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Spondias tuberosa Arruda (Anacardiaceae), popularly known as umbuzeiro or imbuzeiro, is a fruit tree native to the semiarid region of Brazil. The extractive harvesting of its fruits contributes significantly to the economy, generating an annual revenue of approximately $4,2 million. The present study aimed to assess the spatial pattern, allometric variations, fruit measurements, and genetic diversity of trees within a remaining forest of the Caatinga biome, with a focus on intrapopulation analysis. We used intersimple repeated sequence markers and the second-order function density of neighbours to determine the genetic and spatial structure. The density of neighbours was highest within a 10-meter radius. Biometric analyses revealed average fruit lengths of 31.12 mm (±0.22), diameters of 28.68 mm (±0.25), and fresh masses of 15.56 g (±0.33). Diaspores exhibited an average length, diameter, and thickness of 19.27 mm, 13.95 mm, and 11.14 mm, respectively, with a fresh mass of 2.28 g. Notably, the fresh mass demonstrated the highest coefficient of variation. Ten molecular markers were selected, generating 103 highly polymorphic loci (99.03%) with an average informative content of 0.45. Nei’s diversity index (0.37) and Shannon’s index (0.55) indicated moderate genetic diversity. Furthermore, Bayesian analysis revealed a population structure with two distinct genetic groups. The Infinite Allele and Mutation Step Models suggested a significant historical decline in population size, indicative of a genetic bottleneck. As a result, proactive in situ conservation strategies, including establishing protected natural areas, become essential, considering the socioeconomic significance of the species. Additionally, it is recommended to establish germplasm banks for ex situ conservation and the development of managed cultivation initiatives to reduce the pressure on native populations of S. tuberosa caused by extraction.

Amburana cearensis (Fabaceae) is a native tree of the Brazilian northeastern semiarid region, which has considerable economic, medicinal, and social importance, especially in the Caatinga biome. This study aims to identify the scientific knowledge generated about the pharmacological applicability of the species. We analyzed scientific works on the widespread pharmacological use of A. cearensis, adopting the scientometric research method. The medicinal properties were classified according to the uses mentioned in the manuscripts, considering body systems and treated symptoms. They were associated with the International Classification of Diseases and Related Health. We identified a total of 86 articles addressing the medicinal potential of the species, distributed in 57 journals published between 2005 and 2023. There was a significant increase in publications during the period evaluated. Also, the species has been widely used in traditional medicine, which has attracted new studies, especially experimental ones focusing on unraveling its pharmacological potential. One trend observed was a significant geographic bias, since most of the studies investigated were carried out by researchers linked to Brazilian institutions located mainly in the northeast. This region includes the largest number of species occurrence points, explaining the interest of these institutions in recognizing the biological potential of their local or regional flora. In-depth investigations into the medicinal properties and secondary metabolites produced by A. cearensis should continue so that its therapeutic benefits are fully understood. However, it is necessary to link research into chemical and pharmacological properties with consideration of the importance of sustainable management of the species, since it faces risks of extinction. We acknowledge that an earlier version of this manuscript was presented as a dissertation by Ayane Emília Dantas dos Santos to fulfil the academic requirements for the degree of Forest Science at the Federal University of Rio Grande do Norte. The dissertation is available for reference at the following link: https://repositorio.ufrn.br/jspui/bitstream/123456789/46918/1/Cienciometriaetnobotanicamodelagem_Santos_2022.pdf.

Invasive species threaten crops and ecosystems worldwide. Therefore, we sought to understand the relationship between the geographic distribution of species populations and the characteristics of seeds using new techniques such as seed image analysis, multivariate analysis, and machine learning. This study aimed to characterize Leucaena leucocephala (Lam.) de Wit. seeds from spatially dispersed populations using digital images and analyzed their implications for genetic studies. Seed size and shape descriptors were obtained using image analysis of the five populations. Several analyses were performed including descriptive statistics, principal components, Euclidean distance, Mantel correlation test, and supervised machine learning. This image analysis technique proved to be efficient in detecting biometric differences in L. leucocephala seeds from spatially dispersed populations. This method revealed that spatially dispersed L. leucocephala populations had different biometric seed patterns that can be used in studies of population genetic divergence. We observed that it is possible to identify the origin of the seeds from the biometric characters with 80.4% accuracy (Kappa statistic 0.755) when we applied the decision tree algorithm. Digital imaging analysis associated with machine learning is promising for discriminating forest tree populations, supporting management activities, and studying population genetic divergence. This technique contributes to the understanding of genotype-environment interactions and consequently identifies the ability of an invasive species to spread in a new area, making it possible to track and monitor the flow of seeds between populations and other sites.

