Vagner Santiago Do Vale

Forest edge effects are commonly interpreted as radial gradients from the edge toward the interior, but this assumption may oversimplify the spatial organization of heterogeneous tropical forest fragments. Here, we integrated field-based phytosociological data with Sentinel-2 spectral indices to evaluate whether edge-related structural interpretation depends on analytical scale in Semideciduous Seasonal Forest fragments embedded in the Brazilian Cerrado. Five fragments were analyzed using transect-based plots and continuous pixel-level modeling. Basal area showed a strong positive correlation with the Normalized Difference Vegetation Index (NDVI) (r = 0.95), supporting its use as the main spectral proxy for basal-area-related structural variation. Plot-level segmented regression detected statistical transitions along the edge–interior gradient, with breakpoints ranging from approximately 13 to 39 m. However, pixel-level modeling revealed scale-dependent responses, including shorter estimated transition distances in the rural Ipameri fragment (IF) and the Campo Alegre de Goiás fragment (AC), an intermediate transition in the Caldas Novas fragment (CN), a longer estimated transition distance in the UEG–Ipameri fragment (IP), and high internal heterogeneity without a single dominant radial transition in Panga. The first two axes of the Principal Component Analysis (PCA) explained approximately 81% of the total variance, reinforcing the structural–spectral correspondence. These findings show that edge-related spectral–structural patterns are detectable but are not adequately represented by fixed radial zones alone. Pixel-level Sentinel-2 modeling provides a complementary spatial framework for interpreting edge-related heterogeneity in fragmented tropical forests when integrated with field-based structural data.

A large portion of the Brazilian Cerrado vegetation currently exists as small, disturbed, and isolated fragments. Evaluating the degree of anthropogenic disturbance in certain environments has been successfully achieved using bioindicator insects, particularly ants. This study aims to characterize the epigeic and arboreal ant communities in Cerrado fragments in the southeastern region of Goiás, bordered by agricultural crops, during both the dry and wet seasons, and to correlate these ant communities with the structural characteristics of the forest fragments. Morphospecies richness and ant community structure across the different environments were compared, and bioindicator species were proposed using the Indicator Value (IndVal) method. The ant community structure under the evaluated conditions was significantly altered, indicating effects that extend beyond fragment-specific variables and are associated with the surrounding agricultural landscape. The IndVal analysis suggested two environmental quality indicator species for the ground stratum: Pheidole cf. radoszkowskii and Crematogaster stollii. However, it did not point to any significant indicator species for the arboreal stratum. Ants mediate various functional roles and shifts in the structure of local communities, reinforcing the importance of these insects as bioindicators of environmental quality.

Riparian forests are crucial for water resource protection and biodiversity, yet they are frequently degraded by unplanned urban growth. This study evaluated the floristic composition and horizontal structure of tree communities under varying degrees of anthropogenic influence in small-sized (S - Ipameri) and medium-sized (M - Caldas Novas) cities, comparing them with protected rural areas (P). Data were collected from 59 plots (400 m²) across urban streams and legal reserves. We estimated phytosociological parameters, biomass, and carbon stocks, alongside diversity (Shannon and Simpson) and richness (Chao 1). Statistical differences were assessed via Kruskal-Wallis and Dunn’s tests. Floristic and structural similarity were analyzed using Jaccard and Morisita-Horn indices, supplemented by PCoA, PERMANOVA, and Indicator Species Analysis (IndVal).A total of 199 species were sampled. Protected forests (P) exhibited significantly higher structural values, including species richness (19 species/plot), density (1,138.3 ind./ha), and carbon stock (36.8 t/ha). Conversely, urban areas M and S showed reduced and similar values, with carbon stocks of 15.5 t/ha and 17.1 t/ha, respectively. Protected areas maintained native riparian species (e.g., Tapirira guianensis), while urban areas were dominated by exotics (e.g., Leucaena leucocephala, Mangifera indica). Multivariate analyses confirmed biotic homogenization in urban fragments, which function as "novel ecosystems" characterized by new species combinations and significantly lower structural complexity and biomass.

Forest edge effects are commonly interpreted as radial gradients from the edge toward the interior, but this assumption may oversimplify the spatial organization of heterogeneous tropical forest fragments. Here, we integrated field-based phytosociological data with Sentinel-2 spectral indices to evaluate whether edge-effect interpretation depends on analytical scale in Semideciduous Seasonal Forest fragments embedded in the Brazilian Cerrado. Five fragments were analyzed using transect-based plots and continuous pixel-level modeling. Basal area showed a strong positive correlation with NDVI (r = 0.95), supporting its use as the main spectral proxy for vegetation structure. Plot-level segmented regression detected edge-to-interior transitions, with breakpoints ranging from approximately 13 to 39 m. However, pixel-level modeling revealed scale-dependent responses, including shallow gradients in IF and AC, an intermediate transition in CN, a deeper gradient in IP, and high internal heterogeneity without a single dominant radial transition in Panga. The first two PCA axes explained approximately 81% of the total variance, reinforcing the structural–spectral correspondence. These findings show that edge effects are detectable but not adequately represented by fixed radial zones alone. Pixel-level Sentinel-2 modeling improves the spatial interpretation of fragmented tropical forests.

