ResumoNeste trabalho, foi estudada a influência da exploração do látex na anatomia do lenho de seringueiras nativas. Avaliou-se a hipótese de que as características anatômicas são afetadas pela atividade de extração do látex. Para isso, foram coletadas, de forma não-destrutiva, amostras em árvores nativas exploradas e não exploradas. As coletas foram feitas na Reserva Experimental de Catuaba, localizada em Senador Guiomard (AC). A estrutura anatômica do lenho foi analisada, sendo avaliados: o comprimento das fibras (não-gelatinosas e gelatinosas); diâmetro total e diâmetro do lume de fibras não-gelatinosas; diâmetro e frequência dos elementos de vaso; largura, altura e frequência de raios; e a proporção de tecidos. Árvores exploradas e não-exploradas diferiram na estrutura anatômica em relação às características quantitativas. Apenas as variáveis comprimento de fibra gelatinosa, diâmetro do lume das fibras, frequência de raios e proporção de elementos de vaso e raios não apresentaram diferenças significativas pelo teste de Mann-Whitney. Os resultados mais contundentes consistiram em aumento da largura e altura de raios nas árvores extraídas, bem como maiores proporções de fibras gelatinosas nas árvores não-extraídas. As diferenças observadas entre os grupos avaliados podem ser atribuídas à demanda de carboidratos que a regeneração do fluxo de látex ocasiona nesses indivíduos. Recomendam-se maiores estudos acerca do consumo de carboidratos não-estruturais, relacionados diretamente às mudanças na estrutura do xilema de seringueira. Palavras-chave: Seringueira nativa, largura de raios, fibras gelatinosas. AbstractIntra-specific variation in the anatomy of Hevea brasiliensis (Willd. Ex A. Juss.) Mull. Arg. related to tapping activity. The influence of tapping on the wood anatomy of naturally grown rubber trees was studied in this paper. The hypothesis that anatomical characteristics are affected by tapping activity was evaluated. Thus, nondestructive samples were collected from tapped and untapped native trees. Sampling was carried out at Catuaba Experimental Reserve, located in Senador Guiomard (state od Acre, Brazil). The wood anatomical structure was analyzed, and the following features were assessed: fiber length (non-gelatinous and gelatinous); total fiber diameter and lume diameter of non-gelatinous fiber; tangential diameter and frequency of vessel elements; width, height and frequency of rays; and tissue proportion. Tapped and untapped trees differed in anatomical structure in terms of quantitative characteristics. Only the following variables did not show significant differences by the Mann-Whitney test: gelatinous fiber length; fiber lumen diameter; frequency of rays; and proportion of vessel elements and rays. The most remarkable results were the increasing width and height of rays in tapped trees, as well as the greater proportions of gelatinous fibers in untapped trees. The differences observed between the evaluated groups may be attributed to the carbohydrate demand that the regeneration of latex flow c...
Climate change is expected to increase the occurrence of severe droughts in the tropics, and little is known about its influence on tree dynamics. Tree-ring width and remote sensing tools can help understand the impacts of climate change on tree growth. We evaluated the applicability of NDVI to obtain phenological metrics (e.g., start, peak, end, and length of growth season) and explored its relationship with tree-ring width of Tectona grandis (teak). The phenological metrics and tree-ring width were correlated with each other, and with both local (temperature, precipitation, solar insolation, Standardized Precipitation Evapotranspiration Index -SPEI) and large-scale (El Niño) climatic variables. The length of season and tree-ring width of teak were positively correlated with precipitation and negatively correlated with temperature in the initial months of the growth period. Tree-ring width was negatively correlated with El Niño events. Climate variables and length of season from the prior period were correlated with the tree-ring width of the current growing period. This study demonstrated that rather than directly affecting productivity, climate might also affect the length of the growing season, which would affect tree growth in the next season.
The objective of this study was to characterize the wood anatomical structure of a rubber tree clone, under the influence of two different canopy grafts. The following rubber trees were selected in the system of a double-grafted PB 311 + FX 2784 and PB 311 + MDF 180. For each tree, discs of wood were cut from the affected branch immediately below the insertion of clone at right angles to the axis, from which the regions corresponding to tension, in opposite and normal wood, were identified. The anatomical analyses were conducted in accordance with the standards established by the International Association of Wood Anatomy Committee. The Kruskal-Wallis nonparametric test was applied for multiple comparisons among the types of woods and radial positions studied, at 5% of significance. Still, multivariate associations were assessed among the anatomical characteristics of both double-grafted rubber trees, by means of a two-step cluster analysis. Quantitative morphological differences were observed in the wood cells of the double-grafted studied clones. The ray height and the vessels diameter were the most important morphologic characteristics for the distinction. The canopy clone exhibited the ability to modulate the quantitative anatomical characters of the panel clone, depending on the plant’s needs.
Background: Copaiba oil (Copaifera L.) is a raw material used by pharmaceutical, cosmetic, and energy industries. However, the difficulty in locating the oleoresin reservoirs, is an obstacle to its continued supply, affecting the sustainable commercialization of the product. So, the potential of impulse tomography for prospecting oleoresin reservoirs in the trunk of 18 Copaifera sp. trees was tested, in cross-sections at heights levels 0% (DBH), 25%, 50%, 75%, and 100% (1st fork). The impulse tomography prospections (ITP) were performed only at the 0%, in others 12 trees, because of the risk associated with climbing hollow trees. In total 30 trees were tested. Altogether 102 tomograms were analyzed obtaining: average mechanical wave propagation speed (aMPS), minimum mechanical wave propagation speed (minS) and maximum mechanical wave propagation speed (maxS), prospecting height (Hp%) and total tree height (Ht), diameter at the Hp% (Dhp), and low speed mechanical wave propagation percentage areas (LSa%). These variables were analyzed using multivariate analysis. Results:The reservoirs were located exclusively at DBH and confirmed by borer prospection increment in 26.7% of the trees. ITP resulted in 37.3% of correct answers and 62.7% of errors, considering the 99 tomograms. However, it was found that the ITP is efficient to indicate sections for which no significant reservoir or hollow presence is expected to be found. The analysis of the main components showed that, except for Ht, the components are good indicators for the location of the reservoirs. Conclusion:We were able to use tomography to search reservoirs with a significant amount of oleoresin, identify hollow trees, and indicate the exclusion of trees that do not have reservoirs or other alterations.
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