Niche Distribution Research Articles

Niche divergence mechanisms of closely related hybridising bird species. Modeling approach based on remote sensing data of forest habitats

Describing mechanisms that ensure stable co-occurrence of sympatric species is fundamental to understanding the complexity of ecological community dynamics. In this study, the Pied flycatcher and the Collared flycatcher were used as model species for the analysis of co-occurrence patterns of closely related hybridising species that inhabit overlapping forest habitats. I hypothesise that spatial niche partitioning between species emerges as a vital adaptive response to interspecific competition and manifests itself in significant shifts in habitat preferences in syntopic areas but not in the allotopic ones. The study leverages a comprehensive dataset that includes species density in 372 randomly selected 1 km² grid cells across the territory of Poland. The analysis of habitat preferences was performed with linear mixed-effect modeling, whereas a contrast analysis was used to investigate changes in habitat preferences resulting from the presence of a competitor. The findings indicate that both species modify their habitat preferences when transitioning between syntopic and allotopic sites. Remarkably, in regions without competitors, such shifts are significantly less pronounced, as demonstrated by the Pied flycatcher that prefers the same habitats both in allopatric regions and allotopic sites. When these results are compared with other studies on closely related hybridising and non-hybridising species, it turns out that what influences the degree and number of niches subjected to competition is the time that passes from species divergence. This study highlights the imperative need to incorporate co-occurrence parameters of closely related species into niche and species distribution models to enhance their ecological realism.

Spatial heterogeneity in the potential distribution of Aedes mosquitoes in India under current and future climatic scenarios

Aedes is the most globally distributed mosquito genus in the 21st century and transmits various arboviral diseases. The rapid expansion of Ae. Aegypti and Ae. albopictus breeding habitats is a significant threat to global public health, driven by temperature and precipitation changes. In this study, bioclimatic variables were employed to predict the spatial distribution of Ae. aegypti and Ae. albopictus in India. The reference coordinate points of (n = 583) Aedes occurrences at a scale of ∼1 km and nineteen bioclimatic factors were retrieved to train SDM (Species Distribution Models) for both species. Maximum entropy modelling was used to predict the species’ fundamental climatic niche distributions. Future projections were made using global climate models for 2021–2040 and 2081–2100 separately. The models performed reasonably well (AUC > 0.77). Both species thrived in reduced diurnal temperature and higher annual mean temperatures, with suitability increasing alongside precipitation. Ae. aegypti’s projected present and future distribution was broader than that of Ae. Albopictus. The expansion of Aedes suitability varied under different future climatic scenarios. Suitability for Ae. aegypti could expand from between 17.6 and 41.1 % in 2100 under SSP (shared socioeconomic pathways) scenarios 1 and 3, respectively, whereas for Ae. albopictus suitability increased from between 10.2 and 25 % under SSP scenarios 1 and 3 respectively. Preparing for future epidemics and outbreaks requires robust vector distribution models to identify high-risk areas, allocate resources for surveillance and control, and implement prevention strategies.

Divergent Response of Two Bark Beetle-Fungal Symbiotic Systems to Host Monoterpenes Reflects Niche Partitioning Strategies.

The successful establishment of bark beetle-fungus symbionts on plants is required to overcome host defenses. However, little is known about how different bark beetle-fungus symbionts adapt to different niches on the same host plant. Here, we investigated the niche partitioning mechanism of two co-occurring bark beetle-fungus symbiotic systems, Ips nitidus-Ophiostoma bicolor and Dendroctonus micans-Endoconidiophora laricicola, on Qinghai spruce (Picea crassifolia) tree. The lower niche of the spruce trunk inhabited by D. micans showed a higher content of monoterpenes than the upper niche of the trunk inhabited by I. nitidus. Dendroctonus micans showed greater tolerance and higher metabolic efficiency toward monoterpenes than I. nitidus. However, both beetle species showed a similar metabolic profile toward α-pinene, albeit with different levels of metabolites. Additionally, O. bicolor, transmitted by I. nitidus, showed a significantly higher tolerance to monoterpenes and pathogenicity to spruce trees than E. laricicola, transmitted by D. micans. In particular, monoterpenoid metabolites were observed to attenuate the inhibitory effect of high-dose α-pinene on E. laricicola, thus increasing its fitness in a high-dose monoterpene microhabitat. These results show that these two bark beetle-fungus symbionts have adapted to different niches, leading to fitness differences in niche distribution that are at least partly related to the different distribution of monoterpene concentration in the spruce trunk. This research provides a novel perspective for understanding the coevolution between bark beetle-fungus symbionts and their host plants.

