Dense Ombrophilous Forest Research Articles

Assessing the Economic Impact of Forest Management in the Brazilian Amazon Through Real Options Analysis

Reduced-impact logging is a key aspect of sustainable forest management in the Brazilian Amazon. Real Options Analysis (ROA) improves the evaluation of certified projects, increases their value, and supports investor confidence. This study evaluates the economic viability of a forest management investment project in certified areas of the Brazilian Amazon, using ROA to incorporate uncertainty and managerial flexibility into the decision-making process. The analysis focused on an Ombrophilous Dense Forest in its first cutting cycle, with 30 species of diameter at breast height ≥ 50 cm and a projected activity period of 30 years. Timber value was modeled using the mean reversion motion, and a binomial decision model was applied, incorporating options such as deferral, abandonment, and interruption. The deferral option should be exercised with a 100% probability, both in the joint calculation scenario and in separate analyses, highlighting the significant value of this managerial flexibility. In addition, when analyzed using ROA, the value of the project increased by 105% (USD 91,784,176) compared to the traditional net present value approach. The forest management investment project in the Brazilian Amazon is economically viable and the application of ROA reveals significant value added, demonstrating the importance of incorporating flexibility into investment decisions.

TWO HUNDRED YEARS OF BOTANICAL RECORDS: LEGUMINOSAE TREE SPECIES DIVERSITY IN A BRAZILIAN ATLANTIC FOREST HOTSPOT

The Reserva Biológica do Tinguá (REBIO Tinguá) is a protected area in the state of Rio de Janeiro comprising around 26,000 ha of Brazilian Atlantic Forest. We present an updated floristic inventory of Leguminosae tree species in the REBIO Tinguá. Pre-existing herbarium collections and field expeditions carried out in 2021 and 2022 were used as the basis for (i) assembling a comprehensive taxonomically verified checklist of the legumes, (ii) revealing species distribution patterns across the Submontane (‘tingua_s’) and Montane/High Montane Dense Ombrophilous (‘tingua_ma’) Forest physiognomies of the REBIO Tinguá, and (iii) an UPGMA-based floristic similarity analysis to compare the REBIO Tinguá with 28 other areas of Atlantic Forest in Rio de Janeiro state. Of the total 67 legume tree species identified, 35 are endemic to the Atlantic Forest, six are new occurrences for the area, and seven are listed under different threat categories. The legume-based similarity analysis showed clusters that largely reflect the environmental heterogeneity of the region, where ‘tingua_ma’ is grouped with Macaé de Cima, Mendanha and Santo Aleixo, while ‘tingua_s’ is grouped with Paraty Mirim, Pedra Branca, Poço das Antas, Tijuca and REBIO Union. Our study shows that new records can be made for the REBIO Tinguá, despite it being one of the most thoroughly inventoried areas in the state. Our results reinforce the importance of the REBIO Tinguá for biodiversity conservation, because of its great extent, altitudinal amplitude, and above all, its central position in the state, integrating the Mosaico Central Fluminense and the Tinguá–Bocaina biodiversity corridor.

Origin of the Campinaranas and Ecological Resilience Patterns: Analysis in Silves-Amazonas-Brazil

The research addresses the origin of the Campinaranas and the primary characteristics of this Amazonian landscape. The results presented herein are part of a doctoral thesis entitled: The Relationship between the Campinaranas Forests and the Ecological Resilience Process (Amazon, Brazil). The Campinaranas are atypical landscapes in the Amazon, dispersed in the Dense Ombrophilous Forest. They have sandy soils and small-scale vegetation. Various methodological procedures were used to evidence the Campinaranas' origin, based on field research, in which five sample collection points were selected in the Sanabani river basin in Silves, Amazonas -Brazil. These samples enabled an understanding of the main particularities of the Campinaranas (soil, vegetation, and human interventions) through soil analysis (soil chemistry and physics), comparative analysis, a vegetation inventory, and classification of the environment. The main objectives were: 1) To quantify the soil and vegetation variables of the Campinaranas in the study area; 2) To identify the fundamental interventions in the Campinaranas areas and the origin of this environmental system. The results demonstrate that the Campinaranas are diverse environments resulting from the forest's ecological resilience after an intervention event. The analyses verify that environmental changes modify the soil granulometry and, consequently, the entire ensuing structure.

