Niche Modelling Techniques Research Articles

Assessing climate niche similarity between persian fallow deer (Dama mesopotamica) areas in Iran

The Persian fallow deer or Mesopotamian fallow Deer (Dama mesopotamica, Brook 1875), a species of significant ecological importance, had faced the threat of extinction in Iran. One conservation strategy involved the translocation of Persian deer to enclosed areas across Iran, where they were afforded protection from external threats and provided with essential care by human caretakers. While human caretakers diligently attend to their needs and mitigate external threats, climate variables may now become critical factors affecting population dynamics in enclosed areas. This study aims to assess the similarity in climate niches between the original area (Dez and Karkheh) of the Persian deer species and 11 newly enclosed areas. To achieve this, we employed climate data and ecological niche modeling (ENM) techniques to assess the variations in climate among 12 areas. We utilized the environmental equivalency test to determine whether the environmental spaces of area pairs exhibit significant differences and whether these spaces are interchangeable. Extrapolation analyses were also constructed in the next steps to explore climatic conditions in original fallow deer habitats that are non-analogous to those in other parts of Iran. Our results reveal significant disparities in climate conditions between the original and all translocated areas. Based on observations of population growth in specific enclosed areas where translocated deer populations have thrived, we hypothesize that the species may demonstrate a non-equilibrium distribution in Iran. Consequently, these new areas could potentially be regarded as part of the species’ potential climate niche. Extrapolation analysis showed that for a significant portion of Iran, extrapolation predictions are highly uncertain and potentially unreliable for the translocation of Persian fallow deer. However, the primary objective of translocation efforts remains the establishment of self-sustaining populations of Persian deer capable of thriving in natural areas beyond enclosed areas, thus ensuring their long-term survival and contributing to preservation efforts. Evaluating the success of newly translocated species requires additional time, with varying levels of success observed. In cases where the growth rate of the species in certain enclosed areas falls below expectations, it is prudent to consider climate variables that may contribute to population declines. Furthermore, for future translocations, we recommend selecting areas with climate similarities to regions where the species has demonstrated growth rates.

Potential impact of climate change on Nearctic leafhopper distribution and richness in North America

Climate change significantly contributes to shifts in the geographical range of pests and diseases. Leafhoppers (Hemiptera: Cicadellidae), known vectors of phytoplasmas pathogens, are linked to the transmission of more than 600 diseases affecting a thousand plant species worldwide. Despite this, the potential effects of climate change on leafhopper vectors of phytoplasmas remain a critical knowledge gap. To address this gap, our study investigated the potential impact of climate change on 14 species of Nearctic leafhoppers previously associated with phytoplasma-related diseases. Using the MaxEnt species distribution algorithm and other ecological niche modeling techniques, we assessed (i) the expected species richness under current climate conditions and four future scenarios and (ii) the environmental niche similarity among these species across these scenarios. Our projections suggest that the eastern region of North America holds the potential for the highest species richness, a trend expected to persist across all future scenarios, gradually expanding eastward. Notably, our findings indicate the increasing suitability of northern Canada for more species. Network analysis further revealed a remarkable similarity in environmental niches among most leafhopper species. Moreover, across the four future scenarios, there is a tendency for an increase in this similarity. Altogether, our study underscores the potential persistent presence of Nearctic leafhoppers in their current habitats while pointing to a shift toward northern North America in future scenarios. These findings have significant implications for sustainable pest management practices, prompting a necessary discussion on strategies to mitigate climate change and pest migration’s impact on agricultural systems.

G-space versus E-space: Are hornets (Hymenoptera: Vespidae) at equilibrium with honeybees in Asia?

