doctoralThesis
Samambaias e Licófitas: florística e aspectos biogeográficos na Floresta Atlântica no Nordeste do Brasil
Fecha
2018-02-26Registro en:
SILVESTRE, Leandro Costa. Samambaias e Licófitas: florística e aspectos biogeográficos na Floresta Atlântica no Nordeste do Brasil. 2018. 161f. Tese (Doutorado em Sistemática e Evolução) - Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, 2018.
Autor
Silvestre, Leandro Costa
Resumen
The ferns and lycophytes comprise the seedless vascular plants and present the
dominant sporophytic phase. They are currently distributed in several regions, with a
greater predominance in the Tropical region, occurring mainly in the humid forests,
such as the Atlantic and Amazonian Forest, with 915 and 534 species recorded
respectively in Brazil. This work aims to record the occurrence of fern and lycophyte
species in remnants of the Atlantic Forest in the states of Rio Grande do Norte and
Ceará, for the conservation of biodiversity and important for the formation of corridors
in the Atlantic Forest. Through the distribution of the species of the family Pteridaceae
an analysis of panbiogeography was developed aiming to find generalized tracks
compatible with the routes for species exchange between the Atlantic and Amazonian
Forest. Considering that these routes would be viable for the presence of forest
fragments in other phytogeographic domains such as the Caatinga, Cerrado and
Pantanal, a biome distribution model was generated in South America in order to
establish the biome delimitation during the Last Glacial Maximum (glacial period) and
during the Mid Holocene (interglacial period). The registration of ferns and lycophytes
occurred in three conservation units, the Ubajara National Park, the Environmental
Protection Area (EPA) Serra da Meruoca (both in Ceará) and the Relevant Ecological
Interest Area (REIA) Mata da Bica (Rio Grande do Norte). In these areas, the greatest
number of environments possible were visited, mainly those with the highest
occurrence of ferns and lycophytes, the material collected was herborized and
deposited in the RN, UFRN, EAC and JPB herbarium. For the analysis of
panbiogeography, a spreadsheet with the record of Pteridaceae species occurring in
the Northern Atlantic Forest was elaborated then individual tracks, generalized and
panbiogeographic nodes were elaborated by means of the Martitracks and Quantum
Gis softwares. For the modeling of the biomes distribution during the glacial and
interglacial period, the Maxent software was used, with the algorithm of the same name
and the Openmodeller software with the environmental distance algorithm, was used.
The flora recorded in the REIA Mata da Bica and EPA Serra da Meruoca corresponds
to 17 species of ferns and one lycophyte. According to the similarity analysis, a greater
floristic similarity was observed between the EPA Serra da Meruoca and REIA Mata
da Bica with areas of the Caatinga phytogeographic domain, even occurring in the
Atlantic Forest phytophysiognomy. Through the analysis of Panbigeography it was
identified that the spatial homologies found through generalized tracks, corroborate
with the main routes for the interchange of species between the Atlantic and
Amazonian Forests. In relation to the delimitation of the biomes during the glacial and
interglacial periods, it was observed that most areas of the analyzed biomes showed
expansion during the Mid Holocene in comparison with the Last Glacial Maximum.
Expansion occurred in the Tropical and Subtropical Moist Broadleaf Forests (19.52%),
Grasslands, Savannas and Temperate Shrublands (12.12%), and Tropical and
Subtropical Dry Broadleaf Forests (8.76%). There was retraction in the Flooded
Grasslands and Savannas (1.25%) and Tropical & Subtropical Grasslands, Savannas
& Shrublands (6.38%). Areas of stability of wet forests that could act as bridges for
species exchange were also recorded.