Niche Modeling Approach Research Articles

Ecological assessment and environmental niche modelling of Himalayan rhubarb (Rheum webbianum Royle) in northwest Himalaya.

In an era of anthropocene, threatened and endemic species with small population sizes and habitat specialists experience a greater global conservation concern in view of being at higher risk of extinction. Predicting and plotting appropriate potential habitats for such species is a rational method for monitoring and restoring their dwindling populations in expected territories. Ecological niche modelling (ENM) coalesces species existence sites with environmental raster layers to construct models that describe possible distributions of plant species. The present study is aimed to study the potential distribution and cultivation hotspots for reintroducing the high value, vulnerable medicinal herb (Rheum webbianum) in the Union territories of Jammu and Kashmir and Ladakh using population attributes and ecological niche modelling approach. Sixty-three populations inventoried from twenty-eight areas display a significant change in the phytosociological attributes on account of various anthropogenic threats. The current potential habitats coincide with actual distribution records and the mean value of Area Under Curve (AUC) was 0.98 and the line of predicted omission was almost adjacent to omission in training samples, thus validating a robustness of the model. The potential habitat suitability map based on the current climatic conditions predicted a total of 103760 km2 as suitable area for the growth of Rheum webbianum. Under the future climatic conditions, there is a significant reduction in the habitat suitability ranging from -78531.34 Km2 (RCP 4.5 for 2050) to -77325.81 (RCP 8.5 for 2070). Furthermore, there is a slight increase in the suitable habitats under future climatic conditions, ranging from +21.99 Km2 under RCP 8.5 (2050) to +3.14 Km2 under RCP 4.5 (2070). The Jackknife tests indicated Precipitation of Driest Month (BIO14) as the most contributing climatic variable in governing the distribution of R. webbianum. Therefore, scientifically sound management strategies are urgently needed to save whatever populations are left in-situ to protect this species from getting extinct. Present results can be used by conservationists for mitigating the biodiversity decline and exploring undocumented populations of R. webbianum on one hand and by policymakers in implementing the policy of conservation of species with specific habitat requirements by launching species recovery programmes in future on the other.

Rapid range expansion predicted for the Common Grackle (Quiscalus quiscula) in the near future under climate change scenarios

BackgroundClimate change due to anthropogenic global warming is the most important factor that will affect future range distribution of species and will shape future biogeographic patterns. While much effort has been expended in understanding how climate change will affect rare and declining species we have less of an understanding of the likely consequences for some abundant species. The Common Grackle (Quiscalus quiscula; Linnaeus 1758), though declining in portions of its range, is a widespread blackbird (Icteridae) species in North America east of the Rocky Mountains. This study examined how climate change might affect the future range distribution of Common Grackles.MethodsWe used the R package Wallace and six general climate models (ACCESS1-0, BCC-CSM1-1, CESM1-CAM5-1-FV2, CNRM-CM5, MIROC-ESM, and MPI-ESM-LR) available for the future (2070) to identify climatically suitable areas, with an ecological niche modelling approach that includes the use of environmental conditions.ResultsFuture projections suggested a significant expansion from the current range into northern parts of North America and Alaska, even under more optimistic climate change scenarios. Additionally, there is evidence of possible future colonization of islands in the Caribbean as well as coastal regions in eastern Central America. The most important bioclimatic variables for model predictions were Annual Mean Temperature, Temperature Seasonality, Mean Temperature of Wettest Quarter and Annual Precipitation.ConclusionsThe results suggest that the Common Grackle could continue to expand its range in North America over the next 50 years. This research is important in helping us understand how climate change will affect future range patterns of widespread, common bird species.

Exploring the effects of the quaternary glacial–interglacial cycles on the geographic distributions of tropical Andean rodents: species in the genus Aepeomys Thomas, 1898 (Thomasomyini: Sigmodontinae: Cricetidae) as a case study

ABSTRACT The Quaternary glaciations had great impacts on the historical biogeography of small mammal species. Recent studies have showed the effects of these climatic cycles on the diversification of several Neotropical rodents, but these have focused on species whose distributions do not encompass the tropical Andes. Thus, the influences of these climatic dynamics on the evolutionary history of tropical Andean rodent species remain unknown. The effects of these climatic changes were addressed on Aepeomys lugens and A. reigi, two Thomasomyine endemics from the Cordillera de Mérida in the Venezuelan Andes. The past potential geographic distribution of both species was inferred using an ecological niche modeling approach. The estimations obtained indicated that the availability of the suitable climatic conditions for these taxa has varied in size and location during the last 140,000 years. The spatial projection of the niche models onto the climatic scenarios explored indicates that the effects over the historical distributions were smaller in A. lugens than in A. reigi. These results show that the current geographic distribution of both Andean rodents conceals complex biogeographic histories, and characterizations of the demographic history and genetic diversity will be required to understand the evolution of the genus Aepeomys in the Andes.

