Revista Árvore

Implications of using shading meshes and plant density on the leaf anatomy of Corymbia citriodora (Hook.) K.D. Hill & L.A.S. Johnson seedlings

2024-11-13T18:40:20-03:00

Shading meshes are important techniques used during seedling cultivation. However, improper use can lead to excessive shading, which may be intensified by the distribution of seedlings in the tray, directly affecting their growth and development. This study aimed to assess the effect of using colored shading meshes combined with different plant densities on the leaf anatomy and seedling quality of Corymbia citriodora (Hook.) K.D. Hill and L.A.S. Johnson. The experiment was conducted in a protected environment at the Federal University of Santa Maria/Frederico Westphalen campus, from May to September 2018. A completely randomized experimental design was used, in a 2 x 3 factorial scheme with two seedling densities, two shading meshes, and no mesh. The assessed densities consisted of 736 seedlings per m² (high density) and 528 seedlings per m² (medium density). The shading meshes used were in the red and blue colors, and there was a meshless (full sun) treatment as well. Assessments were conducted when seedlings reached 25 cm in height, with the following variables being analyzed: stomatal count, cuticle thickness, adaxial and abaxial epidermis thickness, spongy and palisade parenchyma thickness, as well as seedling quality through the Dickson Quality Index. The use of meshes in different colors and the plant densities altered the anatomical characteristics of Corymbia citriodora, such as cuticle and adaxial epidermis thickness, abaxial epidermis, palisade parenchyma, and leaf thickness. However, these anatomical changes observed in seedlings under different meshes do not necessarily indicate better seedling quality.

Keywords: Seedling quality, Stomata, Solar radiation

Survival and initial growth of seedlings produced in different containers and the use of mulching in anthropized area

2024-06-27T17:59:22-03:00

The demand for seedlings of native tree species for the restoration of altered areas has increased considerably. Therefore, knowing the strategies that favor quality seedling production in the nursery, in addition to survival, growth, and development in the field, is important. This study was to evaluate the survival and initial growth of Inga vera Will and Schinus terebinthifolius Raddi, after 24 months of planting, seedlings in an anthropized area. The experiment was conducted using a factorial scheme (2 × 2), considering the types of containers used in the production of seedlings and the presence or absence of mulching in the surroundings. The survival of the seedlings, as well as their morphophysiological attributes, was verified 24 months after planting. I. vera presented a higher average survival for seedlings grown in plastic bags (86.7%), whereas S. terebinthifolius did not show any difference between treatments. The morphological attributes of increased height (IncH), diameter of the stem (IncSD), crown area (AC), and shoot dry mass (SDM) were favored by the use of plastic bags in seedlings of I. vera. For S. terebinthifolius, the plastic bag favored only IncH, equaling the seedlings produced in containers for the other variables. Using mulching was ineffective in helping the growth of either species, and the physiological attributes were similar for all the treatments tested. Aiming at the high survival and rapid growth of seedlings in the field, it is recommended to produce I. vera in 1.5 L plastic bags, while S. terebinthifolius seedlings can be produced in 180 cm³ containers. Therefore, using mulching as a culture treatment for both species should be investigated in future studies.

Keywords: Inga vera; Schinus terebinthifolius; Morphophysiological attributes; Extreme south of the Atlantic Forest biome

Anatomy as a tool to understand the causes of seed failure: a study of crosses Eucalyptus species

2025-01-13T14:33:20-03:00

Seminal propagation of eucalypt plays a crucial role in breeding programs, serving internal consumption and commercial applications. This study aimed to develop a method for examining anatomical changes in seeds obtained from Eucalyptus crosses to elucidate the causes of seed viability loss and low seed production observed in certain mating pairs. Flower buds/fruits were collected from four different genetic materials (E. grandis, E. urophylla, E. urophylla × E. grandis, and self- pollinated E. urophylla). Crosses classified as good or poor seed producers were sampled at 15-day intervals from anthesis to maturity. After collection, samples were fixed in FAA₅₀ solution (1:1:18 v/v formaldehyde, acetic acid, and 50% ethanol) and stored in 70% ethanol. Subsequently, the samples were subjected to six different preparation methods, involving standard procedures, combinations of high and/or low temperatures, seed softening substances, and vacuum treatment. Flower buds producing unformed seeds exhibited a functional ovary with reduced locules and increased lignification. Aditionally, unformed seeds were covered by thick integuments and displayed abnormal endosperm cells. In cases where the developing ovary was visible, highly lignified tissues with numerous sclereids were observed. By contrast, flower buds with lower lignification had ovaries with well-developed locules, containing seeds with a normal appearance, characterized by a single-layered integument and well-delimited nucleated endosperm cells. Also, self-pollinated materials produced a few seeds, some of which were unformed. Thus, we conclude that anatomical alterations, likely influenced by genetic factors, lead to incompatibility, resulting in limited seed production or the production of unformed seeds in certain Eucalyptus crosses.