ABSTRACT Handroanthus impetiginosus is a Brazilian native tree threatened by illegal logging that needs conservation strategies. Due to the need to obtain seeds of high genetic and physiological quality, this study aimed to select mother trees, aiming at the installation of Seed Collection Areas of H. impetiginosus. Therefore, the genetic diversity and physiological quality of seeds from 63 individuals of a natural population of H. impetiginosus in Rio Grande do Norte, Brazil, were evaluated. The molecular markers revealed that the studied population has high intrapopulation genetic diversity (Nei’s genetic diversity = 0.35; and Shannon index = 0.52). Subsequently, germination and seed vigor tests evaluated the physiological quality of seeds from 63 trees. Of this total, 45 individuals produced seeds of high and intermediate physiological quality. Therefore, individuals with a Nei’s genetic distance < 0.72 and germination greater than 50% can be selected as mother trees, and the population has the potential to propose a Seed Collection Area.

The growing extractive activity in forest areas, the inefficient use of management practices combined with the intensification of socioeconomic activities, are the main factors in the loss of biodiversity. In order to reduce environmental impacts, genetic characterization of populations allows to infer about their real situation. Thus, the present study aimed to perform an analysis of the genetic diversity of populations of Syagrus cearensis using ISSR markers. Populations AQU (Aquicultura), MTB (Mata do Bebo) and MOD (Mata Olho d´água) were sampled, totaling 53 individuals. ISSR markers generated a total of 61 loci. The AQU population had the highest polymorphism index (71%), followed by MTB (57%) and MOD (53%). AQU showed the highest index of genetic diversity, compared to the MTB and MOD populations. There was a high and significant genetic differentiation between populations. Bayesian analysis identified the existence of two groups (K = 2). The genetic bottleneck test was significant for the AQU and MOD populations, according to the SMM model. Thus, the populations of genetic diversity index close to the averages found for tropical species with a similar life history. The presence of a genetic bottleneck was detected in populations. The AQU population presented low sharing of genotypes with the others and should be prioritized in conservation activities.

Copernicia prunifera (Miller) H. E. Moore is a palm tree native to Brazil. The products obtained from its leaf extracts are a source of income for local families and the agroindustry. Owing to the reduction of natural habitats and the absence of a sustainable management plan, the maintenance of the natural populations of this palm tree has been compromised. Therefore, this study aimed to evaluate the diversity and genetic structure of 14 C. prunifera populations using single nucleotide polymorphisms (SNPs) identified through genotyping-by-sequencing (GBS) to provide information that contributes to the conservation of this species. A total of 1,013 SNP markers were identified, of which 84 loci showed outlier behavior and may reflect responses to natural selection. Overall, the level of genomic diversity was compatible with the biological aspects of this species. The inbreeding coefficient (f) was negative for all populations, indicating excess heterozygotes. Most genetic variations occurred within populations (77.26%), and a positive correlation existed between genetic and geographic distances. The population structure evaluated through discriminant analysis of principal components (DAPC) revealed low genetic differentiation between populations. The results highlight the need for efforts to conserve C. prunifera as well as its distribution range to preserve its global genetic diversity and evolutionary potential.

