Sediment microbial community structure associated to different ecological types of mangroves in Celestún, a coastal lagoon in the Yucatan Peninsula, Mexico.

Mangroves are unique coastal ecosystems, which have many important ecological functions, as they are a reservoir of many marine species well adapted to saline conditions and are fundamental as sites of carbon storage. Although the microbial contribution to nutrient cycling in these ecosystems has been well recognized, there is a lack of information regarding the microbial composition and structure of different ecological types of mangrove forests. In this study, we characterized the microbial community (Bacteria and Archaea) in sediments associated with five ecological types of mangrove forests in a coastal lagoon dominated by Avicennia germinans and Rhizophora mangle, through 16S rRNA-V4 gene sequencing. Overall, Proteobacteria (51%), Chloroflexi (12%), Gemmatimonadetes (5%) and Planctomycetes (6%) were the most abundant bacterial phyla, while Thaumarchaeota (30%), Bathyarchaeota (21%) and Nanoarchaeaeota (18%) were the dominant archaeal phyla. The microbial composition associated with basin mangroves dominated by Avicennia germinans was significantly different from the other ecological types, which becomes relevant for restoration strategies.

Association of Rhizophora mangle and ascorbic acid in hydrogels: Evaluation of cytotoxic and immunomodulatory effects

Abstract Polyphenolics from Rhizophora mangle (R. mangle) have shown wound healing and anti- inflammatory effects that may be potentiated by being associated with ascorbic acid, an important substance for collagen and elastin synthesis that plays a role in tissue repair. In our study, we aimed to formulate an association of R. mangle and ascorbic acid in hydrogels and evaluate the association's cytotoxic and immunomodulatory effects. In a pre-formulation study, three gelling polymers (i.e.xanthan gum, poloxamer and hydroxyethyl cellulose) were tested. The selected polymer (i.e. xanthan gum) was used to evaluate cytotoxic and immunomodulatory effects using flow cytometry. Xanthan gum (1.5%) had a homogeneous appearance, an orange colour, a smooth surface, intense brightness and the typical odour, as well as non-Newtonian pseudoplastic behaviour. With a pH of 5.0-5.3 and a non-cytotoxic profile, xanthan gum induced the proliferation and activation of CD4 +, CD8+ and NK T lymphocytes and the production of IL- 2, IL-4, IL-10, IL-17 and TNF-α cytokines in stimulated splenocytes. The results suggest that the association of R. mangle and ascorbic acid in 1.5% xanthan gum hydrogel may be promising in preparations for wound-healing processes

Prevention of necrosis in ischemic skin flaps using hydrogel of Rhizophora mangle.

INTRODUCTION: Necrosis in ischemic cutaneous flaps (ISF) is a type of surgical failure more feared among surgical complications. Currently, synthetic drugs are applied during the treatment of necrosis in ISF and although several substances show improvement in viability, some require application at high systemic doses, which can produce important side effects. Therefore, the search for natural substances with fewer side effects is constant. The use of medicinal plants that stimulate angiogenesis is commonly mentioned in previous studies and in this case Rhizophora mangle L. (R. mangle) highlights that among its main compounds have tannins and flavonoids that are very chemically reactive in various biological activities. This study aimed to associate a natural hydrogel to the 5% extract of R. mangle and to evaluate its potential in the prevention of tissue necrosis in distal portions of ISF in rats, using the model proposed by Macfarlane, et al. (1965). METHODS: Ischemic skin flaps were made in the thin dorsal skin area of 28 Wistar rats and divided into 4 groups, group A: received only saline, group B where the aqueous extract of R. mangle was applied, group C received the 1.5% hydrogel of xanthan gum (XG) + placebo and group D was applied the hydrogel associated with 5% R. mangle extract. Morphometric analyses of the areas of tissue necrosis were performed from photographic records using the software Photoshop® and ImageJ®. In addition, 5 photomicrographs were taken from each histological sample of each animal for histomorphometric analysis that obtained the count of fibroblasts and blood vessels. RESULTS: The mean percentage of necrotic areas was: group (A) - 50,66%, group (B) - 40,49%, group (C) - 37,44% and group (D) - 34,25%. The statistical analysis, using the Kruskal-Wallis test, showed a significant difference (p < 0.001).

Brazilian Semi-Arid Mangroves-Associated Microbiome as Pools of Richness and Complexity in a Changing World.

Mangrove microbiomes play an essential role in the fate of mangroves in our changing planet, but the factors regulating the biogeographical distribution of mangrove microbial communities remain essentially vague. This paper contributes to our understanding of mangrove microbiomes distributed along three biogeographical provinces and ecoregions, covering the exuberant mangroves of Amazonia ecoregion (North Brazil Shelf) as well as mangroves located in the southern limit of distribution (Southeastern ecoregion, Warm Temperate Southwestern Atlantic) and mangroves localized on the drier semi-arid coast (Northeastern ecoregion, Tropical Southwestern Atlantic), two important ecotones where poleward and landward shifts, respectively, are expected to occur related to climate change. This study compared the microbiomes associated with the conspicuous red mangrove (Rhizophora mangle) root soils encompassing soil properties, latitudinal factors, and amplicon sequence variants of 105 samples. We demonstrated that, although the northern and southern sites are over 4,000 km apart, and despite R. mangle genetic divergences between north and south populations, their microbiomes resemble each other more than the northern and northeastern neighbors. In addition, the northeastern semi-arid microbiomes were more diverse and displayed a higher level of complexity than the northern and southern ones. This finding may reflect the endurance of the northeast microbial communities tailored to deal with the stressful conditions of semi-aridity and may play a role in the resistance and growing landward expansion observed in such mangroves. Minimum temperature, precipitation, organic carbon, and potential evapotranspiration were the main microbiota variation drivers and should be considered in mangrove conservation and recovery strategies in the Anthropocene. In the face of changes in climate, land cover, biodiversity, and chemical composition, the richness and complexity harbored by semi-arid mangrove microbiomes may hold the key to mangrove adaptability in our changing planet.

