A weekly conference series paired with lectures entitled “Microbiome-MX: exploring the Microbiota and Microbiome Research in Mexico” was organized to provide a multidisciplinary overview of the most recent research done in Mexico using high-throughput sequencing. Scientists and postgraduate students from several disciplines such as microbiology, bioinformatics, virology, immunology, nutrition, and medical genomics gathered to discuss state of the art in each of their respective subjects of expertise, as well as advances, applications and new opportunities on microbiota/microbiome research. In particular, high-throughput sequencing is a crucial tool to understand the challenges of a megadiverse developing country as Mexico, and moreover to know the scientific capital and capabilities available for collaboration. The conference series addressed three main topics important for Mexico: i) the complex role of microbiota in health and prevalent diseases such as obesity, diabetes, inflammatory bowel disease, tuberculosis, HIV, autoimmune diseases and gastric cancer; ii) the use of local, traditional and prehispanic products as pre/probiotics to modulate the microbiota and improve human health; and iii) the impact of the microbiota in shaping the biodiversity of economically important terrestrial and marine ecosystems. Herein, we summarize the contributions that Mexican microbiota/microbiome research is making to the global trends, describing the highlights of the conferences and lectures, rather than a review of the state-of-the-art of this research. This meeting report also presents the efforts of a multidisciplinary group of scientist to encourage collaborations and bringing this research field closer for younger generations.

Dendrochronology is a very useful science to reconstruct the long-term responses of trees and other woody plants forming annual rings in response to their environment. The present review considered Mexico, a megadiverse country with a high potential for tree-ring sciences given its high climatic and environmental variability. We reviewed papers considering Mexican tree species that were published from 2001 to 2016. Most of these studies examined tree species from temperate forests, mainly in the pine and fir species. The review included 31 tree species. The most intensively sampled family and species were the Pinaceae and Douglas fir (Pseudotsuga menziessi (Mirb.) Franco), respectively. Some threatened tree species were also studied. Dendrochronological investigations were mainly conducted in northern and central Mexico, with Durango being the most sampled state. The reviewed studies were mostly developed for hydroclimatic reconstructions, which were mainly based on the tree-ring width as a proxy for the climate. Tree-ring studies were carried out in both national and foreign institutions. Our review identified relevant research gaps for dendrochronologists such as: (i) biomes which are still scarcely studied (e.g., tropical dry forests) and (ii) approaches still rarely applied to Mexican forests as dendroecology.

Ecological restoration has become an important strategy to conserve biodiversity and ecosystems services. To restore 15% of degraded ecosystems as stipulated by the Convention on Biological Diversity Aichi target 15, we developed a prioritization framework to identify potential priority sites for restoration in Mexico, a megadiverse country. We used the most current biological and environmental data on Mexico to assess areas of biological importance and restoration feasibility at national scale and engaged stakeholders and experts throughout the process. We integrated 8 criteria into 2 components (i.e., biological importance and restoration feasibility) in a spatial multicriteria analysis and generated 11 scenarios to test the effect of assigning different component weights. The priority restoration sites were distributed across all terrestrial ecosystems of Mexico; 64.1% were in degraded natural vegetation and 6% were in protected areas. Our results provide a spatial guide to where restoration could enhance the persistence of species of conservation concern and vulnerable ecosystems while maximizing the likelihood of restoration success. Such spatial prioritization is a first step in informing policy makers and restoration planners where to focus local and large-scale restoration efforts, which should additionally incorporate social and monetary cost-benefit considerations.

‘Megadiversity’ originated as a term in the context of biodiversity conservation in the late 1980s (Mittermeier et al. 2004). It refers to countries with an extremely high level of species richness, usually found in the tropical realm, one or two orders higher in magnitude than in most temperate zone countries. In many ways countries or areas of megadiversity coincide with the slightly longer-established concept of biodiversity hotspots (Myers et al. 2000; Brummitt and Lughadha 2003; see Chapter 2 in this volume). Unlike the concept of hotspots, megadiversity also attempts to take into account degrees of endemism, phylogenetic relatedness, and other measures of diversity applied for identifying biodiversity hotspots as opposed to pure numbers of species or taxa per unit area. More than any academic differentiation, however, the term megadiversity was recently taken up and promoted at the political level, particularly under the Convention of Biological Diversity (CBD), as well as the Convention on International Trade in Endangered Species of Fauna and Flora (CITES). Following the original meeting in Cancun, Mexico, in February 2002, 15 countries formed a group of ‘Like-Minded Megadiverse Countries’ (LMMC) as a forum to address the specific challenges for biodiversity conservation and sustainable use faced by countries with disproportional high levels of biodiversity (‘Cancun declaration 2002’). Later joined by Australia and the USA, this informal group of countries comprises many but by no means all of the recognized global biodiversity hotspots.

The Rupestrian Grassland is an ancient ecosystem characterized by high herbaceous species richness, high endemism, and unique species compositions. The vegetation and habitats in the Rupestrian Grassland are maintained by edapho-climatic factors that limit tree growth and distribution, frequent fires, and, possibly, herbivory. The synergism of the environmental filters caused by these factors and interactions amongst species are the drivers of biodiversity and ecosystem services in this megadiverse environment. But this natural heritage is under threat due to human induced disturbances and by climate change . This book brings to light the most updated synthesis on this unique and paramount ecosystem.

