For all researches, please visit our "Peer-reviewed publications" page.
Barbosa C, Otalora J, Giehl E, Villalobos F, Loyola R, Tessarolo G et al. (2017)
Furcraea foetida (Asparagaceae) is a native plant of Central America and northern South America but there is no information about its country of origin. The species was introduced into Brazil and is now considered invasive, particularly in coastal ecosystems. To date, nothing is known about the environmental factors that constrain its distribution and there is only inconclusive information about its location of origin. We used reciprocal distribution models (RDM) to assess invasion risk of F. foetida across Brazil and to identify source regions in its native range. We also tested the niche conservatism hypothesis using Principal Components Analyses and statistical tests of niche equivalency and similarity between its native and invaded ranges. For RDM analysis, we built two models using maximum entropy, one using records in the native range to predict the invaded distribution (forward-Ecological Niche Model or forward-ENM) and one using records in the invaded range to predict the native distribution (reverse-ENM). Forward-ENM indicated invasion risk in the Cerrado region and the innermost region of the Atlantic Forest, however, failed to predict the current occurrence in southern Brazil. Reverse-ENM supported an existing hypothesis that F. foetida originated in the Orinoco river basin, Amazon basin and Caribbean islands. Prediction errors in the RDM and multivariate analysis indicated that the species expanded its realized niche in Brazil. The niche similarity test further suggested that the niche differences are because of differences in habitat availability between the two ranges, not because of evolutionary changes. We hypothesize that physiological pre-adaptation (especially, the crassulacean acid metabolism), human-driven propagule pressure and high competitive ability are the main factors determining the current spatial distribution of the species in Brazil. Our study highlights the need to include F. foetida in plant invasion monitoring programs, especially in priority conservation areas where the species has still not been introduced.
Keywords: clonal plant, ecological niche models, invasion risk, niche conservatism, reciprocal distribution models
Correa Ayram C, Mendoza M, Etter A, Pérez Salicrup D (2017)
Anthropogenic impact on habitat connectivity: A multidimensional human footprint index evaluated in a highly biodiverse landscape of Mexico
Ecological Indicators 72 895-909.
Evaluating the cumulative effects of the human footprint on landscape connectivity is crucial for implementing policies for the appropriate management and conservation of landscapes. We present an adjusted multidimensional spatial human footprint index (SHFI) to analyze the effects of landscape transformation on the remnant habitat connectivity for 40 terrestrial mammal species representative of the Trans-Mexican Volcanic System in Michoacán (TMVSMich), in western central Mexico. We adjusted the SHFI by adding fragmentation and habitat loss to its original three components: land use intensity, time of human landscape intervention, and biophysical vulnerability. The adjusted SHFI was applied to four scenarios: one grouping all species and three grouping several species by habitat spatial requirements. Using the SHFI as a dispersal resistance surface and applying a circuit theory based approach, we analyzed the effects of cumulative human impact on habitat connectivity in the different scenarios. For evaluating the relationship between habitat loss and connectivity, we applied graph theory-based equivalent connected area (ECA) index. Results show over 60% of the TMVSMich has high SHFI values, considerably lowering current flow for all species. Nevertheless, the effect on connectivity of human impact is higher for species with limited dispersal capacity (100–500m). Our approach provides a new form of evaluating human impact on habitat connectivity that can be applied to different scales and landscapes. Furthermore, the approach is useful for guiding discussions and implementing future biodiversity conservation initiatives that promote landscape connectivity as an adaptive strategy for climate change.
Keywords: Cumulative human impact, Habitat connectivity, Mexico, Multi-species
De Pooter D, Appeltans W, Bailly N, Bristol S, Deneudt K, Eliezer M et al. (2017)
Toward a new data standard for combined marine biological and environmental datasets - expanding OBIS beyond species occurrences
Biodiversity Data Journal 5 e10989.
