Assessing digital accessible botanical knowledge and priorities for exploration and discovery of plant diversity across Mesoamerica.

Digital accessible biodiversity knowledge has the potential to greatly advance botanical research and guide conservation efforts. Evaluating its shortfalls is key to understanding its limits and prioritising regions in need of renewed survey efforts. We used the Royal Botanical Gardens Kew's World Checklist of Vascular Plants to parse publicly available occurrence data downloaded from the Global Biodiversity Information Facility and quantify the spatial distribution of spatial, phylogenetic, and temporal data shortfalls across Mesoamerica. After processing 3578 777 occurrence records for 32 522 species of vascular plants across Mesoamerica, we found evidence of poor data coverage: incomplete characterisation of species diversity, old occurrence records, and low phylogenetic representation. One-third of the region showed large gaps for at least one of these dimensions (hotspots) and < 15% had adequate data coverage across dimensions. Overall, the shortfalls we identified compromise the quality of digitally available occurrence data and hamper research on spatial phylogenetics and species dynamics under anthropogenic disturbances. Our analyses identified areas of opportunity for increased efforts in data digitisation, botanical exploration, sequencing, and biodiversity monitoring. These efforts would serve to increase and rejuvenate knowledge on the geographic distribution of vascular plants in Mesoamerica.

Incorporating evolutionary and threat processes into crop wild relatives conservation.

Crop wild relatives (CWR) intra- and interspecific diversity is essential for crop breeding and food security. However, intraspecific genetic diversity, which is central given the idiosyncratic threats to species in landscapes, is usually not considered in planning frameworks. Here, we introduce an approach to develop proxies of genetic differentiation to identify conservation areas, applying systematic conservation planning tools that produce hierarchical prioritizations of the landscape. It accounts for: (i) evolutionary processes, including historical and environmental drivers of genetic diversity, and (ii) threat processes, considering taxa-specific tolerance to human-modified habitats, and their extinction risk status. Our analyses can be used as inputs for developing national action plans for the conservation and use of CWR. Our results also inform public policy to mitigate threat processes to CWR (like crops living modified organisms or agriculture subsidies), and could advise future research (e.g. for potential germplasm collecting). Although we focus on Mesoamerican CWR within Mexico, our methodology offers opportunities to effectively guide conservation and monitoring strategies to safeguard the evolutionary resilience of any taxa, including in regions of complex evolutionary histories and mosaic landscapes.

Evaluation of animal and plant diversity suggests Greenland's thaw hastens the biodiversity crisis.

Rising temperatures can lead to the occurrence of a large-scale climatic event, such as the melting of Greenland ice sheet, weakening the AMOC and further increasing dissimilarities between current and future climate. The impacts of such an event are still poorly assessed. Here, we evaluate those impacts across megadiverse countries on 21,146 species of tetrapods and vascular plants using the pessimistic climate change scenario (RCP 8.5) and four different scenarios of Greenland's ice sheet melting. We show that RCP 8.5 emission scenario would lead to a widespread reduction in species' geographic ranges (28-48%), which is projected to be magnified (58-99%) with any added contribution from the melting of Greenland. Also, declines in the potential geographical extent of species hotspots (12-89%) and alterations of species composition (19-91%) will be intensified. These results imply that the influence of a strong and rapid Greenland ice sheet melting, resulting in a large AMOC weakening, can lead to a faster collapse of biodiversity across the globe.

Species, taxonomic, and functional group diversities of terrestrial mammals at risk under climate change and land-use/cover change scenarios in Mexico.

There is a need to revise the framework used to project species risks under climate change (CC) and land-use/cover change (LUCC) scenarios. We built a CC risk index using the latest Intergovernmental Panel on Climate Change framework, where risk is a function of vulnerability (sensitivity and adaptive capacity), exposure, and hazard. We incorporated future LUCC scenarios as part of the exposure component. We combined a trait-based approach based on biological characteristics of species with a correlative approach based on ecological niche modeling, assigning risk scores to species, taxonomic (orders), and functional (trophic, body size, and locomotion) groups of terrestrial mammals occurring in Mexico. We identified 15 species projected to lose their climatic suitability. Of the 11 taxonomic orders, Eulipotyphla, Didelphimorphia, Artiodactyla, and Lagomorpha had the highest risk scores. Of the 19 trophic groups, piscivores, insectivores under canopy, frugivores-granivores, herbivores browser, and myrmecophagous had the highest risk scores. Of the five body-sized groups, large-sized species (>15 kg) had highest risk scores. Of the seven locomotion groups, arboreal and semi-aquatics had highest risk scores. CC and LUCC scenarios reduced suitable areas of species potential distributions by 37.5% (with CC), and 51% (with CC and LUCC) under a limited full-dispersal assumption. Reductions in suitable areas of species potential distributions increased to 50.2% (with CC), and 52.4% (with CC and LUCC) under a non-dispersal assumption. Species-rich areas (>75% species) projected 36% (with CC) and 57% (with CC and LUCC) reductions in suitability for 2070. Shifts in climatic suitability projections of species-rich areas increased in number of species in northeast and southeast Mexico and decreased in northwest and southern Mexico, suggesting important species turnover. High-risk projections under future CC and LUCC scenarios for species, taxonomic, and functional group diversities, and species-rich areas of terrestrial mammals highlight trends in different impacts on biodiversity and ecosystem function.