A less data demanding ecophysiological niche modeling approach for mammals with comparison to conventional correlative niche modeling

Ecophysiological models are more data demanding and, consequently, less used than correlative ecological niche models to predict species’ distribution under climate change, especially for endotherms. Hybrid models that integrate both approaches are even less used, and several aspects about their predictions (e.g. accuracy, geographic extent and uncertainty) have been poorly explored. We developed a hybrid model for mammals using hours of activity and hours of heat stress as mechanistic variables, fitted using macroclimatic data and applied to conventional correlative modeling. We then compared the outputs from conventional correlative models with our hybrid model for 58 tropical mammals in term of accuracy, uncertainty, and predicted geographic distribution under climate change. We expected that hybrid models to have higher accuracy than correlative ones, with difference in predicted geographic distribution extent. We found no substantial differences between correlative and hybrid predictions for accuracy, uncertainty, and extent. Although the area predicted as suitable did not differ in extent, they differ in location, with lower congruence between models for future prediction. This result challenged the widespread assumption that hybrid models are more accurate. The ecophysiological model approach proposed here ease ecophysiological data requirements. We propose, therefore, choosing model approach based on study's objective, rather than on data requirements or the assumption that hybrid models have better predictions. The main advantage of the hybrid model is in providing a more complete view of the species response, as proximal (causal) and distal (environment) aspects are combined.

Niche-separation and conservation biogeography of Madagascar’s fork-marked lemurs (Cheirogaleidae: Phaner): Evidence of a new cryptic species?

Ecological niche modeling can provide insights into a species’ demography, ecology and biogeography, and the environmental factors that determine them. Exploration of ecological niche models and niche-divergence among closely-related and cryptic organisms can also be useful for species delineation and discrimination, and such information can inform and facilitate conservation of their populations. In this study, I used an ecological niche modeling approach to investigate the conservation biogeography of the fork-marked lemurs (genus Phaner), a group of cryptic, nocturnal primates that are endemic to Madagascar. I constructed all ecological niche models in MaxEnt, using a range of climatic and habitat-related variables. I examined interspecific niche-separation within the Phaner genus, and among two sub-populations of P. electromontis, a species which has previously been hypothesized to represent two distinct, cryptic taxa. All ecological niche models performed well and with high accuracy, and whilst the percentage contribution of each environmental variable differed between species, the results suggested that climate may be the primary determinant of Phaner distribution. Further, all four Phaner species occupied distinct ecological niches, a result that was also mirrored in the two P. electromontis sub-populations. This suggests that one of the two sub-populations may indeed be a distinct, as-yet undescribed species, but further genetic and ecological research is needed to substantiate this result. Finally, the ecological niche models revealed that only 23.0% of the suitable land area for Phaner occurrence within Madagascar is forested, limiting the geographic distribution of these lemurs. Whilst much of this suitable habitat is thankfully protected, deforestation continues throughout Madagascar, and this under-studied group of lemurs requires further research attention and continued conservation efforts.

Ecological niche models of biotic interactions predict increasing pest risk to olive cultivars with changing climate

AbstractSimple, single‐species approaches in distributional ecology leave open questions of possible roles of biotic interactions. We sought to understand impacts of climate change on current and future potential distributions of Olea europaea sensu lato (host) and Bactrocera oleae (parasite) in Europe, the Middle East, and Africa (EMEA), taking into account potential interspecific interactions. We used ecological niche modeling approaches: For biotic interactions, an initial host model was incorporated into the calibration of the parasite model and an initial parasite model was incorporated into calibration of the host model, as host and parasite populations may respond to the presence of the other species. Absence of olive fruits could reduce the flight ability of the fly parasite, whereas presence of the parasite may make a site less suitable for the olives. The host model was improved by inclusion of the parasite information; the converse was not true for the parasite model. Our results anticipated a significant reduction in the potential distribution of Olea europeae in Africa and Europe under future climate scenarios; in contrast, future climates appear more broadly favorable for the parasite species, which poses new and increasing risks for olive cultivation in the Mediterranean region.

