VARIAÇÃO BIOMÉTRICA DE DIÁSPOROS DE BURITI (Mauritia flexuosa L.f. – ARECACEAE) EM VEREDAS EM DIFERENTES ESTÁGIOS DE CONSERVAÇÃO

http://dx.doi.org/10.5902/1980509816583‘Veredas’ (palm swamps) are phytophysiognomies of the ‘Cerrado’ biome, where the palm tree Mauritia flexuosa Lf. - buriti predominates on the tree layer; this species is considered the key resource for many animals, that use it as shelter and source of food, and also by the man who uses their leaves and fruits as raw material and food. Although, they occur in environments protected by the environmental legislation, human actions have affected the populations of ‘buritis’, by means of the decrease of individuals caused by deforestation, siltation and drainage of these areas. The objective of this study was to evaluate the morphometric parameters of fruits and seeds of Mauritia flexuosa from six different ‘veredas’ at different conservation stages, located in the Environmental Protection Area of ‘Pandeiros’ River (north of Minas Gerais state). In total, 1,800 fruits and seeds were sampled, they were measured in length, width and thickness and, after that, they were weighed. To detect differences in morphometric measurements of fruits and seeds among the sampling areas, the analysis of variance was done. There were differences in morphometric measurements between the studied areas, in which 87.5% of the highest averages occurred in areas with the slightest anthropic interventions. This fact is possibly related to the impacts occurred, besides the genetic variations that may fall upon the individuals.http://dx.doi.org/10.5902/1980509816583As veredas são fitofisionomias do bioma Cerrado, onde, no estrato arbóreo, predomina a palmeira arbórea Mauritia flexuosa L.f. - buriti, espécie considerada recurso-chave para muitos animais, que a utilizam como moradia e fonte alimentar, e também pelo próprio homem, que usa suas folhas e frutos como matéria-prima e alimento. Apesar de ocorrerem em ambientes protegidos pela legislação ambiental, ações antrópicas nas veredas têm afetado as populações do buriti, por meio da diminuição do número de indivíduos ocasionada por desmatamento, assoreamento e drenagem dessas áreas. O objetivo desse trabalho foi avaliar a morfometria de frutos e sementes de buriti oriundos de seis veredas em diferentes estágios de conservação, situadas na Área de Proteção Ambiental do Rio Pandeiros (norte de Minas Gerais). Foram amostrados, no total, 1800 frutos e sementes, que foram mensurados em comprimento, largura, espessura e peso. Para detectar diferenças das medidas morfométricas dos frutos e das sementes entre as áreas de coleta foi feita a análise de variância. Foram observadas variações nas medidas morfométricas de frutos e sementes entre as áreas de estudo, sendo que 87,5% das maiores médias ocorreram em áreas com menores intervenções antrópicas. Esse fato, possivelmente, está relacionado aos impactos ocorridos nas veredas, além das variações genéticas que podem incidir sobre os indivíduos

Efeitos de tratamentos pré-germinativos e do armazenamento na germinação e diásporos de Astronium fraxinifolium Schott (Anacardiaceae)