This study delves into the concept of niche conservatism (NC) and its implications for how hornets (Hymenoptera: Vespidae) and honeybees respond to climate change. Our primary objectives are threefold: firstly, to assess whether distinct environmental niche spaces (E-space) exist between 12 hornets and honeybees like Apis cerana and Apis mellifera in Asia; Secondly, to explore the degree to which Asian hornets have attained geographic equilibrium alongside honeybee species. Lastly, is to investigate how the geographic niche overlap (G-space) between hornets and honeybees could potentially change under climate change scenarios. To accomplish these goals, we employed ordination and ecological niche modeling techniques to analyze 91 pairs of hornets and honeybees in both geographic (G-space) and environmental (E-space) contexts. Then, we projected the potential impacts of climate change on the future geographic overlap between hornets and honeybees, specifically under the SSP585 climate scenario for the year 2070. Our results demonstrated that the environmental niches (E-space) of hornets and honeybees can be treated as interchangeable, indicating they have similar environmental preferences despite being unrelated taxa. We found that Vespa velutina currently exhibits a moderate geographic niche overlap (G-space) of 0.63 with both honeybee species. Meanwhile, Vespa mandarinia demonstrates an overlap of 0.46 with Apis cerana and 0.63 with Apis mellifera. The overlap of Vespa velutina with Apis cerana might potentially decrease to 0.51 and 0.56 with Apis mellifera. For Vespa mandarinia, the overlap could reach 0.41 with Apis cerana and 0.6 with Apis mellifera under a climate change scenario. This study indicates that the limited spatial overlap between honeybees and hornets across certain areas in Asia is more likely influenced by geographical barriers rather than solely environmental unsuitability for hornets. In this study, we delve into the concept of niche conservatism (NC) and its implications for how hornets (Hymenoptera: Vespidae) and honeybees respond to climate change.

Habitat suitability and connectivity modelling predict a latitudinal-driven expansion in the Mediterranean basin for a historically introduced reptile

Species introductions outside their native ranges, often driven by trade and other anthropogenic activities, present significant ecological challenges. Reptiles, frequently traded as pets for their attractiveness, are particularly susceptible to such introductions, leading to shifts in distribution patterns and potential ecological impacts. The common chameleon (Chamaeleo chamaeleon), which has been historically introduced in several European countries, is such an example, yet no overall assessments are available to date for this species. In this study, we used ecological niche models to assess habitat suitability for the common chameleon in the Mediterranean basin for current and future scenarios. Concurrently, circuit theory techniques were employed to evaluate habitat connectivity in two historically introduced areas. We identified areas of high habitat suitability and dispersal corridors in introduced regions. Our results reveal a latitudinal gradient in habitat suitability changes, with the species facing both expansion and decline in different parts of its range, depending on the ecozone considered. Severe declines are noted in southeastern Spain, Tunisia, and Israel, while habitat suitability increases westwards in Portugal, Morocco, and Southern Italy. These insights contribute to a better understanding of the common chameleon’s ecological dynamics, providing a foundation for targeted management and conservation efforts. Our study highlights the importance of integrating ecological niche modelling and circuit theory techniques to predict habitat suitability and identify critical dispersal corridors for effective conservation strategies. Considering the ongoing challenges posed by human-mediated dispersals for the common chameleon, our research establishes a foundation for future studies to enhance our understanding of this elusive species.

Argopistes Motschulsky from Madagascar with descriptions of six new species (Coleoptera, Chrysomelidae, Galerucinae, Alticini).

The revision of the flea beetle genus Argopistes Motschulsky, 1860 in Madagascar is provided. Six new species are described: Argopistesjanakmoravecorumsp. nov., A.laterosinuatussp. nov., and A.vadoni from the northern area; A.jenisisp. nov., A.keiserisp. nov., and A.seyrigisp. nov. from the central area. A new synonym of Argopistesbrunneus Weise, 1895 is established: A.sexguttatus Weise, 1895, syn. nov., since A.sexguttatus is shown to be a chromatic form of A.brunneus. A diagnostic key of the seven Malagasy Argopistes species is provided, with photographs of the habitus, median lobe of the aedeagus, and spermatheca. Finally, based on known occurrences, the current suitable areas for this flea beetle genus in Madagascar are estimated using Ecological Niche Modelling (ENM) techniques.