Extremophiles as a Model of a Natural Ecosystem: Transcriptional Coordination of Genes Reveals Distinct Selective Responses of Plants Under Climate Change Scenarios.

The goal of this research was to generate networks of co-expressed genes to explore the genomic responses of Rhizophora mangle L. populations to contrasting environments and to use gene network analysis to investigate their capacity for adaptation in the face of historical and future perturbations and climatic changes. RNA sequencing data were generated for R. mangle samples collected under field conditions from contrasting climate zones in the equatorial and subtropical regions of Brazil. A gene co-expression network was constructed using Pearson's correlation coefficient, showing correlations among 78,364 transcriptionally coordinated genes. Each region exhibited two distinct network profiles; genes correlated with the oxidative stress response showed higher relative expression levels in subtropical samples than in equatorial samples, whereas genes correlated with the hyperosmotic salinity response, heat response and UV response had higher expression levels in the equatorial samples than in the subtropical samples. In total, 992 clusters had enriched ontology terms, which suggests that R. mangle is under higher stress in the equatorial region than in the subtropical region. Increased heat may thus pose a substantial risk to species diversity at the center of its distribution range in the Americas. This study, which was performed using trees in natural field conditions, allowed us to associate the specific responses of genes previously described in controlled environments with their responses to the local habitat where the species occurs. The study reveals the effects of contrasting environments on gene expression in R. mangle, shedding light on the different abiotic variables that may contribute to the genetic divergence previously described for the species through the use of simple sequence repeats (SSRs). These effects may result from two fundamental processes in evolution, namely, phenotypic plasticity and natural selection.

External and local controls on land-sea coupling assessed by stable isotopic signatures of mangrove producers in estuaries of Pacific Panama.

Foliar stable isotopic signatures of nitrogen, carbon, and sulfur in mangrove vegetation from the Pacific coast of Panama were insensitive to inputs from watersheds with different area of forest land cover, and to seasonal, inter-annual, and global-scale-driven contrasts in rainfall and upwelling. N, C, and S content of mangrove vegetation were not affected by inputs from watersheds with different degrees of deforestation, but showed some influence of down-estuary transformations. While there was substantial variation that remained un-explained, isotopic signatures and nutrient contents were largely determined by species-specific features, and showed substantial small-scale variation reflecting local differences, within-estuary plant-sediment links. The ability of mangrove estuaries to erase effects of deforestation points out that conservation of these wetland ecosystems is important, because, at least in the sites we studied, transformations within mangrove estuaries were strong enough to protect water quality in receiving coastal waters.

Diterpenes and a new benzaldehyde from the mangrove plant Rhizophora mangle

ABSTRACT This work describes the isolation, by high-speed counter-current chromatography, of the diterpenes manool, jhanol and steviol and the benzaldehyde p-oxy-2-ethylhexyl benzaldehyde from the stilt roots hexane extract of the mangrove plant Rhizophora mangle L., Rhizophoraceae. For this, a non-aqueous biphasic solvent system composed of hexane–acetonitrile–methanol 1:1:0.5 (v/v/v) was applied. As far as we know, only steviol was previously isolated in Rhizophoraceae and this is the first time that p-oxy-2-ethylhexyl benzaldehyde is reported.

Sewage input reduces the consumption of Rhizophora mangle propagules by crabs in a subtropical mangrove system.

Mangrove forests are highly productive and play a major role in global carbon cycling. Their carbon accumulation can be influenced through the consumption of nutrient-poor leaves and propagules by herbivore crabs. Anthropogenic nutrient input from sewage contamination is widespread in these often naturally nutrient-limited ecosystems. We hypothesised that sewage-mediated nutrient input to mangrove stands of Paranaguá Bay (southern Brazil), would alter the nutrient sources available for crabs, e.g. through microphytobenthos increase, and that this would reflect in their feeding behaviour. We predicted that propagules of Rhizophora mangle in contaminated stands would experience lower grazing pressure from their two main local consumers (Ucides cordatus and Goniopsis cruentata). We compared herbivory rates on R. mangle propagules in sewage contaminated and uncontaminated mangrove stands. We found that herbivory rates were significantly lower in contaminated than uncontaminated forests, but this pattern could not be clearly attributed to increased nutrient availability.

SOIL-PLANT NUTRIENT INTERACTIONS IN TWO MANGROVE AREAS AT SOUTHERN BRAZIL / Interacciones de nutrientes entre suelo y planta en dos áreas de manglares en el sur de Brasil / Interação entre a composição química de solo e planta em dois manguezais no sul do Brasil

Mangrove forests have a simple architecture. They shelter a few number of arboreal species that grow in a saline environment subject to tidal activity. The research objective was to evaluate possible interactions between physical-chemical soil attributes and plant-leaf nutrient concentrations of different mangrove species. Different mangrove species growing in the same soil, and the same mangrove species growing in two different soil classes were evaluated as to their leaf nutrient concentration patterns. The study was carried out in mangrove areas of the State of Paraná, southern Brazil, in two distinct soil classes: HISTOSOL THIOMORPHIC Salic sodic and GLEYSOL THIOMORPHIC Salic sodic; and three different species: Avicennia schaueriana, Laguncularia racemosa and Rhizophora mangle. Two subareas were delimited within each area from which soil and leaf samples were collected. Samplings from five individuals of each dominant mangrove species were taken from the soil (0-10 cm deep) under each tree crown projection. The data was submitted to statistical analysis using a set of simple and multivariate analysis in order to determine possible differences among mangrove species leaf nutrient concentrations, and whether these differences might be correlated with the soil attributes or not. The results exposed that the nutritional state of the mangrove species is different and independent form the soil attributes in which they grow. Few correlations were found among leaf nutrient concentrations and soil attributes, suggesting differential selective nutrient uptake among species.