Análise sobre o uso da terra no município de Gandu, Baixo Sul Baiano: Interação da cultura cacaueira com o bioma de Mata Atlântica

The present research aims to analyze the land use in the municipality of Gandu, in the Southern Bahian Lowlands, and the interaction of the cocoa crop with the Atlantic Forest biome. As a methodology, theoretical and empirical surveys were carried out on phytophysiognomic diversity, land use and some species of the Atlantic Forest biome, as well as their agroecological relationship with cocoa crop. Interviews were made and questionnaires were applied on the relationship between cocoa production and the forest, field visits to cocoa farms, photographs of the forest (camera), cocoa cultivation in the municipality and also the identification of species with greater incidence in the landscape, use of the GIS (Geographic Information System) system as a geographic database for the analysis of geospatial data and generation of a map of location and land use. The results obtained reveal that most of the interviewees say that there has been degradation in the vegetation cover of the biome in recent decades, the vast majority say that the preservation of the forest is associated with the cultivation of cocoa, and that without it, the devastation of the forest was greater for the implementation of other crops such as cattle raising, bananas and subsistence crops at the time of the witches' broom. The fieldwork, together with the satellite images, shows that the forest is quite altered and this is associated with the use of the land: called capoeirinha, capoeira and capoeirão and more or less preserved fragments of the native ombrophilous forest in mountainous areas. It is concluded that the crop relationship is the most recurrent and oldest land use practice in the municipality of Gandu-Ba and that even with the changes in the dense ombrophilous forest, the cocoa crop contributes to the conservation of the Atlantic Forest biome through its Agroforestry System (AFS) that conserves part of the forest for exotic shading.

Change in a terra firme dense ombrophilous forest after logging in the brazilian Amazon (2006-2016)

The effective management of disturbed forests requires adequate knowledge of forest dynamics. In this study, we assessed the changes in a managed forest using 18 permanent 1 ha plots located in a ‘terra firme’ tropical rainforest in the Eastern Amazon (Paragominas, Brazil). All individuals with a diameter at breast height (DBH) ≥ 20 cm were evaluated in two separate assessments conducted in 2006 and 2016. The results show that, ten years after logging, the managed forest exhibits an imbalance between recruitment (1.54% per year) and mortality (2.23% per year) rates, indicating that it is still in the process of recovering its structure. Nevertheless, biomass tended to increase after logging (28.49 tons per hectare). The characteristics of these changes suggest that the forest is undergoing a silvigenetic process driven by the effects of logging. Furthermore, our observations indicate that the forest remains active and has sufficient potential for new timber production at the end of the cutting cycle, considering the same species and tree sizes.

Clarifying the dubious identity of Vanilla dubia Hoehne (Orchidaceae) and its relatives