Floral Scent Evolution in the Genus Jaborosa (Solanaceae): Influence of Ecological and Environmental Factors.

Floral scent is a key communication channel between plants and pollinators. However, the contributions of environment and phylogeny to floral scent composition remain poorly understood. In this study, we characterized interspecific variation of floral scent composition in the genus Jaborosa Juss. (Solanaceae) and, using an ecological niche modelling approach (ENM), we assessed the environmental variables that exerted the strongest influence on floral scent variation, taking into account pollination mode and phylogenetic relationships. Our results indicate that two major evolutionary themes have emerged: (i) a ‘warm Lowland Subtropical nectar-rewarding clade’ with large white hawkmoth pollinated flowers that emit fragrances dominated by oxygenated aromatic or sesquiterpenoid volatiles, and (ii) a ‘cool-temperate brood-deceptive clade’ of largely fly-pollinated species found at high altitudes (Andes) or latitudes (Patagonian Steppe) that emit foul odors including cresol, indole and sulfuric volatiles. The joint consideration of floral scent profiles, pollination mode, and geoclimatic context helped us to disentangle the factors that shaped floral scent evolution across “pollinator climates” (geographic differences in pollinator abundance or preference). Our findings suggest that the ability of plants in the genus Jaborosa to colonize newly formed habitats during Andean orogeny was associated with striking transitions in flower scent composition that trigger specific odor-driven behaviors in nocturnal hawkmoths and saprophilous fly pollinators.

The specialist of a specialist: the natural history of the predispersal seed predator weevil Hemicolpus abdominalis (Coleoptera: Curculionidae)

1. The reproduction of specialised endophagous insects relies on a fine temporal synchronization between the insect and its host plant phenology.2. Since the spatial distribution and local prevalence of specialised insects depend on both environmental conditions and biotic interactions, in this study, we assessed whether the life cycle of the predispersal seed feeding weevil, Hemicolpus abdominalis (Curculionidae), is synchronised with the reproductive phenology of its host plant, Tocoyena formosa (Rubiaceae) in the Brazilian Cerrado. Following an ecological niche modelling approach, we also tested whether the predicted distribution of this specialised weevil matches that of its host plant.3. We observed a tight synchronization between the weevil reproduction and its host plant reproductive phenology. After emergence from the fruits, adult weevils enter in reproductive diapause, with reproductive development resuming in the next reproductive season, which indicates the univoltism of this species.4. There was a high spatial congruence in the distribution of H. abdominalis and its host plant. Since the reproduction of H. abdominalis is synchronised with the host plant phenology, temporal mismatches between the weevil life cycle, and plant reproduction may affect the long‐term population prevalence of the insect.5. The life cycle of the predispersal seed feeding weevil, H. abdominalis, depends on a close match with the host plant reproductive phenology, whose fruit production is entirely dependent on long‐tongued hawkmoth pollinators. Hence, we highlight the importance of both biotic and abiotic conditions in shaping the distribution range of a specialised endophagous insect.

Ecogeographic Divergence Linked to Dorsal Coloration in Eastern Hog-Nosed Snakes (Heterodon platirhinos)

Animal coloration can benefit fitness via its function in homeostatic regulation, communication, or camouflage. For wide-ranging taxa that are exposed to diverse climatic conditions throughout their range, spatial variation in color morphology might reflect locality-specific adaptive responses to those variable conditions. As a result, these species might vary in their color-climate associations over geographic space. Here, we integrate georeferenced photographs of adult animals with available bioclimatic data to test the hypothesis that dorsal color differences in Eastern Hog-Nosed Snakes (Heterodon platirhinos) reflect ecogeographic divergence. We first assigned each photographed snake into one of four dorsal color phases, namely, black, brown, red-orange, or yellow, and evaluated the spatial dispersion and bioclimatic niche occupancy of each phase by using multiple environmental niche modeling approaches. We then used pairwise comparisons of bioclimatic niche space to explicitly test for niche divergence among the color phases. Overall, black, brown, and red-orange phase H. platirhinos exploited different subsets of the species' geographic range and bioclimatic niche. In contrast, yellow phase snakes partly overlapped with red-orange and brown phase snakes in geographic and bioclimatic space. These findings support our hypothesis, and we discuss some of the possible functions of phase coloration.