Los manglares son bosques de arquitectura simple que albergan pocas especies arbóreas, creciendo en un ambiente salino sometido a la influencia de las mareas. El objetivo de este trabajo fue evaluar las posibles interacciones entre las propiedades fisicoquímicas del suelo y la concentración de nutrientes en hojas de diferentes especies de mangle. Se investigó si las diferentes especies que se desarrollan en la misma clase de suelo tienen concentraciones de nutrientes foliares similares, y si las plantas de mangles de la misma especie que se desarrollan en diferentes tipos de suelos tienen concentraciones foliares similares. El estudio se desarrolló en manglares del Estado de Paraná, sur de Brasil, en dos tipos de suelos diferentes (HISTOSOL TIÓNICO Salino sódico y GLEYSOL TIÓNICO Salino sódico). Se analizaron tres especies vegetales diferentes (Avicennia schaueriana, Laguncularia racemosa y Rhizophora mangle). En cada área se delimitaron dos subáreas para recolectar el suelo y las hojas de cada una de las especies. Se tomaron cinco individuos de cada especie del dosel dominante para recoger hojas y muestras de suelo de 0-10 cm, en la proyección de la copa de los árboles seleccionados. Se realizaron análisis univariados y multivariados para probar si las especies de mangle tienen perfiles nutricionales diferentes, y si existe alguna correlación entre las propiedades del suelo con la composición química de las hojas. Los resultados mostraron que el estado nutricional de las especies de mangle es distinto e independiente de los atributos de los suelos en los que se encuentran. Las concentraciones de elementos en las hojas presentan poca correlación con los nutrientes del suelo, lo que sugiere que la absorción de nutrientes por las plantas es selectiva.

Manguezais são florestas de arquitetura simples, abrigando poucas espécies arbóreas, vegetando em ambiente salino e sujeito ao regime de marés. O objetivo desta pesquisa foi avaliar as possíveis interações entre os atributos físico-químicos do solo e a concentração de nutrientes nas folhas de diferentes espécies de mangue. Assim, foi investigado se as diferentes espécies que se desenvolvem sobre a mesma classe de solo apresentam concentrações de nutrientes foliares similares, e se plantas de mangue da mesma espécie que ocorrem sobre diferentes classes de solo apresentam concentrações de nutrientes foliares similares. O estudo foi desenvolvido em manguezais no Estado do Paraná, Sul do Brasil, em duas classes distintas de solo (ORGANOSSOLO TIOMÓRFICO Sálico sódico e GLEISSOLO TIOMÓRFICO Sálico sódico), e três espécies diferentes de plantas (Avicennia schaueriana, Laguncularia racemosa and Rhizophora mangle). Em cada área foram delimitadas duas subáreas para coleta de solo e folhas das espécies. Cinco indivíduos do dossel dominante de cada espécie para coleta de folhas, na projeção da copa das árvores, e amostras de solo de 0-10 cm foram selecionados. Para testar se espécies de mangue apresentam perfis nutricionais distintos e se há correlação entre os atributos do solo com a composição química foliar um conjunto de análises univariadas multivariadas foram realizadas. Os resultados demonstraram que o estado nutricional das plantas é distinto e individualizado, independente dos atributos do solo em que se encontram as espécies. As concentrações dos elementos nas folhas pouco se correlacionaram com os nutrientes do solo, sugerindo absorção seletiva dos nutrientes pelas plantas.

Paleoambientes de Rhizophora mangle (Rhizophoraceae) en Castilletes, Alta Guajira, Venezuela según las paleoconchas de Crassostrea rhizophorae (Ostreoida: Ostreidae)

Los conchales constituyen un rasgo muy característico de las adaptaciones humanas a los ambientes litorales. Analizar su composición y su variabilidad puede brindar indicios en cuanto a la subsistencia de antiguas poblaciones humanas, procesos de formación e información sobre cambios en el ambiente. Este estudio evaluó el uso de paleoconchas halladas en conchales para inferir las condiciones paleoambientales de un bosque de manglar. Datos de paleoconchas de conchales ubicados en Castilletes-Alta Guajira, Venezuela fueron datados en 3 580 ± 30 años A.P, se incluyeron datos de conchas actuales provenientes de la Laguna de Cocinetas (Castilletes) y de isla Maracas (Lago de Maracaibo). Se examinaron un total de 185 muestras con marcas de fijación de la raíz de mangle, paleoconchas (n = 109) y conchas actuales (n = 76) de C. rhizophorae. Posteriormente, se estimaron los diámetros de las paleoraíces y de las raíces actuales a través de un modelo geométrico utilizando la huella de fijación de la concha. Para validar el modelo se midieron directamente los diámetros de las raíces actuales. Adicionalmente se realizó un estudio fisionómico en los bosques de ambas localidades de estudio, para asociar la estructura del bosque, con el diámetro de las raíces y la información de las conchas. Los resultados mostraron que no hay diferencias significativas entre los diámetros de las raíces obtenidas por el modelo geométrico y los diámetros de las raíces medidas directamente (Castilletes P = 0.160854; Maracas P = 0.617271). Las mediciones de las conchas mostraron que las paleoconchas son más largas que las conchas modernas. Los diámetros de las paleoraíces no mostraron diferencias significativas con las raíces del bosque actual de Castilletes (zona expuesta) P = 0.303518, contrastando con los diámetros de las raíces de isla Maracas (zona protegida) (P = 0.017771). El estudio fisionómico mostro que el bosque actual de Castilletes tiene un DAP y una altura (11.10 y 4.90 m respectivamente) menor que Maracas (34.86 cm y 10.62 m), respondiendo a la exposición a los vientos. Se determinó que el paleobosque y el bosque actual de Castilletes tienen características similares asociadas con ambientes áridos, con fuerte exposición a los vientos. Se concluye que el análisis de las huellas de fijación de las paleoconchas es un método novedoso y de bajo costro que permite obtener información sobre el paleoambiente de los bosques de R. mangle.

