scholarly journals Inferring the Potential Geographic Distribution and Reasons for the Endangered Status of the Tree Fern, Sphaeropteris lepifera, in Lingnan, China Using a Small Sample Size

Horticulturae ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 496
Author(s):  
Xueying Wei ◽  
AJ Harris ◽  
Yuwen Cui ◽  
Yangwu Dai ◽  
Hanjia Hu ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Ecological Niche ◽  
Ecological Niche Modeling ◽  
Small Sample Size ◽  
Small Sample ◽  
Conservation Strategy ◽  
Slope Aspect ◽  
Ecological Niche Models ◽  
Tree Fern ◽  
Endangered Tree

In this study, we investigated suitable habitats for the endangered tree fern, Sphaeropteris lepifera (J. Sm. ex Hook.) R.M. Tryon, based on fieldwork, ecological niche modeling, and regression approaches. We combined these data with the characterization of spore germination and gametophytic development in the laboratory to assess the reasons why S. lepifera is endangered and to propose a conservation strategy that focuses on suitable sites for reintroduction and accounts for the ecology and biphasic life cycle of the species. Our methods represent an integration of process- and correlation-based approaches to understanding the distributional patterns of this species, and this combined approach, while uncommonly applied, is a more robust strategy than either approach used in isolation. Our ecological niche models indicated that cold temperature extremes, temperature stability over long- and short-terms, and the seasonality of precipitation were among the most important abiotic environmental factors affecting the distribution of S. lepifera among the variables that we measured. Moreover, distribution of this fern species is also strongly influenced by the timing of development of male and female gametes. Additionally, we observed that slope aspect, specifically south-facing slopes, facilitates more incoming sunlight for mature trees, and simultaneously, provides greater, much-needed shade for fiddleheads on account of the canopy being denser. We believe that our study can provide important guidance on the restoration of S. lepifera in the wild. Specifically, potential restoration areas can be screened for the specific environmental factors that we infer to have a critical impact on the survival of the species.

scholarly journals Evaluation of Frequency of PGC1-α and CKMM Genes Polymorphisms Among Iranian Elite Hockey Athletes

2021 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Maryam Valipour ◽  
Parvaneh Azarali ◽  
Rostam Alizadeh
Keyword(s):  
Physical Activity ◽  
Environmental Factors ◽  
Sample Size ◽  
Dna Extraction ◽  
Gene Polymorphisms ◽  
Small Sample Size ◽  
Small Sample ◽  
Complex Phenotype ◽  
Genotype Frequencies ◽  
Pcr Rflp

Background: Physical activity is a complex phenotype influenced by millions of genes and environmental factors. It is well known that physical performance and sports ability are linked to genes variations. Objectives: The aim of this study was to evaluate the frequency of PGC1-α and CKMM gene polymorphisms in elite hockey athletes. Methods: Fifty Iranian elite national hockey athletes and 100 non-athletes participated in this study. To determine the genotypes of PGC1-α and CKMM gene polymorphisms, 2 ml of saliva was sampled and used for DNA extraction. To determine the genotypes, the PCR-RFLP method was employed. After examining the variants, the allele and genotype frequencies of subjects were measured. Results: The results showed no significant differences for the PPARGC1A gene in the percentage of AA, GG, and AG genotypes. Similarly, the percentage of these genotypes of the CKMM gene did not differ significantly between athletes and non-athletes. Conclusions: The results suggest that the gene polymorphisms of PGC1-α and CKMM are the same between the Iranian elite hockey athletes and non-athletes, which may be due to the overlapping effect of other genes and/or the small sample size of the study.