Eco-Geography of Feral Cotton: A Missing Piece in the Puzzle of Gene Flow Dynamics Among Members of Gossypium hirsutum Primary Gene Pool

Mexico is the center of origin and genetic diversity of upland cotton (Gossypium hirsutumL.), the most important source of natural fiber in the world. Currently, wild and domesticated populations (including genetically modified [GM] varieties) occur in this country and gene flow among them has shaped the species’ genetic diversity and structure, setting a complex and challenging scenario for its conservation. Moreover, recent gene flow from GM cultivars to wild Mexican cotton populations has been reported since 2011.In situconservation ofG. hirsutumrequires knowledge about the extent of its geographic distribution, both wild and domesticated, as well as the possible routes and mechanisms that contribute to gene flow between the members of the species wild-to-domesticated continuum (i.e., the primary gene pool). However, little is known about the distribution of feral populations that could facilitate gene flow by acting as bridges. In this study, we analyzed the potential distribution of feral cotton based on an ecological niche modeling approach and discussed its implications in the light of the distribution of wild and domesticated cotton. Then, we examined the processes that could be leading to the escape of seeds from the cultivated fields. Our results indicate that the climatic suitability of feral plants in the environmental and geographic space is broad and overlaps with areas of wild cotton habitat and crop fields, suggesting a region that could bridge cultivated cotton and its wild relatives by allowing gene flow between them. This study provides information for management efforts focused on the conservation of wild populations, native landraces, and non-GM domesticated cotton at its center of origin and genetic diversity.

Macroalgae niche modelling: a two-step approach using remote sensing and in situ observations of a native and an invasive Asparagopsis

We are facing a global loss of biodiversity due to climate change. This will lead to unpredictable changes in ecosystems, affecting the goods and services they provide introduction of non-indigenous marine species. This represents one of the major threats to marine biodiversity and therefore, there is a strong need to assess, map and monitor these alien species. The appearance of non-indigenous species is especially dangerous in fragile ecosystems and it is of great importance to better understand the invasion mechanisms of these invasive species. This is the case for invasive alga Asparagopsis armata, present in the Azores Archipelago. In this study we propose a methodology to define the realized ecological niche of this invasive alga, alongside the native Asparagopsis taxiformis, to understand better its distribution and potential impact on native communities and ecosystem services. These objectives comply with the EU Biodiversity strategy for 2020 goals and the need to map and assess ecosystems and their services. The lack of reliable high-resolution data makes this a challenging task. Within this scope, we propose a combination of Remote Sensing, Unmanned Aerial Vehicle based imagery together with in-situ field data to build ecological niche modelling approaches as a cost-effective methodology to identify and characterize vulnerable marine ecosystems. Our results show that this combination can help achieve monitoring, leading to a better understanding of ecological niches and the consequences of non-indigenous species invasion in fragile ecosystems, like small islands, when faced with limited data.

Moderate warming will expand the suitable habitat of Ophiocordyceps sinensis and expand the area of O. sinensis with high adenosine content

Ophiocordyceps sinensis is a valued entomopathogenic fungus endemic to the Tibetan Plateau. Large-scale commercial harvesting and collection have decreased the production and distribution of this fungus, especially for high-quality O. sinensis. Using adenosine content as a quality index of O. sinensis, we developed a comprehensive niche modelling approach to predict the spatial pattern of O. sinensis quality. Based on distribution and quality data for O. sinensis from published field work and experimental data, we separately built a comprehensive habitat suitability model to identify suitable habitats and a spatial quality model to map the adenosine content pattern in O. sinensis. The final model result was defined as the product of the results of the two models. Via this modelling process, we analysed the adenosine content in O. sinensis under baseline climates and different scenarios of future climate change. The model results showed that with increasing temperature, the suitable habitat of O. sinensis tended to shift to the high-latitude and high-altitude hinterland of the Tibetan Plateau, and moderate climate warming expanded the area of suitable habitat for O. sinensis, as well as the area of habitats with high adenosine contents. This study provides information necessary for the conservation and sustainable utilization of O. sinensis, and a comprehensive niche model approach to simulate the contents of effective components in natural medicinal materials; thus, the results can contribute to our understanding of climate change impacts on medicinal materials.