http://dx.doi.org/10.5902/1980509814577The goal of this study was to evaluate the germination and the storage capacity of Astronium fraxinifolium diaspores. Six pre-germination treatments were used in the experiment: control treatment (intact diaspores); diaspores immersed in water at room temperature (25º C) for 5 min; diaspores immersed in water at 70° C for 5 min; diaspores immersed in water at 100° C for 5 min; diaspores immersed in sodium hypochlorite solution (1:1000) for 2 min; and diaspores mechanically scarified with sandpaper #80. To evaluate storage conditions, we tested two different types of packaging (permeable paper bag and transparent glass jar) and two environmental conditions (cold chamber and room conditions), resulting in four treatments. The germination tests were performed for zero (control) and 60, 120, 180, 240, 300 and 360 days after storage. The effects of different treatments on germination and storage of diaspores were evaluated by ANOVA, followed by Tukey test. Regarding to pre-germination treatments, high germination rates were observed in the hypochlorite (98.0 ± 4.22%), control (97.0 ± 4.83%), water at room temperature (96.0 ± 6.99%) and water at 70º C (83.0 ± 29.08%) treatments. Thus, Astronium fraxinifolium diaspores do not present dormancy. During storage, the diaspores remained viable throughout the study period with high germination rates, except for the treatment in paper bags placed in the cold chamber, in which the diaspores lost their viability in the eighth month of storage. Therefore, this is not a recommended storage method for this species.http://dx.doi.org/10.5902/1980509814577Este trabalho teve como objetivo avaliar a germinação e a capacidade de armazenamento de diásporos de Astronium fraxinifolium. Para o experimento de germinação, utilizaram-se seis tratamentos pré-germinativos: tratamento controle (diásporos intactos); diásporos imersos em água a temperatura ambiente (25º C) por 5 min.; diásporos imersos em água a 70° C por 5 min.; diásporos imersos em água a 100° C por 5 min.; diásporos imersos em solução de hipoclorito de sódio (1:1000) por 2 min.; e diásporos escarificados mecanicamente, com lixa nº 80. Para determinar a capacidade de armazenamento, foram testados dois diferentes tipos de embalagem (saco de papel permeável e vidro transparente) e duas condições ambientais (câmara fria e condições de laboratório). Foram realizados testes de germinação antes do armazenamento (tempo zero) e após 60, 120, 180, 240, 300 e 360 dias de armazenamento. Os efeitos dos diferentes tratamentos pré-germinativos e das condições de armazenamento na germinação dos diásporos foram avaliados por meio da ANOVA, seguida do teste de Tukey. Em relação aos tratamentos pré-germinativos, foram observadas altas taxas de germinação nos tratamentos com imersão em hipoclorito (98,0 ± 4,22%), controle (97,0 ± 4,83%), imersão em água destilada a temperatura ambiente (96,0 ± 6,99%) e imersão em água aquecida a 70ºC (83,0 ± 29,08%). Dessa forma, os diásporos de Astronium fraxinifolium não apresentaram dormência. No armazenamento, os diásporos permaneceram viáveis durante todo o período de estudo, apresentando altas porcentagens de germinação, com exceção do tratamento em saco de papel acondicionado em câmara fria, que perdeu a viabilidade no oitavo mês de armazenamento, não sendo, portanto, um método de armazenamento recomendado para esta espécie

Gall-inducing arthropods in a Neotropical savanna area in the EPA of Rio Pandeiros (Bonito de Minas, MG, Brazil): effects of plant species richness and super-host abundance

Several plant-related factors can influence the diversity of gall-inducing species communities. In the present study we performed an inventory of gall-inducing arthropods and we tested if the plant species richness and the abundance of super-host plants (Copaifera oblongifolia) influenced positively in the diversity of gall-inducing arthropod species. The study was realized in an area of Neotropical savanna (cerrado sensu stricto) in the Environmental Protection Area (EPA) of Rio Pandeiros, Minas Gerais, Brazil. Host-plant species and gall-inducing arthropods were sampled in 18 10 × 10 m plots distributed in the vegetation. In total we found 40 arthropod gall morphotypes, distributed on 17 botanical families and 29 plant species. Cecidomyiidae (Diptera) induced the most arthropod galls (85%), and the plant family Fabaceae had the greatest richness of gall morphotypes (16). The plant species Copaifera oblongifolia and Andira humilis (Fabaceae) were the most important host species with five and three morphotypes, respectively. Galling species richness was not affected by none of explanatory variables (plant species richness and abundance of super-host plants). On the other hand, galling species per plant species was negatively affected by plant species richness and positively affected by abundance of super-host plants. This is the first study of arthropod-induced galls conducted in EPA of Rio Pandeiros, Brazil. Our results corroborate previous studies that highlight the importance of super-host plants for galling arthropod diversity on a local scale

EMERGÊNCIA E ESTABELECIMENTO DE PLÂNTULAS DE Guazuma ulmifolia LAM. EM FUNÇÃO DE DIFERENTES TRATAMENTOS PRÉ-GERMINATIVOS

This study tested the influence of mechanical and thermal scarification methods on emergence and establishment of Guazuma ulmifolia seedlings. Seeds were subjected to pre-germination treatments of (1) mechanical scarification (sandpaper), and (2) thermal scarification (hot water), in addition to the control treatment (3) from which the seeds were left intact. The thermal scarification treatment differed from the other treatments featuring the largest number of seedling emergence (70%). The seeds treated with sandpaper achieved the lowest emergence percentage not differing from the control treatment. For the germination speed index no significant difference between treatments has been verified and the emergence peak was between the 13rd and 15th days of incubation in all treatments. In the establishment, the seedlings growth (height, diameter and number of leaves and nodes) presented differences between the treatments. It was observed further development of seedlings after their seeds go through thermal scarification. Therefore, scarification with hot water is the most appropriate method for breaking the dormancy of seeds of Guazuma ulmifolia, providing more vigorous seedlings.Este trabalho testou a influência de métodos de escarificação térmica e mecânica na emergência e estabelecimento de plântulas de Guazuma ulmifolia.As sementes foram submetidas aos tratamentos pré-germinativos de (1) escarificação mecânica (lixa), e (2) escarificação térmica (água quente), além do tratamento-controle (3) no qual as sementes foram deixadas intactas. O tratamento feito com escarificação térmica diferiu dos demais tratamentos, apresentando o maior número de plântulas emergidas. As sementes tratadas com lixa obtiveram a menor porcentagem de emergência, não diferindo do tratamento-controle. Para o índice de velocidade de germinação não foi verificada diferença significativa entre os tratamentos e o pico de emergência de plântulas foi entre o 13º e 15º dia de incubação em todos os tratamentos. Quanto ao estabelecimento, o crescimento (altura, diâmetro e número de folhas e de nós) das plântulas diferiu entre os tratamentos pré-germinativos. Observou-se maior crescimento das plântulas após suas sementes passarem por escarificação térmica. Assim, a escarificação com água quente é o método mais adequado para quebra da dormência das sementes de Guazuma ulmifolia, proporcionando plântulas mais vigorosas