RESUMO O conhecimento da diversidade genética de espécies nativas é de grande valia quando se objetiva o melhoramento e a conservação de populações naturais. Neste sentido, o objetivodeste trabalho foi selecionar iniciadores ISSR (inter repetições de sequências simples) para Hancornia speciosa (Apocynaceae), assim como quantificar a variabilidade genética em uma população natural. Foramamostrados 15 indivíduos de uma população localizada em Natal-RN. Amostras de caule foram coletadas para a posterior extração do DNA. DNA. Para a seleção, 19 primers ISSR foram testados, dos quais seis foram eficientes, apresentando locos nítidos e em maior número (UBC 808; UBC 810; UBC 826; UBC 827; UBC 841 e UBC 842), totalizando 63 locos. Desses, apenas 30 (47,62%) apresentaram polimorfismo. O valor de PIC (conteúdo de informações polimórficas) para os primers selecionados atingiu a média de 0,37, variando de 0,26 a 0,44. A diversidade genética foi considerada baixa dentro da população, com o número de alelos observados (na =1,48), número de alelos efetivos (ne = 1,32), índice de diversidade de Nei (He = 0,18) e índice de Shannon (I = 0,26). Os padrões de diversidade alélica encontrados indicam a ocorrência de um gargalo populacional recente. A utilização de marcadores ISSR para Hancornia speciosa mostrou-se eficaz para a quantificação da diversidade genética dos indivíduos, servindo como aporte para estratégias e planos que visem à conservação e à manutenção da espécie.

Floral biology and pollinators of candeia (Eremanthus erythropappus) were analyzed in a natural population. We studied anthesis, flower morphology, stigmatic receptivity, pollen viability and floral visitors. The small flowers (10.17 mm in length) are pink, hermaphrodites and organized in dense capitula (mean = 29 flowers). We observed a large percentage of viable pollen (77.25%) and relatively scarce nectar availability for floral visitors (0.63 μL). The bees Apis mellifera and Trigona sp. were the most frequent visitors. The length of the bud, style and flowers varied significantly among plants. O objetivo deste trabalho foi examinar e documentar a biologia floral e os polinizadores da candeia (Eremanthus erythropappus) em uma população natural, sendo estudados a antese, a morfologia floral, a receptividade estigmática, a viabilidade de pólen e os visitantes florais. As flores pequenas (10,17 mm de comprimento) são cor de rosa, hermafroditas e organizadas em densos capítulos (média = 29 flores). Foi observada alta porcentagem de pólen viável (77,25%) e relativamente pouca disponibilidade de néctar para os visitantes florais (0,63 μL). As abelhas Apis mellifera e Trigona sp. foram os visitantes mais frequentes. Os comprimentos dos botões, estiletes e flores variaram significativamente entre plantas.

Em ecossistemas fragmentados, comuns no sul de Minas Gerais, os corredores de vegetação são elementos de grande importância ecológica para o fluxo gênico. Os corredores de vegetação na região de Lavras, MG, são estreitos (entre 3 e 6m), de vegetação secundária formada pela colonização de valas e interligam fragmentos remanescentes de vegetação primária. Nestes dois ambientes, é comum a ocorrência da espécie Myrcia splendens, que produz frutos de dispersão zoocórica. Objetivou-se, neste trabalho, a avaliação da estrutura genética espacial em microescala de M. splendens nos ambientes de fragmentos e nas suas conexões. Dez primers ISSR foram utilizados em 168 árvores distribuídas nos cinco fragmentos e em 104 árvores nos quatro corredores de vegetação, gerando um total de 70 locos polimórficos. A AMOVA mostrou que a maior parte da diversidade genética ocorre dentro das populações (96,49% nos fragmentos e 91,15% nos corredores). Nas formações primárias (F1 a F5) e nos corredores C1 e C2 os genótipos estão distribuídos de maneira aleatória. Nos corredores C3 e C4 observou-se estruturação genética espacial, com valores de coancestria positiva e significativa na primeira classe de distância, sendo os valores de Sp de 0,012 (P = 0,009) e 0,014 (P = 0,029), respectivamente.

The aim of this paper was to study the decomposition velocity of the sugar cane leaf in the own plantation in the Chã de Jardim Farm, belonging to Agrarian Sciences Center/UFPB-Areia, PB. It was used 10 g of dry leaves in litter bags measuring 30 cm x 20 cm, being these deposited in the soil superficial and in the depth of 15 cm, with biweekly collections during three months. A subplot design was used with 2 depths, 5 collection times and 3 repetitions. The largest decomposition rates happened in the subsuperficial treatment, mainly in the first 15 days, when it was lost 24.5% of the material, happening a stabilization soon after in the rate of disappearance of the biomass starting from the 30 days. The decomposition in the superficial and subsuperficial treatment followed a standard logarithmic with high correlation coefficient. In the surface, the decomposition rate was slower, having a decomposition peak to the 45 days with 24% of material loss and showing stability starting from 60 days. The superficial decomposition at the end of the experiment was the same percentile reached in the subsuperficial treatment before the 30 days, evidencing, therefore slower decomposition process and nutrients liberation for the soil in larger period.