One hundred years of climate change in Mexico.

Spatial assessments of historical climate change provide information that can be used by scientists to analyze climate variation over time and evaluate, for example, its effects on biodiversity, in order to focus their research and conservation efforts. Despite the fact that there are global climatic databases available at high spatial resolution, they represent a short temporal window that impedes evaluating historical changes of climate and their impacts on biodiversity. To fill this gap, we developed climate gridded surfaces for Mexico for three periods that cover most of the 20th and early 21st centuries: t1-1940 (1910-1949), t2-1970 (1950-1979) and t3-2000 (1980-2009), and used these interpolated surfaces to describe how climate has changed over time, both countrywide and in its 19 biogeographic provinces. Results from our characterization of climate change indicate that the mean annual temperature has increased by nearly 0.2°C on average across the whole country from t2-1970 to t3-2000. However, changes have not been spatially uniform: Nearctic provinces in the north have suffered higher temperature increases than southern tropical regions. Central and southern provinces cooled at the beginning of the 20th century but warmed consistently since the 1970s. Precipitation increased between t1-1940 and t2-1970 across the country, more notably in the northern provinces, and it decreased between t2-1970 and t3-2000 in most of the country. Results on the historical climate conditions in Mexico may be useful for climate change analyses for both environmental and social sciences. Nonetheless, our climatology was based on information from climate stations for which 9.4-36.2% presented inhomogeneities over time probably owing to non-climatic factors, and climate station density changed over time. Therefore, the estimated changes observed in our analysis need to be interpreted cautiously.

Spatial Risk Distribution of Dengue Based on the Ecological Niche Model of Aedes aegypti (Diptera: Culicidae) in the Central Mexican Highlands.

Dengue is the most important viral disease transmitted by mosquitoes, predominantly Aedes (Stegomyia) aegypti (L.) (Diptera:Culicidae). Forty percent of the world's population is at risk of contracting the disease, and a large area of Mexico presents suitable environmental conditions for the life cycle of Ae. aegypti. In particular, the Central Mexican Highlands have a high population density, increasing the risk of transmission and propagation of dengue. In the present study, the potential distribution of Ae. aegypti was modeled under an ecological niche approach using the maximum entropy technique with the aim of determining the spatial risk distribution of dengue. The final model of five variables (minimum temperature of the coldest month |Bio6|, precipitation of the wettest month |Bio13|, precipitation seasonality |Bio15|, the normalized difference vegetation index (NDVI), and relative humidity) contributed to more than 90% of the model's performance. The results of the potential distribution model were then compared with the number of dengue cases per locality during the 2009-2015 period considering four suitability of presence categories. Category 4 corresponded with the highest suitability of presence (0.747 to 1) and the greatest risk of dengue (odds ratio [OR] = 103.27; P < 0.001). In conclusion, the present ecological niche model represents an important tool for the monitoring of dengue and the identification of high-risk areas.

Inferring space from time: On the relationship between demography and environmental suitability in the desert plant O. rastrera.

Demographic analyses and ecological niche modeling (ENM) are two popular tools that address species persistence in relation to environmental conditions. Classic demography provides detailed information about the mechanisms that allow a population to grow or remain stable at a local scale, while ENM infers distributions from conditions suitable for species persistence at geographic scales by relating species' occurrences with environmental variables. By integrating these two tools, we may better understand population processes that determine species persistence at a geographic scale. To test this idea, we developed a model that relates climate to demography of the cactus Opuntia rastrera using 15 years of data from one locality. Using this model we determined the geographic area where populations would have positive growth rates given its climatic conditions. The climate-dependent demographic model showed poor performance as a distribution model, but it was helpful in defining some mechanisms that determine species' distributions. For instance, high rainfall had a negative impact on the population growth rate by increasing mortality. Rainy areas to the west of the distribution of O. rastrera were identified as unsuitable both by our climate-dependent demographic model and by a popular ENM algorithm (MaxEnt), suggesting that distribution is constrained by excessive rains due to high mortality. Areas projected to be climatically suitable by MaxEnt were not related with higher population growth rates. Instead, we found a strong correlation between environmental distance to the niche centroid (center of the niche hypervolume, where optimal conditions may occur) and population growth rate, meaning that the niche centroid approach is helpful in finding high-fitness areas.

Twentieth century turnover of Mexican endemic avifaunas: Landscape change versus climate drivers.

Numerous climate change effects on biodiversity have been anticipated and documented, including extinctions, range shifts, phenological shifts, and breakdown of interactions in ecological communities, yet the relative balance of different climate drivers and their relationships to other agents of global change (for example, land use and land-use change) remains relatively poorly understood. This study integrated historical and current biodiversity data on distributions of 115 Mexican endemic bird species to document areas of concentrated gains and losses of species in local communities, and then related those changes to climate and land-use drivers. Of all drivers examined, at this relatively coarse spatial resolution, only temperature change had significant impacts on avifaunal turnover; neither precipitation change nor human impact on landscapes had detectable effects. This study, conducted across species' geographic distributions, and covering all of Mexico, thanks to two large-scale biodiversity data sets, could discern relative importance of specific climatic drivers of biodiversity change.

