masterThesis
Relações florísticas e ambientais no litoral semiárido do Rio Grande do Norte, Brasil
Fecha
2017-08-31Registro en:
MOURA, Edweslley Otaviano de. Relações florísticas e ambientais no litoral semiárido do Rio Grande do Norte, Brasil. 2017. 39f. Dissertação (Mestrado em Sistemática e Evolução) - Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, 2017.
Autor
Moura, Edweslley Otaviano de
Resumen
Brazil has the largest forest remnants on the planet, a great complexity of environments and
high species diversity. All this biodiversity is threatened mainly by human intervention in
natural areas and more intensely in the coastal zone, where the largest urban areas are located.
In this context, the Caatinga and Atlantic forest are some of the most threatened domains in
Brazil. This study aimed to answer the following questions: 1) what the floristic composition
along a stretch of coastal vegetation in semi-arid environment? 2) is there variation in this
composition? 3) what are the main factors? 4) in which domains species have the most affinity?
For this, 120 sample units (UAs) of 10 × 10 m were unsystematically allocated in six blocks of
1 × 5 km in the coastal region of Rio Grande do Norte state. In all UAs the occurrence of plant
species of all habits was noted. The floristic data were crossed with climatic variables and
analyzed through R and Microsoft Excel software. 148 species were recorded and Fabaceae,
Rubiaceae, Poaceae and Euphorbiaceae were the richest families. Exotic species also had a
relevant participation in the communities, mainly in block 6, where they dominated. Among
the variables surveyed, only maximum monthly temperature (Tmax) did not have collinearity
with the other variables, suggesting that temperature in a general way and the supply of water
through rainfall, more than the other factors, is what influences the most distribution of species
along the coast. The coast range from the central portion of the state towards the west is more
related to each other and the eastern band forms a distinct group from the other coastal regions
of the northern range of the state. The species richness was decreasing in the east-west direction,
which together with the higher precipitation rates, reflects the relation of the regions more to
the east with the Atlantic Forest domain. Towards the state countryside the floristic composition
presents greater relation with the adjacent phytogeographic domain, the Caatinga. The coastal
formations from the central portion to the western of the state have a greater relationship with
the Caatinga domain.