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<p>Se analizó la dinámica espacial de la cobertura de manglar en el humedal costero El Cabildo-Amatal-Gancho Murillo, Chiapas, México, determinando su impacto por procesos de fragmentación. El análisis de cambios demostró una pérdida de 509 ha de manglar en un período de 17 años y una tasa de deforestación anual del 1.05%. Las métricas estimadas indican que el sistema se conforma por 38 parches de manglar mayores a 0.36 ha en el 2011, presentando un aumento del 58% en su número con respecto a 1994. La dimensión fractal de 1.4 y la tasa de fragmentación indican un paisaje impactado. Los resultados muestran que debido a los cambios en el sistema es necesario implementar planes de manejo costero.</p><p> </p><p><span>LAND COVERAGE CHANGES AND FRAGMENTATION <span>OF MANGROVES IN THE SOCONUSCO REGION, <span>CHIAPAS, MEXICO, 1994-2011</span></span><br /></span></p><p><strong>ABSTRACT</strong><br /> We analyzed the spatial dynamics of the mangrove coverage of El Cabildo-Amatal-Gancho Murillo coastal wetland in Chiapas, Mexico by determining their impact by fragmentation processes. The analysis of changes showed a loss of 509 ha of mangrove in a 17-year period and an annual deforestation rate of 1.05 %. The metrics indicate that the system was composed of 38 largest mangrove patches greater than 0.36 ha in 2011, which represents an increase of 58% regarding its size in the year 1994. The fractal dimension of 1.4 and the fragmentation rate estimated suggest that the landscape has been impacted. Altogether, the results show that, due to changes in the system, it is necessary to implement coastal management plans.</p><p> </p><p> </p>

Fiddler crabs are essential to understanding tropical coastal wetlands' dynamics and analyzing carbon budgets because they are the primary epibenthic biomass. They have a high consumption of detritus/bacterial biomass and generate high rates of bioturbation in sediments, affecting storage and export carbon budgets. In the present study, we analyzed the feeding ecology and bioturbation of Uca princeps with field experiments (i.e., daily food intake) and laboratory/analysis. This study estimated the daily food intake, evacuation rates, organic matter/carbon content, and bioturbation rate by feeding this species in two seasons (cold and warm). We found that the percentage of daily intake of U. princeps measured in dry weight in November 2008 was 16.2% and 17.4% for females and males, while in April, the food intake was much higher with 38.4% and 41.6%, respectively. The average bioturbation of this species through their feeding activities was ~ 0.3 Mg ha− 1 day− 1. The results suggest that the females are more selective in their feed. The evacuation rate was 0.84 h− 1 for females and 0.87 h− 1 for males. Therefore, U. princeps plays a vital role within the peri-urban ecosystem by removing/altering high quantities of organic matter from the sediments, transforming them into biomass, and influencing biophysical modifications in the peat.

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