| Abstract Detail
Ecological Section Lopez-Portillo, Jorge [1], Bartolo, Olga [2], Basañez, Agustin [2], Vasquez Reyes, Víctor M. [1], Gomez Aguilar, Leon R. [1], Avila Reyes, Yeny E. [2]. Massive mangrove mortality at Tampamachoco lagoon, Tuxpan, Veracruz, Mexico. World mangrove cover has reportedly been reduced about 35% from the 1980´s, mainly by conversion to grasslands, shrimp farms, or urban, touristic and industrial development. The mangrove forest of the Tampamachoco lagoon, at 21° latitude in the Gulf of Mexico coast, has a dead area of 20 ha contiguous to a thermoelectric plant. We sought to explain the causes of this massive death which began to 20 years ago and is still expanding. We traced two control W-E transects and two transects that crossed the dead area, all parallel to the slope and measured microrelief and water table height and salinity at regular intervals. We also measured tree height and DBH in 10 m x 10 m plots placed regularly along the transects and designed a scale to estimate the damage in each tree that considered from slight loss of canopy leaves to total dead of the individual. Intact areas are composed of mixed mangrove forests of Rhizophora mangle and Avicennia germinans or monospecific A. germinans in the distal, East part of the transects. The areas with massive tree death were occupied by a monospecific A. germinans forest. Soil level has collapsed in the dead zones, 5-10 cm lower than its equivalent in the live area. During the dry season salinity in the dead zones was higher than 100 ppt vs. 80 ppt in a similar position along the healthy transects. Two hypotheses were explored to explain hipersalinity and consequent death of mangroves: E-W seawater intrusion from water discharge channels built for the thermoelectric plant, or interruption of N-S water flow through the forest by elevated maintenance roads, followed by evaporation. Soil cores, water table levels and salinity allowed us to exclude seawater intrusion and supported the interruption of N-S water flow, suggesting the procedure of future rehabilitation.
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1 - Instituto de Ecología, A. C, Departamento de Ecología Funcional, Km 2.5 Antigua Carretera a Coatepec 351, Xalapa, Veracruz, 91070, México
2 - Universidad Veracruzana, Facultad de Ciencias Biologicas y Agropecuarias, Tuxpan, Veracruz, 92850, Mexico
Keywords:
hipersalinity
salinity stress
black mangrove
red mangrove
Avicennia
Rhizophora.
Presentation Type: Oral Paper:Papers for BSA Sections
Session: 34
Location: Alpine B/Snowbird Center
Date: Tuesday, July 28th, 2009
Time: 8:00 AM
Number: 34001
Abstract ID:896 |