Niche evolution during allopatric and sympatric diversification of Aeonium (Crassulaceae) on the Canary Islands

Abstract Although species radiations on island archipelagos are broadly studied, the geographic and ecological modes of speciation that underlie diversification are often not fully understood. Both allopatry and sympatry play a role during radiations, particularly on islands with profound habitat diversity. Here, we use the most diverse Canary Island plant radiation, Aeonium (Crassulaceae), to phylogenetically test two hypotheses: (1) allopatric speciation, which predicts that closely related taxa are ecologically similar but do not co-occur, and (2) sympatric speciation, whereby closely related taxa co-occur geographically but are ecologically distinct. We fitted niche and spatial distribution models based on extensive field surveys to quantify geographic and ecological divergence among taxa integrated in a phylogenetic context. Contrary to our expectation, phylogenetically closely related species tend to occupy similar ecological niches, revealing that ecological niche divergence among species accumulates slowly, even in sympatry. This suggests that evolutionary young taxa may be partially reproductively isolated due to subtle phenotypic differences, such as reproductive morphology and phenology, rather than by ecological niche and may putatively exacerbate divergence among populations. Thus, allopatry and sympatry are complementary speciation mechanisms on oceanic islands, jointly spurring this enigmatic radiation.

The ongoing range expansion of the invasive oak lace bug across Europe: current occurrence and potential distribution under climate change

In recent years, the oak lace bug, Corythucha arcuata, has emerged as a significant threat to European oak forests. This species, native to North America, has in the last two decades rapidly extended its range in Europe, raising concerns about its potential impact on the continent's invaluable oak populations. To address this growing concern, we conducted an extensive study to assess the distribution, colonization patterns, and potential ecological niche of the oak lace bug in Europe.We gathered 1792 unique presence coordinates from 21 Eurasian countries, utilizing diverse sources such as research observations, citizen science initiatives, GBIF database, and social media reports. To delineate the realized niche and future distribution, we employed an ensemble species distribution modelling (SDM) framework. Two future greenhouse gas scenarios (RCP 4.5 and RCP 8.5) were considered across three-time intervals (2021–2040, 2061–2080, and 2081–2100) to project and evaluate the species' potential distribution in the future.Our analysis revealed that significant hotspots rich in host species occurrence for this invasive insect remain uninvaded so far, even within its suitable habitat. Furthermore, the native ranges of Turkey oak (Quercus cerris L.) and Hungarian oak (Quercus frainetto L.) species offer entirely suitable environments for the oak lace bug. In contrast, the pedunculate oak and sessile oak distribution ranges currently show only 40 % and 50 % suitability for colonization, respectively. However, our predictive models indicate a significant transformation in the habitat suitability of the oak lace bug, with suitability for these two oak species increasing by up to 90 %. This shift underlines an evolving landscape where the oak lace bug may exploit more of its available habitats than initially expected. It emphasises the pressing need for proactive measures to manage and stop its expanding presence, which may lead to a harmful impact on the oak population across the European landscape.

Ecological Niche and Spatial Distribution Models of the Russian Sturgeon Acipenser gueldenstaedtii Brandt et Ratzeburg (1833) in the Northern Part of the Caspian Sea Based on Long-Term Monitoring Data (1992–2011) in the Summer Period

Ecological Niche and Spatial Distribution Models of the Russian Sturgeon Acipenser gueldenstaedtii Brandt et Ratzeburg (1833) in the Northern Part of the Caspian Sea Based on Long-Term Monitoring Data (1992–2011) in the Summer Period