Keywords: Seed viability; Anatomical analysis; Controlled crosses

Effect of wastewater and phosphate fertilization on photosynthetic pigments and macronutrients of Moringa oleifera Lam.

2024-11-22T18:32:55-03:00

The use of unconventional resources, such as treated domestic wastewater, has proven to be a promising alternative for agricultural irrigation in semi-arid regions, contributing to water sustainability. This study evaluated the effects of fertigation with wastewater and phosphate fertilization on photosynthetic pigments (chlorophyll A, chlorophyll B and carotenoids) and the concentration of macronutrients (N, P and K) in leaves of Moringa oleifera Lam. The experiment was conducted in a greenhouse at the Professor Ignácio Salcedo Experimental Station of the National Institute of Semiarid (INSA), in Campina Grande-PB, in a haplic PLANOSOL soil. The experimental design was in randomized blocks, with a 5 x 2 factorial scheme (five concentrations of wastewater and two levels of phosphate fertilization), totaling 10 treatments. Irrigation was performed manually, and the drained volume was collected to calculate evapotranspiration. At 90 days, the levels of chlorophyll A, B and carotenoids did not differ significantly between the treatments with wastewater, but phosphate fertilization increased the levels of N and P in the plant. Wastewater, applied at up to 75%, increased the N level and, at 100%, increased P and K. It is concluded that wastewater, with adequate management, is viable for Moringa cultivation, but caution is required due to possible chemical interactions and content proportions in the soil.

Keywords: Irrigation efficiency; Water reuse; Fertigation; Chlorophylls; Sustainability

Effect of increased carbon dioxide concentration on the elements Ca, Fe, K, Mg, Mn, and Na in Senna reticulata

2025-03-07T15:21:20-03:00

The CO₂ is the main gas responsible for the greenhouse effect, and assessing its effects on plant species is crucial for future research. The aim of this study was to test the impact of increased CO₂ on the elements Ca, Fe, K, Mg, Mn, and Na in leaflets, roots, and stems of Senna reticulata. The plants were exposed to 360 mg.kg^-1 and 720 mg.kg^-1 of CO₂ in a controlled environment. The samples were solubilized with HNO₃ and analyzed by flame atomic absorption spectrophotometry. The increase in CO₂ to 720 mg.kg^-1 resulted in a 56.05% increase in Ca in the root, with reductions in the leaflet (1.11%) and stem (10.21%); reduction of Fe in all parts (leaflet 1.99%, root 19.16%, stem 41.73%); reduction of K in the leaflet (15.40%) and increases in the root (35.42%) and stem (3.17%); increase in Mg in all parts (leaflet 15.06%, root 111.46%, stem 6.15%); reduction of Mn in the leaflet (19.97%) and stem (16.69%) and increase in the root (1.47%); and reduction of Na in the leaflet (52.59%) and increases in the root (234.73%) and stem (168.38%). Exposure to 720 mg.kg^-1 of CO₂ induces adaptations in the distribution of elements in Senna reticulata compared to exposure to 360 mg.kg^-1.

Keywords: Nutritional management; Global warming; Climate bioindicators

Effect of free and nanoencapsulated nitric oxide donor on the response of tree plants during the hardening off process