Modeling the habitat suitability of two exotic freshwater crayfishes in Mesoamerica and the Caribbean:Cherax quadricarinatus(von Martens, 1868) andProcambarus clarkiiGirard, 1852 (Decapoda: Astacidea: Parastacidae, Cambaridae)

AbstractBiological invasions are among the main threats to the diversity of freshwater ecosystems, particularly invasions of freshwater crayfishes, which have negatively impacted native populations and ecosystem functions. Various invasions of freshwater crayfishes have been relatively well documented, allowing the use of Ecological Niche Modeling (ENM) techniques to forecast their potential invasive distribution. Modeling the most environmentally suitable areas for exotic species can provide guidelines to allocate resources, thus contributing to the control and management of invasions. We modelled the potential distribution of Cherax quadricarinatus (von Martens, 1868) and Procambarus clarkiiGirard, 1852 in Mesoamerica and the Caribbean using global occurrence data and ten environmental variables to ensemble a model using nine different algorithms. Our models showed that C. quadricarinatus has a high probability of invasion in tropical lowland areas, with the presence of exotic populations of this species already reported. Our results support that P. clarkii has a higher probability of invasion in some of the mountain ranges and plateaus of the study region, where this species has already established non-native populations. These models visualize the high-risk areas of invasion of these two non-native crayfish species in Mesoamerica and the Caribbean. A regional approach for monitoring and control of the invasive populations is encouraged as well as regulations for trade and aquaculture of freshwater crayfishes.

Economic costs of the invasive Yellow-legged hornet on honey bees

Biological invasions have ecological impacts worldwide with potential massive economic costs. Among other ecosystem services such as nitrogen cycle, carbon sequestration and primary production, invasive alien species are particularly known to impact pollination. By predating honey bees (Apis mellifera), the invasive Yellow-legged hornet (Vespa velutina nigrithorax) increases the mortality risk of European bee colonies; however, little is known about its economic costs. We developed an analytic process combining large-scale field data, niche modelling techniques and agent-based models to spatially assess the ecological and economic impacts of the Yellow-legged hornet on honey bees and beekeeping in France. In particular, we estimated (i) the hornet-related risk of bee colony mortality, (ii) the economic cost of colony loss for beekeepers and (iii) the economic impact of livestock replacement compared to honey revenues at regional and national scales. We estimated an overall density of 1.08 hornet nest/km2 in France, based on the field record of 1260 nests over a searched area of 28,348 km2. However, this predator density was heterogeneously spread out across the country as well as the distribution of managed honey bee colonies. Overall, this hornet-related risk of bee colony mortality could reach up to 29.2 % of the beekeepers' livestock at national scale each year in high predation scenario. This national cost could reach as much as € 30.8 million per year due to colony loss, which represents for beekeepers an economic impact of livestock replacement of 26.6 % of honey revenues. Our results suggest non-negligible ecological and economic impacts of the invasive Yellow-legged hornet on honey bees and beekeeping activities. Moreover, this study meets the urgent need for more numerous and accurate economic estimations, necessary to calculate the impact of biological invasions on biodiversity and human goods, with a view to enhance policies of biodiversity conservation.

A new species and a new record for Cedrela (Meliaceae, Sapindales) in Ecuador: morphological, molecular, and distribution evidence

A new Cedrela (Meliaceae) species, Cedrela angusticarpa, is described through a combination of taxonomic, morphological, and molecular analyses. Cedrela kuelapensis, originally described as an endemic species of northern Peru, is also reported here as a new record for Ecuador. Cedrela angusticarpa has oblong or oblong-lanceolate glabrous leaflets, rounded at the base. Inflorescences are up to 70 cm long, and flowers present a cupuliform calyx with five regular teeth. Fruits are narrowly obovoid capsules. Through molecular analyses using nine microsatellite loci, it is evident that samples from C. angusticarpa form their own genetic cluster when compared to the most morphologically similar species, C. odorata, suggesting that they belong to a new separate species. Additionally, here we report that C. angusticarpa has a very narrow geographic range, recorded between 550 and 1300 m in elevation, and restricted to the relatively small areas of northwestern Ecuador. Climatic niche modelling techniques were used as a proxy for assessing potential distributions and habitat loss percentages for both C. angusticarpa and C. kuelapensis. Finally, IUCN Red List categories and criteria were applied to assess the conservation status of both Cedrela species analyzed here.

