Palmeiras da Amazônia brasileira: uma abordagem sobre o uso e a estrutura anatômica dos estipes

Abstract

The Amazon Forest stands out from other Neotropical forests due to its high biological diversity and its great importance for global climate stability. Among monocotyledons, the family Arecaceae (palms) has particularly great abundance and richness in the region. Despite the ecological, ethnological and economic importance of several palms, they are still poorly understood or structurally unknown, especially with regard to stem anatomy, for which information is scarce and fragmented. This study aimed to expand knowledge of native palms in the Brazilian Amazon using an integrated and applied approach to the valorization, conservation and sustainability of this important natural resource and its goods and services provided to society. Species of known use were inventoried and the cortical and subcortical regions of stems of palms with different habits were described and analyzed comparatively. The analysis related forms of use, taxonomic identification and to the support for scientific evaluations of the potential use of economically promising species already used empirically used in the construction of housing, furniture, utensils and handicrafts. The results initially present, in Item 3 of this work, the status of knowledge regarding stems of palms from the Brazilian Amazon (Types and uses of stems of palms from the Brazilian Amazon: a review). Analysis of this dataset brings together use types with the habits and types of lignified stems of native species. The results are relevant for understanding stem use categories, highlighting promising alternatives for the development of new sustainable products and sources of income for communities in the region. Item 4 (Anatomical and histochemical structure of stems of palms of different habits and the greatest record of use in the Brazilian Amazon) presents a macro and microstructural evaluation of the fibrovascular bundles of the species with the greatest record of local use, namely: Desmoncus polyacanthos, Euterpe oleracea and Socratea exorrhiza. The aim was to identify qualitative-quantitative parameters for identifying and relating the uses and quality of stems. The following fourteen anatomical and histochemical characteristics were identified: sclerenchymatic cap shape; punch plate type; punch plate bar number; phytolith type; brownish-brown cap on the sheaths of vascular bundle caps and coloration of fundamental parenchyma; growth pattern; fundamental parenchyma cell shape; fiber/sclereid distribution in the sclerenchyma cap; fusiform sclereid presence in the sclerenchymatous cap; fiber end diversity; sclerenchyma cap height and width; total diameter, wall thickness and wall lamellae fiber/sclereid number; metaxylem vessel diameter; perforation plate bar number; and lignin type in walls of lignified tissues. These characteristics were decisive for differentiating growth habit types and, consequently, for a better understanding of stem use types, since habits are generally associated with how palms are used. Item 5 (Phytoliths in palms and their intrinsic relationship with intercellular pits), finalizes the results with an investigation of new anatomical evidence for characterizing phytolith shapes and their relationship with the pit structure of sclerenchyma cells in stem vascular bundles. These results expand knowledge about biomineralization and the mechanism of deposition of these inorganic structures along the surface of these cell walls. Ultimately, the results corroborate the diversity and informative potential of palm stems and fill knowledge gaps for the family Arecaceae with relevant and unpublished data. The results also provide support for both the identification of other species of palms of the Brazilian Amazon with sustainable economic potential and the development of public policies that value generated products and conserve local biodiversity.