Shell middens are a very characteristic feature of coastal human adaptations. Component and variability analysis offer clues to subsistence of ancient human populations, formation processes and information of environmental changes. In this study, we tested the use of paleoshells found in shell midden to infer paleoenviroment conditions of R. mangle forest. We presented data of paleoshells from shell middens, located on Castilletes-Alta Guajira, Venezuela, dated from 3 580 ± 30 años B.P years, and we included data of actual shells from mangrove forests located on Cocinetas laggon (Castilletes) and Maracas Island (Maracaibo lagoon). We examined 185 samples of fixing traces marked by mangrove roots on paleoshells (n = 109) and actual shells (n = 76) of C. rhizophorae. Subsequently, we estimated paleoroot and modern root diameter using a geometric model using shell's trace. To validate this model, we directly measured modern roots. Furthermore, a physiognomic study was made in both sites to associate mangrove forest with roots diameter and shells information. Results showed that there were no significant differences between estimated root diameter values obtained from traces of modern shells and the ones recorded by direct measurement of roots (Castilletes P = 0.160854; Maracas P = 0.617271); allowing the use of geometric model to obtain estimated values of paleoroots. Shell measurements showed that paleoshells were larger than modern shells. Paleoroot diameters showed no significant differences with modern Castilletes's mangrove roots (exposed zone) (P = 0.303518), contrasting with Maracas's roots (protected zone) (P = 0.017771). Physiognomic study showed that modern Castilletes forests had diameter at breast height (DBH) and tree height (11.10 m and 4.90 m, respectively) lower than Maracas (34.86 cm and 10.62 m), responding to the wind exposure and salinity. Diameters and quantity of roots per tree were higher in Castilletes (3.01 cm y 11 roots/tree) than Maracas (2.39 cm y 7 roots/tree). We determined that paleoforests and modern forests from Castilletes have similar characteristics associated to arid environment with stronger wind exposition. We concluded that paleoshells trace analysis is a low cost and novel method that allows obtaining information about paleoenvironment of R. mangle forests.

Distribution of Cu, Fe, Mn, and Zn in Two Mangroves of Southern Brazil

ABSTRACT This study assessed the relation between Cu, Fe, Mn, and Zn in the soils of the mangroves of Antonina and Guaratuba, on the coastline of the State of Paraná, and in the leaf tissues of A. shauerianaR. mangle, and L. racemosa through the analysis of correlation levels between these two compartments. Leaf samples were collected for ten individuals of each species in a 1000 m2 area delimited in each mangrove. Soil samples from 0-10 cm depth were taken from under the crown projection area of the selected trees to be submitted to chemical analysis. In the soils, metallic micronutrients presented the following order: Fe > Mn > Zn > Cu. In the leaves, concentrations were species dependent. InA. shaueriana and R. mangle, the profile was Mn > Fe > Zn > Cu, while in L. racemosa, the sequence was: Fe > Mn > Zn > Cu. Correlation analyses revealed only four significant correlations for Mn, Zn, and Cu in the soil and plant compartments. These results suggested that significant correlations depended on abiotic factors, inhibition between the elements, and immobilization and/or adsorptions of these metals by the soil.

Myxomycetes from mangroves: species occurring in the state of Maranhão, northeastern Brazil / Myxomycetes em manguezais: espécies ocorrentes no estado do Maranhão, nordeste do Brasil

Mangrove swamps and forests cover over 137,000 km2 distributed latitudinally among subtropical zones, 7% of which are in Brazil, with a greater density in the countrys northernmost region. Considering that the community of Myxomycetes recorded for this environment is hardly known, three areas located in the state of Maranhão were investigated. Two field trips were conducted, one at the beginning of the rainy season and another during the dry season. In each area, two plots (125 m2) equidistant 100 m apart from each other were surveyed. In these areas, standing dead tree trunks and dead branches still attached to the mother plant that were above the tideline, were examined. On these same occasions, samples of the aerial litter and from the cortex of living trees (Rhizophora) were collected for the preparation of moist chambers cultures. Twenty-one specimens were obtained from field and moist chambers, belonging to 11 species, distributed in nine genera and five families. Seven species are new records from Maranhão. There was a predominance of r-strategist (73%) over K-strategist (27%) species. Cribraria violacea, Comatricha tenerrima, Echinostelium minutum, and Fuligo septica are new worldwide records from mangrove environments, and Oligonema flavidum is reported for the first time from Brazil.(AU)