Dimorphandra mollis é uma espécie nativa do Cerrado com grande potencial econômico e tem sido alvo de intensa exploração, principalmente de seus frutos por causa do princípio ativo do composto rutina, importante para a produção de fármacos. Algumas propostas têm surgido para uma coleta controlada desses frutos, de forma a minimizar a perda de diversidade genética, entretanto existem poucas informações sobre aspectos ecológicos e genéticos da espécie. Nesse sentido, realizou-se o estudo da estrutura genética por meio de marcadores aloenzimáticos, visando dar subsídios a propostas de conservação de populações naturais de D. mollis. Dez locos polimórficos foram utilizados para estimar as frequências alélicas referentes a 180 indivíduos, distribuídos em três populações naturais (Campina Verde, Vargem da Cruz e Pau de Fruta) no Município de Jequitaí, Norte de Minas Gerais, Brasil. Os resultados indicam alta diversidade genética da espécie ( ou = 0,463), sendo pequena a variabilidade genética entre populações ( > ou = 0,025). Foi verificada ausência de endogamia dentro das populaçõe s( ou = -0,018 ( 0,007). O fluxo gênico estimado no conjunto das populações foi alto, com igual a 4,0, e suficiente para contrapor os efeitos da deriva genética. a alta diversidade genética nas populações da espécie indica potencial para a conservação genética in situ e também para o seu manejo. As estratégias de manejo da espécie devem considerar o tamanho efetivo populacional, no intuito de manter os níveis de variabilidade genética observados e a regeneração natural nas áreas. Palavras-chave: Fava d'anta, Marcadores aloenzimáticos e Variabilidade genética.Dimorphandra mollis is a native species of Cerrado and has high economic value due to the active compound Rutin present in its fruit, which has made it a target of intense commercial exploitation. Some proposals to minimize the negatives genetic/physiological effects of exploitation have been proposed, but little is known about the ecology or genetic structure of natural populations of this species. To delineate conservation programs, it is necessary to elucidate the levels of genetic variation in local natural populations. The genetic variability was assessed using ten allozyme loci. The genetic structure of the species was carried out using a sample of 180 individuals distributed in three natural populations located in the North of Minas Gerais, Brazil. The results showed a high level of genetic diversity within the species ( or = 0.463). Analysis of genetic structure indicated that most of the genetic variability of D. mollis is within its natural populations with low difference among populations ( or = 0.025). Inbreeding within the populations ( or = -0.018) and among them ( or = 0.007) was insignificant. Gene flow among populations was or = 4.0, indicating to be enough to prevent the effects of genetic drift. The high genetic diversity index in these populations indicates potential for in situ genetic conservation and management. Management strategies for this species should take into consideration the effective population size in order to keep the high levels of genetic variability observed and allow natural regeneration in the areas.

Phylogeography has become a powerful approach for elucidating contemporary geographical patterns of evolutionary subdivision within species and species complexes. The aim of this paper was to evaluate the extracted quality of DNA and amplification of noncoding chloroplast DNA for phylogeography studies in Ficus bonijesulapens. The comparative analysis of protocol DNA extraction was based in the CTAB method and protocol from Mogg and Bond. DNA samples were assessed for successful PCR amplification of universal primers for the amplification of noncoding regions of cpDNA. Amplified DNA was separated by electrophoresis, stained with ethidium bromide and photographed under UV light. The protocol Moog e Bond produced the best DNA quality. This method will be used because it produces a high quality DNA in a short time and is less expensive. The primers HA, SG, BF, Q16, F32, FV, DT, CS and JA provided the strongest support for the inferred phylogeography, genetic diversity centers and for successful management in tree-conservation programmes.