Species’ Invasions

2011 ◽  
Author(s):  
A. Townsend Peterson ◽  
Jorge Soberón ◽  
Richard G. Pearson ◽  
Robert P. Anderson ◽  
Enrique Martínez-Meyer ◽  
...  
Keyword(s):  
Ecological Niche ◽  
Ecological Niche Modeling ◽  
Biotic Interactions ◽  
Niche Modeling ◽  
Future Research ◽  
Ecological Niche Models ◽  
Species Invasions ◽  
Future Research Directions ◽  
Native And Introduced Ranges ◽  
Niche Models

This chapter discusses the use of ecological niche modeling to study species invasions, and more specifically to identify and understand genuine exceptions to ecological niche equivalency between native and introduced ranges of species. In addition, it examines the degree to which the geographic course of species’ invasions can be anticipated based on scenopoetic variables and biotic interactions. The chapter also reviews practical considerations that must be taken into account when exploring the utility of ecological niche models in understanding species’ invasions, such as using niche conservatism to predict likely changes in the distributional potential of invasive species under scenarios of changing environmental conditions. Finally, it describes caveats and limitations of the approach and outlines future research directions and challenges involved in the application of niche modeling ideas in species invasions.

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

Animals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 649 ◽  
Author(s):  
Emilio Clarke-Crespo ◽  
Claudia N. Moreno-Arzate ◽  
Carlos A. López-González
Keyword(s):  
Ecological Niche ◽  
Ecological Niche Modeling ◽  
Distribution Patterns ◽  
Hard Tick ◽  
Ecological Niche Models ◽  
Generalist Species ◽  
Public Health Decision ◽  
Vector Borne Diseases ◽  
Temperature And Precipitation ◽  
Niche Models

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.

scholarly journals Novel insights into the historical biogeography of the streak-breasted scimitar babbler complex (Aves: Timaliidae: Pomatorhinus ruficollis complex)

2015 ◽  
Vol 61 (5) ◽  
pp. 910-921 ◽  
Author(s):  
Sushma Reddy ◽  
Árpád S. Nyári
Keyword(s):  
Ecological Niche ◽  
Ecological Niche Modeling ◽  
Southern China ◽  
Hainan Island ◽  
Central China ◽  
Integrative Approach ◽  
Suitable Habitat ◽  
Ecological Niche Models ◽  
Last Interglacial ◽  
History Of

Abstract The Streak-breasted Scimitar Babblers of the Pomatorhinus ruficollis species complex are found in most of the forested habitats across southern and eastern Asia. The diversification history of this group is obscured by high plumage variation across populations and conflicting genetic signal across loci. We combined genetic and geographic data from several recent studies to investigate how these species diversified across China using both phylogenetic and ecological niche modeling analyses. These two lines of evidence are consistent in showing that two well-sampled species, P. reconditus and P. nigrostellatus, in central and southern China respectively, likely experienced a history of isolation and expansion as suitable habitat contracted during the last interglacial and expanded in patchy extent during the glacial maximum. The genetic analysis showed that populations of P. nigrostellatus on Hainan Island are very similar to the ones in nearby mainland southern China. We recovered two well-supported clades within P. reconditus that were not geographically structured with both containing individuals from the same localities across central China. This phylogenetic result corresponded to the ecological niche models that showed expansion from refugia since the last interglacial. This study illustrates the value of using an integrative approach and detailed geographic sampling to help understand the recent diversification of birds in China.

scholarly journals Prediction of high CPT yielding ecotypes of Nothapodytes nimmoniana (Graham) Mabb. in Western Ghats using Ecological Niche Modeling

2018 ◽  
Vol 7 (12) ◽  
pp. 2451-2458
Author(s):  
Cordilea Hannah ◽  
Joyce Sudandara Priya ◽  
Kasthuri Bhai N.
Keyword(s):  
Habitat Suitability ◽  
Western Ghats ◽  
Ecological Niche ◽  
High Performance ◽  
Ecological Niche Modeling ◽  
Ecological Niche Models ◽  
Natural Habitats ◽  
Nothapodytes Nimmoniana ◽  
Bioclimatic Variables ◽  
Chemical Content

