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1.
Environ Sci Pollut Res Int ; 29(16): 24334-24347, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35099694

ABSTRACT

Human activities have impacted many environments on earth, and thus several species are facing an increased risk of extinction. The environmental crisis requires rapid tools to assess the ecosystem health accurately. Studies have been conducted with visual indices that quantify habitat integrity by predicting species richness and diversity. However, whether a diverse clade can predict habitat integrity has not been used. The genus Argia (Rambur, 1842) is one of the most locally diverse groups in southeastern Mexico. In this context, we hypothesized that the occurrence, species richness, and diversity of adults Argia spp. could be a better predictor of the Visual-Based Habitat Assessment Score (VBHAS) than the other taxonomic levels or less diverse clades. We found that the richness and diversity of Argia spp. are positively correlated with VBHA scores, as same as taxonomic ratios. Simultaneously, VBHA scores increase to 23.51 times when Argia spp. diversity increases. We discuss the possible use of a diverse Odonata clade, as Argia spp. could surrogate habitat integrity for local long-term biomonitoring programs. This approach requires testing with other indices and verifying a reliable and consistent relationship between diverse clades and environmental assessment scores.


Subject(s)
Odonata , Animals , Biodiversity , Biological Monitoring , Ecosystem , Humans , Mexico
2.
Environ Sci Pollut Res Int ; 28(2): 1381-1396, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33097996

ABSTRACT

The order Odonata has been regularly used as an indicator of the ecosystem's condition. The objective of this review was to analyze the importance of Odonata for environmental assessments (assessment types, statistical approach, life stages, and sampling method, or particular metric), summarizing the current state, the trends, and identifying related research issues in the Neotropical region. Therefore, we selected 62 articles from 2007 to 2018 based on published research to monitor Odonata assessments in the Neotropical region. We compiled a database and ran statistical analyses for the observed frequencies. We found that ecosystem health was the most frequent assessment type and quality the most used objective. In the case of statistical tests and metrics, multivariate analyses and species richness were most used in these papers. However, because there is a great diversity of habitats in this region, there is no unique monitoring protocol to assess the quality of ecosystem health and it is needed to create a proposal for a standard evaluation protocol. Consequently, guidelines for monitoring are presented, and we suggest three stages to establish a specific protocol for each site, which records the set of species most sensitive to the exchange rate evaluated, as well as the use of rarefaction methods, the index of diversity based on the area under the curve, and multivariate analysis, among other recommendations.


Subject(s)
Odonata , Animals , Biodiversity , Databases, Factual , Ecosystem , Multivariate Analysis
3.
Rev. biol. trop ; 67(6)dic. 2019.
Article in English | LILACS-Express | LILACS | ID: biblio-1507572

ABSTRACT

Introduction: Understanding how species respond to climate change is critical for implementing conservation strategies. Objective: We explain through potential distributions and changes in altitudinal variation, the possible impacts of climate change in an endangered micro-endemic rodent of Mexico with narrow altitudinal range, Heteromys nelsoni and a rodent with a wide distributional and altitudinal range, Heteromys goldmani. Methods: We obtained historical and current records of both Heteromys species. Potential distribution models were generated using Maxent, including altitudes for each species and bioclimatic layers. We determined the Extent of Occurrence and Area of Occupancy for H. nelsoni according to the criteria of the IUCN in order to generate information about its risk status. Results: The altitude is not a variable that determines a shift in the distribution caused by climate change. In contrast, the temperature and precipitation are important for the potential distribution of both Heteromys species. The future changes in climatic conditions could reduce the area of suitable habitat for both species. Conclusions: The distribution surface is not greater than 33.44 km2 for H. nelsoni. Therefore, is urgent to re-evaluate their conservation status by the IUCN, mainly in its B criterion, and to take specific actions for their conservation. We suggest the creation of a terrestrial protected area.