Structure and robustness of the Neotropical ant‐gardens network under climate change

Abstract Knowing, predicting, and comparing the interactions among species of different assemblages allows the determination of both the structure and robustness of the ecological networks. However, this has been little studied for species assemblages with obligate associations across a wide geographic scale and under a global climate change context. We studied the Neotropical ant‐gardens (AGs), considered as a specialised mutualist system constituted of epiphytic plants that specifically inhabit nests of arboreal ants. We used the niche modelling and complex networks approaches to infer the interactions (range overlaps) between the ants and epiphytes that comprise the AGs and thus constructed AG quantitative networks for the current time and future scenarios of climate change. Also, we compared the structure (nestedness and modularity) and specialisation of the AG network with other ecological networks, and we evaluated their robustness through the simulated extinction of species. The AG network was formed by six ant species and 16 epiphyte species, generally of wide distribution. This low species number coincided with specialised networks, but the structure was more similar to that of the facultative networks, since it presented high nestedness and low modularity and specialisation. The network structure was maintained under the climate change scenarios, which also coincides with its high robustness in the face of the extinction of species. The AGs are a specialised system of wide distribution, but ant–epiphyte interactions are generalist, suggesting that the Neotropical AG network is cohesive and robust in the face of global perturbations.

Habitat suitability of cetaceans in the Gulf of Mexico using an ecological niche modeling approach.

BackgroundThe Gulf of Mexico (GOM) is a semi-enclosed sea where the waters of the United States, Mexico and Cuba converge. Al least 21 species of cetaceans inhabit it. The only mysticete (baleen whale) is found in the northeast (U.S. waters). The distribution of the 20 species of odontocetes (toothed cetaceans) is well understood in U.S. waters, but practically unknown in Mexican and Cuban waters. In this study we used sighting data from several odontocete species to construct habitat suitability maps in order to identify geographical regions suitable for high diversity throughout the GOM.MethodsHistorical datasets of georeferenced sightings from across the GOM were used to implement the maximum entropy algorithm (MaxEnt) to model the habitat suitability of each species. Five environmental predictors were used, selected for their influence over the occurrence of cetaceans: two oceanographic predictors (sea surface temperature and chlorophyll-a concentration), and three bathymetric predictors (depth, slope, and distance to 200-m isobath). A spatial approach based on the habitat suitability maps was used to identify the suitable regions.ResultsOnly 12 species were modeled, which were the ones with the minimum sample size required. The models performed well, showing good discriminatory power and slight overfitting. Overall, depth, minimum sea surface temperature, and bottom slope were the most contributing predictor in the models. High suitability areas of 10 species were located on the continental slope, and four suitable regions were identified: (1) the Mississippi Canyon and the Louisiana-Texas slope in the northern GOM, (2) the west Florida slope in the east-northeastern GOM, (3) the Rio Grande slope in the west-northwestern GOM, and (4) the Tamaulipas-Veracruz slope in the west-southwestern GOM.ConclusionsWe were able to detect four geographic regions in the GOM where a high diversity of odontocetes is expected, all located on the continental slope. Although the methodology to identify them (spatial overlap) is a very conservative approach, it is useful for conservation and management purposes. The paucity of data did not allow all species to be modeled, which highlights the importance of establishing transboundary monitoring programs.

Potential Distribution of Aedes (Ochlerotatus) scapularis (Diptera: Culicidae): A Vector Mosquito New to the Florida Peninsula.