Background and aims – Brazil has more than 40 species of Vanilla. Some taxa have been considered to be obscure since they are known only from the type specimen. This is the case of some south-eastern Brazilian species such as V. dubia and V. dungsii. While studying the diversity of Brazilian Vanilla, plants of an unidentified species were found in Ubatuba, São Paulo, Brazil. After flowering, it was confirmed that the species corresponded to the obscure V. dubia. Material and methods – A redescription of V. dubia is provided and a morphological comparison with the related taxa V. dungsii and V. paulista is presented. An illustration of V. dubia is provided, and its geographic distribution is presented. The identity of the enigmatic V. dungsii is also clarified based on holotype examination and on images of living specimens. Key results – Vanilla dubia is recognized by its coriaceous leaves with prominent vascular bundles in transverse section, by its white 3-lobed labellum with yellow lobes and undulate-crenulate margins, and by its tuberculate appendages on the apical portion of the labellar crest. Morphological characteristics suggest a close relationship of V. dubia with V. dungsii and V. paulista.Vanilla dubia occurs in the Dense Ombrophilous Forest, while V. paulista occurs in the Semi-deciduous Mesophytic Forest, and V. dungsii is endemic to the Dense Montane Ombrophilous Forest. Based on current data, V. dubia is assessed as Endangered. Conclusion – Evaluation of vegetative and reproductive characters from living and herbaria specimens is crucial to understanding the identity and species boundaries of Vanilla. The data presented here show that the species occurring in the Atlantic Forest, V. dubia and V. dungsii, are more closely related to each other than to V. paulista, which occurs in Semi-deciduous Mesophytic Forests. A proposal to change the status of V. dungsii as a subspecies of V. dubia can be further considered.

A new species of Psidium and notes on Neomitranthes from the state of São Paulo, Brazil

Psidium riobonito, a new species of Myrtaceae from the Atlantic Forest of the northeastern portion of the Brazilian state of São Paulo, was collected in High Montane Dense Ombrophilous Forest and is described here. Morphological characters assign the new species to Psidium sect. Apertiflora, due to its leaves with brochidodromous veins, marginal vein parallel to the margin, inflorescences in auxotelic racemes, flowers with open buds with 5 calyx lobes, in addition to dark purple fruits when ripe, with few seeds. Psidium riobonito is morphologically close to P. involutisepalum and P. myrtoides, but differs by the marginal veins 2 to 5 mm from the margin (vs. 1 to 2 mm in P. myrtoides and 1.5 to 2 mm in P. involutisepalum), glabrous or glabrescent leaves when mature (vs. pubescent or sparsely pubescent mainly along the midrib on the abaxial surface in P. myrtoides and sparsely pubescent in P. involutisepalum), pedicels 14–26 mm long (vs. 3–12 mm in P. myrtoides and 8–10 mm in P. involutisepalum). The relationship of P. riobonito to morphologically close species, comments on its taxonomy, ecology and informal conservation status, and a table with morphological characteristics of P. sect. Apertiflora are also provided. We also present for the first time the descriptions of the fruits of Neomitranthes capivariensis and N. pedicellata.

Lianas in tropical dry seasonal forests have a high hydraulic efficiency but not always a higher embolism resistance than lianas in rainforests.

Lianas have higher relative abundance and biomass in drier seasonal forests than in rainforests, but whether this difference is associated with their hydraulic strategies is unclear. Here, we investigate whether lianas of seasonally dry forests are safer and more efficient in water transport than rainforest lianas, explaining patterns of liana abundance. We measured hydraulic traits on five pairs of congeneric lianas of the tribe Bignonieae in two contrasting forest sites: the wet 'Dense Ombrophilous Forest' in Central Amazonia (~2 dry months) and the drier 'Semideciduous Seasonal Forest' in the inland Atlantic Forest (~6 dry months). We also gathered a broader database, including 197 trees and 58 liana species from different tropical forests, to compare hydraulic safety between habits and forest types. Bignonieae lianas from both forests had high and similar hydraulic efficiency but exhibited variability in resistance to embolism across forest types when phylogenetic relationships were taken into account. Three genera had higher hydraulic safety in the seasonal forest than in the rainforest, but species across both forests had similar positive hydraulic safety margins despite lower predawn water potential values of seasonal forest lianas. We did not find the safety-efficiency trade-off. Merging our results with previously published data revealed a high variability of resistance to embolism in both trees and lianas, independent of forest types. The high hydraulic efficiency of lianas detected here probably favours their rapid growth across tropical forests, but differences in hydraulic safety highlight that some species are highly vulnerable and may rely on other mechanisms to cope with drought. Future research on the lethal dehydration threshold and the connection between hydraulic resistance strategies and liana abundance could offer further insights into tropical forest dynamics under climatic threats.