2024-07-19T16:00:50-03:00

Nitric oxide (NO) plays a crucial role as a signaling molecule in several biological processes in plants, participating in the response to different types of environmental stresses. The technique of nanoencapsulation of NO donors appears as a promising approach to expand and enable the exogenous application of NO nitric oxide in environmental restoration programs. Therefore, this study aimed to verify the effect of using a NO donor, in free and encapsulated form, on the hardening off of seedlings of three tree species: Hymenaea courbaril L., Amburana cearensis (Allemão) A.C. Smith, and Hymenaea stigonocarpa Mart. ex Hayne. The seedlings were grown for 3 months under moderate shade and translocated to the hardening off sector, where they remained for 3 months under the treatments: chitosan nanoparticles containing S-nitrosoglutathione (NP-CS-GSNO) at concentrations of 0.025, 0.5, 0.1, and 0.2 mM, free S-nitrosoglutathione, at concentrations of 0.1 and 0.2 mM, or the Control. For H. stigonocarpa, treatments with free or nanoencapsulated GSNO did not differ from each other, differing only from the Control. H. courbaril presented similar behavior in relation to growth variables, however, in the analysis of physiological variables, only the NP-CS-GSNO 0.1 and 0.2 mM treatments differed from the other treatments. A. cearensis maintained similar behavior to H. courbaril, with only a difference in the Control treatment in relation to the other treatments. These results indicate that GSNO presents beneficial physiological effects when made available to native forest species, such as H. stigonocarpa, H. courbaril, and A. cearensis, triggering protective and incremental activities regarding photosynthesis, stomatal conductance, and biomass formation.

Keywords: Nanotechnology; Environmental stress; Acclimation

Growth and production of Eucalyptus clones in silvopastoral system

2025-04-09T10:25:04-03:00

The aim of this study was to analyze the growth and production of two eucalypt clones grown in a silvopastoral system in the municipality of Coronel Pacheco, MG, Brazil and select the best volumetric model for the clones in this arrangement. This silvopastoral system is composed of two commercial eucalypt hybrids, GG100 and I144 (Eucalyptus urophylla x Eucalyptus grandis), at 79 months of age, planted at a spacing of 14.0 x 2.8 meters, Urochloa decumbens as forage component and grazing by Brangus cattle. A completely randomized design with two treatments (clones) and six replicates (plots) was used. The diameter with bark of all trees in the plots and the total height of the first ten trees were measured, along with a rigorous volume determination of five trees per diameter class to obtain volumetric production and fit the growth and production model. Forest inventory measurements were taken on six occasions from 21 to 79 months of age. The Spurr (1952) model showed a high quality of fit and adjusted coefficient of determination and low residual standard error. The I144 clone showed a larger diameter and higher productivity compared to GG100 clone. And also, higher wood volume and average annual increment (AAI). Both clones showed a high potential to adapt to the region environment, however, I144 clone was the most suitable for use in silvopastoral systems under similar conditions to the study.

Keywords: Forest modeling; Productivity capacity; Crop-livestock-forest integration

Modeling as a tool for predicting the productive capacity of wood harvesting

2025-05-05T18:17:12-03:00

Carrying out an assertive planning in logistics and forest harvesting is essential to reduce the operational costs, as well as guaranteeing a constant supply of wood for the manufacturing unit, without compromising the integrity of the fleet of machinery in the field. This study addressed the analysis of the productive capacity of two important wood harvesting machines, the Feller-Buncher, and the Harvester, with an objective to propose a technical modeling to optimize the logistics associated with these machines. Eight machines were analyzed in planted forests with different productivity (0.08 to 0.58 m³/tree). Machinery productivity was also evaluated for each forest condition. Regression analysis, means tests, and statistical inferences were carried out to present the results. The relationship between machinery productivity and forest productivity obtained through regression analysis was explained with up to 97% accuracy. The productivity curves indicated stabilization with the increase of the mean individual volume per tree (MIV). The forest being harvesting machines evaluated showed a reduction in cost per cubic meter harvested, as forest productivity increased. The productive capacity of the harvester dedicated exclusively to processing, although superior, presents a disadvantage in practical terms, mainly due to the requirement for a new machine in the felling process, therefore increasing the production cost.

Keywords: Forestry operations; Wood harvesting; Operational income; Productivity of forestry machines

Unveiling ecological dynamics and patterns in an urban-to-rural gradient of forest fragments in the Atlantic Forest biome

