Phenological monitoring for environmental impact assessment in estuarine mangroves in Northeastern Brazil

Abstract

Mangroves are one of the most productive ecosystems on the planet however they have undergone progressive environmental changes due to anthropic pressures. Information on phenological behavior can be used as an instrument in the construction of conservation projects of natural resources. The present study was carried out in four estuarine areas in Acaraú, Ceará, Brazil, with the aim of analyzing of phenological behavior regarding reproductive components of three mangrove species in different areas subject to different environmental impacts (solid waste, deforestation and shrimp farm effluent) and a low impacted area, during a period of one year. patterns of flowering and fruiting: Fournier Index (percentage of intensity) and the index of activity. The flowering of Avicennia spp. and Rhizophora mangle, under natural conditions, occurred all year round, and it showed irregular patterns. Regarding fruiting, Laguncularia racemosa was the species that presented the highest values for the two phenological indices analyzed. Rainfall and salinity seemed to exert a more selective force when species were subjected to an anthropic impact. The comparative analysis of the different phenological evaluation methods carried out in this study indicated that they provide different and complementary data about the reproductive behavior of the plant and how the impacts to which these environments are subjected may be negatively interfering with the flora of this ecosystem.

Keywords:
Phenology; Mangrove; Antropic pressure