Seasonally Dry Tropical Forests (SDTFs) are situated in regions prone to significant water deficits. This study aimed to evaluate and quantify the dynamics and spatial patterns of vegetation and water bodies through the analysis of physical–hydrological indices for a remnant of FTSD between 2013 and 2021. Basal area, biomass, and tree number were monitored in 80 permanent plots located in two areas of an SDTF remnant with different usage histories. To assess vegetation and water resource conditions, geospatial parameters NDVI, NDWIveg, NDWI, and MNDWI were estimated for the period from 2013 to 2021. The observed patterns were evaluated by simple linear regression, principal component analysis (PCA), and principal component regression (PCR). Area 2 presented higher values of basal area, biomass, and number of trees. In area 1, there was an annual increase in basal area and biomass, even during drought years. The NDVI and NDWIveg indicated the vulnerability of vegetation to the effects of droughts, with higher values recorded in 2020. NDWI and MNDWI detected the water availability pattern in the study area. Physical–hydrological indices in the dynamics of tree vegetation in dry forests are influenced by various factors, including disturbances, soil characteristics, and precipitation patterns. However, their predictive capacity for basal area, biomass, and tree number is limited, highlighting the importance of future research incorporating seasonal variability and specific local conditions into their analyses.

Seasonally dry tropical forests (SDTFs) represent about 41.5% of the planet’s tropical forests. The objective of this study was to characterize the annual mortality and recruitment patterns of stems and trees between the years 2012–2021 in a Caatinga remnant in the state of Pernambuco, Brazil, through geostatistical modeling, and to associate the drought events recorded in the region with vegetation dynamics. Mortality and recruitment of stems and trees were monitored in 80 permanent plots located in an SDTF remnant, counted year by year between 2012 and 2021. The standardized precipitation index (SPI) was calculated to quantify the deficit or excess of rainfall in the evaluated period. The data were then subjected to geostatistical analysis based on the calculation of classical semivariances. As a result, there was a loss of 68.33% of trees and 61.93% of stems in the forest community during 2012–2021, which were associated with the water deficit caused by drought events recorded based on precipitation data and SPI calculation for the region. The Gaussian semivariogram model better represented the spatial variability of mortality and recruitment of stems and trees. An accumulative effect of droughts on increasing mortality rates and reducing recruitment during the study period was observed. The relationship between tree and stem mortality and recruitment rates and drought events highlights the impact of water deficit on vegetation, emphasizing the importance of considering extreme climatic events in the proper management of natural resources.

Precise estimates of dendrometric and morphometric variables are indispensable for effective forest resource conservation and sustainable utilization. This study focuses on modeling the relationships between shape (morphometric), dimension (dendrometric) and density (N) to assess the sustainability of forest resources. It sheds light on the current state of site characteristics, reproduction, and the structure of Araucaria angustifolia trees at selected forest remnants across multiple sites in Santa Catarina, Southern Brazil. Individual trees and their dendrometric variables, such as the diameter at breast height (d), height (h), crown base height (cbh), annual periodic increment (API) in growth rings, and morphometric variables, including four radii of the crown in cardinal directions, were evaluated. These measurements allowed us to calculate various morphometric indices and crown efficiency, enabling the assessment of both vertical and horizontal structural conditions. Statistical analysis confirmed a positive relationship of the crown volume (cv) and crown surface area (csa) with the crown length (cl). Conversely, the crown efficiency, density, increment rate, and reproductive structure production declined. These morphometric relationships emphasize the complex dynamics within these forest ecosystems, irrespective of the chosen site, indicating that horizontal and vertical forest structures have stagnated and have been characterized by limited change in the last ten years. Such results raise concerns about sustainability, highlighting the need for proper conservation measures and sustainable forest management practices. Our findings underscore the need for substantial adjustments in the structure and dynamics of the forest, particularly on selected rural properties where this tree species is abundant, to ensure long-term sustainability.