Os objetivos deste trabalho foram analisar a dinâmica da maturação dos frutos e avaliar quantitativamente algumas características físicas dos frutos de Miconia albicans (Swartz) Triana em um remanescente de Floresta Estacional Semidecídua Montana. A atividade, intensidade e sincronia de 20 indivíduos foram analisadas em relação aos eventos de frutificação, correlacionando-os com as variáveis climáticas. Analisou-se a morfometria (comprimento, largura e massa) de 130 frutos de 10 indivíduos. A intensidade da fenofase de frutos maduros nas plantas correlacionou-se significativamente com a precipitação média do período (rS = 0,611; P < 0,05). A espécie possui número elevado de pequenas sementes por fruto ( = 28,05 ± 1,45 d.p.). O coeficiente de correlação entre a massa fresca do fruto e a da polpa foi de rS = 0,988 (P < 0,001), ou seja, a massa fresca do fruto é linearmente proporcional à quantidade de polpa. Esta contribui, em média, com 94% da massa fresca total do fruto, demonstrando a importância da espécie para os frugívoros. Os resultados indicaram o período de alta sincronia intrapopulacional das fenofases analisadas, o que pode ser útil na orientação da coleta de sementes visando à criação de bancos de germoplasma e produção de mudas para a recuperação de áreas degradadas.The aim of this study was to examine the dynamics of fruit maturation and quantitatively assess some physical characteristics of the fruits of Miconia albicans (Swartz) Triana in a remnant of Montane Seasonal Semideciduous Forest. The activity and synchrony of 20 individuals were analyzed in regard to the proportion of fruiting events, and to help to determine their correlation to abiotic factors. Morphometric traits (fruit length, diameter and mass) of 130 fruits from ten individuals were analyzed. The number of fruits maturing showed a significant correlation with the mean precipitation (rS = 0.611; P < 0.05). M. albicans presented a high number of small seeds per fruit ( = 28.05 ± 1.45 s.d.). The fresh mass of the fruit was approximately equal to the pulp mass (rS = 0.988; P < 0.05). Thepulp contributed with 94% of the total mass, demonstrating the potential importance of this species for frugivores. The results indicate the period of high intrapopulation synchrony of the studied phenophases, which can be a useful guide in the collection of seeds for germoplasm banks and recovery of degraded areas.

We studied patterns of genetic differentiation in a connected landscape with an interesting history of human habitat conversion that began two centuries ago, during the Brazilian colonization period. In the fragments of Brazilian Atlantic seasonal forest and corridors of secondary forest, Protium spruceanum is an abundant native, mass-flowering/insect-pollinated and bird-dispersed tree. Genetic diversity was analyzed from 230 individuals in five fragments (1 to 11.8 ha) and four corridors (460 to 1000 m length) using allozyme loci. We did not find evidence of inbreeding within fragments or corridors, but the proportion of heterozygotes () were significantly higher in fragments than in the secondary vegetation corridors, based on Goudet's G-test (P = 0.036). Genetic differentiation was low and no pattern of isolation by distance was detected. All fragments generally present low historical genetic differentiation with corridors that they are connected, indicating possible gene flow via seeds and pollen. Due to the consistently low differentiation observed among them and the absence of a significant reduction in gene diversity in second-growth forests, we conclude that corridors of second-growth forests would be an important alternative in the genetic connection of isolated forest fragments.Foram estudados os padrões de diferenciação genética em uma paisagem conectada com uma interessante história de conversão humana do habitat, que iniciou há dois séculos durante o período colonial do Brasil. Nos fragmentos de floresta estacional Atlântica e corredores de floresta secundária, Protium spruceanum é uma arbórea nativa abundante, com floração massiva, polinizada por insetos e dispersa por pássaros. A distribuição da diversidade genética foi analisada por meio de locos aloenzimáticos em 230 indivíduos em cinco fragmentos (1 a 11,8 ha) e quatro corredores (460 a 1000 m). Foi observada ausência de endogamia nos fragmentos e corredores, mas a proporção de heterozigotos () foi significativamente maior nos fragmentos do que nos corredores de vegetação secundária, conforme teste G de Goudet (P = 0,036). A diferenciação genética foi baixa e nenhum padrão de isolamento pela distância foi observado. Observou-se, em geral, menor diferenciação genética entre fragmentos e corredores vizinhos, indicando possível fluxo gênico por sementes e pólen. Assim, conclui-se que os corredores de floresta secundária podem ser uma alternativa na conexão genética de fragmentos isolados. Isto é assim consistente com a baixa diferenciação observada entre eles e na ausência de uma redução significante da diversidade genética nos corredores de floresta secundária.

