Structural characteristics of mangrove forests in Brazilian estuaries: A comparative study

Abstract

Resumen.-Se caracterizó la estructura de la vegetación de los bosques de manglares en 9 estuarios en el estado de Ceará, nordeste de Brasil, con el propósito de compararlos y lograr concesión de subvenciones para su conservación. Se utilizó el método de los cuadrados múltiples, con 3 transectos de 5 cuadrantes en cada sitio. Se obtuvieron valores de diámetro y área basal de los árboles, la dominancia, la densidad del tronco y la frecuencia relativa de cada especie, además de las variables para el análisis de los sedimentos. Los resultados de los parámetros estructurales obtenidos mostraron diferencias entre los bosques de la muestra, de forma que los niveles más altos de densidad se hallaron en los ríos Acaraú, Ceará y Guriú. El rio Guriú además presentó los menores valores de altura, área basal y Diámetro a la altura del pecho (DAP). El análisis de agrupamiento de especies indica una separación de 3 grupos: 1) Cocó y Ceará, 2) Acaraú, Jaguaribe y Pacoti, y 3) Aracatimirim y Guriú. Los bosques de manglares en Curú y Barra Grande no conformaron ningún grupo con los anteriores. El Análisis de Componentes Principales (ACP) indicó que los sedimentos recogidos en los estuarios presentan una composición distinta. Las diferencias entre los sitios se deben tener en cuenta cuando se proponga la administración, ya que cada manglar exige estrategias diferentes para su mantenimiento.Palabras clave: Ceará, estructura de la planta, sedimento, vegetaciónAbstract.-The aim of this study was the characterization of mangrove forests in 9 estuaries in the state of Ceará, northeastern Brazil, with the purpose of comparing them and providing subsidies for their conservation. We used the method of multiple squares, having 3 transects of 5 quadrats at each site. We obtained values for the diameter and basal area of the individuals, dominance, trunk density and relative frequency per species, as well as variables for the analysis of sediment. The results obtained regarding structural parameters showed differences among the sampled forests, where the highest density levels were found in the Acaraú, Ceará and Guriú rivers. The Guriú River also presented the smallest values for height, Diameter at Breast Height (DBH) and basal area. The grouping analysis indicates 3 groups of forests: 1) Cocó and Ceará; 2) Acaraú, Jaguaribe and Pacoti, and 3) Aracatimirim and Guriú. The mangrove forests in Curú and Barra Grande were not grouped. The Principal Component Analysis (PCA) indicated that the sediments collected in the estuaries present a distinct texture composition. The differences between the areas must be taken into consideration when proposing management, as each mangrove demands different strategies for its maintenance.

Effects of Anthropogenic Pressures on the Structure of Floristic Components of Mangroves in the Cameroon Estuary

“…Basal areas in this study (27.87 to 115m 2 ha -1 ) are greater or equal to those obtained by Perera [21] and [22] in a mangrove in Sri Lanka with values ranging from 27.10 to 48.25m 2 ha -1 . However, our basal area values are much higher than those obtained by Maia [23] which range from 0.60 to 2.97m 2 ha -1 in the mangroves of the estuaries of Brazil and those obtained by Aheto [24] in the mangroves of the Kakum River estuary in Ghana. The basal areas in this study are also higher than those obtained by Din [10] which find average basal area of 8.804m 2 ha -1 for Rhizophora racemosa and 5.167m 2 ha -1 for Avicennia germinans in the mangroves of the Wouri estuary.…”

Mangrove Productivity and Phenology in Relation to Hydroperiod and Physical–Chemistry Properties of Water and Sediment in Biosphere Reserve, Centla Wetland, Mexico

“…The location of the mangrove in relation to the topography and coastal geomorphology is an important descriptor in the classification of mangrove forests (Twilley, 1998). The physical–chemical characterization of mangroves is one means of evaluating the response of mangroves to existing environmental conditions and of generating further data to support mangrove conservation (Camargo & Coutinho, 2012). Specifically, in mangroves, species composition and growth are directly affected by the physical composition of soils and by the proportions of clay, silt, and sand in soils, which determine the permeability and the hydraulic conductivity of water and also influence soil salinity and water content (Kathiresan & Bingham, 2001).…”

The effect of extreme climatic events on littorinid snails in two estuarine environments, temperate (NW Spain) and tropical (NE Brazil)

“…The Acaraú estuary features a predominance of unconsolidated sedimentary substrates and mangrove forests composed of Rhizophora mangle Linnaeus, 1753, Laguncularia racemosa (Gaertner, 1805), Avicennia germinans (Linnaeus) Stearn 1958, andA. shaueriana Stapft &Leechman (Maia andCoutinho, 2012).…”