Biologia reprodutiva, distribuição espacial e conservação de Hadrolaelia coccinea (Lindl.) Chiron & V.P. Castro (Orchidaceae, Laeliinae) no Parque Estadual do Ibitipoca, Minas Gerais, Brasil

Abstract

Ecological interactions are of extreme importance to every ecosystem, once the relationships between plants and pollinators have a structuring role for natural and agricultural systems. The reproductive phase is a defining moment in the lifecycle of any organism, influenced by the biotic and abiotic conditions, that draws the reproductive characteristics. In this way the distribution of the species is highly related to the mechanisms of dispersion and conditions of the place to determine the density and the high diversity of species that we find in the planet. Furthermore, often the anthropogenic impact is a striking factor in this whole relationship. Orchidaceae is a cosmopolitan family found in almost all continents of the Earth, except in Antarctica, with about 24500 species. In Brazil the domain of the Atlantic Forest stands out in number of species, reaching 50% of all species found in the country. Laeliinae is the third largest subtribe of Orchidaceae, with about 2080 species exclusively distributed in the Neotropical Region, being often desired by collectors due to the morphological and chromatic diversity of their flowers. Hadrolaelia coccinea (Lindl.) Chiron & V.P.Castro occurs in the South and Southeast regions of Brazil, being endemic to the Atlantic Domain. The flowers are main characteristic is its intense red color, with great ornamental appeal. In the Parque Estadual do Ibitipoca this species has a predatory collection history, where a subpopulation is extinct in the place. In this way, a study was carried out evaluating aspects of the reproductive biology, spatial distribution and anthropogenic impact in order to evaluate the situation of the species in said park. In the first chapter the study of biology reproductive was fullfiled assessing phenology, possible pollinators, aspects of floral biology, crossing systems and viable sees of natural pollinations, through the tretazolium test. The system is described annual - flowering patterns, with main strategy - GFD – Generalized Food Deception, for not offering floral reward for its pollinator, deceiving him through the another species with which she shares morphological characteristics and which offer nectar. By the floral characteristics the mechanism of pollination is "Key- hole flower" having the hummingbird as a potential pollinator. It presents a self- compatible and allogamic system, with cross-pollination as a rule, since there is the presence of a physical barrier that avoids self-pollination. Consequently, it presents a low fruiting rate, but with a high number of seeds. In the second chapter was evaluated the spatial distribution through of four transects of 200 x 8 m distributed inside and border of dwarf cloud forest, in transition cloud shrub. Your spatial distribution was evaluates through os Índice Morisita (IM) Variance/Avarage rate (R). The individuals in the both environment were accounted in groups of youth and adults, registering the forophytes. The statistical significance of test was compared by test t. The correlation of circumference of the trunks with the abundance of individuals of H. coccinea was done through of a linear regression. The results showed an aggregate distribution pattern, with differences of abundance between the interior and border environments of the dwarf cloud forest, but the density of young and mature individuals did not have significant difference. There is a preference for a species of phorophyte, Eremanthus erythropappus (DC.) MacLeish (Asteraceae), popularly called candeia, with CAP having a small influence on the density of individuals on the phorophytes. In the third chapter we evaluated the anthropogenic impact on H. coccinea in areas where the circulation of tourists, through the establishment of four transects of 200 x 8 m in two environment, at where tourists pass are allowed (T) and circulation is not allowed (ST), and registrer the abundance of individuals in the forophytes. The statistical significance was fulfill of Mann-Whitney. The subpopulation of T presents a low rate of individuals, opposing what occurs in the environment ST, which presents a subpopulation with high number of individuals.