Wood Basic Density in Large Trees: Impacts on Biomass Estimates in the Southwestern Brazilian Amazon

Wood basic density (WD) plays a crucial role in estimating forest biomass; moreover, improving wood-density estimates is needed to reduce uncertainties in the estimates of tropical forest biomass and carbon stocks. Understanding variations in this density along the tree trunk and its impact on biomass estimates is underexplored in the literature. In this study, the vertical variability of WD was assessed along the stems of large trees that had a diameter at breast height (DBH) ≥ 50 cm from a dense ombrophilous forest on terra firme (unflooded uplands) in Acre, Brazil. A total of 224 trees were sampled, including 20 species, classified by wood type. The average WD along the stem was determined by the ratio of oven-dry mass to saturated volume. Five models were tested, including linear and nonlinear ones, to fit equations for WD, selecting the best model. The variation among species was notable, ranging from 0.288 g cm−3 (Ceiba pentandra, L., Gaertn) to 0.825 g cm−3 (Handroanthus serratifolius, Vahl., S. Grose), with an average of 0.560 g cm−3 (±0.164, standard deviation). Significant variation was observed among individuals, such as in Schizolobium parahyba var. amazonicum (H. ex D.), which ranged from 0.305 to 0.655 g cm−3. WD was classified as low (≤0.40 g cm−3), medium (0.41–0.60 g cm−3), and high (≥0.61 g cm−3). The variability in WD along the stem differs by wood type. In trees with low-density wood, density shows irregular variation but tends to increase along the stem, whereas it decreases in species with medium- and high-density wood. The variation in WD along the stem can lead to underestimations or overestimations, not only in individual trees and species but also in total stocks when estimating forest biomass. Not considering this systematic bias results in significant errors, especially in extrapolations to vast areas, such as the Amazon.

Different Species Proportions Influence Silvicultural Heterogeneity of Trees in a Restoration of a Ombrophilous Dense Forest in Lowlands

In order to generate strategies for the use of native species for ecological restoration, this paper presents the effects resulting from planting with facilitating tree species, in different proportions, after 13 years of forest restoration, in an area previously used for cattle buffaloes. The implantation was carried out in the Ombrophilous Dense Forest in the Lowlands, in the Atlantic Rainforest biome of the coastal plain of the state of Paraná and consisted of the plantation of 10 native species, distributed in two treatments: equal (A) and unequal (B) proportions of trees per species. After conducting a forest census, it was identified that the silvicultural expression of the facilitating tree species in the treatments differed significantly, and proportion A contributed to a scenario with greater silvicultural heterogeneity in the areas, which may be beneficial to the evolution of the ecological dynamics of the forest restoration process. In addition, the monitoring of Alchornea glandulosa, Inga edulis, and Myrsine coriacea expressed better development in the area and high resilience to the environmental adversities arising from the cattle ranching activity previously carried out, especially in relation to invasive grasses; therefore, they are recommended for use in the forest restoration of associated ecosystems.

A new species of Mollinedia (Monimiaceae, Laurales) from the Quadrilátero Ferrífero, Brazil.

Monimiaceae comprises approximately 26 genera and 250 species, with a pantropical distribution, predominantly occurring in humid forests. In Brazil, it is represented by five genera and 47 species, most of which are found in the Atlantic Forest, particularly in dense ombrophilous forest. Nevertheless, studies on this family in other biomes and vegetation types in Brazil are still scarce. The Quadrilátero Ferrífero (QF), a region located in the state of Minas Gerais, exhibits high plant species richness and endemism. During collections and analysis of herbarium materials from this region, some specimens of Mollinedia caught our attention due to a combination of characteristics that do not match those of any described species within the genus. For this reason, we describe this new taxon and assess its risk of extinction. Additionally, we review the occurrences of Monimiaceae in the QF and provide maps of its geographical distribution. With the description of this new species, the region now hosts eight species of Monimiaceae, two from the genus Macropeplus and six from Mollinedia. The new species is the first endemic species of the Monimiaceae family to be described in the QF. Concerning the extinction risk assessment, the new species was assessed as critically endangered.