Os manguezais ocupam mais de 137.000 km2, distribuídos latitudinalmente entre as zonas subtropicais e 7% encontra-se no Brasil, com maior densidade entre os estados do Pará e Maranhão, na região norte do país. Considerando que a comunidade de mixomicetos registrada para este ambiente é pouco conhecida, três áreas localizadas no estado do Maranhão foram investigadas. Duas excursões foram realizadas, uma no início da estação chuvosa e outra na estiagem. Em cada área, foram georeferenciadas e exploradas duas parcelas (125 m2) equidistantes 100 m uma da outra foram avaliadas. Nestas, foram explorados troncos mortos em pé e galhos mortos ainda presos à planta-mãe, acima da linha da maré. Nas mesmas ocasiões foram coletadas amostras de folhedo aéreo e córtex de árvores vivas (Rhizophora) para montagem de câmaras-úmidas. Foram obtidos 21 espécimes de campo e câmara-úmida, pertencentes a 11 espécies, distribuídas em nove gêneros e cinco famílias. Sete espécies são novos registros para o Maranhão. Predominaram espécies r-estrategistas (73%), e 27% K-estrategistas. Cribraria violacea, Comatricha tenerrima, Echinostelium minutum e Fuligo septica são novos registros para o ambiente de manguezal, e Oligonema flavidum é registrada pela primeira vez no Brasil.(AU)

Myxomycetes from mangroves: species occurring in the state of Maranhão, northeastern Brazil

Abstract Mangrove swamps and forests cover over 137,000 km2 distributed latitudinally among subtropical zones, 7% of which are in Brazil, with a greater density in the countrys northernmost region. Considering that the community of Myxomycetes recorded for this environment is hardly known, three areas located in the state of Maranhão were investigated. Two field trips were conducted, one at the beginning of the rainy season and another during the dry season. In each area, two plots (125 m2) equidistant 100 m apart from each other were surveyed. In these areas, standing dead tree trunks and dead branches still attached to the mother plant that were above the tideline, were examined. On these same occasions, samples of the aerial litter and from the cortex of living trees (Rhizophora) were collected for the preparation of moist chambers cultures. Twenty-one specimens were obtained from field and moist chambers, belonging to 11 species, distributed in nine genera and five families. Seven species are new records from Maranhão. There was a predominance of r-strategist (73%) over K-strategist (27%) species. Cribraria violacea, Comatricha tenerrima, Echinostelium minutum, and Fuligo septica are new worldwide records from mangrove environments, and Oligonema flavidum is reported for the first time from Brazil.

Resumo Os manguezais ocupam mais de 137.000 km2, distribuídos latitudinalmente entre as zonas subtropicais e 7% encontra-se no Brasil, com maior densidade entre os estados do Pará e Maranhão, na região norte do país. Considerando que a comunidade de mixomicetos registrada para este ambiente é pouco conhecida, três áreas localizadas no estado do Maranhão foram investigadas. Duas excursões foram realizadas, uma no início da estação chuvosa e outra na estiagem. Em cada área, foram georeferenciadas e exploradas duas parcelas (125 m2) equidistantes 100 m uma da outra foram avaliadas. Nestas, foram explorados troncos mortos em pé e galhos mortos ainda presos à planta-mãe, acima da linha da maré. Nas mesmas ocasiões foram coletadas amostras de folhedo aéreo e córtex de árvores vivas (Rhizophora) para montagem de câmaras-úmidas. Foram obtidos 21 espécimes de campo e câmara-úmida, pertencentes a 11 espécies, distribuídas em nove gêneros e cinco famílias. Sete espécies são novos registros para o Maranhão. Predominaram espécies r-estrategistas (73%), e 27% K-estrategistas. Cribraria violacea, Comatricha tenerrima, Echinostelium minutum e Fuligo septica são novos registros para o ambiente de manguezal, e Oligonema flavidum é registrada pela primeira vez no Brasil.

Myxomycetes from mangroves: species occurring in the state of Maranhão, northeastern Brazil / Myxomycetes em manguezais: espécies ocorrentes no estado do Maranhão, nordeste do Brasil

Abstract Mangrove swamps and forests cover over 137,000 km2 distributed latitudinally among subtropical zones, 7% of which are in Brazil, with a greater density in the country’s northernmost region. Considering that the community of Myxomycetes recorded for this environment is hardly known, three areas located in the state of Maranhão were investigated. Two field trips were conducted, one at the beginning of the rainy season and another during the dry season. In each area, two plots (125 m2) equidistant 100 m apart from each other were surveyed. In these areas, standing dead tree trunks and dead branches still attached to the mother plant that were above the tideline, were examined. On these same occasions, samples of the aerial litter and from the cortex of living trees (Rhizophora) were collected for the preparation of moist chambers cultures. Twenty-one specimens were obtained from field and moist chambers, belonging to 11 species, distributed in nine genera and five families. Seven species are new records from Maranhão. There was a predominance of r-strategist (73%) over K-strategist (27%) species. Cribraria violacea, Comatricha tenerrima, Echinostelium minutum, and Fuligo septica are new worldwide records from mangrove environments, and Oligonema flavidum is reported for the first time from Brazil.