Microbial Diversity and Nitrogen Cycling in Peat and Marine Soils: A Review

Nitrogen is an essential nutrient for living organisms in peat and marine soils, and its transformation within the soil matrix is a complex process mediated by various microbes that inhabit these ecological niches. The metabolism of nitrogen is governed by microbially mediated biogeochemical transformations, such as nitrification, anammox, and denitrification, which contribute to the assimilated pool of nitrogen and fixed nitrogen loss. One of the major challenges facing the field of peat and marine microbiology is the lack of understanding of the correlation between ecosystem-driven nitrogen transformation and microbial diversity. This is crucial because of growing concerns regarding the impacts of human-induced activities and global climate change on microbial nitrogen-cycling processes in peat and marine soils. Thus, this review aimed to provide a comprehensive overview of the current understanding of the microbial communities involved in peat and marine nitrification, anammox, and denitrification; the factors influencing the niche differentiation and distribution of the main functional components; the genes involved; and the main effects of human-induced activities and global climate change on the peat and marine nitrogen cycle. The implications of this review will facilitate an understanding of the complex mechanisms associated with ecosystem function in relation to nitrogen cycling, the role of peat and marine soils as carbon sinks, pollution remediation using naturally occurring populations of diverse microbes, and the development of policies to mitigate the effects of anthropogenic influences in peat and marine soils.

Climate change will likely facilitate invasion of Asian orchid Eulophia graminea into new areas

Climate change plays an increasing role in the global biodiversity crisis. Alteration in local climatic conditions not only can negatively affect native biodiversity but also can accelerate the introduction and spread of invasive species. In this study the ecological niche modelling approach was used to evaluate possible changes in the distribution of suitable niches of invasive orchid Eulophia graminea within its native (Asia) and non-native geographical range (America, Australia). We mapped the current potential range of this species and analysed three various projections of future climate (for 2100) each with four different climate change scenarios (SSPs). Calculated niche overlap indexes indicated low similarity of niches occupied by native and invasive populations of E. graminea and Australian populations seem to be the most unique, while American and Asian groups share partially similar niches. The occurrence of the American population of E. graminea was correlated especially with the temperature seasonality, while the Asian and Australian populations with annual precipitation and precipitation of the wettest quarter. As indicated in our analyses within Asia and America, E. graminea does not occupy all climatically suitable niches. On the other hand, in Australia the species studied already occupies all appropriate niche space. Climate change will likely be favorable for species studied to expand its range if the biotic components of its niche space (e.g., mycorrhizal fungi) will respond similarly. The most significant range expansion is predicted to occur in Australia which is interesting considering the marginally suitable habitats that E. graminea currently occupies.

Niche analyses and the potential distribution of four invasive bumblebees worldwide.

The introduction of bees for agricultural production in distinct parts of the world and poor management have led to invasion processes that affect biodiversity, significantly impacting native species. Different Bombus species with invasive potential have been recorded spreading in different regions worldwide, generating ecological and economic losses. We applied environmental niche and potential distribution analyses to four species of the genus Bombus to evaluate the similarities and differences between their native and invaded ranges. We found that B. impatiens has an extended environmental niche, going from dry environmental conditions in the native range to warmer and wetter conditions in the invaded range. Bombus ruderatus also exhibited an extended environmental niche with drier and warmer conditions in the invaded range than in its native range. Bombus subterraneus expanded its environmental niche from cooler and wetter conditions in the native range to drier and warmer conditions in the invaded range. Finally, B. terrestris showed the most significant variation in the environmental niche, extending to areas with similar and different environmental conditions from its native range. The distribution models agreed with the known distributions for the four Bombus species, presenting geographic areas known to be occupied by each species in different regions worldwide. The niche analysis indicate shifts in the niches from the native to the invaded distribution area of the bee species. Still, niche similarities were observed in the areas of greatest suitability in the potential distribution for B. ruderatus, B. subterraneus, and B. terrestris, and to a lesser degree in the same areas with B. impatiens. These species require similar environmental conditions as in their native ranges to be established in their introduced ranges. Still, they can adapt to changes in temperature and humidity, allowing them to expand their ranges into new climatic conditions.