Strong relationships between soil and vegetation in reference ecosystems of a riparian atlantic rainforest in the upper Doce River watershed, southeastern Brazil

Habitat loss and fragmentation have been impacting ecosystem services essential for human survival. The Brazilian Atlantic rainforest, a biodiversity hotspot, has suffered from historical deforestation and, more recently, from an environmental disaster caused by the Fundão dam collapse that released ore tailings drastically affecting a large territory in the Doce River watershed. This work aims to assess the relationships between soil properties and vegetation in a reference ecosystem to provide guidelines for restoration projects in areas affected by the dam collapse. We conducted phytosociological (vegetation characteristic) and soil quality studies in three distinct natural sites and studied different vegetation strata to better understand plant species composition in reference sites along the impacted Doce River and their potential role in community structuring and functioning. We recorded 140 species, 78 in the tree stratum, and 90 in the sapling stratum. Furthermore, our results highlight the influence of soil on floristic composition in the Atlantic rainforest. Smallscale edaphic variation influenced species composition in both sapling and tree strata. We also identified species of the same genus with strong association with the extremes of the edaphic gradient. Therefore, we highlight that studies in various regions along the Doce River watershed are of utmost importance to evaluate the association between species and soils. The particularities of the species are crucial to the effectiveness of restoration processes since this plant-soil correlation should not be extrapolated even within the same genus. This knowledge is of strategic relevance to provide scientificbased guidance for restoring these environments, aiming at the recovery of biodiversity and ecosystem services.Fil: Ramos, Letícia. Universidade Federal de Minas Gerais; BrasilFil: Negreiros, Daniel. Universidade Federal de Minas Gerais; BrasilFil: Ferreira, Bárbara S. Silva. Universidade Federal de Minas Gerais; BrasilFil: Figueiredo, João Carlos Gomes. Universidade Estadual de Montes Claros; BrasilFil: Paiva, Dario C.. Florida International University; Estados UnidosFil: Oki, Yumi. Universidade Federal de Minas Gerais; BrasilFil: De Souza Justino, Wénita. Universidade Federal de Minas Gerais; BrasilFil: Dos Santos, Rubens Manoel. Universidade Federal de Lavras; BrasilFil: Aguilar, Ramiro. Universidade Federal de Minas Gerais; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Nunes, Yule Roberta Ferreira. Universidade Estadual de Montes Claros; BrasilFil: Fernandes, G Wilson. Universidade Federal de Minas Gerais; Brasi

Aspectos estruturais e similaridade florística entre fragmentos de floresta tropical seca com diferentes históricos de manejo no norte de minas gerais, Brasil

In order to produce useful knowledge to the initiatives of protection and management of forest fragments, more specifically for tropical dry forests which suffer with frequent anthropic activities, and due to the lack of specific studies, this article aimed describe the structure and the floristic similarity among three areas of dry forest with different management histories. The study was developed in Capitão Enéas municipality, Northern Minas Gerais, Brazil, where three fragments were evaluated, being one in regeneration for 30 years, another submitted to occasional fire and the third with selective cut in small scale. The sampling was developed through the point quarter method considering all the alive phanerophyte individuals with circumference at breast height (CBH) ≥ 15 cm. In the three fragments, 512 individuals, distributed in 60 species, 47 genera, and 23 families were sampled. The most representative families were Fabaceae (26), Anacardiaceae (4), Bignoniaceae (3) and Combretaceae (3). However, fourteen families were represented by only one species. Only eight species were common to all fragments - Myracrodruon urundeuva standed out with 26.9% of all sampled individuals - while a great number of species were exclusive of each fragment. The floristic and structural differences between the fragments are possibly related to the history and intensity of management in each area besides the topography variations and the presence or absence of limestone outcrops. These results show the importanceof each fragment, indicating that the loss of anyone would cause negative impacts on the regional flora and consequently to the associated biodiversity