2025-03-18T13:19:14-03:00

The floristic composition and forest structure have been extensively documented as a well-established basis for ecological studies. However, distinctions along the urban-to-rural gradient are limited for neotropical ecosystems. Therefore, we analyzed the floristic, diversity, and spatial distribution patterns of tree species along an urban-to-rural gradient of forest fragments in the Atlantic Forest Biome. Thus, a 1.0 ha area was sampled in each fragment (urban, peri-urban, and rural) based on 50 unit samples of 20.0 x 10.0 m. Data on species, diameter at breast height (DBH), total height, and position (x and y coordinates) were collected. Analyses were conducted on the secondary succession stage, phytosociology, data distribution, floristic similarity, diversity indices, and spatial distribution (total and main species). A significant floristic difference was found among the fragments along the urban-to-rural gradient (p<0.01), with the rural forest in a late-successional regeneration stage and the others in an intermediate stage. Urban and rural forests differed significantly in diversity (p<0.01). The urban fragment exhibited an aggregated species distribution up to 50.0 m, while the peri-urban fragment showed up to 30.0 m aggregation. Spatial distribution in the rural fragment was completely random. However, the distribution pattern of a considered species varies depending on the fragment type. We identified differences among the three forest fragments (floristics, diversity, and spatial distribution of species) due to the influence of the urban ecosystem. The procedures adapted to assess the secondary forest succession stage were found to be reliable to mitigate the subjectivity in Conama Resolution 02/1994.

Keywords: Mixed Ombrophilous Forest; Urban ecology; Urban forest

Edentree: A web application for optimal rotation age analysis

2025-04-22T10:45:30-03:00

The R/Shiny package is a tool that allows the creation of interactive web applications, transforming complex analyses into accessible interfaces. In the forestry sector, Shiny’s potential is still little explored, despite its applications in areas such as forest inventory, fire monitoring, LiDAR data analysis, and biomass and carbon estimates in Brazilian forests. This tool has been adopted by researchers and companies for its ability to generate interactive statistical reports and dashboards, contributing to data visualization and supporting forestry decision-making. From this, the objective of this research was to develop a web application in R/Shiny for the forestry field that, through the calculation of biological and financial indicators, would assist the user in making decisions regarding their forestry project. The main packages used to create the web application interface were: Shiny, bs4Dash, and golem, which offer pre-built functionalities and allow the application to be developed with less effort. For validation, data from a Eucalyptus urograndis forest plantation in Alagoinhas, Bahia, collected in 2021, were used, along with Microsoft Excel and Planin® software. As a result, a functional and online web application was obtained for the forestry field, with satisfactory performance in the validation stages, meeting the established criteria. Thus, the developed tool can contribute to support decision-making during the planning and management of forest plantations.

Keywords: Shiny; R; Forestry sector; Financial viability

Firewood quality of Eucalyptus spp. clones for agroindustry supply in Mato Grosso, Brazil

2025-04-27T10:26:08-03:00

The use of renewable energy sources from biomass has been increasing in the agricultural sector, with a focus on wood produced from eucalyptus plantations. Given the economic significance of the state of Mato Grosso, Brazil, this study aimed to evaluate the energy potential of different eucalyptus clones planted in the state, with an emphasis on their use in agroindustry. Three trees were selected from each of eleven different eight-year-old genetic materials in a clonal test located in Tangará da Serra, MT. The bark percentage, basic density, higher heating value, and both elemental and structural chemical composition of the wood were determined. A cluster analysis was then performed. Additionally, a case study was conducted considering firewood consumption and costs for drying corn and soybeans. The bark percentage ranged from 5.00 to 11.04%. Basic density varied from 478 to 588 kg.m⁻³, with significant differences among the three groups formed; the best-performing clones had values approximately 6% higher than the others. Higher heating values ranged from 4,609.33 to 4,743.67 kcal.kg⁻¹. Total lignin content also varied between clones, with one group standing out by ranging from 27.81% to 29.76%. Total extractive content ranged from 3.72 to 7.76%. The average energy density was 2.50 Gcal.m⁻³, with no significant differences between the clones. Cluster analysis identified two main groups. The evaluated eucalyptus clones showed satisfactory characteristics for energy use, with clones 1, 4, and 10 standing out. The use of eucalyptus clones with superior energy properties can reduce wood consumption for drying grains such as soy and corn by up to 20%.

Keywords: Energy clones; Combustion; Renewable energy

Adsorption of 2,4- dichlorophenoxyacetic acid (2,4-d) herbicide on activated carbon of Brazil nut shell

