Intraspecific variation of Paubrasilia echinata (Fabaceae) wood along a latitudinal gradient in Brazil

Molecular and taxonomy approach have been made to understand the differences among the three morphotypes of Paubrasilia echinata, termed laranja, café and arruda. However, there is no wood anatomic study considering these morphotypes and their probable anatomical similarity. Considering as an endangered species with historical relevancy, it is crucial to recognize its wood anatomy to its conservation. This study aims to investigate the wood anatomy of P. echinata collected along its occurrence area (between 5°53′S 34°04′W and 22°56′S 42°30′W) and to examine the anatomical relationship among arruda, laranja and café morphotypes that was previously reported by molecular studies. The results indicate that the wood anatomy varied along its range of distribution a gradient of axial parenchyma and vessel features between the lower and higher latitudes was observed. Since arruda occurs in the collection sites of all four states studied, while café and laranja only in Bahia, the three morphotypes can be identified into of two groups based on wood anatomy: one formed by arruda samples and another by café and laranja, which differs from the previous molecular analysis. Combinations between higher percentage of axial parenchyma and wider vessels were observed in samples from RJ guarantying conductance and safety, while samples from RN and PB have smaller solitary vessels and scanty axial parenchyma, which could prevent embolisms. The present results do not support the categorization into subspecies or varieties. The findings also suggest that café and laranja share similar features than with arruda morphotype.publishe

O SABER BOTÂNICO ATRAVÉS DA SERINGUEIRA: COMO CONSERVAR O QUE NÃO CONHECEMOS?

The study aims to investigate the knowledge of population of Belém-PA on rubber trees, considering that it is a native Amazon species, of recognized historical and economic importance. The research-action practice method was used to increase the analysis and greater scope of the study’s intentionality, with an application of 85 semi-open questionnaires, involving men and women, with 55 % of the interviewed being students. It was observed that the population knows little about the rubber tree and its basic morphological aspects, showing more interest by animals than by plants. Likely, these gaps in knowledge occur because the overly theoretical way in which the teaching of botany is ministered, which may cause a certain aversion to discipline. One of the ways to minimize the distance between individuals and plants is the implementation of new teaching strategies focusing on a better teaching-learning process through the relation between botany and individual’s experience, which will produce greater autonomy of knowledge and reflections on society.Keywords: Euphorbiaceae; bio-diversity conservation; teaching botany; teaching-learning process; Amazon.O estudo tem como objetivo investigar o conhecimento da população sobre aspectos botânicos básicos acerca da seringueira no município de Belém-PA, tendo em vista que é uma espécie nativa da Amazônia, de reconhecida importância histórica e econômica. Utilizou-se o método pesquisa-ação prática para o enriquecimento das análises e maior alcance da intencionalidade do estudo, com a aplicação de 85 questionários semiabertos, envolvendo homens e mulheres, sendo que 55% dos entrevistados eram estudantes. Observou-se que tais indivíduos pouco sabem sobre a espécie em questão e seus aspectos morfológicos básicos, demonstrando mais interesse por animais do que por plantas. Estas lacunas no conhecimento ocorrem, possivelmente, pela forma excessivamente teórica do ensino de botânica, o que pode causar certa aversão à disciplina. Uma das formas de minimizar a distância existente entre os indivíduos e as plantas é a implementação de novas estratégias de ensino, visando um melhor processo de ensino-aprendizado através da relação da botânica com a vivência de cada indivíduo, o que produzirá maior autonomia do conhecimento e maiores reflexões para a sociedade.Palavras chave: Euphorbiaceae, conservação da biodiversidade, ensino de botânica, processo ensino-aprendizagem, Amazônia

Diversity of growth responses to recent droughts reveals the capacity of Atlantic Forest trees to cope well with current climatic variability

Understanding the behavior of trees and how they will respond to future climate change is a crucial conservation challenge, especially for tropical species. Despite the high diversity of tree species in Brazil, little is known about their tolerance limits. The study of tree rings is a valuable method for the analysis of growth dynamics with superposed epoch analysis being a good way to understand whether past dry years induce decreased tree growth, how long it takes to recover growth after a dry period, and the resilience of trees. This study investigated seven legume species (deciduous and evergreen) from three different sites in the Atlantic Forest in the state of Rio de Janeiro, Brazil. The studied trees seem to have coped well with the drought periods experienced thus far with no common pattern of recovery among species at the same site. The trees were not affected in a similar way and so different mechanisms are likely involved in preventing significant decreases in growth. These data are important for conservation policies because they reveal that each species requires a unique analysis.We thank the Laboratorio de Botanica Estrutural from Instituto de Pesquisas Jardim Botanico do Rio de Janeiro and the CNPq (Conselho Nacional de Desenvolvimento Científico Tecnologico) for the PDJ and Pesquisador Visitante fellowships, as well as CAPES (Coordenaçao de Aperfeiçoamento de Pessoal de Nível Superior), PPBIO (Programa de Pesquisa em Biodiversidade), and FAPERJ (Fundaçao Carlos Chagas Filho de Amparo `a Pesquisa do Estado do Rio de Janeiro) for the research fellowship grant

Climate signals in tree rings of Paubrasilia echinata (Leguminosae-Caesalpinioidea) from the Atlantic Forest of Brazil

Paubrasilia echinata once grew so abundantly along the tropical coast of South America that the names given to the tree by early Europeans colonists—Bresil, Brasil, Brazil—became synonymous with an entire geography. Today, despite restoration and protection efforts, the species remains under threat of extinction throughout Brazil’s Atlantic Forest. Considering the past overexploitation and ongoing climate changes, the future of P. echinata significantly depends upon human understanding of the species’ growth dynamics and growth-climate relations. Therefore, this work aims to: (1) demonstrate the feasibility of calendar dating P. echinata tree rings; (2) build chronologies by analyzing its growth rings; and (3) establish with detail the specific influence of climate on annual radial xylem production. Differences in vessel and axial parenchyma frequency, local distended rays and marginal parenchyma were the wood anatomical markers used to distinguish boundaries between adjacent rings so that dendrochronological methods could be applied. For climate-growth responses, we developed tree-ring width chronologies from wild and cultivated trees. Results revealed that seasonal rainfall is the most important factor influencing P. echinata growth. More specifically, positive correlation was observed between the tree-ring chronology of wild trees and precipitation during the rainy months of the growing season, while the tree-ring chronology of cultivated trees correlated negatively with precipitation in months before the growth period. Wild trees showed increment growth rates lower than planted trees. Rainfall’s observed effect on P. echinata is, of course, not surprising. However, our results contribute a detailed quantitative record of that effect, which expands the body of ecological knowledge regarding P. echinata necessary for ongoing conservation efforts under current and future human-caused climate change.Fil: Macedo, Tahysa Mota. Universidade Federal do Rio de Janeiro; Brasil. Instituto de Pesquisas Jardim Botânico do Rio de Janeiro; BrasilFil: Barros, Claudia Franca. Instituto de Pesquisas Jardim Botanico Do Rio de Janeir; BrasilFil: de Lima, Haroldo Cavalcante. Instituto de Pesquisas Jardim Botanico Do Rio de Janeir; BrasilFil: Brandes, Arno Fritz das Neves. Universidade Federal Fluminense; BrasilFil: Da Costa, Warlen Silva. Universidade Estadual Do Norte Fluminense Darcy Ribeiro; BrasilFil: Costa, Cecília Gonçalves. Universidade Federal do Estado do Rio de Janeiro; BrasilFil: Roig Junent, Fidel Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; Argentina. Universidad Mayor; Chil