(PT) Inventário polínico para acervo palinológico da vegetação de canga da serra sul de Carajás, Pará

Author(s): MACAMBIRA. Higor Jardim
Summary: The implementation of a palynological collection will provide a greater taxonomic detailing of plant species and the comparative analysis of pollen types found in Quaternary sediment samples from the Serra dos Carajás, State of Pará. Furthermore, the data contained in the collection will subsidize paleoenvironmental and paleoclimate studies at Serra dos Carajás, as they will allow the accurate identification of plant species, physical space and abiotic factors that affect the ecosystem and determine the distribution of the populations of a particular community. This work aims to start the installation of a palynological collection and develop an applied study on its use in the system of Poaceae pollen grains, the lateritic crusts (canga) of the Serra dos Carajás and its applications in ecological and paleoecological studies. Therefore, existing exsiccatae in the herbarium of the Carajás Zoobotanical Park and the herbarium of Museu Paraense Emilio Goeldi were examined for preparation of flower buds for pollen analysis. Initially, 228 slides relative to 57 species of monocots were prepared, organized and catalogued according to Cronquist (1981, 1988) with the newest additions catalogued according to APG II and APG III. This material will be deposited in Technolach cabinets that can store up to 6.534 slides, at Carajás Zoobotanical Park, which reinforces the interest of Vale in the exhibition and propagation of scientific work developed by Vale Technological Institute. Among the species of monocots, pollen grains of the Poaceae Family belonging to the genus Andropogon, Mesosetum, Mnesithea, Eragrostis, Paspalum and Rhytachne were morphologically and statistically analyzed in an attempt to group congeneric species that occour in dry and wet environments in the canga of the Serra dos Carajás. This family is difficult to characterize morphologically, and its occurrence and relative predominance in the fossil record are generally associated to drier climate and savannization. As such, the statistical analysis indicates that the parameters: grain size (width and length) and annulus width may be the most adequate for inter genus differentiation. However, amongst the genus that occurs in dry and humid environments, only the Axonopus genus was possible to be individualized. So, the use of the abundance of Poaceae on paleoenvironmental studies to determine climate changes must be performed with caution, since the difficulty in identifying the grains at the level of species and genus due to high similarity of morphological characteristics, can cause errors in the interpretation of data inferred from the abundance of this family. In light of this, it’s necessary to include more genus of Poaceae in this study to validate or not this preliminary conclusion. That is why a palynological collection will be able to give a greater taxonomical detail of the vegetal species and comparative analysis of the pollen types found in sediment samples for a sure identification of these species and so that interpretative problems in future paleoenvironmental studies may be minimized.
Year: 2015
Pages: 78 f.
Year of publication: 2015
Supervision: José Tasso Felix Guimarães, Dr.
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Course: Master's Degree in Sustainable Use of Natural Resources in Tropical Regions