Recruitment models after reduced impact logging in the Amazon rainforest

Recruitment models in rainforests are important for studies on forest management sustainability and can guide the assessment of remaining stocks and timber harvesting. Therefore, the objective of this study was to estimate recruitment after Reduced Impact Logging (RIL) by using two categories of models: a distance-independent individual-tree model (ITM) and a matrix model of forest dynamics or transition matrix (TMM). Data from continuous inventories conducted in a Dense Ombrophilous Forest in Paragominas, Pará state, Brazil, were utilized. Two transects of 9 ha each were installed at an area with Reduced Impact Logging, the data was collected in 2005 (nine months after logging), then in 2006, 2008, 2010 and 2012. Considering a period of 8 years after RIL, the individual tree-based model and transition matrix give consistent predictions of the recruitment in the study area. However, we observed slight superiority by the ITM, which presented values closer to the real ones for the total number of trees per hectare.

Functional traits and water-transport strategies of woody species in an insular environment in a tropical forest.

Plants survive in habitats with limited resource availability and contrasting environments by responding to variation in environmental factors through morphophysiological traits related to species performance in different ecosystems. However, how different plant strategies influence the megadiversity of tropical species has remained a knowledge gap. We analyzed variations in 27 morphophysiological traits of leaves and secondary xylem in Erythroxylum pulchrum and Tapirira guianensis, which have the highest absolute dominance in these physiognomies and occur together in areas of restinga and dense ombrophilous forest to infer water-transport strategies of Atlantic Forest woody plants. The two species presented different sets of morphophysiological traits, strategies to avoid embolism and ensure water transport, in different phytophysiognomies. Tapirira guianensis showed possible adaptations influenced by phytophysiognomy, while E. pulchrum showed less variation in the set of characteristics between different phytophysiognomies. Our results provide essential tools to understand how the environment can modulate morphofunctional traits and how each species adjusts differently to adapt to different phytophysiognomies. In this sense, the results for these species reveal new species-specific responses in the tropical forest. Such knowledge is a prerequisite to predict future development of the most vulnerable forests as climate changes.

Eltroplectris paranaënsis: a new species of Spiranthinae (Orchidaceae) from the nebular Atlantic Rain Forest

During a field expedition to the Serra do Mar in the state of Paraná, a new species of Spiranthinae was found, which occurs as a humicolous in the understory of the Upper Montane Dense Ombrophilous Forest, also called Cloud Forest. Phylogenetic analysis of the Stenorrhynchos clade, in which the genus is inserted, using nuclear internal transcriber spacer data, confirms that the new species belongs to the genus Eltroplectris with high support, and it is a sister to the species E. triloba and E. schlechteriana. Eltroplectris paranaënsis can be recognized and differentiated from congeners by its small habit, leaves with a narrow-elliptical-lanceolate blade, parviflorous inflorescence, light-green and white flowers, and the trilobed lip with an entire margin.

Dormancy in seeds of brazilian cerrado and dense Ombrophilous forest

The Cerrado and the Dense Ombrophilous Forest are important brazilian biomes that together cover more than half of the country's territory. They have a vast and rich plant diversity which often has a block in the germination process called dormancy. Dormancy can be defined as an obstruction in the germination of viable and intact seeds, even when all the favorable conditions are present. This work aimed to verify, through a literature survey, the occurrence of dormancy in seeds of plant species of the Brazilian Cerrado and Dense Ombrophilous Forest, comparing its occurrence between ecological groups of species, biomes and types of dormancy. The results showed that in Cerrado dormancy was observed in 56% of the species, whereas in Dense Ombrophilous Forest this number reduces to 42%. These data revealed an association between the presence of dormancy and the Cerrado. Also, in this biome, it was possible to verify a higher occurrence of physical dormancy in the seeds, with up to 63% of its dormant species presenting this type of dormancy. Pioneer species of Cerrado exhibited a greater dormancy percentage when comparing to climax, while this fact was not noticed in the forest, which resulted in an association between the ecological group of pioneer species from Cerrado and the dormancy process. These results show that dormancy may be related to more arid biomes and physical dormancy appears to be the most common type in these environments. Moreover, dormancy seems to be correlated with pioneer species of Cerrado, but not Forest