Simple SummaryAedes scapularis is an important mosquito species capable of transmitting viruses and parasites to humans and animals. Aedes scapularis was previously known to occur throughout large portions of the Americas, from the lower Rio Grande Valley of southern Texas to Argentina and on several Caribbean Islands. Recently, this mosquito became established in southern Florida, marking the first time Ae. scapularis was found on the Florida Peninsula. Now that Ae. scapularis has reached the Florida Peninsula, it is expected to continue to expand its geographic distribution to fill contiguous areas with suitable environments. Here, we use a modeling approach that correlates environmental variables with known geographic collection locations of Ae. scapularis to predict the potential distribution of this species. The output of this model provides new information for mosquito control and public health agencies to help monitor the spread of this exotic vector mosquito and suggests a need for surveillance for the expansion of this mosquito in many of Florida’s coastal counties.Aedes scapularis is a neotropical mosquito known to transmit pathogens of medical and veterinary importance. Its recent establishment in southeastern Florida has potential public health implications. We used an ecological niche modeling approach to predict the abiotic environmental suitability for Ae. scapularis across much of the Americas and Caribbean Islands. Georeferenced occurrence data obtained from the Global Biodiversity Inventory Facility and recent collection records of Ae. scapularis from southern Florida served as input for model calibration. Environmental layers included bioclimatic variables provided in 2000 to 2010 average Modern Era Retrospective-analysis for Research and Applications climatic (MERRAclim) data. Models were run in the software program Maxent. Isothermality values often found in costal environments, had the greatest contribution to model performance. Model projections suggested that there are areas predicted to be suitable for Ae. Scapularis across portions of the Amazon Basin, the Yucatán Peninsula, the Florida Peninsula, and multiple Caribbean Islands. Additionally, model predictions suggested connectivity of highly suitable or relatively suitable environments spanning the United States Gulf Coast, which may facilitate the geographic expansion of this species. At least sixteen Florida counties were predicted to be highly suitable for Ae. scapularis, suggesting that vigilance is needed by vector control and public health agencies to recognize the further spread of this vector.

Pemodelan Spasial Kesesuaian Habitat Elang Jawa (Nisaetus bartelsi) di Taman Nasional Bromo Tengger Semeru (Spatial Modeling of Javan Hawk-Eagle (Nisaetus bartelsi) Habitat Suitability in Bromo Tengger Semeru National Park)

Bromo Tengger Semeru National Park (TNBTS) is a conservation area as the habitat of endemic species in Java Island, such as the Javan hawk-eagle (Nisaetus bartelsi). One of the spatial models of habitat is the Ecological Niche Modeling (ENM) approach. This study aimed to determine habitat suitability for the Javan hawk-eagle in TNBTS. The research was conducted from September 2019 to January 2020. The habitat suitability model used the present coordinate point data and the Javan hawk-eagle habitat environment variables. The data were then analyzed to build a Javan hawk-eagle habitat suitability model using the Maximum Entropy (MaxEnt) algorithm. The results showed three models of habitat suitability categories, i.e.: high of 15,131.18 ha (30%), medium 11,216.61 ha (22%), and low 23,298.41 ha (48%). The evaluation of the Javan hawk-eagle habitat suitability model in TNBTS has an excellent model accuracy with an AUC value of 0.97 and a standard deviation of 0.93.Keywords: endemic, habitat, Javan hawk-eagle, maximum entropy, spatial modeling

Effects of climatic change on the potential geographic distribution of the threatened West‐Central African endemic genus, Talbotiella

AbstractClimate change is considered to be a leading cause of species extinction, yet the likely effects of climate change on geographic distributions and conservation status of many threatened African plants have not seen detailed evaluation. Here, we used ecological niche modelling approaches to explore and evaluate climate change effects on potential geographic distributions of plants of the threatened West‐Central African genus Talbotiella. Our models showed that suitability was lower in the northern parts of its range in West Africa and at it's southern extremes in West‐Central Africa. Areas of West Africa between Liberia and southwestern Ghana were identified as potentially suitable areas where new populations or species of the genus could be discovered. Our model transfers to future conditions showed range shifts and contractions in the geographic distribution of the genus; species of the genus are threatened by additional factors such as habitat loss or degradation, agriculture and development of industrial infrastructure. Although species of the genus will likely persist in protected areas, conservation efforts should also include ex situ conservation approaches, particularly as regards individual species in the genus. This study shows how niche modelling approaches could be used to enhance the conservation and discovery of African biodiversity.