Calibration areas in ecological niche and species distribution modelling: Unravelling approaches and concepts

AbstractAimThe calibration area (CA) corresponds to the geographic region used by different algorithms that estimate the species' environmental preferences and delimit its geographic distribution. This study intended to identify, test and compare current literature's most commonly employed approaches and methods for CA creation, highlighting the differences with the accessible area (M), a frequently misapplied concept.LocationGlobal.TaxonArthropods, amphibians, reptiles, birds and mammals.MethodsWe conducted a literature review and analysed 129 recent articles on species distribution that use correlative models to identify the methods used to establish the CA and their frequency. We also evaluated seven of the most widely used methods for 31 species from different taxa.ResultsWe found that the most frequently used methods in literature corresponded to biogeographic entities (BE). Moreover, according to our evaluation, those methods that seek to establish the CA through the accessible area approach (including BE and ‘grinnell’) were the best evaluated. Finally, we highlight the advantages and disadvantages of the analysed methods in selecting CA.Main ConclusionsAlthough we cannot fail to recognize the usefulness and validity of the different methods to establish CAs, we suggest calibrating ecological niche and species distribution models in light of explicit a priori hypotheses regarding the extent of accessible areas (M) as a delimitation of the CA, which theoretically includes the species' dispersal ability and its barriers. We recommend using the BE method, which is simple to establish and highly operational.

Environmental sympatry through time: spatio-temporal distribution and conservation status of two sympatric anuran species (Leptodactylidae) in South America

Introduction: Leptodactylus latinasus and Physalaemus cuqui are sympatric anuran species with similar environmental requirements and contrasting reproductive modes. Climatic configuration determines distribution patterns and promotes sympatry of environmental niches, but specificity/selectivity determines the success of reproductive modes. Species distribution models (SDM) are a valuable tool to predict spatio-temporal distributions based on the extrapolation of environmental predictors. Objectives: To determine the spatio-temporal distribution of environmental niches and assess whether the protected areas of the World Database of Protected Areas (WDPA) allow the conservation of these species in the current scenario and future. Methods: We applied different algorithms to predict the distribution and spatio-temporal overlap of environmental niches of L. latinasus and P. cuqui within South America in the last glacial maximum (LGM), middle-Holocene, current and future scenarios. We assess the conservation status of both species with the WDPA conservation units. Results: All applied algorithms showed high performance for both species (X̅TSS = 0.87, X̅AUC = 0.95). The L. latinasus predictions showed wide environmental niches from LGM to the current scenario (49 % stable niches, 37 % gained niches, and 13 % lost niches), suggesting historical fidelity to stable climatic-environmental regions. In the current-future transition, L. latinasus would increase the number of stable (70 %) and lost (20 %) niches, suggesting fidelity to lowland regions and a possible trend toward microendemism. P. cuqui loses environmental niches from the LGM to the current scenario (25 %) and in the current-future transition (63 %), increasing the environmental sympathy between both species; 31 % spatial overlap in the current scenario and 70 % in the future. Conclusion: Extreme drought events and rainfall variations, derived from climate change, suggest the loss of environmental niches for these species that are not currently threatened but are not adequately protected by conservation units. The loss of environmental niches increases spatial sympatry which represents a new challenge for anurans and the conservation of their populations.

The effect of El Niño and La Niña episodes on the existing niche and potential distribution of vector and host species of American Cutaneous Leishmaniasis

Leishmaniasis is a zoonotic disease transmitted to humans by a protozoan parasite through sandfly vectors and multiple vertebrate hosts. The Pan American Health Organization reported a declining trend in cases, with Brazil, Colombia, Peru, Nicaragua, and Bolivia having the most cases in 2020. There are still knowledge gaps in transmission and the parasite-host relationship. Ecological niche modeling has been used to study host-vector relationships, disease dynamics, and the impact of climate change. Understanding these aspects can aid in early surveillance and vector control strategies. The potential distribution of five host species associated with the transmission of cutaneous leishmaniasis (CL) was modeled. Occurrence data were collected for each host species, and environmental variables were used to build the models. Climatic data from El Niño, La Niña, and Neutral episodes were used to compare the predicted distributions. Additionally, the potential distributions of four vector species were compared to identify overlaps with host species. Niche analysis was conducted to evaluate changes in vector niches across episodes and to identify host-vector pairs based on niche overlap in geographic and environmental spaces. After spatial thinning, 467 records were obtained, and 1,190 candidate models were evaluated for each species. Results showed the distribution of occurrences in the environmental space, highlighting a high risk of extrapolation beyond the calibration areas. Movement-Oriented Parity analysis revealed distinct distribution patterns under different climate conditions, with areas of environmental similarity identified. Bradypus variegatus exhibited a broad potential distribution, while Dasypus novemcinctus and Didelphis marsupialis had more restricted ranges. Sylvilagus braziliensis covered most of the Neotropics. Our study provides valuable insights into ecological niches and geographic ranges of these species, contributing to the understanding of cutaneous leishmaniasis transmission dynamics.