Camptothecin (CPT) is one of anticancer drug that is widely used for treating various cancers. In India, the drug is primarily sourced from natural habitats of the red listed species Nothapodytes nimmoniana. Ecological niche models are potential tools to define and predict the “ecological niche” of a species that exhibit ecological variations. The predicted ecological niche of a species indicates their survival fitness against Bioclimatic variables. The habitat suitability was predicted using Maxent for different ecotypes of Nothapodytes nimmoniana (Graham.) Mabb. In this study the synonymised populations of N. nimmoniana in the Western Ghats were cogitated as five different ecotypes. The predicted habitat suitability of different ecotypes were evaluated and correlated against CPT content using high performance thin layer chromatography. The study shows a significant positive correlation between the predicted habitat quality and chemical content. The ecotypes growing in sites predicted as highly suitable showed high content of camptothecin compared to those growing in poorly suitable sites. Thereby enabling precise identification of “chemical hot-spots” which will eventually establish a strong foot hold on monoculture of the species, an effort towards conservation.

Environmental Data

2011 ◽  
Author(s):  
A. Townsend Peterson ◽  
Jorge Soberón ◽  
Richard G. Pearson ◽  
Robert P. Anderson ◽  
Enrique Martínez-Meyer ◽  
...  
Keyword(s):  
Ecological Niche ◽  
Ecological Niche Modeling ◽  
Spatial Scales ◽  
Species Distributions ◽  
Niche Modeling ◽  
Environmental Data ◽  
Potential Utility ◽  
Ecological Niche Models ◽  
Ancillary Data ◽  
Niche Models

This chapter focuses on the conceptual and applied aspects of environmental data in the context of building and interpreting ecological niche models. It first examines how different suites of environmental factors may affect species distributions across a range of spatial scales before discussing which and how many variables are needed for ecological niche modeling. It then reviews the diverse sources of environmental datasets that are of potential utility in ecological niche modeling and concludes by considering a number of challenges involved in designing and choosing environmental data for ecological niche modeling. These challenges include data preparation, data quality, spatial extent, resolution in space and time, types of environmental data, and ancillary data.

scholarly journals Geographic Distribution of Colombian Spittlebugs (Hemiptera: Cercopidae) via Ecological Niche Modeling: A Prediction for the Main Tropical Forages' Pest in the Neotropics

2021 ◽  
Vol 5 ◽  
Author(s):  
Luis M. Hernández ◽  
Paula Espitia ◽  
David Florian ◽  
Valheria Castiblanco ◽  
Juan Andrés Cardoso ◽  
...  
Keyword(s):  
Geographic Distribution ◽  
Ecological Niche ◽  
Ecological Niche Modeling ◽  
Niche Modeling ◽  
Economic Losses ◽  
Economic Damage ◽  
Extensive Literature ◽  
Design Strategies ◽  
Ecological Niche Models ◽  
Global Biodiversity Information Facility

Spittlebugs (Hemiptera: Cercopidae) are the main tropical pests in Central and South America of cultivated pastures. We aimed to estimate the potential distribution of Aeneolamia varia, A. lepidior, A. reducta, Prosapia simulans, Zulia carbonaria, and Z. pubescens throughout the Neotropics using ecological niche modeling. These six insect species are common in Colombia and cause large economic losses. Records of these species, prior to the year 2000, were compiled from human observations, specimens from CIAT Arthropod Reference Collection (CIATARC), Global Biodiversity Information Facility (GBIF), speciesLink (splink), and an extensive literature review. Different ecological niche models (ENMs) were generated for each species: Maximum Entropy (MaxEnt), generalized linear (GLM), multivariate adaptive regression spline (MARS), and random forest model (RF). Bioclimatic datasets were obtained from WorldClim and the 19 available variables were used as predictors. Future changes in the potential geographical distribution were simulated in ENMs generated based on climate change projections for 2050 in two scenarios: optimistic and pessimistic. The results suggest that (i) Colombian spittlebugs impose an important threat to Urochloa production in different South American countries, (ii) each spittlebug species has a unique geographic distribution pattern, (iii) in the future the six species are likely to invade new geographic areas even in an optimistic scenario, (iv) A. lepidior and A. reducta showed a higher number of suitable habitats across Colombia, Venezuela, Brazil, Peru, and Ecuador, where predicted risk is more severe. Our data will allow to (i) monitor the dispersion of these spittlebug species, (ii) design strategies for integrated spittlebug management that include resistant cultivars adoption to mitigate potential economic damage, and (iii) implement regulatory actions to prevent their introduction and spread in geographic areas where the species are not yet found.