The Ocean Biogeographic Information System (OBIS) is the world’s most comprehensive online, open-access database of marine species distributions. OBIS grows with millions of new species observations every year. Contributions come from a network of hundreds of institutions, projects and individuals with common goals: to build a scientific knowledge base that is open to the public for scientific discovery and exploration and to detect trends and changes that inform society as essential elements in conservation management and sustainable development. Until now, OBIS has focused solely on the collection of biogeographic data (the presence of marine species in space and time) and operated with optimized data flows, quality control procedures and data standards specifically targeted to these data. Based on requirements from the growing OBIS community to manage datasets that combine biological, physical and chemical measurements, the OBIS-ENV-DATA pilot project was launched to develop a proposed standard and guidelines to make sure these combined datasets can stay together and are not, as is often the case, split and sent to different repositories. The proposal in this paper allows for the management of sampling methodology, animal tracking and telemetry data, biological measurements (e.g., body length, percent live cover, ...) as well as environmental measurements such as nutrient concentrations, sediment characteristics or other abiotic parameters measured during sampling to characterize the environment from which biogeographic data was collected. The recommended practice builds on the Darwin Core Archive (DwC-A) standard and on practices adopted by the Global Biodiversity Information Facility (GBIF). It consists of a DwC Event Core in combination with a DwC Occurrence Extension and a proposed enhancement to the DwC MeasurementOrFact Extension. This new structure enables the linkage of measurements or facts - quantitative and qualitative properties - to both sampling events and species occurrences, and includes additional fields for property standardization. We also embrace the use of the new parentEventID DwC term, which enables the creation of a sampling event hierarchy. We believe that the adoption of this recommended practice as a new data standard for managing and sharing biological and associated environmental datasets by IODE and the wider international scientific community would be key to improving the effectiveness of the knowledge base, and will enhance integration and management of critical data needed to understand ecological and biological processes in the ocean, and on land.
Keywords: Darwin Core Archive, data standardisation, ecosystem data, environmental data, oceanographic data, sample event, species occurrence, telemetry data
Feldman R, Peers M, Pickles R, Thornton D, Murray D (2017)
Global Ecology and Conservation 9 1-10.
Species interactions like parasitism influence the outcome of climate-driven shifts in species ranges. For some host species, parasitism can only occur in that part of its range that overlaps with a second host species. Thus, predicting future parasitism may depend on how the ranges of the two hosts change in relation to each other. In this study, we tested whether the climate driven species range shift of Odocoileus virginianus (white-tailed deer) accounts for predicted changes in parasitism of two other species from the family Cervidae, Alces alces (moose) and Rangifer tarandus (caribou), in North America. We used MaxEnt models to predict the recent (2000) and future (2050) ranges (probabilities of occurrence) of the cervids and a parasite Parelaphostrongylus tenuis (brainworm) taking into account range shifts of the parasite’s intermediate gastropod hosts. Our models predicted that range overlap between A. alces/R. tarandus and P. tenuis will decrease between 2000 and 2050, an outcome that reflects decreased overlap between A. alces/R. tarandus and O. virginianus and not the parasites, themselves. Geographically, our models predicted increasing potential occurrence of P. tenuis where A. alces/R. tarandus are likely to decline, but minimal spatial overlap where A. alces/R. tarandus are likely to increase. Thus, parasitism may exacerbate climate-mediated southern contraction of A. alces and R. tarandus ranges but will have limited influence on northward range expansion. Our results suggest that the spatial dynamics of one host species may be the driving force behind future rates of parasitism for another host species.
Keywords: Boreal, Cervidae, Climate change, Evolution, Parasitism, Synergistic effects
González-Salazar C, Stephens C, Sánchez-Cordero V (2017)
Arboviruses are often maintained in complex cycles involving vertebrates such as mammals or birds and blood-feeding mosquitoes. However, the role of wildlife hosts in their emergence or re-emergence in human populations has received little attention. The recent emergence of Zika virus in America, and previous occurrences of chikungunya and dengue, forces us to confront a potential new disease-emergence phenomenon. Using a spatial data mining framework to identify potential biotic interactions, based on the degree of co-occurrence between different species, we identified those mammal species with the highest potential for establishing mammal–vector interactions, considering as principal vector Aedes aegypti. Seven of the top ten identified mammal species with highest potential were bats, with two of them having previously been confirmed as positive hosts for dengue in Mexico. We hope that this will raise interest of Mexican public health authorities and academic institutions to assess the role of wild hosts in the maintenance and spread of arboviruses.