Resumo Os manguezais ocupam mais de 137.000 km2, distribuídos latitudinalmente entre as zonas subtropicais e 7% encontra-se no Brasil, com maior densidade entre os estados do Pará e Maranhão, na região norte do país. Considerando que a comunidade de mixomicetos registrada para este ambiente é pouco conhecida, três áreas localizadas no estado do Maranhão foram investigadas. Duas excursões foram realizadas, uma no início da estação chuvosa e outra na estiagem. Em cada área, foram georeferenciadas e exploradas duas parcelas (125 m2) equidistantes 100 m uma da outra foram avaliadas. Nestas, foram explorados troncos mortos em pé e galhos mortos ainda presos à planta-mãe, acima da linha da maré. Nas mesmas ocasiões foram coletadas amostras de folhedo aéreo e córtex de árvores vivas (Rhizophora) para montagem de câmaras-úmidas. Foram obtidos 21 espécimes de campo e câmara-úmida, pertencentes a 11 espécies, distribuídas em nove gêneros e cinco famílias. Sete espécies são novos registros para o Maranhão. Predominaram espécies r-estrategistas (73%), e 27% K-estrategistas. Cribraria violacea, Comatricha tenerrima, Echinostelium minutum e Fuligo septica são novos registros para o ambiente de manguezal, e Oligonema flavidum é registrada pela primeira vez no Brasil.

Capacidad de regeneración natural del bosque de manglar del Estero Tortuga, Osa, Puntarenas, Costa Rica / Natural regeneration capacity of the mangrove forest of Tortuga Estuary, Osa, Puntarenas, Costa Rica

Resumen Este estudio se realizó entre Febrero 2011 y Enero 2012, en el bosque de mangle del Estero Tortuga. Se establecieron un total de seis parcelas, de 9 m2 cada una, con el fin de evaluar el porcentaje de supervivencia y la tasa de crecimiento de las plántulas de Rhizophora racemosa (G. Mey.) y Pelliciera rhizophorae (Triana & Planch.). Al final del estudio todas las parcelas presentaron un 100% de mortalidad, lo que indica que la zona no está reclutando árboles jóvenes y por lo tanto no se está regenerando naturalmente. Los resultados de este estudio sugieren que la baja influencia de la marea, la baja salinidad del manto freático y la alta tasa de deposición de sedimentos, son las causas de la nula supervivencia de las plántulas y del deterioro de los individuos adultos. Se realizó un análisis comparativo de las zonas de manglar declaradas Patrimonio Natural de Estado y el ecosistema de manglar del Estero Tortuga, el cual muestra que existen áreas que no se encuentran protegidas bajo esta categoría. Se recomienda actualizar esta información con el fin de contar con un registro preciso sobre la ubicación de los manglares de la zona. Además, es prioritario que se aborde el manejo de la cuenca Térraba Sierpe, con el fin de disminuir la cantidad de sedimentos que se depositan en los manglares de la zona.

Abstract The study was conducted from February 2011 to January 2012, in the mangrove forest of Tortuga Estuary. A total of six parcels, each measuring 9m2, were established in the area, to evaluate the survival and growth rates of the mangrove seedlings. By the end of the study all parcels presented 100% mortality, indicating that the area is not recruiting young trees and therefore is not regenerating naturally. The results of this study suggest that the low salinity of the water table and the high rate of deposition of sediments, are the causes of the low survival rate of the seedlings and could also be affecting the adult individuals. The adult trees presented deteriorated health signs such as decomposition of their stilt roots and total loss of foliage. The borders of this ecosystem were georeferenced and compared with the official map that declares the Natural Patrimony of the Country, to determine areas that should be protected under this category. In general the mangrove forest of this estuary can be divided in two zones: the first one is characterized by a mature forest of mainly two species: Rhizophora racemosa (G. Mey.) and Pelliciera rhizophorae (Triana & Planch.). The second one is located in the banks of sand of the estuary, where the dominant specie is Laguncularia racemosa (C.F. Gaertn) in young stages. Both of these areas include mangrove ecosystems that are not included in the Natural Patrimony category. Rev. Biol. Trop. 63 (Suppl. 1): 209-218. Epub 2015 April 01.

Complejidad estructural de los manglares de Playa Blanca, Escondido y Rincón de Osa, Golfo Dulce, Costa Rica / Structural complexity of mangroves in Playa Blanca, Escondido and Rincón de Osa, Golfo Dulce, Costa Rica

Resumen Este estudio reporta las características estructurales y distribución de las especies en los bosques de mangle de Playa Blanca, Escondido y Rincón en Golfo Dulce, Pacífico Sur de Costa Rica. Se realizaron múltiples transectos en cada uno de los manglares. Cada 10m a lo largo de cada transecto se delimitaron parcelas cuadradas de 5x5m. En cada parcela se midió el diámetro a la altura del pecho y altura de los árboles de mangle y se tomaron muestras de sedimento y de agua intersticial (salinidad). Se determinó la densidad total y por especie para cada manglar, el área basal y valor de importancia por especie y la complejidad general entre los manglares. Las especies dominantes en los tres manglares estudiados fueron Rhizophora racemosa y Pelliciera rhizophorae. Los manglares de Playa Blanca y Rincón presentaron mayor similitud en la estructura del bosque entre sí que con el manglar de Escondido. Playa Blanca fue el bosque de mayor altura del dosel y menor densidad; mientras que Escondido presentó mayor densidad y menor altura, así como el menor número de especies y el único donde se encontró la especie Conocarpus erectus. La composición de especies presente en estos manglares coincide con la reportada para la región. Sin embargo, la variación en estructura y complejidad entre los tres manglares es mayor a las similitudes con otros de la región. El estudio histórico y topográfico de estos manglares puede aclarar las variaciones en estructura y complejidad encontrada actualmente entre ellos.