2024-09-13T16:45:46-03:00

Activated carbon is a material with a high fixed carbon content and large surface area, whose capacity for adsorbing organic compounds depends on the precursor material and the process it undergoes. 2,4-D is a molecule associated with numerous health hazards and is widely used in Brazil for weed control. In rural areas, its use can lead to contamination of surface and groundwater. This study aimed to evaluate the adsorption potential of 2,4-dichlorophenoxyacetic acid (2,4-D) using carbon derived from Brazil nut shell activated at 800 °C, comparing activation atmospheres of water steam and CO₂. Activated carbons, both with water steam and CO₂, were characterized in terms of pore diameter distribution using the Brunauer–Emmett–Teller (BET) theory, morphology by scanning electron microscopy (SEM), and thermal stability by thermogravimetric analysis (TGA). The activated carbons with steam and CO₂ presented high surface areas (397 ± 8 m²/g and 325 ± 7 m²/g, respectively). The micrographs showed high porosity in the activated carbons, and the loss of only 20% of their mass in the thermogravimetric test confirmed the material’s thermal stability. The adsorption kinetics assay was performed by High-Performance Liquid Chromatography (HPLC) over time ranging from 0 to 120 minutes. The equilibrium time was 45 minutes for water steam-activated carbon, achieving 92.51% removal, and 120 minutes for CO₂-activated carbon with 84.81% of 2,4-D removed. The pseudo-second-order kinetic model best fit the data.

Keywords: Adsorption, Herbicide, Potability

Wooden bridges in Amazonia: Recommending regional forest species for structural maintenance

2025-01-22T13:27:25-03:00

Wooden bridges are essential structures for communities, especially in the Amazon region, where they have played a crucial role in territorial unification. Most were built without the supervision of specialized technicians. Maintenance of these structures is essential to ensure their durability, given the use of different wood species and the challenges of natural degradation. This study aims to list suitable Amazonian species for each structural element of DNIT-type bridges (National Department of Earth Infrastructure), taking into account natural durability, mechanical strength and dimensional stability. The justification lies in the need to increase the useful life of these structures, taking into account factors such as environmental degradation and biological attacks. To this end, bibliographic data on the species identified in two bridges on the BR319 was studied, selecting and separating them into groups, for use at points most susceptible to attack and points subject to the weather, which meet the structural calculation, and also have good dimensional stability. The results listed eigth possible forest species for appropriate use in the maintenance of DNIT-type Amazonian wooden bridges.

Keywords: Sustainable forest management; Natural durability; Species grouping

A Correlation between the kappa number and the Ventorim index in the bleaching process

2024-12-09T15:25:40-03:00

The determination of the kappa number in the bleaching process is typically conducted with a pulp quantity between 3 and 4 grams, allowing for the calculation of values above four. However, after the oxidative extraction stage with hydrogen peroxide, the pulp presents a kappa number lower than this value. Therefore, the present study proposes a new method for determining the kappa number by creating the Ventorim bleaching index, which avoids the inconveniences associated with traditional kappa number analysis. For this study, industrial oxygen-delignified pulp was used. Four different ECF bleaching sequences were performed: OD(E+P)DD, OAD(E+P)DP, OADEDP, and OAEDP, along with the determination of the kappa number and the Ventorim bleaching index. The Ventorim index was based on the four chlorine-free bleaching sequences (ECF), all of which achieved a final brightness of 90% ISO, with very similar R² values and linear regressions. Consequently, a single equation was generated using all the data: Y=0.7202x+0.1464. This unified approach simplifies the analysis and broadens the applicability of the Ventorim bleaching index in the pulp and paper industry.

Keywords: Bleaching; Kappa number; Ventorim bleaching index

Fiber quality indices of Corymbia spp. and Eucalyptus spp. wood for the selection of genetic materials for pulp production

2024-10-20T12:33:48-03:00

The selection of genetic materials for obtaining cellulosic pulp and paper production necessitates evidence of efficiency in terms of silvicultural performance and industrial processing. In this context, this study aimed to select genetic materials from Eucalyptus spp. and Corymbia spp. for pulp production. The selection was achieved through cluster analysis, based on the morphological traits of the main anatomical elements of the wood, the screened brown pulp yield, and fiber quality indices (Runkel ratio, slenderness ratio, Mulsteph coefficient, and flexibility coefficient). Sixteen genetic materials were evaluated, each represented by three trees of average diameter, collected at 81 months of age with a planting spacing of 6x1.5 m, from plantations located in the municipality of Itamarandiba - MG, Brazil. Axiovision 4.8 software was used to measure the dimensions of fibers and vessels under an optical microscope. Information regarding the screened pulping yield for these genetic materials was obtained from literature. Three distinct groups of genetic materials emerged from cluster analysis. In group I, hybrids with longer and less flexible fibers (Runkel ratio >1, wall fraction >50%, and flexibility coefficient <50%) predominated, making them more suitable for manufacturing absorbent papers. In contrast, groups II and III comprised genetic materials with higher screened yields (>52.0%), lower wall fractions (<50%), and other fiber quality indices indicating a predominance of more flexible fibers (flexibility coefficient >50% and slenderness ratio >51%). These fibers are primarily more suitable for producing tear- and burst-resistant papers, intended for packaging and bags.