The potential for expansion of irrigated rice under alternate wetting and drying in Burkina Faso

Achieving rice self-sufficiency in West Africa will require an expansion of the irrigated rice area under water-scarce conditions. However, little is known about how much area can be irrigated and where and when water-saving practices could be used. The objective of this study was to assess potentially irrigable lands for irrigated rice cultivation under water-saving technology in Burkina Faso. A two-step, spatially explicit approach was developed and implemented. Firstly, machine learning models, namely Random Forest (RF) and Maximum Entropy (MaxEnt) were deployed in ecological niche modeling (ENM) approach to assess the land suitability for irrigated rice cultivation. Spatial datasets on topography, soil characteristics, climate parameters, land use, and water were used along with the current distribution of irrigated rice locations in Burkina Faso to drive ENMs. Secondly, the climatic suitability for alternate wetting and drying (AWD), an irrigation management method for saving water in rice cultivation in irrigated systems, was assessed by using a simple water balance model for the two main growing seasons (February to June and July to November) on a dekadal time scale. The evaluation metrics of the ENMs such as the area under the curve and percentage correctly classified showed values higher than 80% for both RF and MaxEnt. The top four predictors of land suitability for irrigated rice cultivation were exchangeable sodium percentage, exchangeable potassium, depth to the groundwater table, and distance to stream networks and rivers. Potentially suitable lands for rice cultivation in Burkina Faso were estimated at 21.1 × 105 ha. The whole dry season was found suitable for AWD implementation against 25–100% of the wet season. Soil percolation was the main driver of the variation in irrigated land suitability for AWD in the wet season. The integrated modeling and water balance assessment approach used in this study can be applied to other West African countries to guide investment in irrigated rice area expansion while adapting to climate change.

Two cytotype niche shifts are of different magnitude in Solidago gigantea.

Polyploidy may serve to contribute to range size if autopolyploid cytotypes are adapted to differing ecological conditions. This study aims to establish the geographic distribution of cytotypes within the giant goldenrod (Solidago gigantea), and to assess whether cytotypes exhibit differing ecological tolerances and morphology. A range-wide set of 629 Solidago gigantea individuals was obtained through field collecting, sampling from herbarium specimens, and incorporating existing chromosome counts. Cytotype of each unknown sample was estimated by observing allele numbers at twelve microsatellite loci, a strategy that was assessed by comparing estimated to known cytotype in 20 chromosome-counted samples. Abiotic ecological differentiation was assessed for two transitions: diploid-tetraploid and tetraploid-hexaploid. Morphological differentiation among cytotypes was assessed. Microsatellite repeat variation accurately estimated cytotype in 85% of samples for which ploidy was known. Applying this approach to samples of unknown ploidy established that the three cytotypes are non-randomly distributed. Although niche modeling and MANOVA approaches identified significant differences in macro-climatic conditions for both cytotype transitions, the tetraploid to hexaploid transition was more substantial. Leaf length and width did not differ among cytotypes. Although leaf vestiture exhibited strong trends, no absolute differences were observed among cytotypes. With the largest such study to date, we established niche transitions among giant goldenrod cytotypes of differing magnitudes. Collectively, this suggests that whole-genome duplication has contributed to Solidago gigantea's large range.

Ecological Niche Modeling: An Introduction for Veterinarians and Epidemiologists

Most infectious diseases in animals are not distributed randomly. Instead, diseases in livestock and wildlife are predictable in terms of the geography, time, and species affected. Ecological niche modeling approaches have been crucial to the advancement of our understanding of diversity and diseases distributions. This contribution is an introductory overview to the field of distributional ecology, with emphasis on its application for spatial epidemiology. A new, revised modeling framework is proposed for more detailed and replicable models that account for both the biology of the disease to be modeled and the uncertainty of the data available. Considering that most disease systems need at least two organisms interacting (i.e., host and pathogen), biotic interactions lie at the core of the pathogen's ecological niche. As a result, neglecting interacting organisms in pathogen dynamics (e.g., maintenance, reproduction, and transmission) may limit efforts to forecast disease distributions in veterinary epidemiology. Although limitations of ecological niche modeling are noted, it is clear that the application and value of ecological niche modeling to epidemiology will increase in the future. Potential research lines include the examination of the effects of biotic variables on model performance, assessments of protocols for model calibration in disease systems, and new tools and metrics for robust model evaluation. Epidemiologists aiming to employ ecological niche modeling theory and methods to reconstruct and forecast epidemics should familiarize themselves with ecological literature and must consider multidisciplinary collaborations including veterinarians to develop biologically sound, statistically robust analyses. This review attempts to increase the use of tools from ecology in disease mapping.