Spatial modeling reveals a growing threat to the world's largest rhodolith beds

Rhodolith beds comprise a highly biodiverse and productive ecosystem that dominates the mid and outer shelf of the tropical eastern South American coast. Conservation planning and specific conservation measures are lacking, while impacts over rhodolith beds are escalating due to carbonate mining, and other activities such as oil and gas exploration and seaport dredging. Primary data detailing the spatial extent and characteristics of rhodolith beds within the Brazilian Economic Exclusive Zone (EEZ) depend on extensive acoustic surveys and ground truthing, which are costly and logistically challenging. Here, we compiled an extensive database of rhodolith occurrence from the scientific and grey literature. ‘Ensemble’ Ecological Niche Modelling (EENM) techniques predicted the total area suitable for rhodoliths across the Brazilian EEZ and gave insight into the environmental variables driving their distribution in this region. Using the suitability map produced from the ensemble model, we compared rhodolith spatial overlap with oil and gas and mining activities and marine protected areas (MPAs). Light, saturation state of calcite and minimum temperature were the main predictors of rhodolith occurrence. Rhodoliths were predicted to occur over ∼167,379 km2 of the Brazilian EEZ largely (∼95%) in the Amazonas (AM), Northeastern Brazil (NB) and Eastern Brazil (EB) ecoregions. The representation of rhodoliths in areas with mining and oil and gas activities was similar for the EEZ as a whole. Within each ecoregion, representation of rhodolith beds in MPAs is negatively related with their overlap with mining and oil and gas activities. Eastern Brazil (EB) stood out as the area with the highest representation of rhodoliths under threat, in an area 6.7 times larger than those represented in MPAs, including the south region of the largest continuous extension of rhodolith beds, in the Abrolhos bank. Within the NB and AM ecoregions, which are under growing industrialization, rhodolith beds are poorly represented in no-take MPAs. Our results provide a basis for moving toward more effective management and conservation strategies for rhodolith beds in Brazil's EEZ.

Truly Absent or Sampling Gaps? Insights on the Potential Distribution of Duttaphrynus hololius (Günther, 1876) from Peninsular India

Duttaphrynus hololius is an uncommon species of toad presumably endemic to peninsular India. Since the original description, no records originated from the type locality “Malabar” or the Western Ghats. At the same time, several authors reported it from the other parts of peninsular India and the Eastern Ghats. This led to confusion and made previous workers question the true origin of the type locality of D. hololius. Some works also predict the distribution of this species based on niche modelling techniques. This work provides new records from the Western Ghats and vicinity for the first time after its description with new molecular data. We also discuss pre-colonial and colonial “Malabar” and predict the suitable range of D. hololius under different climatic scenarios based on the further analysis carried out herein using the species distribution modelling approach.

Eco-Cultural Niche Breadth and Overlap Within the Cucuteni–Trypillia Culture Groups During the Eneolithic

One of the most applied tools for documenting cultural variability and for tracing cultural trajectories within the environmental context is eco-cultural niche modeling and its associated methodology. The niche breadth characterization quantitatively evaluates the links between a given adaptive system and ecological constraints, which provides valuable information for archeology. For this purpose, in this study, 10 independent climatic and topographic environmental variables were interpolated, and eco-cultural niche modeling techniques were used to determine whether these differences in geographic distributions and niche breadth are consequences of differences in five Cucuteni–Trypillia groups that flourished in Eastern Europe during the Eneolithic (cal. 5,400/5,300–2,800/2,700 BCE). Our results showed that the eco-cultural niches of Cucuteni–Trypillia groups are significantly overlapping, and the expansion trend of the last two cultural groups (Late Eneolithic–cal. 4,100/4,000–2,800/2,700 BCE) into the northeastern steppe regions was not due to ecological niche differences but rather a result of other cultural factors. Furthermore, we highlighted that the first three Cucuteni–Trypillia groups (Early-to-Middle Eneolithic—cal. 5,400/5,300–4,100/4,000 BCE) had slightly more constrained ecological niches in the mid-Holocene ecosystems than the Late Eneolithic groups. The results have significant implications for understanding the geographical range dynamics and distribution of the last great Chalcolithic society of Old Europe and contribute to the characterization of ecological niches they have exploited during the cultural evolutionary process.

Combining ecological niche models with experimental seed germination to estimate the effect of climate change on the distribution of endangered plant species in the Brazilian Cerrado.

