Do restoration strategies in mangroves recover microbial diversity? A case study in the Yucatan peninsula

Abstract

Mangrove forests are fundamental coastal ecosystems for the variety of services they provide, including green-house gas regulation, coastal protection and home to a great biodiversity. Mexico is the fourth country with the largest extension of mangroves of which 60% occurs in the Yucatan Peninsula. Understanding the microbial component of mangrove forests is necessary for their critical roles in biogeochemical cycles, ecosystem health, function and restoration initiatives. Here we study the relation between the microbial community from sediments and the restoration process of mangrove forests, comparing conserved, degraded and restored mangroves along the northern coast of the Yucatan peninsula. Results showed that although each sampling site had a differentiated microbial composition, the taxa belonged predominantly to Proteobacteria (13.2-23.6%), Desulfobacterota (7.6-8.3%) and Chloroflexi (9-15.7%) phyla, and these were similar between rainy and dry seasons. Conserved mangroves showed significantly higher diversity than degraded ones, and restored mangroves recovered their microbial diversity from the degraded state (Dunn test p-value Benjamini-Hochberg adjusted = 0.0034 and 0.0071 respectively). The structure of sediment microbial β-diversity responded significantly to the mangrove conservation status and physicochemical parameters (organic carbon content, redox potential, and salinity). Taxa within Chloroflexota, Desulfobacterota and Thermoplasmatota showed significantly higher abundance in degraded mangrove samples compared to conserved ones. This study can help set a baseline that includes the microbial component in health assessment and restoration strategies of mangrove forests.

Fig 1. Study sites and the conservation status of the sampled plots.

In each location red (conserved), green (degraded) and blue (restored) points show the conservation status, light blue layer shows water bodies (INEGI, 2010 [40]) and light green layer shows mangrove coverage (CONABIO, 2021 [41]). The vectorial data of Mexico administrative boundaries are from the following source: https://www.geoboundaries.org. The vectorial data of Yucatan hydrography are from the following source: INEGI, 2010 [40]. The vectorial data of Yucatan’s mangrove coverage are from the following source: CONABIO [41]. The pipeline to construct the map with R libraries: ggplot2, ggspatial, sf and ggpubr is available in Github (https://doi.org/10.5281/zenodo.11269158). The terms of use of vectorial information can be consulted in https://www.geoboundaries.org/index.html#usage, https://en.www.inegi.org.mx/inegi/terminos.html and http://geoportal.conabio.gob.mx/metadatos/doc/html/mx_man20gw.html respectively [42].

Fig 2. Alpha diversity (1/D).

Microbial genetic diversity (inverted Simpson index) in sediments along the northern coast of Yucatan.

Fig 3. Relative microbial abundance.

The most abundant microbial orders found along the northern coast of Yucatan. Taxa within the “Other” category have abundances lower than 0.5%.

Fig 4. Principal coordinate analysis (PCoA).

Dispersion of sediment microbial composition along the northern Yucatan coast. Distances were measured with Weighted UniFrac metrics. Ellipses account for 85% of the samples within each group. Mangrove conservation status (colors) and study sites (shapes).

Fig 5. Canonical correspondence analysis (CCA).

Ordination from weighted UniFrac distances. Conservation status: red circles (conserved), green triangles (degraded), blue squares (restored). Vectors correspond to physicochemical variables: temperature (T°), salinity (Sal), organic carbon (OC), Redox potential and pH.

Fig 6. ASVs (including all sites) that show significant differences in their abundance (between degraded and conserved mangroves).

Orders (vertical axis) and corresponding phyla (colors) along the northern YP coast are shown. Positive values show more abundant ASVs in degraded samples, while negative values show less abundant ASVs in degraded samples.

Fig 7. ASVs (including all sites) that show significant differences in their abundance (between degraded and restored mangroves).

Orders (vertical axis) and corresponding phyla (colors) along the northern YP are shown. Positive values show more abundant ASVs in degraded samples, while negative values show less abundant ASVs in degraded samples.