Dormancy in seeds of brazilian cerrado and dense Ombrophilous forest

The Cerrado and the Dense Ombrophilous Forest are important brazilian biomes that together cover more than half of the country's territory. They have a vast and rich plant diversity which often has a block in the germination process called dormancy. Dormancy can be defined as an obstruction in the germination of viable and intact seeds, even when all the favorable conditions are present. This work aimed to verify, through a literature survey, the occurrence of dormancy in seeds of plant species of the Brazilian Cerrado and Dense Ombrophilous Forest, comparing its occurrence between ecological groups of species, biomes and types of dormancy. The results showed that in Cerrado dormancy was observed in 56% of the species, whereas in Dense Ombrophilous Forest this number reduces to 42%. These data revealed an association between the presence of dormancy and the Cerrado. Also, in this biome, it was possible to verify a higher occurrence of physical dormancy in the seeds, with up to 63% of its dormant species presenting this type of dormancy. Pioneer species of Cerrado exhibited a greater dormancy percentage when comparing to climax, while this fact was not noticed in the forest, which resulted in an association between the ecological group of pioneer species from Cerrado and the dormancy process. These results show that dormancy may be related to more arid biomes and physical dormancy appears to be the most common type in these environments. Moreover, dormancy seems to be correlated with pioneer species of Cerrado, but not Forest

Atlantic Forest Ecosystems: Are There Significant Differences When Compared at the Same Stage of Regeneration?

For the monitoring and assessment of Atlantic Forest ecosystems, key indicators of the regeneration stage are considered. However, the current classification of these stages by experts does not consider the possible differences among such ecosystems. In order to test the hypothesis of significant differences, Atlantic Forest ecosystems in southern Brazil were compared at the same stage (initial, medium, and advanced stages of regeneration). An extensive database of the floristic forest inventory of Santa Catarina state, southern Brazil, with 460 sampling units, was used, addressing the seasonal deciduous forest (SDF), dense ombrophilous forest (DOF), and mixed ombrophilous forest (MOF). The regeneration stage of each sample unit was previously classified by experts using five key indicators (basal area per hectare—BA/ha; number of individuals per hectare—N/ha; number of species—S; Shannon biodiversity index—H’; and diameter at breast height—DBH). The Kruskal–Wallis method and pairwise multiple comparisons based on Dunn’s procedure were applied, considering two-way tests with 5% significance, and 95% power. The statistical tests confirmed the research hypothesis, namely, that the key indicators had significant differences in the later regeneration stages of Atlantic Forest ecosystems. For instance, S in DOF was statistically higher (p < 0.001) than in MOF and SDF (44 ± 9); N in SDF was significantly lower (394 ± 248 at mid-stage) compared to MOF (475 ± 233) and DOF (545 ± 173); and H’ showed increasing differences towards more advanced stages. Considering that the stage of forest regeneration is the main criterion for decision-making between suppression and conservation of forest ecosystems, the results achieved should support the review of current procedures applied to the classification of successional stages. Given the demonstrated differences, in the next steps of research, we will evaluate and propose specific standards for each Atlantic Forest ecosystem, i.e., intervals of discriminating values for the key indicators applicable to this biome.