Introducción: El entendimiento de cómo las especies responden al cambio climático es crítico para la implementación de estrategias de conservación. Objetivo: Explicar a través de distribuciones potenciales y cambios en la variación altitudinal, los posibles impactos del cambio climático en un roedor micro endémico de México, en peligro de extinción y con un rango altitudinal estrecho, Heteromys nelsoni y un roedor con una amplia distribución y rango altitudinal, Heteromys goldmani. Metodología: Obtuvimos registros históricos y actuales de ambas especies. Los modelos de distribución potencial se generaron utilizando Maxent, incluyendo altitudes y capas bioclimáticas. Determinamos la extensión de su presencia y el área de ocupación para H. nelsoni según los criterios de la IUCN, para generar información sobre su estado de riesgo. Resultados: La altitud no es una variable que determina un cambio en la distribución causada por el cambio climático. En contraste, la temperatura y precipitación son importantes para la distribución potencial de ambas especies de Heteromys. Los análisis sugieren que los cambios futuros en las condiciones climáticas podrían reducir el área de hábitat adecuado para ambas especies. Conclusión: La superficie de distribución de H. nelsoni no es mayor a 33.44 km2. Es urgente reevaluar su estado de conservación de la UICN, principalmente en su criterio B y tomar medidas específicas para su conservación. Sugerimos la creación de un área terrestre protegida.

4.
J Therm Biol ; 48: 56-64, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25660631

ABSTRACT

The persistence of reptile populations in a specific location is influenced by individuals' capacity to regulate their body temperatures, among other factors. Anthropogenic climate change may pose a risk to the survival of ectothermic animals due to their dependence on external heat sources to thermoregulate. In this study, we calculated indices of thermal habitat quality, thermoregulatory precision, and thermoregulatory effectiveness for the endemic spiny-tailed iguana Ctenosaura oaxacana. We evaluated these indices and the thermoregulatory behavior of the iguanas in the four types of vegetation that provide the most favorable conditions for thermoregulation. We also performed our experiments during both the wet and dry seasons to capture the full range of thermal conditions available to C. oaxacana over the course of a year. Finally, we evaluated the potential niche for the iguana in the years 2020, 2050, and 2080. Thermoregulation depends on both seasonal and environmental factors in this species. We found that thermoregulation effectiveness in both wet and dry seasons depends not only on the thermal conditions of the immediate environment, but also on the cover vegetation and habitat structure available across the range of habitats the species uses. Thus, heterogeneous habitats with dispersed vegetation may be most suitable for this species' thermoregulatory strategy. Likewise, niche modeling results suggested that suitable habitat for our study species may continue to be available for the next few decades, despite global warming tendencies, as long as cover vegetation remains unaltered. Our results suggest that thermoregulation is a complex process that cannot be generalized for all ectothermic species inhabiting a given region. We also found that temperature changes are not the only factor one must consider when estimating the risk of species loss. To understand the necessary thermal conditions and extinction risk for any ectothermic species, it is necessary to focus studies on the species' general ecology.


Subject(s)
Behavior, Animal , Body Temperature Regulation/physiology , Global Warming , Iguanas/physiology , Animals , Body Temperature , Ecosystem , Female , Male , Mexico , Models, Theoretical , Plants , Seasons , Temperature
5.
Rev. biol. trop ; 62(4): 1523-1533, oct.-dic. 2014. tab
Article in English | LILACS | ID: lil-753708

ABSTRACT

Oaxaca hosts one of the greatest biodiversity in México, occupying first place in avian diversity compared to other regions of the country. However, the area is undergoing serious problems such as high deforestation rates, soil erosion and over exploitation and extinction of species. These factors have all contributed to the current loss of biodiversity. Also, biological inventories are still incomplete. One of the least explored sites is the semiarid zone of Tehuantepec isthmus, around the locality of Santa Maria del Mar, Oaxaca, México. The area includes floodable grasslands, mangrove areas and dry forest, providing a range of potential habitats for different species. Our objective was to evaluate the effect of temporal lakes on spatial and temporal composition of the avifauna in Santa Maria del Mar, in order to generate information regarding this group within the region and the state, and to understand the importance of flood areas for resident and transitory birds. We conducted 12 avifauna surveys between July 2006 and June 2008, and established two transects of 2km length in each of four habitat types (beach, grassland, dry forest, and mangrove). We found a total of 75 species, corresponding to 16 orders and 30 families. Within an area of 26km², we significantly found 10.1% of the total number of bird species recorded for the entire state, and 6.6% of the total reported in Mexico. The families most represented were: Ardeidae, Laridae and Scolopacidae. Over the entire study period, dry forest was the most diverse habitat; followed by mangrove, grassland and the beach. Of all the species recorded, 38.6% were found at the edge or in the temporal lakes. We found a significant difference in species composition between seasons in the grassland, but no difference in the other habitats. Our results showed a significant effect of temporary lakes on avian diversity during the wet season; it also demonstrated the importance of grassland conservation given its relevance for presence of waterbirds. We suggested a continued and more intense monitoring; and proposed the designation of the area as an important Conservation Bird Area (AiCA).


