Spatial patterns of diversity at local and regional scales in a tropical lagoon

Abstract

The present study reports estimates of alpha (), beta () and gamma () diversity for the fish community of Chacmochuch Lagoon (SE Mexico), a natural protected area located in the northern portion of the Mesoamerican Barrier Reef System. Fish specimens were sampled in 2004 and 2006. Field work was carried out at three climatic peaks: at 13 stations using a 70 m-long beach seine. The collected data were supplemented with information obtained from a previous work conducted in 2002 and were then analyzed with multivariate statistical methods. In addition, fish composition results from this study were compared to those reported for other similar ecosystems of the region. A total of 68 fish species were recorded, determined as peripheral (high-salinity species, usually marine affinity) most of them. Most of the fish species collected were determined as rare, and a few number of species were determined as common and dominant. Salinity, TSD, temperature, dissolved oxygen and other variables were measured to determine the influence over the fish communities, four groups of sites where determined. Results indicated a gradual decrease in the degree of species replacement towards the interior of the system (away from the coast). The estimated value of gamma diversity was high compared to that reported for other coastal systems of the region and, due to the high degree of habitat heterogeneity found in this system; beta diversity had a greater contribution to gamma diversity than alpha diversity. This lagoon acts as a nursing area for many of the fish species collected in this study as indicated by the presence of juvenile stages.En el presente estudio, se midió y se determinó la biodiversidad alfa (), beta () y gamma () de la comunidad de peces en el Sistema Lagunar Chacmochuch, un Área Natural Protegida (ANP) localizada en la zona norte del Sistema Arrecifal Mesoamericano. El trabajo de campo se realizó en 13 sitios de muestreo durante los ciclos anuales 2004 y 2006, considerando los tres picos climáticos representativos de la región. Para la captura se utilizo un chinchorro de 70 m de largo. La matriz de información utilizada para el análisis se complemento con datos obtenidos a partir de un trabajo realizado durante el periodo 2002. Análisis multivariados fueron utilizados para la generación de resultados. Los resultados de la composición de peces se compararon con los reportados para otros ecosistemas similares de la región. Un total de 68 especies fueron registradas siendo periféricas (especies de alta salinidad y afinidad marina) la mayoría de ellas. Del registro, la mayoría de las especies se determinaron como especies raras, un número menor fueron especies comunes y dominantes. La salinidad, SDT, temperatura, oxigeno disuelto y otras variables fueron medidas para determinar su efecto sobre la comunidad de peces, encontrando cuatro agrupaciones de sitios. Los resultados indican una disminución gradual de las especies hacia el interior del sistema (al alejarse de la costa). La diversidad gamma es alta comparada a...

Composition and floral diversity in Andean grasslands in natural post-harvest restoration with Lepidium meyenii Walpers

“…Água vol. 14 n. 5, e2351 -Taubaté 2019 2017 (Caballero-Vázquez and Vega-Cendejas, 2012). Beta diversity, on the other hand, implies knowing the degree of replacement of species between communities or the number of species that share two or more communities (Moreno, 2001).…”