Potential cultivation areas of Euterpe edulis (Martius) for rainforest recovery, repopulation and açai production in Santa Catarina, Brazil

Euterpe edulis is an endangered palm species that provides the most important non-timber forest product exploited in its natural habitat, the Brazilian Atlantic Forest hotspot1,4. From 1991 to 2017, pasturelands, agriculture, and monoculture of tree plantations were responsible for 97% of Atlantic Forest deforested areas in Brazil and Santa Catarina was one of the Brazilian states with the greatest loss of forest area14. In the last decade, E. edulis fruits reached their highest commercial value, producing the southeastern equivalent of Amazonian ‘‘açai’’ (Euterpe oleracea)5,7,8. As a shade-tolerant species, E. edulis adapts very well to agroforestry systems8,10. To evaluate potential areas for cultivation of E. edulis through agroforestry systems, we developed and applied a spatial model for mapping suitable areas. To accomplish this, we analyzed multisource biophysical data and E. edulis distribution data from the Forest Inventory of Santa Catarina. We identified two areas with potential occurrence of the species, one in the domains of coastal Dense Ombrophilous Forest where the species is more common and another in the domains of inland Deciduous Seasonal Forest where its occurrence was suspected, but not proven, until 2021. Today, Deciduous Seasonal Forest is the most fragmented and impacted by agriculture. Our model, together with confirmed areas of occurrence, indicates that deciduous seasonal forest region should be prioritized for production and recovery of E. edulis through agroforestry systems.

GEOSPATIAL DISTRIBUTION OF FOREST SPECIES IN THE BOTANICAL GARDEN OF RECIFE, PERNAMBUCO, BRAZIL

The adoption of appropriate strategies for the conservation and management of forest ecosystems associated with the Atlantic Forest depends on understanding the pattern of spatial distribution of forest species, mainly in protected areas. Thus, this study aimed to evaluate the geospatial distribution of forest species in a fragment of Atlantic Forest (Lowland Dense Ombrophilous Forest) in the Botanical Garden of Recife, Pernambuco, Brazil. The phytosociological study was carried out by the plot method, with 40 plots of 10 m x 25 m, systematically distributed, where all living individuals that showed circumference at 1.3 m above the ground ≥ 15 cm were identified and georeferenced. To identify the existence of floristic similarity between the plots, the obtained data were subjected to hierarchical cluster analysis. The spatial variability of forest species was characterized using geostatistical analysis. The data were interpolated by kriging, followed by the construction of thematic maps of spatial distribution. Hierarchical cluster analysis revealed the formation of two groups of plots. The forest species Artocarpus heterophyllus, Dialium guianense, Helicostylis tomentosa, Hevea brasiliensis, Pouteria durlandii and Thyrsordium spruceanum showed spatial dependence. The use of geostatistics allowed visualizing the spatial distribution arrangements and identifying the concentration sites of these species. Information on the geospatial distribution of forest species can be used for the preservation, conservation and management of forest remnants.

Diametric Growth of a Forest under Reduced-Impact Logging in the Eastern Region of the Brazilian Amazon

Growth is a component of forest dynamics that encompasses changes in species composition, interactions between species, and stand structure. We evaluated the effect of the presence of lianas, crown shape, and light exposure on the periodic annual increment of trees (PAI) in two phytophysiognomies: the ombrophilous dense forest and the ombrophilous open forest with lianas. This study was conducted in the eastern Brazilian Amazon in 13 permanent monitoring plots of 50 m × 50 m (2500 m2) in the same annual production unit. The area has been subjected to reduced-impact logging from 2014 to 2016. The increment in tree diameter varied significantly between both forests (opens forests: 1.28 cm yr−1; dense forests: 0.82 cm yr−1). Light exposure influenced the increment in tree diameter in the ombrophilous open forest with lianas, while the crown shape and light exposure significantly affected the ombrophilous dense forest. Our study emphasizes the usefulness of the periodic annual increment in exploring the differences between contrasting phytophysiognomies in a single annual production unit in the Brazilian Amazon that is subject to reduced-impact logging.