76 research outputs found
Ethno-pharmacological Study about Lafoensia replicata Pohl. in East Maranhão, Brazil: A Promising Species for Bioprospection
This work aimed at carrying out a study on the local therapeutic uses of mangabeira (Lafoensia replicata Pohl.), an important plant in the northeastern cerrado. 32 interviews were conducted with informants from the community Manga, Barão do Grajaú, Maranhão. Respondents, 18 women and 14 men, reported eight different uses for the plant. Regarding the number of instructions for use, there were no significant differences between genders, eight nominations described by women and seven by men. Regarding the distinctions of knowledge among the age group proposed for the analysis, there were no statistical differences. The plant part most indicated for use was the stem bark. All informants indicated consensually that the medicine prepared from the plant should be administered orally and over half of the respondents mentioned that the plant had no restrictions on consumption (53%). However, 17 respondents said that the treatment is contraindicated during pregnancy, and even five people did not recommend the use on children. It was not possible to substantiate the ethno-pharmacological information in this study with the literature since there is insufficient research on this species. There is some research focusing on uses and activities of Lafoensia pacari A. St.-Hil, therefore, this study also recommends L. replicata Pohl. as a potential therapeutic species.Esta pesquisa objetivou realizar estudo sobre os usos terapêuticos da mangabeira (Lafoensia replicata Pohl.), uma importante planta do cerrado nordestino. Foram realizadas 32 entrevistas com informantes da comunidade Manga, Barão de Grajaú, interior do Maranhão. Os entrevistados, 18 mulheres e 14 homens, informaram oito usos diferentes para a planta. Quanto ao número de indicações de uso, não houve diferenças significativas entre os gêneros: oito indicações descritas pelas mulheres e sete pelos homens. Com relação a distinções no conhecimento entre as classes de idade propostas para análise, também não houve distinções estatísticas. A parte mais indicada como usada foram as cascas do caule. Todos os informantes indicaram consensualmente que o remédio preparado a partir da planta deve ser administrado por via oral, e mais da metade dos informantes mencionou que a planta não apresenta restrições ao consumo (53%). Contudo, 17 entrevistados afirmaram que o tratamento é contraindicado durante a gravidez e, ainda, cinco pessoas não recomendaram o uso para crianças. Diante de tudo isso, não foi possível, com as informações etnofarmacológicas deste estudo, alicerçar a literatura especializada, já que há insuficiência de pesquisas com a espécie estudada. Há alguns estudos enfocando usos e atividades de L. pacari A. St.-Hil. Dessa forma, esse estudo recomenda também L. replicata Pohl. como uma potencial espécie terapêutica
Folhas de Laguncularia racemosa com galhas são menos atrativas para herbívoros mastigadores?
Evolutionary interactions between herbivores and plants have resulted in an impressive variety of adaptations, and herbivory pressure has led to the evolution of chemical, mechanical and phenological defense in plants. Coastal mangrove forests provide a very tractable system in which to study the dynamics of herbivory. The objective of this work was to evaluate if galled leaves of the mangrove tree Laguncularia racemosa (L.) Gaerten (Combretaceae) are less consumed by chewing insects. Monthly excursions were carried to the Maracaipe Mangrove in Pernambuco, to collect adult leaves from 60 plants of L. racemosa: 240 ungalled leaves consumed by chewing insects (CL), 240 galled leaves consumed by chewing insects (CLG) and 240 galled leaves not consumed by chewing herbivores (LG). Other leaves were collected in August, in order to quantify total phenolic concentration: 40 intact leaves of individuals with low rate of infestation by galls (LL) and 40 of individuals with high infestation (HL) were thus collected. CLG displayed a lesser loss of foliar area to chewing herbivores. The results show a significant amount of phenols in HL (35.63 mg) and LG (32.7 mg). This high phenol concentration is probably repelling chewing phytophagous. It is known that herbivores tend to avoid leaves that were previously predated by another herbivore. Possibly galls are influencing the feeding performance of the chewing insects. Key words: chemical defenses, total phenolic, mangrove.Interações evolutivas entre herbívoros e plantas resultaram numa impressionante variedade de adaptações, e uma pressão de herbivoria levou a evolução de defesas químicas, mecânicas e fonológicas em plantas. Manguezais são sistemas excelentes para estudos da dinâmica de herbivoria. O objetivo deste trabalho foi investigar se ha interação entre a galha induzida por acaro e herbívoros mastigadores em folhas de Laguncularia racemosa (Combretaceae). Foram realizadas excursões mensais (Novembro/2004 a Outubro/2005) ao manguezal de Maracaipe (PE), para coletar 240 folhas expandidas de cada categoria: consumidas por mastigadores (CL), consumidas e com galhas (CLG) e apenas galhadas (LG), provenientes de 60 plantas. Para as folhas que apresentavam indícios da atividade alimentar de mastigadores foi mensurada a porcentagem de herbivoria. A fim de testar se ocorre defesa induzida nas folhas de L. racemosa pela presença da galha foram quantificados os compostos fenólicos totais em folhas de cada categoria. Uma coleta de 40 folhas sem galhas foi realizada em indivíduos com baixa infestação (LL) e em indivíduos com alta infestação (HL) para quantificar os fenóis a fim de analisar se a defesa induzida seria sistêmica ou localizada. CLG obteve menor área foliar perdida pelo herbívoro mastigador. Foi registrada uma quantidade maior de fenóis em HL e LG. Uma alta concentração de fenóis provavelmente esta repelindo os mastigadores. Sabe-se que herbívoros tendem a evitar folhas previamente herbivoradas, pois podem conter maior concentração de defesas químicas. Possivelmente a galha esta influenciando o desempenho alimentar do inseto mastigador. Palavras-chave: defesa química, compostos fenólicos totais, manguezal
Valuation of the Aroeira (Myracrodruon urundeuva Allemão): perspectives on conservation
Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates
Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis).
Time period: Tree-inventory plots established between 1934 and 2019.
Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm.
Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield.
Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes.
Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests.
Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types
Geography and ecology shape the phylogenetic composition of Amazonian tree communities
AimAmazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types.LocationAmazonia.TaxonAngiosperms (Magnoliids; Monocots; Eudicots).MethodsData for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny.ResultsIn the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types.Main ConclusionNumerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions
Geography and ecology shape the phylogenetic composition of Amazonian tree communities
Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types.
Location: Amazonia.
Taxon: Angiosperms (Magnoliids; Monocots; Eudicots).
Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran\u27s eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny.
Results: In the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R = 28%). A greater number of lineages were significant indicators of geographic regions than forest types.
Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions
Mapping density, diversity and species-richness of the Amazon tree flora
Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4
While the increasing availability of global databases on ecological communities has advanced our knowledge
of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In
the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of
Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus
crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced
environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian
Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by
2050. This means that unless we take immediate action, we will not be able to establish their current status,
much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio
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