Predicting the geographic distribution of plants that provide ecosystem services is essential to understand the adaptation of communities and conserve that group toward climate change. Predictions can be more accurate if changes in physiological characteristics of species due to those changes are included. Thus, we aimed to evaluate the impacts of climate change on the different hierarchical levels of Apuleia leiocarpa (Vogel) J. F. Macbr. (Fabaceae). Therefore, we experimentally evaluate the effect of different temperatures on the initial development (vigor) and estimate the impact of climate change on the potential geographic distribution of the species, using ecological niche approaches. For the experiment, we used 11 temperature intervals of 2°C ranging from 21 to 41°C. We used ecological niche modeling techniques (ENM) to predict the species' environmental suitability in future climate scenarios. The association between the experiment and niche models was obtained by testing the relationships of temperature increase on the species vigor and geographic distribution. This conceptual model to determine the direct and indirect effects of temperature was generated using the methodological framework of structural equation models. The experiment showed that the seeds had the highest growth at 31°C. ENMs indicated that due to climate change, there is a tendency for the plant to migrate to regions with milder temperatures. However, such regions may be unsuitable for the plant since they do not have ideal temperatures to germinate, which may cause a drastic reduction in their availability in a future climate change scenario. The inclusion of seed germination through experimental research allowed us to detect an area that is less suitable for germination despite being climatically suitable for the species. Thus, research that integrates the effect of climate on the different stages of the organism's development is essential to understand the impact of climate change on biodiversity.

Systematic study and niche differentiation of the genus Aporocactus (Hylocereeae, Cactoideae, Cactaceae)

Background: Aporocactus is an epiphytic or saxicolous genus that is endemic to Mexico and has a distribution restricted to cloud forests and pine-oak forests. As with many cacti, Aporocactus presents taxonomic conflicts, especially regarding species delimitation, since five species in this genus have been described and accepted by some authors, while others accept only two species.
 Questions: How many species comprise Aporocactus? What are their relationships? Do these species show differences in their climatic preferences?
 Studied species: The five putative species in Aporocactus were investigated.
 Study site and dates: This study was conducted in 2015 and 2016. The collection sites were in Hidalgo, Puebla, Querétaro, Veracruz, and Oaxaca states, Mexico.
 Methods: In this study, phylogenetic analyses were performed using chloroplast DNA markers from different Aporocactus populations and related genera, and ecological niche modeling techniques were also employed.
 Results: The phylogenetic analyses indicated that Aporocactus is composed of only two species: A. flagelliformis and A. martianus . Additionally, the phylogenetic analyses corroborated that Aporocactus is an early diverging group related to Weberocereus and Selenicereus . Finally, niche modeling and niche identity testing indicated that the niches of the two species of Aporocactus are significantly differentiated and niches are more different than would be expected by chance.
 Conclusions: Despite being a genus with only two species, Aporocactus represents a useful model for investigating such topics as the ecology of pollination, genetic populations, and flower development to characterize the evolution of these specialized cacti.

The impact of global climate change on the number and replacement of provisioning ecosystem services of Brazilian Cerrado plants.

It is essential to predict areas of losses or exchanges of ecosystem services to adapt communities to the impacts caused by climate change. Particularly for provisioning ecosystem services provided by economically important plant species, understanding the association between climate change impacts and deforestation of native vegetation increases the accuracy of those predictions. Thus, we aim to (i) map the richness of provisioning ecosystem services from economically important native plants; (ii) use forecasts (present and future) of the distribution of ecosystem services to assess areas of changes in the number and type of provisioning ecosystems services. We evaluated provisioning ecosystem services from 110 Cerrado native species of economic importance for the local population. We determined the potential distribution of these plants using ecological niche modeling techniques, which were grouped according to the 21 different services provided. The forecasts for variation in richness and type of service used four future climate change scenarios (RCPs 4.5 and 8.5 in 2050 and 2070). The service losses detected in our models were associated with variables representing the progress of native vegetation deforestation in the biome due to agricultural expansion. Currently, ecosystem services can be found simultaneously in practically the entire biome. However, changes in the global climate will impact the potential geographic distribution of those plants, causing many areas in the biome to have reduced availability of potential ecosystem services. Moreover, due to the association between exposure to climate change and deforestation of native vegetation, the northern region of the biome will likely have the distribution of ecosystem services severely affected.