Predicting the potential ecological niche distribution of Slovenian forests under climate change using MaxEnt modelling

The aim of the article is to assess the potential impacts of climate change on Slovenian forests in the period 2080–2100 based on two climate scenarios: SSP1-2.6 (optimistic) and SSP5-8.5 (pessimistic) using the MaxEnt software. Slovenian forests are divided at the ecological community level into thirteen forest vegetation types. Analyses of changes in ecological niche areas, distances of vectors between centroids of present areas and future ecological niches, and general spatial changes are carried out. In addition, changes in the altitudinal zones of forest vegetation types were investigated. The results indicate significant changes for Thermophilous beech forests and Thermophilous hop-hornbeam, sessile oak, downy oak, Scots pine and black pine forests. The potential changes in the altitudinal zones of forest vegetation types indicate a clear trend of forest vegetation types moving to higher altitudinal zones.

The niche and value creation mechanism of the innovation ecosystem of crowd innovation space: a multi-case study

ABSTRACT Twelve crowd innovation spaces (from China) are selected as case samples, and the niche distribution model of the crowd innovation space’s innovation ecosystem is constructed based on structural hole theory. Further, this research reveals the interactive relationship and value creation mechanism among the innovation ecosystem's components from the value co-creation theory perspective. The research draws the following conclusions from three aspects: (1) The niche of the components of the crowd innovation space ecosystem is characterised by multiple levels, which can be divided into the core layer, convergence layer, and support layer. (2) In the innovation ecosystem, crowd innovation space is at the convergence layer. By filling structural holes, the innovation ecosystem can reach the ‘no holes’ state. Thus, it can promote the connection of the components of the innovation ecosystem to form a network of innovation resources such as knowledge and technology; (3) The value creation in the crowd innovation space’s innovation ecosystem is two-dimensional. Based on whether there is direct interaction or not, value creation can be divided into value co-creation and value auxiliary-creation. Relationship embeddedness and value co-creation are two important mechanisms of value creation in the innovation ecosystem of crowd innovation space.

Late Quaternary communities of shrews, Soricidae, from Ural and Far East Regions of Russia: A protocol for the multifactorial morphospace building

The present paper is a preliminary attempt to develop a protocol for analyzing Late Pleistocene and Holocene paleocommunities of soricids using modern approaches for the morphological data analysis. First, we assessed the abilities of fossil soricid collections from Ural and Far East localities to provide a complex interregional analysis of the phenotype variation. Accordingly, for the first time in the general context, the study provides a species list and chronological position of Ural and Far East shrew fossil samples in terms of inter- and intraregional comparisons to reveal general and specific responses of paleocommunities to climatic fluctuations. Second, under the modern approaches, we prepared 182 three-dimensional models of hemimandibles or isolated m1 and built the morphospace of m1 shape for seven Sorex species from the Upper Pleistocene layer MKl-13 and Middle Holocene layer MKl-7 of Medvezhyi Klyk Cave (South Primorye, Russia). Recent samples from East Siberia (Yakutia) and the northern part of the Far East (Magadanskaya Oblast' and Khabarovsky Kray; “cold” habitats) and South Primorye (“warm” habitats) were included into morphospace to actualize potential responses of the fossil samples to Late Quaternary climate fluctuations. Our analysis revealed: (i) a weak reaction of m1 shape of almost all species to the “cold” and “warm” environmental conditions, except S. daphaenodon Thomas, 1907 and S. caecutiens Laxmann, 1788; (ii) two groups of species, namely “generalized” and “specialized” in m1 shape, in line with the idea of distribution of trophic niches among coexisted shrews; (iii) a diagnostic character for fossil samples of S. unguiculatus Dobson, 1890 and S. isodon Turov, 1924.