Keywords: Aedes aegypti, Arbovirus, Chikungunya, Dengue, Wildlife host, Zika virus
López-Alcaide S, Nakamura M, Smith E, Martínez-Meyer E (2017)
Would behavioral thermoregulation enables pregnant viviparous tropical lizards to cope with a warmer world?
Sceloporus lizards depend on external heat to achieve their preferred temperature (Tse1) for performing physiological processes. Evidence both in the field and laboratory indicates that pregnant females of this genus select body temperatures (Tb) lower than 34°C as higher temperatures may be lethal to embryos. Therefore, thermoregulation is crucial for successful embryo development. Given the increase in global air temperature, it is expected that the first compensatory response of species that inhabit tropical climates will be behavioral thermoregulation. We tested if viviparous Sceloporus formosus group lizards in the wild exhibited differences in thermoregulatory behavior to achieve the known Tse1 for developing embryos regardless of local thermal conditions. We quantified field active body temperature, thermoregulatory behavior mechanisms (time of sighting, microhabitat used and basking time), and available microhabitat thermal conditions (i.e., operative temperature) for ten lizard species during gestation, distributed along an altitudinal gradient. We applied both conventional and phylogenic analyses to explore if Tb or behavioral thermoregulation could be regulated in response to different thermal conditions. These species showed no significant differences in field Tb during gestation regardless of local thermal conditions. In contrast, they exhibited significant differences in their behavioral thermoregulation associated to local environmental conditions. Based on these observations, the differences in thermoregulatory behavior identified are interpreted as compensatory adjustments to local thermal conditions. We conclude that these species may deal with higher stressing environmental temperatures scenarios forecasted to the tropics by modulating their thermoregulatory behavior repertoire as first reaction.
Keywords: Altitudinal gradient, Sceloporus formosus, behavior, global warming, thermal stress
Moo-llanes D, Arque-chunga W, Carmona-castro O, YaÑez-arenas C, YaÑez-trujillano H, CheverrÍa-pacheco L et al. (2017)
Medical and Veterinary Entomology.
The Peruvian Andes presents a climate suitable for many species of sandfly that are known vectors of leishmaniasis or bartonellosis, including Lutzomyia peruensis (Diptera: Psychodidae), among others. In the present study, occurrences data for Lu. peruensis were compiled from several items in the scientific literature from Peru published between 1927 and 2015. Based on these data, ecological niche models were constructed to predict spatial distributions using three algorithms [Support vector machine (SVM), the Genetic Algorithm for Rule-set Prediction (GARP) and Maximum Entropy (MaxEnt)]. In addition, the environmental requirements of Lu. peruensis and three niche characteristics were modelled in the context of future climate change scenarios: (a) potential changes in niche breadth; (b) shifts in the direction and magnitude of niche centroids, and (c) shifts in elevation range. The model identified areas that included environments suitable for Lu. peruensis in most regions of Peru (45.77%) and an average altitude of 3289 m a.s.l. Under climate change scenarios, a decrease in the distribution areas of Lu. peruensis was observed for all representative concentration pathways. However, the centroid of the species' ecological niche showed a northwest direction in all climate change scenarios. The information generated in this study may help health authorities responsible for the supervision of strategies to control leishmaniasis to coordinate, plan and implement appropriate strategies for each area of risk, taking into account the geographic distribution and potential dispersal of Lu. peruensis.