Predictive Analysis of Oak Forest Habitat under Different Climatic Change Scenario in Sikkim Himalayas

Sikkim Himalayas are known for its rich biodiversity. Being part of the North eastern Region, which is one of the Biodiversity Hotspots, it is rich in natural resources and supporting a vast variety of flora and faunas. Over a period of time this region has experienced a phenomenal increase in the population; as a result, the rich native tropical evergreen forest has been exploited to a great extent. The Oak forest habitat, which is essentially a part of dense evergreen, and semi evergreen forest are gradually getting open up and exposed to further deterioration. Oak forests habitat, being sensitive to particular climate and physiographic conditions is likely to be affected due to the changing climate scenario. Present study is an attempt to investigate the influence of climate change on Oak forest habitat in Sikkim Himalayas. The current distribution of the Oak forest derived by using satellite remote sensing and field visits and the climate and topographic information has been used to generate climatic envelope of Oak forest habitat. Future scenarios of Oak forest habitat and their potential spatial distribution have been predicted for the year 2050 and 2100 through ecological niche modeling and Geo-spatial techniques.

Niche divergence contributes to geographical parthenogenesis in two dandelion taxa.

Many sexual‐asexual complexes show a distinct pattern where the asexuals have larger and more northerly ranges than closely related sexuals. A prime candidate to explain this so‐called “geographical parthenogenesis” is ecological niche divergence between the sexuals and asexuals. Modern niche modelling techniques allow testing niche divergence by directly comparing the niches of sexuals and asexuals. In this study, I use such techniques to perform range‐wide tests of whether nine bioclimatic variables, including annual mean temperature and annual precipitation, contribute to geographical parthenogenesis in two dandelion taxa: Taraxacum section Ruderalia and Taraxacum section Erythrosperma, which are both comprised of sexual diploids and asexual triploids. For both sections, I found evidence of niche divergence, though the exact nature of this divergence was different for the two sections. In section Ruderalia, the sexuals preferred warmer and wetter conditions, whereas in section Erythrosperma, the sexuals preferred dryer conditions. Using Species Distribution Modelling, consistent differences between the sexuals and asexuals were found when looking at the niche determinants: the variables that are most important for modelling the distribution. Furthermore, and in contrast with theoretical expectations that predict that the sexuals should have a wider niche, in section Erythrosperma the asexuals were found to have a wider niche than the sexuals. In conclusion, differences in niche optima, niche determinants, and niche width all contribute to the pattern of geographical parthenogenesis of these two dandelion taxa. However, the results also indicate that the exact causation of geographical parthenogenesis is not uniform across taxa.

Difference in ecological niche breadth between Mesolithic and Early Neolithic groups in Iberia

The Mesolithic settlement of Iberia was mainly concentrated along the coastal areas, which contrasts with the wide geographic distribution achieved in a relatively short time by Early Neolithic groups. However, there was a chronological delay in the arrival of agriculture in the northern latitudes of Iberia. In the current study, paleoclimate values were interpolated from the composite benthic stable oxygen and ecological niche modelling techniques were used to determine whether these differences in the geographic distributions and spread patterns are consequences of differences in the ecological niches of the last hunter-gatherers and the first farmers. Results show that Mesolithic and Early Neolithic groups were not adapted to different ecological niches, and therefore the slowdown in the incursion of Neolithic groups into the north of Iberia was not due to their incompatibility with the environmental conditions. Furthermore, the adoption of production economies entailed an ecological niche expansion, which became essential for the observed demographic trends and the settlement distribution changes in the Mesolithic–Neolithic transition. We argue that the broader ecological niche of the first farmers probably allowed them to occupy large territories, whereas the narrower ecological niche of Mesolithic groups could have made the last hunter-gatherers more vulnerable to the climatic changes that affected the coastal ecosystems in the Mid-Holocene.

Past, present and future distributions of bumblebees in South America: Identifying priority species and areas for conservation