Ecological niche modeling on the effect of climatic change and conservation of Ternstroemia lineata DC. (Ternstroemiaceae) in Mesoamerica

Botany ◽  
2012 ◽  
Vol 90 (7) ◽  
pp. 637-650 ◽  
Author(s):  
Isolda Luna-Vega ◽  
Othón Alcántara-Ayala ◽  
Raúl Contreras-Medina ◽  
César A. Ríos-Muñoz
Keyword(s):  
Climatic Change ◽  
Ecological Niche ◽  
Ecological Niche Modeling ◽  
Cloud Forest ◽  
Production Method ◽  
Emission Scenarios ◽  
Ecological Niche Models ◽  
Bioclimatic Modeling ◽  
Rule Set ◽  
Niche Models

A bioclimatic modeling of the tree Ternstroemia lineata DC. (Ternstroemiaceae) was undertaken. The genus itself is considered as diagnostic or characteristic of the Mexican cloud forest. Ternstroemia lineata has the broadest distribution of all species in this family in Mexico and northern Central America. This species consists of two subspecies, T. lineata subsp. lineata and T. lineata subsp. chalicophila (Loes.) B.M. Barthol. Ecological niche models for both subspecies were generated using the genetic algorithm for rule-set production method. The ecological models for the years 2020, 2050, and 2080 were obtained under the effects of global climatic change considering two emission scenarios (A2a and B2a). When climatic change values were introduced, the ecological niche representation for both subspecies contracted in such a way that they became almost lost throughout their entire geographical range. In both cases, predictions for all years in both scenarios contracted more than 90%. This species may not be able to adapt to modifications caused by climatic change to future conditions, so it is at risk of extinction in the immediate future.

scholarly journals Ecological niche modeling as an effective tool to predict the distribution of freshwater organisms: The case of the Sabaleta Brycon henni (Eigenmann, 1913)

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247876
Author(s):  
Daniel Valencia-Rodríguez ◽  
Luz Jiménez-Segura ◽  
Carlos A. Rogéliz ◽  
Juan L. Parra
Keyword(s):  
Minimum Temperature ◽  
Ecological Niche ◽  
Potential Distribution ◽  
Ecological Niche Modeling ◽  
Predictive Accuracy ◽  
National Level ◽  
Ecological Niche Models ◽  
Precipitation Seasonality ◽  
Bioclimatic Variables ◽  
Species Occurrences

Ecological niche models (ENMs) aim to recreate the relationships between species and the environments where they occur and allow us to identify unexplored areas in geography where these species might be present. These models have been successfully used in terrestrial organisms but their application in aquatic organisms is still scarce. Recent advances in the availability of species occurrences and environmental information particular to aquatic systems allow the evaluation of these models. This study aims to characterize the niche of the Sabaleta Brycon henni Eigenmann 1913, an endemic fish of the Colombian Andes, using ENMs to predict its geographical distribution across the Magdalena Basin. For this purpose, we used a set of environmental variables specific to freshwater systems in addition to the customary bioclimatic variables, and species’ occurrence data to model its potential distribution using the Maximum Entropy algorithm (MaxEnt). We evaluate the relative importance between these two sets of variables, the model’s performance, and its geographic overlap with the IUCN map. Both on-site (annual precipitation, minimum temperature of coldest month) and upstream variables (open waters, average minimum temperature of the coldest month and average precipitation seasonality) were included in the models with the highest predictive accuracy. With an area under the curve of 90%, 99% of the species occurrences and 68% of absences correctly predicted, our results support the good performance of ENMs to predict the potential distribution of the Sabaleta and the utility of this tool in conservation and decision-making at the national level.

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