Oaxaca alberga una biodiversidad de las más grandes en México, ocupando el primer lugar en diversidad de aves si se le compara con otras regiones del país. Sin embargo, el área sufre serios problemas tales como altas tasas de deforestación, erosión de suelo y sobre explotación y extinción de especies. Todos estos factores han contribuido con la actual pérdida de diversidad biológica. Además, los inventarios biológicos aún están incompletos. Una de las zonas menos exploradas es la parte semiárida del istmo de Tehuantepec, en los alrededores de la localidad de Santa María del Mar, Oaxaca, México. El área incluye pastizales inundables, áreas de manglar y de selva seca, y provee de una gama de hábitat potenciales para diversas especies. Nuestro objetivo fue evaluar el efecto de las lagunas temporales en la composición espacial y temporal de la avifauna en Santa María del Mar, con el propósito de generar información relacionada con este grupo dentro de la región y del estado, además de comprender la importancia de las áreas inundables para las aves residentes y migratorias. Entre julio 2006 y junio 2008 realizamos 12 monitoreos de la avifauna, y establecimos dos transectos de 2km de longitud para cada uno de los cuatro tipos de hábitat (playa, pastizal, selva seca y manglar). Encontramos un total de 75 especies, correspondendiendo a 16 órdenes y 30 familias. Dentro de un área de 26km², de manera significativa registramos el 10.1% del total de aves registradas para todo el estado y el 6.6% del total de especies registradas para México. Las familias mejor representadas fueron: Ardeidae, Laridae y Scolopacidae. Para todo el periodo de estudio, la selva seca fue el hábitat más diverso, seguido por el manglar, el pastizal abierto y la playa. Del total de especies registradas, el 38.6% se encontraron en el borde o dentro de lagunas temporales. Encontramos una diferencia significativa en la composición de especies entre temporadas en el pastizal, pero no se encontró diferencia entre el resto de los hábitat. Nuestros resultados muestran un efecto significativo de las lagunas temporales sobre la diversidad de la avifauna durante la temporada lluviosa; también evidencian la importancia de la conservación de los pastizales, dada su relevancia para la presencia de aves acuáticas. Sugerimos realizar un monitoreo continuo e intensivo, y proponemos que la zona sea designada como un área de importancia para la Conservación de las Aves (AiCA).


Subject(s)
Animals , Biodiversity , Birds/classification , Lakes , Mexico , Population Density , Population Dynamics , Seasons
6.
Rev Biol Trop ; 62(4): 1523-33, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25720185

ABSTRACT

Oaxaca hosts one of the greatest biodiversity in México, occupying first place in avian diversity compared to other regions of the country. However, the area is undergoing serious problems such as high defor- estation rates, soil erosion and over exploitation and extinction of species. These factors have all contributed to the current loss of biodiversity. Also, biological inventories are still incomplete. One of the least explored sites is the semiarid zone of Tehuantepec isthmus, around the locality of Santa Maria del Mar, Oaxaca, México. The area includes floodable grasslands, mangrove areas and dry forest, providing a range of potential habitats for different species. Our objective was to evaluate the effect of temporal lakes on spatial and temporal composition of the avifauna in Santa Maria del Mar, in order to generate information regarding this group within the region and the state, and to understand the importance of flood areas for resident and transitory birds. We conducted 12 avifauna surveys between July 2006 and June 2008, and established two transects of 2km length in each of four habitat types (beach, grassland, dry forest, and mangrove). We found a total of 75 species, corresponding to 16 orders and 30 families. Within an area of 26 km2, we significantly found 10.1% of the total number of bird species recorded for the entire state, and 6.6% of the total reported in Mexico. The families most repre- sented were: Ardeidae, Laridae and Scolopacidae. Over the entire study period, dry forest was the most diverse habitat; followed by mangrove, grassland and the beach. Of all the species recorded, 38.6% were found at the edge or in the temporal lakes. We found a significant difference in species composition between seasons in the grassland, but no difference in the other habitats. Our results showed a significant effect of temporary lakes on avian diversity during the wet season; it also demonstrated the importance of grassland conservation given its relevance for presence of waterbirds. We suggested a continued and more intense monitoring; and proposed the designation of the area as an Important Conservation Bird Area (AICA).


Subject(s)
Biodiversity , Birds/classification , Animals , Lakes , Mexico , Population Density , Population Dynamics , Seasons
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