Keywords: Lutzomyia peruensis, Peru, bartonellosis, climate change, ecological niche, leishmaniasis
Rengifo-correa L, Stephens C, Morrone J, TÉllez-rendÓn J, GonzÁlez-salazar C (2017)
Chagas disease is one of the most important vector-borne zoonotic diseases in Latin America. Control strategies could be improved if transmissibility patterns of its aetiologic agent,
Trypanosoma cruzi, were better understood. To understand transmissibility patterns of Chagas disease in Mexico, we inferred potential vectors and hosts of T. cruzifrom geographic distributions of nine species of Triatominae and 396 wild mammal species, respectively. The most probable vectors and hosts of T. cruziwere represented in a Complex Inference Network, from which we formulated a predictive model and several associated hypotheses about the ecological epidemiology of Chagas disease. We compiled a list of confirmed mammal hosts to test our hypotheses. Our tests allowed us to predict the most important potential hosts of T. cruziand to validate the model showing that the confirmed hosts were those predicted to be the most important hosts. We were also able to predict differences in the transmissibility of T. cruziamong triatomine species from spatial data. We hope our findings help drive efforts for future experimental studies.
Keywords: Trypanosoma cruzi, ecological epidemiology, potential hosts, spatial data mining
Ramos-Dorantes D, Villaseñor J, Ortiz E, Gernandt D (2017)
Revista Mexicana de Biodiversidad.
Pinaceae is the most species rich conifer family in Mexico. Here we describe the diversity and geographic distribution of the family in the state of Puebla based on revision of herbarium specimens and field exploration. 572 georeferenced records for 15 species and 1 variety were mapped. These were included in potential distribution models to predict the most species-rich regions in the state and quantify the known species distributions in 10′ × 10′ (latitudinal × longitudinal) cells. The conservation status of each taxon was evaluated by calculating its area of occupation and conservation category within the state. A species–accumulation curve agreed with the number of taxa employed, suggesting that the family is relatively well sampled. The resulting potential distribution models indicated that the regions of highest predicted diversity in the state correspond well to the actual diversity estimates, although in some sites more species were predicted than were recorded. The Sierra Madre Oriental and the Trans-Mexican Volcanic Belt were the biogeographic regions with the greatest known and potential richness. Finally, the regional evaluation of conservation status provides relevant information for local conservationists and authorities, given that 12 of the 16 taxa were determined to be at risk.
Keywords: Abies, Conservation status, Pinus, Potential distribution, Pseudotsuga, Richness
Aguilar-Lopez J, Pineda E, Luria-Manzano R, Canseco-Marquez L (2016)
Species Diversity, Distribution, and Conservation Status in a Mesoamerican Region: Amphibians of the Uxpanapa-Chimalapas Region, Mexico
Tropical Conservation Science 9(4) 1940082916670003.
The Uxpanapa-Chimalapas region, with one of the most extensive and best preserved tropical forest areas in Mexico, is undergoing major anthropogenic changes, and only some portions of the territory are under the protection of local communities. Although the biodiversity of the region is known to be high, no study has yet analyzed the diversity of amphibian species in the region or contributed to valuing the region in a context of amphibian conservation. Based on a review of databases and the existing scientific literature, as well as our own fieldwork, in this study, we analyze the amphibian species richness, species composition, their spatial distribution, and their conservation status in the Uxpanapa-Chimalapas region. Additionally, we compare this information with the available data for seven other tropical regions in central-northern Mesoamerica. The amphibian fauna recorded at the study region comprises 51 species, which makes it the richest tropical region in amphibian species in central-northern Mesoamerica and Mexico. Among the regions compared, this one stands out as the one with the most distinctive composition of amphibian species, sharing on average only 35% of its species with the other regions. However, it is also the region with the highest number of threatened species since one third of its species are in higher extinction risk categories. These characteristics turn the Uxpanapa-Chimalapas into a high-priority region for both Mexico and Mesoamerica, and a regional conservation plan is necessary for the immediate protection of areas where the forest is being replaced and to promote or to support community protected areas.
Keywords: amphibian fauna, conservation value, species composition, species richness