Abstract: An important question in conservation biology is the extent to which the number of taxonomic supraspecific categories can serve as surrogates of species richness. This issue has been little explored in highly diverse areas. We used 113 floristic inventories from throughout Mexico, a megadiverse country, to evaluate the potential of higher‐taxon richness for predicting local species richness of vascular plants. This large biodiversity data set includes the main vegetation types found across the country. In all, 247 families, 2,398 genera, and 11,890 species were used for the analysis, representing 99.6%, 90.2%, and 53.2% of the respective totals recorded in the country. We hypothesized that the number of genera and species would be accurately predicted by the richness of the higher taxon. To avoid getting spurious regressions resulting from the logical increase in lower‐taxon richness as a higher taxon becomes richer, we calculated new response variables by subtracting from the number of elements in the lower taxon group the number of those in the higher taxon; these variables were “excess species” (number of species minus number of genera or families) and “excess genera” (number of genera minus number of families). Our results indicate that genera provide very effective surrogates for estimation of local species richness (R2= 0.85), whereas families have a more limited potential for this purpose (R2= 0.64). The predictive capacity of the diversity of higher taxon increased when the analyses were constrained to particular vegetation types (maximum R2= 0.95 for genera). This surrogate method may be a valuable tool in locating and designing representative systems of protected areas for vascular plant diversity, especially in megadiverse countries, where conservation efforts are hindered by the lack of complete inventories and insufficient resources.

Abstract Mexico is a biologically megadiverse country, but its biodiversity is endangered due to high deforestation rates. Impacts of land-use/cover-change and climate change are unevenly distributed, which hinders the execution of conservation practices. Consequently, an adequate spatial conservation prioritization is crucial to minimize the negative impacts on biodiversity. Global and national efforts to prioritize conservation show that >45 % of Mexico should be protected. This study develops an applicable spatial conservation prioritization to minimize impacts on biodiversity, under three scenarios. They integrate exposure to land-use/cover-change and climate change scenarios, adaptive capacity to deal with the exposure, and the distribution of endemic species on risk of extinction. Our results show that by 2050 between 11.6 %, 13.9 % and 16.1 % of Mexico would reach score ≥50 in vulnerability (VI), under the optimistic, BAU, and the worst-case scenarios, respectively. By 2070, these figures would rise to 11.9 %, 14.8 % and 18.4 %. Amphibians are the most threatened vertebrates with 62.2 % of endemic species being critically endangered or endangered, while 39.2 %, 11.8 %, and 8.5 % of endemic mammals, birds and reptiles are endangered or critically endangered. The distribution of these amphibians accounts for 3.3 % of the country’s area, while mammals, birds, and reptiles represent 9.9 %, 16.2 %, and 28.7 % of Mexico. Moreover, seven municipalities (0.39 % of the country) represent 30 % of the most vulnerable areas (VI = 70). This study offers relevant information at the levels of municipality and species to help decision-makers prioritize national efforts for the conservation of ecosystems and biodiversity under land-use/cover and climate change. This study is replicable in other regions which aim to adapt decision-making and land management for biodiversity conservation.

Abstract Mexico is a megadiverse country, with 10% of all known species found within its borders. The CONABIO catalogue registers rotifers as one of the best-studied groups of animals in Mexico, with the number of species recorded representing 18% of the total global rotifer fauna. However, this registry does not record a single exotic species of Rotifera in Mexico. Here, we confirm the presence of six species of exotic rotifers in Mexican inland waters, highlighting the case of Kellicottia bostoniensis, recorded in Mexico since the 1990’s, but never as an exotic species.

Biases in data availability have serious consequences on scientific inferences that can be derived. The potential consequences of these biases could be more detrimental in the less‐studied megadiverse regions, often characterized by high biodiversity and serious risks of human threats, as conservation and management actions could be misdirected. Here, focusing on 134 bat species in Mexico, we analyze spatial and taxonomic biases and their drivers in occurrence data; and identify priority areas for further data collection which are currently under‐sampled or at future environmental risk. We collated a comprehensive database of 26,192 presence‐only bat records in Mexico to characterize taxonomic and spatial biases and relate them to species' characteristics (range size and foraging behavior). Next, we examined variables related to accessibility, species richness and security to explain the spatial patterns in occurrence records. Finally, we compared the spatial distributions of existing data and future threats to these species to highlight those regions that are likely to experience an increased level of threats but are currently under‐surveyed. We found taxonomic biases, where species with wider geographical ranges and narrow‐space foragers (species easily captured with traditional methods), had more occurrence data. There was a significant oversampling toward tropical regions, and the presence and number of records was positively associated with areas of high topographic heterogeneity, road density, urban, and protected areas, and negatively associated with areas which were predicted to have future increases in temperature and precipitation. Sampling efforts for Mexican bats appear to have focused disproportionately on easily captured species, tropical regions, areas of high species richness and security; leading to under‐sampling in areas of high future threats. These biases could substantially influence the assessment of current status of, and future anthropogenic impacts on, this diverse species group in a tropical megadiverse country.

Mexico that stands out as a megadiverse country is the fifth nation in terms of species richness. The country is home to 25,000–30,000 species of plants and currently 7461 useful plants are registered, of which 2168 are edible according to ethnobotanical data base of Mexican useful plants (BADEPLAM). In this chapter, edible plants are divided into six subcategories and describe some of the edible species recorded across different ethnobotanical research conducted in different regions of Mexico. We conclude that although the food habits in the country have undergone drastic changes in recent decades, and not always for the better, numerous food plant resources in Mexico continue to be widely utilized mainly by rural populations.