Keywords: Runkel ratio; Mechanical resistance of cellulose pulp; Fiber flexibility

Anatomical and physical analysis of the bark of three Amazonian tree species as a tool for species identification

2025-04-27T10:29:29-03:00

Accurate species identification is crucial for conservation efforts and combating illegal logging. This study analyzes the anatomical characteristics and physical properties of the bark of three tropical species: Bertholletia excelsa, Cedrela odorata, and Eschweilera coriacea, to assess their potential for rapid species identification. The hypothesis proposed was that anatomical and physical differences in the bark would allow for effective identification. The study was conducted in the southeastern region of Peru, in the department of Madre de Dios, where nine trees from the three species were randomly selected. Bark samples were collected at breast height (DBH) from the trees. The samples were analyzed macroscopically, microscopically, and for physical properties such as moisture content, basic density, and volumetric shrinkage. The results showed that B. excelsa had the thickest (14.11 cm) and most fibrous bark, while C. odorata had thinner bark (9.33 cm), with a more regular organization. E. coriacea had the thinnest (8.83 cm) and most flexible bark. Regarding physical properties, B. excelsa exhibited the highest moisture content (68.71%), while C. odorata showed the highest basic density (740 kg/m³). This study demonstrates that anatomical and physical characteristics of bark are effective tools for the identification of tree species, contributing to conservation and the prevention of illegal logging.

Keywords: Illegal logging; Identification of phloem; Timber species

Influence of different drying methods on yield, density, color, and chemical composition of the essential oil of Ocotea lancifolia (Schott) Mez leaves

2025-01-16T16:25:27-03:00

The compounds in essential oils (EOs) are directly linked to their potential use. Drying methods are used to process large amounts of plant material while maintaining or even maximizing quality. This study observed the influence of different drying methods on the yield, density, organoleptic properties, and chemical components of EOs from Ocotea lancifolia leaves, comparing them with oils from fresh leaves. Fresh plant material (F) was subjected to hydrodistillation, a method also used for leaves after air drying (AIR), freeze-drying (FL), microwaving (MW), and oven drying at 45°C (OD 45) or 60°C (OD 60). Drying and extraction were performed in triplicate, using 350 g of fresh leaves and 250 g for the other samples. Yield was calculated as a percentage. Chemical compositions were analyzed by gas chromatography (GC). EO yields were: 0.4863% (F); 0.7400% (AIR); 1.050% (FL); 1.1167% (MW); 0.5867% (OD 45) and 0.7487% (OD 60). Microwaving and freeze-drying provided the highest yields. No differences in densities were observed. A drastic color change was noted in the EOs from leaves dried in an oven at 45°C and 60°C. The major compound identified was caryophyllene oxide, with percentages varying among treatments. Other components showed significant differences in structure and/or percentage. Drying time and temperature influenced modifications and degradation of some compounds, sometimes resulting in changes in EOs color and composition.

Keywords: Natural compound; Plant extractive; Caryophyllene oxide

Spatio-temporal analysis of forest fragmentation and landscape management scenarios in the Peruípe river basin, state of Bahia, Brazil

2025-05-14T17:52:02-03:00

This study aimed to evaluate the spatiotemporal changes in vegetation fragments and the degree of forest fragmentation in the Peruípe River Basin, state of Bahia, between 1985 and 2021. Forest fragments were analyzed using landscape metrics related to size, edge, shape, and isolation using the Patch Analyst 5.2 extension in ArcGIS 10.8. Over the 36-year period, only minor changes were observed, with a 0.36% variation in the vegetation classes. The degree of fragmentation in the landscape decreased during the evaluation. However, it can still be concluded that the basin exhibits a high degree of fragmentation because the vegetation remains discontinuous, forming forest mosaics within a matrix that is predominantly pasture and forestry areas. Furthermore, most forest fragments in the Peruípe River Basin are smaller than five hectares (ha). Landscape management scenarios showed the importance of small fragments in the area, as they reduced the average isolation between fragments. In the scenario in which PPAs were restored, the forest area increased, whereas the number of fragments decreased. These results indicate that restoring PPAs can minimize the impact of forest fragmentation. These results are expected to contribute to the development of management and conservation strategies for the Peruípe River Basin.