Inventários fitossociológicos de fitofisionomias do Cerrado avaliam parâmetros estruturais como densidade, altura, área basal e cobertura de copa, fundamentais para a classificação e compreensão da vegetação. Embora a cobertura de copa seja relevante na distinção das fitofisionomias, sua mensuração manual apresenta limitações em precisão e eficiência. Métodos modernos, como o uso de drones com sensores RGB, vêm ganhando destaque devido à alta resolução espacial e rapidez na coleta de dados pois possibilitam o cálculo de índices de vegetação que refletem a densidade e o vigor da vegetação. Em estudo realizado no cerrado stricto sensu da Universidade Estadual de Goiás, em Ipameri-GO, utilizou-se inventário fitossociológico aliado a imagens de drone para estimar a cobertura de copa e identificar os melhores índices de vegetação. Foram amostradas 144 árvores distribuídas em 32 espécies, com destaque para Qualea grandiflora, Curatella americana e Coccoloba mollis, indicativas de impactos antrópicos, como queimadas e presença de gado. A biomassa seca estimada foi de 19,657 Mg ha-¹, dentro dos padrões do cerrado stricto sensu goiano. A baixa riqueza (32) e moderada diversidade de Shannon (3,02) evidenciaram moderada diversidade, compatível com áreas impactadas. A contagem de cobertura de copa via pixels e índices de vegetação indicam que a cobertura de copa local está entre 35 a 40%. A integração de tecnologias como drones e análises digitais representa um avanço para estudos

The Cerrado biome encompasses different vegetation types, ranging from savanna-like vegetation to forest-like vegetation, represented by a vegetational continuum from Cerrado Típico, Cerrado Denso and Cerradão, respectively. Nevertheless, there are still uncertainties on whether these different vegetation types do not only differ in their vegetation structure, but also in their species compositions. Based on vegetation surveys from 167 plots in the central Brazilian Cerrado, we addressed two questions: (i) How variable is the vegetation structure and species between different Cerrado vegetation types? Second, (ii) how strongly are vegetation structure and species composition linked? To answer these questions, we performed hierarchical clustering for species composition and vegetation structure. Our results showed that for species composition only 18% of the variance was explained by hierarchical clustering, while for vegetation structure 82% of variance was explained. Additionally, there was a significant difference in the structure metrics between clusters, showing that it is possible to clearly identify different Cerrado vegetation types based on vegetation structures, but not by species composition. Finally, we suggest that trait plasticity in Cerrado trees should drive structural differences among vegetation types, which could be the focus of future studies.

Habitat fragmentation and reduction in the Cerrado are the primary threats to this biome’s biodiversity. The amount of habitat in the landscape has been proposed as the sole predictor variable for species richness in fragmented areas, potentially replacing the combined effects of fragment size and isolation (habitat amount hypothesis). This study aimed to test the influence of sampled fragment area, number of fragments, and habitat amount in local landscapes on the species richness of medium- and large-sized mammals in the Cerrado, southeastern Goiás, Brazil. The applicability of the habitat amount hypothesis to medium- and large-sized mammals in fragmented Cerrado habitats was thus evaluated. Medium- and large-sized mammal species were recorded from 2014 to 2018 in 14 Cerrado fragments in southeastern Goiás, Brazil. Using Landsat 7 and 8 satellite imagery from the year 2000 and the mammal sampling period, landscapes were delineated by creating buffers with a radius of 2 km from the central point of each sampled fragment. Through visual classification of these landscapes, the following variables were obtained: habitat amount in the landscape (HA), number of fragments (NP), and area of the sampled fragment (HF). The results indicate that the habitat amount in the past landscape (14 to 18 years before sampling) was the best predictor variable for the species richness and composition of medium- and large-sized mammals. The HA variable from the sampling period and the AREA variable from both periods also significantly influenced species composition. Therefore, considering the historical landscape context, the habitat amount hypothesis was applied to mammals in the Cerrado areas studied.

Avaliou-se a composição e diversidade do cerrado localizado na Unidade de Conservação Municipal de Ipameri-GO, um dos biomas mais ameaçados do país. Foi realizado o levantamento florístico das espécies presentes na Unidade que se trata de um cerrado sensu stricto por meio da alocação de 10 parcelas de 20 m x 20 m, amostrando indivíduos com circunferência igual ou acima a 0,15 m e a 0,3 m de altura. Foram levantadas 69 espécies arbustivas e arbóreas, obtendo uma riqueza florística alta, através do índice de Shannon foi 3,32. O índice de equabilidade encontrado indicou alta uniformidade na área. Apenas três espécies ocorreram em todas as parcelas sendo elas Qualea gradiflora, Tachigali vulgaris e Xylopia aromatica. Os indivíduos amostrados em proporção estão em diferentes fases de crescimento avaliados assim através de suas alturas e diâmetros.

A altura total das árvores refere-se a um dos componentes de maior custo na realização de inventários florestais, o que revela a necessidade de novas ferramentas que auxiliem na economia de tempo e capital. O objetivo deste estudo foi avaliar a eficiência, praticidade e tempo no processo de mensuração de árvores de eucalipto através da aplicabilidade de distintos métodos. O experimento foi realizado em plantio de Eucalyptus urograndis dispostos em três renques, situado no município de Ipameri, Goiás. O plantio possuía sete anos de idade plantados em linhas duplas (3 m x 2 m x 17m). Foram mensuradas 55 árvores, com a avaliação da altura total (H). As aferições foram realizadas através do aplicativo telemóvel Smart Measure v. 1.6, clinômetro digital Haglof e o método da vareta. Com base nas avaliações, não houve diferença estatística para a mensuração da altura total de árvores de eucalipto para as avaliações realizadas com clinômetro e aplicativo, com destaque a utilização do aplicativo telemóvel Smart Measure v. 1.6, em função a redução no tempo da mensuração realizada. Deste modo sendo considerado como um método alternativo viável, prático, versátil e gratuito.