to analyze the genetic variability and diversity for adult individuals of J. micrantha along an urban-rural gradient in the Araucaria Forest. Fifteen individuals were sampled, with five from each remaining forest type. Initially, 10 ISRR primers were tested. Five mother trees were chosen from each site (urban, peri-urban, and rural) with a minimum distance of 100 m. The experimental design was a RCBD with 15 progenies, three provenances, three blocks, and 20 plants per plot, totaling 900 seedlings.

Results: The average percentage of polymorphic loci was 93.33%. The urban population showed a greater loss of genetic diversity (H=0.1806). 79% of the genetic diversity was found within populations. The observed gene flow value (Nm) was 1.8790, indicating that there were no random losses of alleles within populations. The fragments did not exhibit significant differences, but there were significant differences among the progenies. The stem diameter (SD) and the height-diameter relationship (H/SD) emerged as the key traits for selecting new individuals due to their higher heritability (< 0.50), accuracy (< 0.70), and relative coefficient of variation (< 7%).

Conclusion: The urban fragment is the most affected, but gene flow between fragments prevents the random loss of alleles. The analysis suggests that these fragments form a unique population, despite geographic barriers. Thus, the three fragments can be considered when choosing superior individuals for future progeny tests in genetic improvement programs for the species.

POTENTIAL OF METATOPOLINE IN THE IN VITRO MULTIPLICATION AND ROOTING OF Eucalyptus globulus Labill. CLONES

Facundo Esquivel — 2024-08-30

Background: Eucalyptus globulus Labill. is a species of great interest to the pulp industry. However, it has a low rooting capacity, which makes it difficult to clone on a commercial scale. In micropropagation, the supply of cytokinins is necessary to stimulate proliferation, but the type and concentration of cytokinins can negatively affect adventitious rooting. This study evaluated the effect of metatopoline
(mT) and benzyladenine (BA) on in vitro multiplication, elongation, and rooting of E. globulus clones. In the multiplication medium, concentrations of 0.44 and 0.88 µmol BA, 0.41 and 0.83 µmol mT, and a control medium without cytokinins were supplied.

Results: During the multiplication phase, mT increased the proliferation rate. In addition, mT presented lower production of small explants, less than 0.5 cm in height. In the rooting phase, easy rooting clones treated with 0.41 µmol of mT reached rooting percentages of 91%, while with the use of BA it was 50%. However, in clones with difficult rooting, no differences were observed in relation to the type of cytokinin. Explants treated with mT developed longer roots than those originated with BA, which presented roots similar to those of the control treatment (T).

Conclusion: With the use of mT in the multiplication medium, the in vitro elongation, proliferation and rooting of E. globulus was improved, therefore improving the quality of the in vitro explants for the acclimatization stage.

ADDITIVE EQUATIONS SYSTEM TO ESTIMATE ABOVEGROUND BIOMASS BY STRUCTURAL COMPONENT AND TOTAL OF THREE GIANT BAMBOO SPECIES IN MEXICO

Casimiro Ordóñez-Prado — 2024-05-21

Background: Bamboo species have a high potential to produce biomass and stock carbon. However, biometric tools are not available to estimate biomass production for most giant bamboo taxa. The aim was to develop an additive equation system to estimate the aboveground biomass by structural component and the total of the three bamboo species. Destructive sampling was applied, and a sample of 101 mature bamboo specimens was collected. The nonlinear power allometric model was used to integrate two additive equations systems, which were formed by the structural components of biomass: culm, branches and leaves as well as aboveground biomass total. The predictor variables were: diameter at breast height (D) for the S1 system, and D in combination with the total height (D2H) for the S2 system.

Results: It was determined that the SUR method in combination with the dummy variables technique and the correction of heteroscedasticity is an adequate fit strategy. Given that the additivity property is fulfilled, specific values of the parameters of each system and by taxon are identified. In addition, the variance of the error stabilizes. The aboveground biomass of the culm constitutes 86.40%, 90.48%, and 93.94% for Bambusa oldhamii Munro, Guadua aculeata Rupr., and Guadua angustifolia Kunth, respectively. The S1 system was selected, and its statistics regarding the total aboveground biomass were 0.92, 4.9 kg, -0.35 kg, and 0.05 for the fit statistics R2adj, RMSE, S, and E, respectively.

Conclusion: This biometric tool will easier to carry out aboveground biomass inventories, as well as to infer the carbon content and CO2 equivalent at the specimen level.

21st CENTURY CLIMATE CHANGE THREATENS ON THE BROWN BEAR

Ahmet acarer — 2024-04-22

BACKGROUND: Today, the biggest threat to mammalian predators with wide distribution areas is habitats fragmentation or change climate conditions. We aimed to reveal the habitat suitability modeling and mapping of the Brown bear, which is an important large mammal in Turkey's borders, under change climate. The habitat suitability modelling was determined using the present (2010) and future (2040-2070-2100) chelsa climate scenarios (IPSL-CM6A-LR SSP126-SSP370-SSP585) Maxent method with the present data obtained by examining all studies on Brown bear. Then, the mapping result values for the different years and scenarios revealed were classified as 0.5 unsuitable habitats, 0.51-0.8 suitable habitats and 0.81-1.0 most suitable habitats.

RESULTS: We determined that the variables contributing to the habitat suitability model of Brown bear are annual precipitation amount, the average annual air temperature, the precipitation amount of the wettest month, the ruggedness and elevation. According to the mapping results revealed according to different years and scenarios; Brown bear have suitable habitat a minimum of 14.87% of the study area in today, 12.56% in 2040 year, 10.93% in 2070 year and 8.24% in 2100 year. According to the SSP585 climate scenario of 2100 year, the habitat suitability of the Brown bear decreases by approximately 45%. According to the climate envelope model created with MaxEnt, the change climate in the 2100 year endangered the Brown bear.

CONCLUSION: Therefore, these results will be a source of information for the sustainability of the extinction of the Brown bear, for the pre-protection of existing and potential habitats and for reducing the impact of change climate conditions.

EFFECTS OF FLIGHT AND SMOOTHING PARAMETERS OF NUMBER OF TREES WITH AERIAL IMAGERY IN A NATIVE BRAZILIAN ATLANTIC FOREST REMNANT

Carla Talita Pertille — 2024-07-09

Background: The objective of this study was to detect native trees from different flight configurations and smoothing techniques in Canopy Height Models (CHMs) in a native remnant in the municipality of Curitiba, State of Paraná, Brazil. To do so, eight flights were carried out with a Phantom 4, with two flight planning applications (Litchi and Pix4Dcapture) and two flight arrangements (single and double), totaling four flights for each application. All flights were processed using the Pix4Dmapper program. The LiDAR database was obtained with a DJI Matrice 300 system and from this data, the Digital Terrain Model (DTM) of the area was extracted. From the UAV data, the Digital Surface Model (DSM) of each flight was obtained. Subtracting each DSM from the DTM resulted in the CHMs for each UAV flight flown. The CHMs were smoothed with the CHMsmoothing function and three search window sizes were tested (6.5 x 6.5, 8 x 8, and 10 x 10).

Results: The results of the ITD approach revealed that in unsmoothed and smoothed CHMs, the search window of size 8 resulted in the best precision metrics, with the highest recall, precision, and F-score values. In the smallest window size, there was the highest number of false positives while in the largest window size, the omitted trees were more representative.

Conclusion: The best combination between flight parameters and smoothing techniques was with the Litchi application, with a single flight and 80% lateral and longitudinal overlap, resulting in individuals detected with an F-score of 0.94