Future distribution of the epiphytic leafless orchid (Dendrophylax lindenii), its pollinators and phorophytes evaluated using niche modelling and three different climate change projections

The identification of future refugia for endangered species from the effects of global warming is crucial for improving their conservation. Because climate-driven shifts in ranges and local extinctions can result in a spatial mismatch with their symbiotic organisms, however, it is important to incorporate in niche modelling the ecological partners of the species studied. The aim of this study was to evaluate the effect of climate change on the distribution of suitable niches for the ghost orchid (Dendrophylax lindenii) and its phorophytes and pollinators. Thus, its five species of host trees and three pollen vectors were included in the analysis. Climatic preferences of all the species studied were evaluated. The modelling was based on three different climate change projections and four Shared Socio-economic Pathway trajectories. All the species analysed are characterized by narrow temperature tolerances, which with global warming are likely to result in local extinctions and range shifts. D. lindenii is likely to be subjected to a significant loss of suitable niches, but within a reduced geographical range, both host trees and pollen vectors will be available in the future. Future conservation of this orchid should focus on areas that are likely be suitable for it and its ecological partners.

Historical Climate Change Dynamics Facilitated Speciation and Hybridization Between Highland and Lowland Species of Baripus Ground Beetles From Patagonia

One of the largest beetles of Patagonia, Baripus (Cardiophthalmus), includes 20 currently described species. Its distribution ranges from the tip of Patagonia, on Tierra del Fuego Island, to isolated patches along the Andes and extra-Andes mountains in northern Patagonia on the Payunia at >3000 m elevation. Here, using RADseq data, evidence is found of mixed ancestry in different lineages. Phylogenetic network reconstruction shows two hybridizing edges between lowland and highland species. Using environmental niche modeling, we show changes in geographic distribution of potential niches of species during the last glacial maximum compared to their present distribution. Increasing potential niche overlap among different species pairs possibly explains how lineages came into secondary contact, supporting the hypothesis of hybridization. In addition, morphological evolution is studied using geometric morphometrics on the network, and evidence of transgressive evolution has been found involving the pronotum shape, as well as highland/lowland habitat preferences. Finally, based on genomics and morphological data and using an integrative coalescent-based species delimitation approach, the separate evolution of two lineages in early stages of speciation is found. Taken together, dynamics of diversification of Baripus beetles in both space and time are discussed.

Niche suitability and spatial distribution patterns of anurans in a unique Ecoregion mosaic of Northern Pakistan.

The lack of information regarding biodiversity status hampers designing and implementing conservation strategies and achieving future targets. Northern Pakistan consists of a unique ecoregion mosaic which supports a myriad of environmental niches for anuran diversity in comparison to the deserts and xeric shrublands throughout the rest of the country. In order to study the niche suitability, species overlap and distribution patterns in Pakistan, we collected observational data for nine anuran species across several distinct ecoregions by surveying 87 randomly selected locations from 2016 to 2018 in Rawalpindi District and Islamabad Capital Territory. Our model showed that the precipitation of the warmest and coldest quarter, distance to rivers and vegetation were the greatest drivers of anuran distribution, expectedly indicating that the presence of humid forests and proximity to waterways greatly influences the habitable range of anurans in Pakistan. Sympatric overlap between species occurred at significantly higher density in tropical and subtropical coniferous forests than in other ecoregion types. We found species such as Minervarya spp., Hoplobatrachus tigerinus and Euphlyctis spp. preferred the lowlands in proximal, central and southern parts of the study area proximal to urban settlements, with little vegetation and higher average temperatures. Duttaphrynus bengalensis and D. stomaticus had scattered distributions throughout the study area with no clear preference for elevation. Sphaerotheca pashchima was patchily distributed in the midwestern extent of the study area as well as the foothills to the north. Microhyla nilphamariensis was widely distributed throughout the study area with a preference for both lowlands and montane terrain. Endemic frogs (Nanorana vicina and Allopaa hazarensis) were observed only in locations with higher elevations, higher density of streams and lower average temperatures as compared to the other seven species sampled. It is recommended to provide legal protection to amphibians of Pakistan, especially endemic species, through revision in the existing wildlife laws. We suggest studying the effectiveness of existing amphibian tunnels and corridors or designing new ones tailored to the needs of our species to prevent their local extinction due to ongoing or proposed urban development which might affect their dispersal and colonization.