Abstract This study reports the structural characteristics and distribution of species in the mangrove forests of Playa Blanca, Escondido and Rincón de Osa in Golfo Dulce, South Pacific of Costa Rica. Multiple lineal transects were carried out at each of the mangrove forests. Every 10 meters along each transect the diameter at breast height, basal area, and height was determined for all mangrove trees within a 5x5meter square plot. Sediment and interstitial water (salinity) samples were also collected at each plot. Total density of the stand was determined, as were the density of each mangrove species, the importance value and basal area per species, and general complexity indices for each mangrove forest. The dominant species at all three mangroves were Rhizophora racemosa and Pelliciera rhizophorae. Forest structure was more similar between Playa Blanca and Rincón mangroves than with Escondido. Playa Blanca was the forest with the tallest canopy height and lowest density, while Escondido had the highest density and the shortest canopy height. Escondido was also the forest with the least number of species and the only one where Conocarpus erectus was present. Species composition and dominance at these mangroves coincides with that reported for the region. However, the variation in structure and complexity among the three mangroves is greater than the commonalities with mangroves in the region. Topographical and historical analysis of these mangroves could further elucidate the present structure and complexity variation among them. Rev. Biol. Trop. 63 (Suppl. 1): 199-208. Epub 2015 April 01.

Root biomechanics in Rhizophora mangle: anatomy, morphology and ecology of mangrove's flying buttresses.

BACKGROUND AND AIMS: Rhizophora species of mangroves have a conspicuous system of stilt-like roots (rhizophores) that grow from the main stem and resemble flying buttresses. As such, the development of rhizophores can be predicted to be important for the effective transmission of dynamic loads from the top of the tree to the ground, especially where the substrate is unstable, as is often the case in the habitats where Rhizophora species typically grow. This study tests the hypothesis that rhizophore architecture in R. mangle co-varies with their proximity to the main stem, and with stem size and crown position. METHODS: The allometry and wood mechanical properties of R. mangle (red mangrove) trees growing in a mangrove basin forest within a coastal lagoon in Mexico were compared with those of coexisting, non-buttressed mangrove trees of Avicennia germinans. The anatomy of rhizophores was related to mechanical stress due to crown orientation (static load) and to prevailing winds (dynamic load) at the study site. KEY RESULTS: Rhizophores buttressed between 10 and 33 % of tree height. There were significant and direct scaling relationships between the number, height and length of rhizophores vs. basal area, tree height and crown area. Wood mechanical resistance was significantly higher in the buttressed R. mangle (modulus of elasticity, MOE = 18·1 ± 2 GPa) than in A. germinans (MOE = 12·1 ± 0·5 GPa). Slenderness ratios (total height/stem diameter) were higher in R. mangle, but there were no interspecies differences in critical buckling height. When in proximity to the main stem, rhizophores had a lower length/height ratio, higher eccentricity and higher xylem/bark and pith proportions. However, there were no directional trends with regard to prevailing winds or tree leaning. CONCLUSIONS: In comparison with A. germinans, a tree species with wide girth and flare at the base, R. mangle supports a thinner stem of higher mechanical resistance that is stabilized by rhizophores resembling flying buttresses. This provides a unique strategy to increase tree slenderness and height in the typically unstable substrate on which the trees grow, at a site that is subject to frequent storms.

Ecological relations between mangrove leaf litter and the spatial distribution of the gastropod Melampus coffeus in a fringe mangrove forest / Relações ecológicas entre a serrapilheira de manguezal e a distribuição espacial do gastrópodo Melampus coffeus em uma borda de floresta de mangue

Leaf litter represents a food source to many organisms that may directly contribute to organic matter decomposition. In addition, the physical presence of these vegetal detritus contributes for the modification of some environmental areas and produce microhabitats that may act as a refuge against predators and desiccation for many animals. The pulmonate gastropod Melampus coffeus (Linnaeus, 1758) (Ellobiidae) is a very common specie in Atlantic Coast mangrove forests and feeds on fallen mangrove leaves. It was hypothesized that the spatial distribution of Melampus coffeus is directly affected by mangrove leaf litter biomass deposition. Thus, this research aimed at evaluating the spatial distribution of these gastropods in relation to the biomass of mangrove leaf litter through a twelve-month period. The study area was established in the middle estuary of Pacoti River, state of Ceará, Brazil where two adjacent zones with different topographic profiles were determined. Samples of Melampus coffeus and leaf litter were collected monthly, throughout a year, from the mangrove ground surface. The results indicated that the presence of twigs in mangrove litter favor the occupation by smaller individuals of M. coffeus, probably because smaller individuals are more susceptible to predator attacks and desiccation than larger ones, and twigs and branches may provide a safe microhabitat

A serapilheira representa fonte de alimentos para diversos organismos que podem contribuir diretamente para a decomposição de matéria orgânica. A presença física desses detritos vegetais pode modificar áreas do ambiente e promover a formação de microhabitats, servindo de refúgio para diversos animais contra predadores e dessecação. O gastrópode Melampus coffeus (Linnaeus, 1758) (Ellobiidae) é comum em florestas de mangue na costa do Atlântico e se alimenta de folhas de mangue caídas. Nesse trabalho foi assumida a hipótese de que a distribuição espacial do Melampus coffeus é diretamente afetada pela deposição de serapilheira no manguezal. Objetivou-se avaliar a distribuição espacial desses gastrópodes em relação à serapilheira de mangue durante doze meses de coletas. A área de estudo foi estabelecida no médio estuário do rio Pacoti, Estado do Ceará, Brasil onde foram determinadas duas zonas de diferentes perfis topográficos. Amostras de Melampus coffeus e de serapilheira foram coletadas mensalmente. Os resultados indicaram que a presença de galhos na superfície do solo do manguezal favorece a ocupação do ambiente por indivíduos dessa espécie de molusco de menor tamanho, provavelmente porque indivíduos menores são mais suscetíveis ao ataque de predadores e à dessecação e a presença de galhos pode formar microhabitats mais seguros