[Potential distribution of jaguar, Panthera onca (Carnivora: Felidae) in Guerrero, Mexico: persistence of areas for its conservation]. / Distribución potencial del jaguar Panthera onca (Carnivora: Felidae) en Guerrero, México: persistencia de zonas para su conservación.

Studies about the permanence of natural protected areas are important, because they contribute to the promotion of the conservation target and to optimize economical and human resources of specific areas. Although there are no natural protected areas in Guerrero, it has suitable habitat for the jaguar, a common species used for planning and management of conservation areas. Since, there is actual evidence that environmental and anthropogenic variables may modify vertebrate species distribution with time, in this study we predicted the potential distribution of Panthera onca using MaxEnt for this Southeastern region. In addition, we made a projection considering the effect of a moderate climate change scenario, to evaluate the stability of the conservation area for a period of 24 years. Furthermore, we applied three threat scenarios for the actual prediction to define conservation priorities areas. In our results, we have found that 18 361Km2 (29%) of this state has a permanent suitable habitat for jaguar conservation in the Sierra Madre del Sur and Pacific coast, with a possible loss of 2 000km2 in 24 years. This habitat is characterized by a 56% of temperate forest (mainly conifers and hardwoods 34%), and 35% of tropical deciduous forest. With the projections, the Southeastern region resulted with the higher anthropogenic impacts, while at the same time, an area of 7 900km2 in the Central-Western state was determined as a priority for conservation. To assure jaguar conservation, we propose the inclusion of this new conservation area, which is located in the Sierra Madre del Sur, with which we may potentially preserve other 250 species of threatened vertebrates. This way, the suggested habitat conservation may represent a local effort in Guerrero and will strengthen the biological corridor network for P. onca protection in Latin America.

Distribución potencial del jaguar Panthera onca (Carnivora: Felidae) en Guerrero, México: persistencia de zonas para su conservación / Potential distribution of jaguar, Panthera onca (Carnivora: Felidae) in Guerrero, Mexico: per- sistence of areas for its conservation

Studies about the permanence of natural protected areas are important, because they contribute to the promotion of the conservation target and to optimize economical and human resources of specific areas. Although there are no natural protected areas in Guerrero, it has suitable habitat for the jaguar, a common species used for planning and management of conservation areas. Since, there is actual evidence that environmental and anthropogenic variables may modify vertebrate species distribution with time, in this study we predicted the potential distribution of Panthera onca using MaxEnt for this Southeastern region. In addition, we made a projection considering the effect of a moderate climate change scenario, to evaluate the stability of the conservation area for a period of 24 years. Furthermore, we applied three threat scenarios for the actual prediction to define conservation priorities areas. In our results, we have found that 18 361Km2 (29%) of this state has a permanent suitable habitat for jaguar conservation in the Sierra Madre del Sur and Pacific coast, with a possible loss of 2 000km2 in 24 years. This habitat is characterized by a 56% of temperate forest (mainly conifers and hardwoods 34%), and 35% of tropical deciduous forest. With the projections, the Southeastern region resulted with the higher anthropogenic impacts, while at the same time, an area of 7 900km2 in the Central-Western state was determined as a priority for conservation. To assure jaguar conservation, we propose the inclusion of this new conservation area, which is located in the Sierra Madre del Sur, with which we may potentially preserve other 250 species of threatened vertebrates. This way, the suggested habitat conservation may represent a local effort in Guerrero and will strengthen the biological corridor network for P. onca protection in Latin America.

Guerrero se caracteriza por presentar extensiones considerables y adecuadas de hábitat para el jaguar, pero carece de áreas naturales protegidas. Son importantes los estudios sobre la persistencia de las áreas naturales protegidas debido a que ofrecen escenarios geográficos con mayor certidumbre de cumplir con el objetivo de la conservación biológica a largo plazo y con la optimización de recursos humanos y económicos. Existe evidencia de que variables ambientales y antropogénicas modifican la distribución de muchas especies de vertebrados, por lo que es necesario incluir estas variables como criterio en la selección de reservas. Se estimó la distribución potencial del jaguar utilizando MAxENT, misma que se uso como criterio para proponer áreas naturales protegidas en el Estado. Se realizó una proyección en el futuro para considerar el efecto de un escenario moderado de cambio climático y así poder proponer una zona de conservación que sea estable en un periodo de 24 años. También se aplicaron tres criterios de riesgo en la predicción actual para definir prioridades de conservación. Se determino que el 29% del estado es hábitat idóneo para el jaguar y será persistente en el futuro. Se propone al área ubicada en la Sierra Madre del Sur para la conservación de P. onca y potencialmente 250 especies de vertebrados amenazados ante la UICN. Conservar el hábitat de P. onca en Guerrero fortalecerá la red de corredores para la conservación del jaguar en Latinoamérica.