Estudos de biometria de frutos e sementes são importantes para o entendimento da variabilidade existente nas espécies nativas. Apesar da importância ecológica e econômica de Talisia esculenta, não se conhecem as características biométricas dos frutos e não há informações sobre a emergência das plântulas. Objetivou-se caracterizar fisicamente frutos e sementes e estudar os efeitos do armazenamento sobre a emergência das plântulas. Analisou-se a biometria de 260 frutos e sementes. A emergência de plântulas foi avaliada a partir de sementes recém-coletadas e armazenadas por 15, 30 e 60 dias. As médias de massa de matéria fresca, comprimento e diâmetro dos frutos foram, respectivamente, 15,02 g, 32,59 mm e 26,33 mm e para as sementes 4,49 g, 25,08 mm e 13,62 mm. A massa de matéria fresca do fruto foi proporcional à quantidade de polpa (rS = 0,826; P < 0,05), indicando potencial para a seleção e melhoramento genético da espécie. A emergência das plântulas de Talisia esculenta obtidas de sementes recém-colhidas foi de 88%. As sementes possuem longevidade curta, com ausência de germinação após 30 e 60 dias de armazenamento.Studies of biometrical characteristics of fruits and seeds are important to understand the variability of native species. In spite of the ecological and economical importance of Talisia esculenta, the biometrical characteristics of fruits and information about seedling emergence are unknown. The aim of this paper was to characterize fruits and seeds biometrically and to determine the effects of storage on seedling emergence. The biometry of 260 fruits and seeds was analyzed. The seedling emergence of newly-collected seeds and after 15, 30, and 60 days of storage was evaluated. The means for the fruits fresh mass, length, and diameter were, respectively, 15.02 g, 32.59 mm, and 26.33 mm and for the seeds 4.49 g, 25.08 mm, and 13.62 mm. The fresh mass of the fruit was proportional to the pulp amount (rS = 0.826; P < 0.05). These values indicated the potential for the selection and genetic improvement of the species. The seedling emergence of newly-collected seeds was 88%. The seeds of Talisia esculenta have a short viability period, with absence of germination at 30 and 60 days of storage.

The area of the extreme North of Minas, due to your character ecotone, involves a large number of physiognomies and floristic complexes, but presumably unknown. Thus, the aim of this research was to determine the structure and the floristic composition of an area of arboreal caatinga in Juvenília, Minas Gerais. Hopes to contribute with information that allow, in the future, that is arrived to a classification it aims at and coherent of this vegetation. A sample of 10 (20x20m) plots was allocated (400m2), distributed on a parallel transect to the largest axis of the fragment, and to each 20 meters in this transect two plots were allocated, distanced 10 meters to each other, totaling 0.4ha. All the individuals were registered with CBH (circumference at breast height) > 10cm. In the structure, 36 species with diversity of H' = 2.4 and eqüability of J' = 0.67 were sampled, values middlemen if compared with results of other works developed at Brazilian deciduous seasonal forests. Acacia martii, Caesalpinia pluviosa, Eugenia uniflora and Tabebuia impetiginosa presented the largest values in all the structural parameters analyzed. This links with the high abundance of those species. The community's diameter distributions tended to the normality with smaller amount of individuals in the classes smaller and larger diametric.