Ecological relations between mangrove leaf litter and the spatial distribution of the gastropod Melampus coffeus in a fringe mangrove forest / Relações ecológicas entre a serrapilheira de manguezal e a distribuição espacial do gastrópodo Melampus coffeus em uma borda de floresta de mangue

Leaf litter represents a food source to many organisms that may directly contribute to organic matter decomposition. In addition, the physical presence of these vegetal detritus contributes for the modification of some environmental areas and produce microhabitats that may act as a refuge against predators and desiccation for many animals. The pulmonate gastropod Melampus coffeus (Linnaeus, 1758) (Ellobiidae) is a very common specie in Atlantic Coast mangrove forests and feeds on fallen mangrove leaves. It was hypothesized that the spatial distribution of Melampus coffeus is directly affected by mangrove leaf litter biomass deposition. Thus, this research aimed at evaluating the spatial distribution of these gastropods in relation to the biomass of mangrove leaf litter through a twelve-month period. The study area was established in the middle estuary of Pacoti River, state of Ceará, Brazil where two adjacent zones with different topographic profiles were determined. Samples of Melampus coffeus and leaf litter were collected monthly, throughout a year, from the mangrove ground surface. The results indicated that the presence of twigs in mangrove litter favor the occupation by smaller individuals of M. coffeus, probably because smaller individuals are more susceptible to predator attacks and desiccation than larger ones, and twigs and branches may provide a safe microhabitat(AU)

A serapilheira representa fonte de alimentos para diversos organismos que podem contribuir diretamente para a decomposição de matéria orgânica. A presença física desses detritos vegetais pode modificar áreas do ambiente e promover a formação de microhabitats, servindo de refúgio para diversos animais contra predadores e dessecação. O gastrópode Melampus coffeus (Linnaeus, 1758) (Ellobiidae) é comum em florestas de mangue na costa do Atlântico e se alimenta de folhas de mangue caídas. Nesse trabalho foi assumida a hipótese de que a distribuição espacial do Melampus coffeus é diretamente afetada pela deposição de serapilheira no manguezal. Objetivou-se avaliar a distribuição espacial desses gastrópodes em relação à serapilheira de mangue durante doze meses de coletas. A área de estudo foi estabelecida no médio estuário do rio Pacoti, Estado do Ceará, Brasil onde foram determinadas duas zonas de diferentes perfis topográficos. Amostras de Melampus coffeus e de serapilheira foram coletadas mensalmente. Os resultados indicaram que a presença de galhos na superfície do solo do manguezal favorece a ocupação do ambiente por indivíduos dessa espécie de molusco de menor tamanho, provavelmente porque indivíduos menores são mais suscetíveis ao ataque de predadores e à dessecação e a presença de galhos pode formar microhabitats mais seguros(AU)

La relación entre peltigera sp. y rhizophora magle en arroyo de plata (Bolívar), caribe Colombiano / The relationhip between peltigera sp. and rhizophora manglein arroyo de pllata (bolivar), Colombian caribbean region

Objetivo: determinar la distribución y el estado de los rodales de manglar en Arroyo de Plata (Departamento de Bolívar). Metodología: se realizaron labores de campo a través del arbolado, mediante el muestreo biológico de la flora y de los parámetros físicos y químicos del agua y de los suelos a lo largo de transectos dentro del bosque. Resultados: la composición del rodal incluye cinco especies, Rhizophora mangle (mangle rojo, colorao o colorado), Avicennia germinans (mangle salado, prieto, negro o iguanero), Laguncularia racemosa (mangle blanco, amarillo o bobo), Conocarpus erecta (mangle zaragoza) y Pelliciera rhizophorae (mangle piñuelo). Asociado a la especie pionera (R. mangle) se encontró el líquen (Peltigera sp.), cuya relación se lleva a cabo solo cuando el mangle está en estado de degradación y los parámetros fisicoquímicos de las aguas y los suelos, son extremos. Conclusión: Los manglares mostraron características mixtas, tipo maduro ribereño y de cuenca, donde la especie invasora P. rhizophorae presenta el mayor IVI, debido a su alta densidad. El registro de los líquenes Peltigera sp. y su presencia en los manglares del Caribe colombiano no solo es el primero para esta Región, su distribución puede estar restringida a la zona costera, es incidental, y demuestra su gran capacidad de adaptación a los cambios ambientales, y puede ser considerada entre los en bio-indicadores de las características ambientales, especialmente de las alteraciones actuales de los suelos y las aguas.

Objective: To determine the distribution and status of mangrove stands in Arroyo de Plata (Department of Bolívar). Methodology: Field work was conducted through woodland, using biological sampling of the flora and the physical and chemical parameters of water and soil along transects within the forest. Results: The composition of the stand includes five species, Rhizophoramangle (red, colorao or colorado mangrove), Avicenniagerminans (salty, dark color, black or iguanero mangle) Laguncularia racemosa (white, yellow or bobo mangrove), Conocarpus erecta (zaragoza mangle) and Pelliciera rhizophorae (tea mangrove). The lichen (Peltigera sp), was found associated with the pioneer species (R. mangrove) whose relationship is carried out only when the mangrove is in a state of degradation and the physical-chemical parameters of water and soil, are extreme. Conclusion: Mangroves showed mature coastal basin type mixed characteristics, where the invasive species P. rhizophorae has the highest IVI due to its high density. Registration of Peltigera sp lichens and its presence of the Colombian Caribbean mangrove is not only the first for this region, its distribution may be restricted to the coastal zone, it is incidental and demonstrates its ability to adapt to environmental changes, and can be considered between the bio-indicators of environmental characteristics, especially of the the current alterations of soil and water.