Knowledge of the formation and correlation of reproductive structures with dendro/morphometric variables of the Araucaria angustifolia tree species is a tool for its conservation and viability for sustainable forest management. We counted visually in araucaria trees the number of male strobili in RGB images acquired by Remotely Piloted Aircraft System (RPAs) over forest remnants. The diameter at the breast height (d), total height (h), crown radii (cr), crown base height (cbh), periodic annual increment in d based on increment rolls were measured, and the morphometric indices and crown efficiency were calculated with these variables. The relationships of these variables with male strobili production were analyzed by Pearson’s correlation and multivariate analysis techniques (cluster, factorial analysis, and main components). The morphometric variables correlated with the production of male strobili were d (r = 0.58, p-0.0002), crown diameter (r = 0.62, p < 0.0001), crown area (r = 0.62, p < 0.0001), coverage index (r = 0.51, p-0.001) and slenderness (r = −0.39, p-0.01). We argue that the production of male strobili is related to the vitality, dimension, density, growth space, and position in the stratum of the tree inside the forest, inferring a relationship between reproductive structures with the shape, size, growth space, and tree density. Such aspects shall be considered in future forest management initiatives in Southern Brazil.

Mimosa caesalpiniifolia is a native species from Northeast Brazil, with good soil and climate adaptation, fast growth and potential for multiple use. Because of these characteristics, it has been considered a promising species for forestry. This work aimed to evaluate the growth and productivity of Mimosa caesalpiniifolia at 75 months of age, in a homogeneous plantation located in the state of Rio Grande do Norte, Northeastern Brazil. The data were collected in a 0.05 ha plot with 84 individuals, submitted to thinning at 12 and 55 months. The variables height (H), diameter at breast height (DBH), and diameter at base (DAB) were evaluated. The productivity of the plantation was estimated in terms of total volume (m³) and stacked volume (st), number of stems and mean annual increment (MAI). On average, the individuals were 4.85 m tall, 12.05 cm in diameter at the base (DAB) and 8.42 cm DBH. Each individual presented an average of 6.07 stems. The estimated productivity was 43.88 m³ ha^-1, with MAI of 7.02 m³ ha^-1 year^-1, and the estimated stacked wood volume was 111.89 st ha^-1. The results showed the high potential of the species for the production of stakes and fence posts, as well as for the production of kindling and firewood, aiming at the use of all the biomass produced. Therefore, the planting of this species for the production of wood serves as an alternative to meet demands in the Northeast of Brazil.

A produção de mudas é um aspecto importante quando se quer obter um produto de boa qualidade. Entre os procedimentos realizados para essa atividade, a escolha do substrato possui uma grande importância, pois define os parâmetros de qualidade das mudas produzidas. Dentre as alternativas, o lodo de esgoto pode ser utilizado como substrato, associando sua utilização com a produção de mudas de Moringa oleifera, espécie que atualmente vem sendo alvo de diversos estudos, devido a suas caraterísticas morfológicas e nutricionais. Assim, o objetivo deste trabalho foi avaliar o crescimento de mudas de Moringa oleifera em diferentes concentrações de lodo de esgoto tratado com calcário. As sementes foram coletadas na área experimental da Escola Agrícola de Jundiaí (EAJ). O lodo foi fornecido pela estação de tratamento de esgoto da Universidade Federal do Rio Grande do Norte (UFRN). O experimento foi conduzido em casa de vegetação na EAJ. O tratamento do lodo foi realizado em temperatura ambiente com calcário para sua higienização. O experimento compreendeu seis tratamentos: T0: 100% areia (controle); T20: 20% de biossólido + 80% de areia; T40: 40% de biossólido + 60% areia; T60: 60% de biossólido + 40% areia; T80: 80% de biossólido + 20% areia; T100: 100% de biossólido. Totalizando-se 32 unidades amostrais (repetições) para cada tratamento. Os dados foram analisados no programa Bioestat. De acordo com as análises realizadas, as mudas submetidas aos tratamentos T0, T80 e T100 tiveram crescimento em altura inferior às mudas dos outros tratamentos, onde os melhores resultados foram para o T20, T40 e T60. Não houve diferença estatística entre os valores médios de diâmetro do coleto das mudas nos tratamentos com a presença do lodo, havendo apenas diferença destas para as mudas submetidas ao tratamento controle (T0). As mudas submetidas ao T60 apresentaram melhores resultados de crescimento em altura, relação H/D e número de folhas. Não houve diferença nas médias das variáveis PMSA, PMST e IQD, diferente do que ocorreu com a PMSR e a razão PMSA/PMSR, onde houve diferença estatística, se sobressaindo com maiores médias o T0 e o T60, respectivamente. Pode-se concluir que as concentrações de lodo que apresentaram melhores resultados foram de 40 e de 60%. Observou-se menor crescimento das mudas submetidas aos tratamentos controle (T0), T80 e T100. Portanto, o uso de lodo para a produção de mudas é uma alternativa tecnicamente viável.