Os objetivos deste estudo foram caracterizar e comparar a composição florística de oito fragmentos de Mata Seca Calcária e Caatinga Arbórea localizados no norte do Estado de Minas Gerais. O levantamento das espécies arbóreas foi realizado através de visitas periódicas aos fragmentos para coleta de material botânico. Nos oito fragmentos foram encontradas 114 espécies arbóreas pertencentes a 40 famílias botânicas. Dentre as 89 espécies encontradas nos fragmentos de Mata Seca, 37 (42%) foram peculiares a essa formação. No entanto, das 75 espécies amostradas nos remanescentes de Caatinga Arbórea, 25 (33%) ocorreram apenas nesses fragmentos. A análise de agrupamento sugere que a composição florística dos fragmentos é afetada pela fitofisionomia e pelas condições bioecológicas locais a que estes fragmentos estão submetidos. Além disso, a relação observada entre a área dos fragmentos e o número de espécies arbóreas, evidenciou que área é um bom indicador da riqueza de espécies arbóreas nos fragmentos florestais. Portanto, os resultados deste estudo indicaram que fatores históricos (fitofisionomia) e ecológicos (área dos fragmentos e ocorrência de perturbações antrópicas) constituem importantes elementos caracterizadores da composição e riqueza de espécies em fragmentos florestais do norte de Minas Gerais.The objective of this study was to characterize and compare the floristic composition of eight fragments of Calcareous Dry Forest and Arboreal Caatinga in the north of Minas Gerais State, Brazil. The survey of the tree species was performed by periodic visits to the fragments. We found 114 tree species belonging to 40 botanical families in the eight fragments. Of a total of 89 species found in the Calcareous Dry Forest fragments, 37 (42%) were typical of this formation. On the other hand, from the 75 species sampled in the Arboreal Caatinga remnants, 25 species (33%) occurred only in these fragments. The cluster analysis suggested that the floristic composition of the fragments was affected by the phytophysiognomy and by local bioecological conditions. The observed relationship between remnant area and tree species richness suggests that area was a good indicator of species richness in the forest fragments. The results of this study indicate that both historical (phytophysiognomy) and ecological (e.g., remnant area and occurrence of human disturbance) factors constitute important elements that determine the composition and richness of tree species of forest fragments in the north of Minas Gerais State.

Aspidosperma pyrifolium (Apocynaceae) and Caesalpinia pyramidalis (Fabaceae) share the same habitat in the Brazilian Caatinga domain. In this paper, we investigate the intra and inter-species interactions between these two plants using spatial pattern analysis among cohorts. The results showed that the adult trees of each species present higher densities at distances shorter than 9 m to 12 m. However, due to seed dispersal via autochory, we expected a more aggregate density for C. pyramidalis than A. pyrifolium as the later disperses seeds through anemochory. Difference in spatial aggregation among cohorts was not observed and therefore the results contradict the expectations of the Janzen-Connell hypothesis. It is likely that this is associated with anthropogenic factors in the past such as fire, animal husbandry and logging. Using a bivariate analysis of the neighborhood density, we also confirmed the significant coexistence between the two species. This coexistence could be explained by the process of positive interspecific interactions, such as facilitation, which is common in semi-arid regions under stressful conditions.

The objective of this study was to assess the genetic variability in two natural populations of Calophyllum brasiliense located along two different rivers in the state of Minas Gerais, Brazil, using RAPD molecular markers. Eighty-two polymorphic fragments were amplified using 27 primers. The values obtained for Shannon index (I) were 0.513 and 0.530 for the populations located on the margins of the Rio Grande and Rio das Mortes, respectively, demonstrating the high genetic diversity in the studied populations. Nei’s genetic diversity (He) was 0.341 for the Rio Grande population and 0.357 for the Rio das Mortes population. These results were not significantly different between populations and suggest a large proportion of heterozygote individuals within both populations. AMOVA showed that 70.42% of the genetic variability is found within populations and 29.58% is found among populations (ФST=0.2958). The analysis of kinship coefficients detected the existence of family structures in both populations. Average kinship coefficients between neighboring individuals were 0.053 (P

O objetivo desta pesquisa foi definir métodos práticos e de baixo custo para superar a dormência de sementes de Caesalpinia ferrea var. ferrea Mart. ex. Tul. (pau ferro, jucá), utilizando os seguintes tratamentos: T0: testemunha; T1: permanência de sementes na temperatura de 5 ºC por doze horas; T2: imersão em água a 100 ºC por dez segundos; T3: escarificação manual das extremidades durante dez segundos; T4: imersão em água a 100 ºC por dez segundos e permanência na temperatura de 5 ºC durante uma hora e T5: imersão em água na temperatura ambiente por 12 horas. O experimento foi desenvolvido durante oito dias e os tratamentos constaram de quatro repetições com 50 sementes, sendo avaliada a porcentagem de germinação, o índice de velocidade de germinação e o índice de brotamento. A escarificação manual com lixa nº 120 foi o tratamento que apresentou maior percentual de germinação, atingindo 95,5% já no segundo dia e terminando com 97%, seguido pela imersão em água a 100 ºC com 88,5% de germinação.

