Recent records of Avicennia bicolor (Acanthaceae) on the Mexican Pacific coast with notes on its distribution and conservation status

Abstract

Background. The mangrove Avicennia bicolor was first recorded in Mexico in 1946, however until now there is no basic information about its distribution supported by herbarium specimens. Goals. Three recent records of A. bicolor are provided at a new location in Mexico on the coastal wetlands of the Gulf of Tehuantepec, Chiapas; and the information about its known records on the American Pacific is summarized. Methods. Plant specimens were collected, which then, were dried, corroborated and deposited in four national herbaria. In the field, some structural attributes of the mangroves were determined such as density, basal area and height. A database and publications of species records were reviewed to preliminarily analyze their known distribution in the Pacific. Results. In Mexico, A. bicolor has been recorded only on the coastal wetlands of Mar Muerto and Los Patos-Solo Dios. The preliminary ecological diagnosis showed its presence in relatively dense stands (234 ± 86 trees ha-1) and with high structural development (basal area: 16.1 m2 ha-1, height: 13.9 m). Although its presence is apparently conspicuous in several localities of Panama and Costa Rica, data on the species in the coastal strip between the Gulf of Fonseca and the Gulf of Tehuantepec is lacking. Conclusions. The importance of these records is evident, considering the scarce information available on A. bicolor and its restricted distribution in Mexico. We consider it appropriate to increase the ecological studies in its distribution area and give it protection through its inclusion in the Official Mexican Standard (NOM-059).