Climatic niche convergence through space and time for a potential archaeophyte (Acacia caven) in South America

Based on the niche conservatism hypothesis, i.e. the idea that niches remain unchanged over space and time, climatic niche modelling (CNM) is a useful tool for predicting the spread of introduced taxa. Recent advances have extended such predictions deeper in time for plant species dispersed by humans before the modern era. The latest CNMs successfully evaluate niche differentiation and estimate potential source areas for intriguing taxa such as archaeophytes (i.e., species introduced before 1492 AD). Here, we performed CNMs for Acacia caven, a common Fabaceae tree in South America, considered an archaeophyte west of the Andes, in Central Chile. Accounting for the infraspecific delimitation of the species, our results showed that even when climates are different, climatic spaces used by the species overlap largely between the eastern and western ranges. Despite slight variation, results were consistent when considering one, two, or even three-environmental dimensions, and in accordance with the niche conservatism hypothesis. Specific distribution models calibrated for each region (east vs west) and projected to the past, indicate a common area of occupancy available in southern Bolivia—northwest Argentina since the late Pleistocene, which could have acted as a source-area, and this signal becomes stronger through the Holocene. Then, in accordance with a taxon introduced in the past, and comparing regional vs continental distribution models calibrated at the infraspecific or species level, the western populations showed their spread status to be mostly in equilibrium with the environment. Our study thus indicates how niche and species distribution models are useful to improve our knowledge related to taxa introduced before the modern era.

Geographic Distribution of the Genus Panstrongylus Berg, 1879 in the Neotropic with Emphasis on Trypanosoma cruzi Vectors.

Panstrongylus is a Neotropical taxa of 16 species, some more widespread than others, that act as vectors of Trypanosoma cruzi, the etiologic agent of Chagas disease (CD). This group is associated with mammalian reservoir niches. There are few studies of the biogeography and niche suitability of these triatomines. Using zoo-epidemiological occurrence databases, the distribution of Panstrongylus was determined based on bioclimatic modelling (DIVA GIS), parsimonious niche distribution (MAXENT), and parsimony analysis of endemic species (PAE). Through 517 records, a wide presence of P. geniculatus, P. rufotuberculatus, P. lignarius, and P. megistus was determined and recorded as frequent vectors of T. cruzi in rainforest habitats of 24-30 °C. These distributions were modeled with AUC >0.80 and <0.90, as well as with the seasonality of temperature, isothermality, and precipitation as relevant bioclimatic variables. Individual traces for each taxon in Panstrongylus-1036 records-showed widely dispersed lines for frequent vectors P. geniculatus, P. lignarius, P. rufotuberculatus, and P. megistus. Other occasional vectors showed more restricted dispersal, such as P. howardi, P. humeralis, P. lenti, P. lutzi, P. tupynambai, P. noireaiui, and P. chinai. Areas of defined environmental variation, geological change, and trans domain fluid fauna, such as the American Transition Zone and the Pacific Domain of Morrone, had the highest Panstrongylus diversity. Pan-biogeographic nodes appear to be areas of the greatest species diversity that act as corridors connecting biotopes and allowing fauna migration. Vicariance events in the geologic history of the continent need to be investigated. The geographical distribution of Panstrongylus overlapped with CD cases and Didelphis marsupialis/Dasypus novemcinctus presence, two important reservoirs in Central and South America. The information derived from the distribution of Panstrongylus provides knowledge for surveillance and vector control programs. It would increase information on the most and less relevant vector species of this zoonotic agent, for monitoring their population behavior.