Knowledge of genetic structure at different scales and correlation with the current landscape is fundamental for evaluating the importance of evolutionary processes and identifying conservation units. Here, we used allozyme loci to examine the spatial genetic structure (SGS) of 230 individuals of Protium spruceanum, a native canopy-emergent in five fragments of Brazilian Atlantic forest (1 to 11.8 ha), and four ecological corridors (460 to 1 000 m length). Wright's 𝐹𝑆𝑇 statistic and Mantel tests revealed little evidence of significant genetic structure at the landscape-scale (𝐹𝑆𝑇=0.027; 𝑟𝑀=−0.051, 𝑃=.539). At fine-scale SGS, low levels of relatedness within fragments and corridors (𝑆𝑝=0.008, 𝑃>.05) were observed. Differences in the levels and distribution of the SGS at both spatial scales are discussed in relation to biological and conservation strategies of corridors and forest fragments.

Cattleya granulosa é uma orquídea ameaçada de extinção endêmica da região litorânea do Nordeste do Brasil. Este estudo teve como objetivos avaliar os níveis de agregação espacial em uma população preservada da espécie, em uma área de 4.225 m2 da unidade de conservação do Parque das Dunas, em Natal, RN. Além de caracterizar o hábito de vida da população, foi utilizada a função de segunda ordem da densidade de vizinhos (NDF) para determinar o padrão espacial nas classes de distância, com o uso do programa SpPack. Quanto ao hábito de vida, 73% das plantas eram epífitas (N = 136) e 27% terrestres (N = 50). As epífitas têm especificidade com um único forófito, indivíduos arbóreos de Eugenia spp. (Myrtaceae). C. granulosa possui padrão espacial agregado, com maior densidade de vizinhos (NDF) no raio de até 5 m. Esses dados sugerem um potencial dispersivo restrito e com influência direta sobre ações de conservação biológica da espécie.

ABSTRACT The continuing fragmentation of forests has been a threat to the maintenance of genetic resources. Genetic diversity is fundamental to the survival of species in natural environments in the long term, as well as being the basis for genetic improvement. The objective of this study was to evaluate the genetic diversity in natural populations of Hancornia speciosa and to contribute to the development of conservation strategies. We sampled 105 individuals of H. speciosa, distributed in seven populations. The ISSR (Inter-Simple Sequence Repeat) markers provided 70 loci, of which 81% were polymorphic. The mean genetic diversity of Nei (h) was 0.19, and the Shannon index (I) was 0.27. The h and I diversity indices ranged respectively from 0.16 to 0.24 in the PAD (Parque das Dunas) population and from 0.21 to 0.29 in MAC (Macaíba) population. Resulting from a Bayesian analysis, the genotypes were divided into four groups (K = 4). The allelic diversity patterns observed indicated the occurrence of the genetic bottleneck in all populations, according to the stepwise mutation model (SMM). The infinite allele model (IAM) revealed an imbalance between mutation and genetic drift only in the PAD population. Genetic conservation strategies for H. speciosa should cover each genetic group that was differentially structured. We recommend in situ conservation and the creation of germplasm banks, especially with the PAD population which demonstrated the lower genetic diversity and decreased effective population size according to the two mutational models.

Abstract This study aimed to estimate the genetic diversity of three Elaeis guineensis populations in Rio Grande do Norte state, as well as to verify the decreases in effective population size. The population with the highest polymorphism was MAT (Mata) with+ 57 loci (72%), followed by RIA (Riacho) with 54 loci (68%) and HOR (Horta) with 34 loci (43.03%). The RIA population was shown to be the most genetically diverse, with Nei (h = 0.28) and Shannon (I = 0.41) diversity indices. There was high genetic differentiation among populations (AMOVA, analysis of molecular variance = 42%), which was separated into three distinct genetic groups according to a Bayesian analysis. There was a significant population decrease (P < 0.05) for the HOR population in the IAM (infinite allele model) and SMM (stepwise mutation model), and for the RIA population in the IAM. The data obtained in this study may support ex-situ conservation projects for Elaeis guineensis, contributing to the selection of genotypes and their sustainable use.