Keywords: Landscape ecology; Landscape metrics; Geoprocessing

Landscape environmental heterogeneity shaping tree community composition and structure in riparian forests

2025-05-08T09:37:24-03:00

Although riparian vegetation is widely recognized for its positive impact on soil and water quality and its role in ecological conservation, there is still a gap in understanding the effect of environmental heterogeneity on tree community composition and structure in riparian landscapes. Riparian forests are ecosystems with abrupt variations in topographic, edaphic, and hydrological features, resulting in the formation of microenvironments with specific plant compositions. We evaluated the influence of the topographical gradient on edaphic and hydrological attributes and their association with tree species composition, diversity, and structure in three remnants of riparian forests in Minas Gerais, at high slope, low slope and alluvium positions. Ten 400 m² plots were set up in each area. All trees and shrubs within the plots with diameter at breast height (DBH) greater than 5 cm were recorded. The abundance was correlated with the topographic, edaphic, and hydrological variables of the plots through multivariate analysis. The highest species richness (122) and diversity (H' 3.99) were associated with the low slope, while the alluvium had the highest tree density (3005 trees ha^-1) and basal area (43.99 m² ha^-1). Cluster analysis and canonical correspondence indicated that the species distribution is mainly influenced by soil moisture and fertility. Understanding the dynamics of riparian forests is essential for strategic decision-making in tropical forest management towards the promotion of ecosystem services, forest restoration and sustainable development goals.

Keywords: Alluvium forest; Ttopographic gradient; Microenvironment; Relationship species-environment; Edaphic conditions; Quantitative ecology

Who let them out? Invasion of alien marmoset species in the Callithrix aurita natural range

2025-02-27T12:48:47-03:00

The microregion of Viçosa, southeastern Brazil, is part of the range of Callithrix aurita, an endangered marmoset, which suffers several ecological problems caused by the introduction of alien congeners species. We sampled 39 forest fragments and combined playback census and occupancy models to evaluate whether the city of Viçosa may act as a dispersal center of alien species and their hybrids (i.e., Callithrix sp.). Likewise, we explored whether landscape features (i.e., native forest, native forest in the regeneration stage, and eucalyptus fields) may favor the occupancy probability of Callithrix sp. in sampled fragments. We detected Callithrix sp. in 17 (out of 39) fragments. A group formed only by individuals of the C. aurita was not found in any fragment, even though we found individuals of the native species in a group formed by hybrids. The probabilities of occupancy and detection of Callithrix sp. were 0.93 and 0.12 respectively. None of the analyzed variables showed greater support than the null model, showing no direct relationship with the distribution of Callithrix sp. in the sampled fragments, indicating their ecological plasticity. The absence of groups of C. aurita may be not simply due to the occurrence of the Callithrix sp., but also due to the defaunation process originated from the human activities that fragmented the continuum forest before the invasion process started. However, the human alterations may have also facilitated the invasion process of Callithrix sp., putting the native species at a significant risk of genetic erosion and local extinction.

Keywords: Conservation; Invasive species; Landscape analysis

Federal protected areas in Brazil and Italy: A comparative analysis

2025-03-21T16:19:00-03:00

Protected areas (PA) play a crucial role in preserving global biodiversity and ecosystem services. They ensure the protection of endemic species, preserve sensitive environments, and, in some cases, contribute to the livelihoods of local communities. Currently, there are 265,908 protected areas across 245 countries and territories, covering 16.64% of the planet's land and 7.74% of its marine areas. This article compares national legislation on PA in Brazil and Italy, evaluating their alignment with IUCN standards. In Brazil, Law No. 9,985/00, which establishes the National System of Conservation Units (SNUC), regulates protected areas, while in Italy, Law 394/91 guides the classification and management of these areas. The classifications of both countries were analyzed based on the framework established by the International Union for Conservation of Nature (IUCN) and its World Commission on Protected Areas (WCPA). Brazil's nomenclature shows greater similarity to the IUCN standard, although it is not fully adopted, and includes a greater number of classifications than the standard. Italy strictly follows the exact number of categories established by IUCN criteria and has a nomenclature that largely differs from the IUCN standard. Adopting a more standardized nomenclature between countries facilitates international comparisons and promotes a more effective exchange of knowledge on management practices.

Keywords: Environmental legislation; International comparison; Conservation