Abstract Climate change has been commonly associated with a decline of bumblebee populations around the world. However, most information regarding the impacts of climate change on bumblebees is derived from North America and Europe, and little is known about South American species. Here we applied ecological niche modelling techniques to estimate the past, present and future distributions of six Bombus species found in South America. These data were used to estimate climatically stable areas (CSAs) for each species and, combined with information on land cover and protected area network, identify species and areas for the conservation of these important pollinators. The models predicted a reduction in climatically suitable habitats from Last Glacial Maximum (LGM) to the present for most species. Similarly, all species were predicted to lose climatically suitable areas in future climate scenarios, ranging from 9% to 78%, depending on the species and climate change scenario. The percentage of legally protected CSAs varied between 4.0% and 48.2% among species, mainly due to differences in the protected area network among the biomes in which they occur. A significant portion of the distribution range of most species includes agricultural areas, which likely increases bumblebee exposure to pesticides. Based on the estimated habitat loss due to climate change, as well as from land cover and protected area, our results indicate that Bombus bellicosus, Bombus brevivillus and Bombus brasiliensis are the most endangered species of those evaluated. Synthesis and applications. Our findings provide a framework for conservation strategies of six species of South American bumblebees, by prioritizing species and areas for conservation considering their distribution range and the climatically stable areas under different climate change scenarios.

Ecological Niche Models of Four Hard Tick Genera (Ixodidae) in Mexico.

Simple SummaryVector-borne diseases currently represent a significant threat to public health, mainly due to the changes that humans are producing in ecosystems and climates. Analyzing the environmental conditions that allow the establishment and survival of ticks could help determine possible sites for the appearance of infectious outbreaks. In this study, nine ecological niche models were generated from different algorithms to determine the current potential distribution of four tick genera in Mexico. Temperature and moisture have been considered as the main factors limiting tick distribution. However, the analysis of the ecological niche models determined that the four genera exhibited different distribution patterns, which may be associated with their physiological and ecological differences. This type of analysis can improve our understanding of the dynamics of ticks and, therefore, can be very useful in monitoring programs of the diseases they transmit.Ticks are vectors of a large number of pathogens of medical and veterinary importance, and in recent years, they have participated in the rise of multiple infectious outbreaks around the world. Studies have proposed that temperature and precipitation are the main variables that limit the geographical distribution of ticks. The analysis of environmental constraints with ecological niche modeling (ENM) techniques can improve our ability to identify suitable areas for emergence events. Algorithms used in this study showed different distributional patterns for each tick genera; the environmental suitability for Amblyomma includes warm and humid localities below 1000 m above the sea level, while Ixodes is mainly associated with ecosystems with high vegetation cover. Dermacentor and Rhipicephalus genus presented wider distribution patterns; the first includes species that are well adapted to resist desiccation, whereas the latter includes generalist species that are mostly associated with domestic hosts in Mexico. Ecological niche models have proven to be useful in estimating the geographic distribution of many taxa of ticks. Despite our limited knowledge of tick’s diversity, ENM can improve our understanding of the dynamics of vector-borne diseases and can assist public health decision-making processes.

Sympatric and allopatric niche shift of endemic Gypsophila (Caryophyllaceae) taxa in the Iberian Peninsula.

Several species of the Gypsophila genus are endemic to the Iberian Peninsula, including gypsophytes of particular ecological, evolutionary and biochemical interest, and taxa that have undergone both sympatric and allopatric genetic differentiation. The niche shift among these taxa has been assessed using ecological niche modelling and ordination techniques, adopting a niche overlap approach to compare the similarity and equivalency of the ecological niches. We used the Maximum Entropy method to study the potential distribution of these taxa in different eras: the Last Glacial Maximum (LGM), the Mid Holocene and the current conditions. We present evidence of niche shift during the speciation of G. bermejoi, with a strong niche overlap between the parental taxa (G. struthium subsp. struthium and G. tomentosa), yet both overlap much more weakly with the hybrid species. This phenomenon may be explained by genetic and epigenetic interactions, and it has been described in other species. We also studied the sister subspecies G. struthium subsp. struthium and G. struthium subsp. hispanica, with mostly allopatric distributions and with the Iberian System mountain range acting as a geographical barrier. The Iberian System and other mountain ranges may have favored differences in the climatic conditions on either side of the mountain range, which is consistent with an incipient process of bioclimatic ecological speciation. These results seem to indicate that niche shift can occur over very different timespans. In the case of G. bermejoi, speciation may have produced significant niche shifting in one or two generations due to its alloploid nature. By contrast, G. struthium subsp. struthium and G. struthium subsp. hispanica seem to have undergone a more gradual process of allopatric genetic differentiation driven by bioclimatic factors. Both these processes are relatively recent and they will have been strongly influenced by the climate change at the end of LGM.