10 páginas, 7 figuras, 1 tabla.[EN]: Mangrove loss in Mexico led to the development of different recovery programs focused on building and maintaining greenhouses, reforestation, and the construction of drainage systems along coastal roads to reestablish surface water flows. However, these recovery strategies have not been as successful as expected because they were not based on an evaluation of environmental characteristics required for mangrove development in the context of new hydrological and sedimentary conditions. The studies performed over the last ten years by the mangrove group at Centro de Investigación y de Estudios Avanzados (CINVESTAV), in collaboration with other institutions, resulted in a conceptual framework that we present here as a methodological approach for the ecological restoration of mangroves in the Yucatán Peninsula. The conceptual framework is based on the relationships among the geomorphology, hydrology, and structural and functional characteristics of mangroves that are associated with the environmental services offered by these ecosystems. The methodological approach is fundamentally concerned with the particular characteristics of the karstic environmental setting of the Yucatán Peninsula as well as social and economic aspects of restoration. This approach to mangrove restoration includes stages for planning, implementing, and monitoring mangrove restoration programs in karstic environments.[ES]: La pérdida de manglares en México ha llevado al desarrollo de diferentes programas para abordar su recuperación. En la Península de Yucatán estos programas se han centrado principalmente en la construcción y mantenimiento de invernaderos, la reforestación y la construcción de sistemas de alcantarillas en las carreteras costeras para restablecer los flujos de las aguas superficiales. Sin embargo, estas estrategias de recuperación no tuvieron el éxito que se esperaba, principalmente porque no se basaron en la caracterización ambiental como un criterio para identificar las condiciones hidrológicas y de sedimentos necesarias para el desarrollo de manglares. Los estudios realizados durante los últimos diez años por el grupo manglares en el Centro de Investigación y de Estudios Avanzados (CINVESTAV), en colaboración con otras instituciones, han dado lugar a un marco conceptual que se presenta aquí como un enfoque metodológico para la restauración ecológica de los manglares en la Península de Yucatán. El marco conceptual se basa en las relaciones que hay entre la geomorfología, la hidrología y características estructurales y funcionales de los manglares, y que están asociados con los servicios ambientales que ofrecen estos ecosistemas. El enfoque metodológico es fundamentalmente relacionado a las características particulares del entorno kárstico de la Península de Yucatán, así como aspectos sociales y económicos de la restauración. Este enfoque de la restauración de manglares incluye las etapas de la planificación, implementación y seguimiento de los programas de restauración de manglares en ambientes kársticos.Funds for studies\ud and mangrove restoration projects in\ud Yucatán were from CONACyT-66223,\ud JICA, CONAFOR, SEMARNAT, and\ud CONABIO-FN009 and GH009.Peer reviewe

The restoration of mangroves has gained prominence in recent decades. Hydrological rehabilitation has been undertaken to connect impaired mangroves with the sea, lagoons or estuaries. Because mangrove hydrodynamics occurs on the surface and interstitial spaces in the sediment, we propose to determine the hydrological flow paths to restore the hydrological regimes of the impaired mangroves. The hydrological flow paths were determined through a micro basin analysis based on microtopographic data to generate a digital elevation model. Applying this methodological approach, the hydrology of an impaired area on a barrier island in the Gulf of Mexico was restored by excavating, desilting or clearing the channels on the identified hydrological flow paths. This area was compared to one in which impaired mangroves were reconnected to the marine lagoon but disregarding the flow paths. Data collected in both areas were evaluated by flood level analysis, using two methods: (i) a simple linear regression model (SLRM) and (ii) spectral analysis (SA), also known as dominant frequency analysis. The results suggest that restoration based on the hydrological flow paths was more effective than the direct opening to the nearest main water body without accounting for the microtopography. In both areas, soil salinity and sulfides decreased after hydrological reconnection. However, a greater efficiency in the investment of time and human resources was achieved when preferential flow paths were identified and taken into account. The methodological procedures described in this study are of universal application to other mangrove restoration programs.

Background: Mangrove forests provide many ecosystem services, including the provision of habitat that supports avian biodiversity. However, hurricanes can knock down trees, alter hydrologic connectivity, and affect avian habitat. In 1995, Hurricanes Opal and Roxanne destroyed approximately 1,700 ha of mangrove forest in Laguna de Términos, Mexico. Since then, hydrological restoration has been implemented to protect the mangrove forest and its biodiversity. Methods: Since avian communities are often considered biological indicators of ecosystem quality, avian diversity and species relative abundance were evaluated as indicators of mangrove restoration success by comparing undisturbed mangrove patches with those affected by the hurricanes. Using bird surveys, similarity analyses, and generalized linear models, we evaluated the effects of water quality variables and forest structure on the relative abundance and diversity of the avian community in disturbed, restored, and undisturbed mangrove patches. Results: Higher bird species richness and relative abundances were found in disturbed and restored sites compared to the undisturbed site. After restoration, values of frequency of flooding, water temperature, tree density, and the number of tree species were more similar to that of the undisturbed site than to the values of the disturbed one. Such variables influenced the relative abundance of bird guilds in the different habitat conditions. Furthermore, some insectivorous bird species, such as the Yellow Warbler and Tropical Kingbird, were found to be similarly abundant in both undisturbed and restored sites, but absent or very low in occurrence at the disturbed site. Conclusions: Collectively, our results strongly suggest that hydrologic restoration helps to enhance niche availability for different bird guilds, including water and canopy bird species. Our work can help inform management strategies that benefit avian communities in mangrove forests and wetland systems.

We evaluated the success of the ecological restoration of a degraded mangrove forest by monitoring the natural regeneration of Avicennia germinans (black mangrove). The restoration actions focused on hydrological rehabilitation by desilting tidal channels and modifying the microtopography to enhance or restore water flow. As a result of these efforts, a population of black mangrove established naturally. Six sampling sites including restored and reference areas were established. We measured seedling survival; tree density, height, and growth rate; and the physical and chemical characteristics of soil and water. According to a redundancy analysis, microtopography and hydroperiod contributed the most to the establishment and development of the black mangrove. Microtopography ranged from 0.08 to 0.14 m above sea level. In the case of the hydroperiod, water level ranged from 0.11 to 0.14 m, flooding duration ranged from 439 to 529 h per month, and frequency was 7 to 8 floods per month. Our results highlight the contribution of microtopography and hydroperiod to the natural establishment of black mangrove. It is important to consider these 2 variables in mangrove ecological restoration.