scholarly journals Temporal stability of an endemic Mexican treefrog

Author(s):  
Griselda Cruz-Ruiz ◽  
Crystian S. Venegas-Barrera ◽  
Hermilo Sanchez-Sanchez ◽  
Javier Manjarrez

The demographic characteristics of an amphibian population fluctuate independently over time, mainly in response to the temporal variation of environmental factors, especially precipitation and temperature. These temporal fluctuations may contribute to the effective size of an amphibian population and could be used to inform the current conservation status of a species. During a five year (2004-2008) period, we studied the relative abundance, sex ratio, and size-age structure of a population of metamorphosed individuals of the endemic treefrog Hyla eximia in Central Mexico. We also studied the species’ relationship with climatic variables such as temperatura and precipitation. We found an interannual constant abundance during the study period. However, interannual differences were observed in the population structure by age-sex category (males, females, or juveniles), with increased abundance of juveniles during the rainy months (August-November). The annual abundance of H. eximia was positively correlated with rainfall, but negatively with monthly temperature. We found the sex ratio was male-biased (2:1) except for year 2008. Also, differences in snout-vent length (SVL) were found between years, suggesting changes in recruitment of new individuals. We conclude that variations in abundance, and frequencies by age-sex category, of H. eximia are related to seasonal variations in temperature and precipitation characteristics of temperate zones. However, this temporal stability may suggest that anurans have an unusual capacity to persist even in the face of human-induced habitat change.

2015 ◽  
Author(s):  
Griselda Cruz-Ruiz ◽  
Crystian S. Venegas-Barrera ◽  
Hermilo Sanchez-Sanchez ◽  
Javier Manjarrez

The demographic characteristics of an amphibian population fluctuate independently over time, mainly in response to the temporal variation of environmental factors, especially precipitation and temperature. These temporal fluctuations may contribute to the effective size of an amphibian population and could be used to inform the current conservation status of a species. During a five year (2004-2008) period, we studied the relative abundance, sex ratio, and size-age structure of a population of metamorphosed individuals of the endemic treefrog Hyla eximia in Central Mexico. We also studied the species’ relationship with climatic variables such as temperatura and precipitation. We found an interannual constant abundance during the study period. However, interannual differences were observed in the population structure by age-sex category (males, females, or juveniles), with increased abundance of juveniles during the rainy months (August-November). The annual abundance of H. eximia was positively correlated with rainfall, but negatively with monthly temperature. We found the sex ratio was male-biased (2:1) except for year 2008. Also, differences in snout-vent length (SVL) were found between years, suggesting changes in recruitment of new individuals. We conclude that variations in abundance, and frequencies by age-sex category, of H. eximia are related to seasonal variations in temperature and precipitation characteristics of temperate zones. However, this temporal stability may suggest that anurans have an unusual capacity to persist even in the face of human-induced habitat change.


PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1274 ◽  
Author(s):  
Griselda Cruz-Ruiz ◽  
Crystian S. Venegas-Barrera ◽  
Hermilo Sanchez-Sanchez ◽  
Javier Manjarrez

The demographic characteristics of an amphibian population fluctuate independently over time, mainly in response to the temporal variation of environmental factors, especially precipitation and temperature. These temporal fluctuations may contribute to the size of an amphibian population and could be used to determine the current conservation status of a species. During a five year (2004–2008) period, we studied the relative abundance, sex ratio, and age-sex structure of a population of metamorphosed individuals of the endemic treefrogHyla eximiain Central Mexico. We also studied the species’ relationship with climatic variables such as temperature and precipitation. We found an interannual constant abundance during the study period. However, interannual differences were observed in the population structure by age-sex category (males, females, or juveniles), with decreased abundance of males and juveniles during the rainy months (August–November). The annual abundance ofH. eximiawas positively correlated with rainfall, but negatively with monthly temperature. We found the sex ratio was male-biased (2:1), except for year 2008. Also, differences in snout-vent length (SVL) were found between years, suggesting changes in recruitment of new individuals. We conclude that variations in abundance, and frequencies by age-sex category, ofH. eximiaare related to seasonal variations in temperature and precipitation characteristics of temperate zones. However, this temporal stability may suggest that anurans have an unusual capacity to persist even in the face of human-induced habitat change.


2019 ◽  
Vol 70 (1) ◽  
pp. 27-30
Author(s):  
Toni Koren ◽  
Matea Martinović

The caterpillars of the Southern Swallowtail, Papilio alexanor have been recorded in the vicinity of Trebinje, Bosnia & Herzegovina. This is the first recent observation of this species in the country and the third observation so far. Opopanax chironium is confirmed as the larval host plant in Bosnia and Herzegovina, which was expected due to the recent observations from Croatia. Its status and distribution in the country are still not clear, and further surveys are recommended in order to reconfirm the historical records as well as to assess its current conservation status. Due to the limited extent of its occurrence, we propose to include it in the Red list of fauna of Bosnia & Herzegovina as Vulnerable (VU).


2021 ◽  
Vol 13 (2) ◽  
pp. 187
Author(s):  
Rui Sun ◽  
Shaohui Chen ◽  
Hongbo Su

As an important part of a terrestrial ecosystem, vegetation plays an important role in the global carbon-water cycle and energy flow. Based on the Global Inventory Monitoring and Modeling System (GIMMS) third generation of Normalized Difference Vegetation Index (NDVI3g), meteorological station data, climate reanalysis data, and land cover data, this study analyzed the climate dynamics of the spatiotemporal variations of vegetation NDVI in northern China from 1982 to 2015. The results showed that growth season NDVI (NDVIgs) increased significantly at 0.006/10a (p < 0.01) in 1982–2015 on the regional scale. The period from 1982 to 2015 was divided into three periods: the NDVIgs increased by 0.026/10a (p < 0.01) in 1982–1990, decreased by −0.002/10a (p > 0.1) in 1990–2006, and then increased by 0.021/10a (p < 0.01) during 2006–2015. On the pixel scale, the increases in NDVIgs during 1982–2015, 1982–1990, 1990–2006, and 2006–2015 accounted for 74.64%, 85.34%, 48.14%, and 68.78% of the total area, respectively. In general, the dominant climate drivers of vegetation growth had gradually switched from solar radiation, temperature, and precipitation (1982–1990) to precipitation and temperature (1990–2015). For woodland, high coverage grassland, medium coverage grassland, low coverage grassland, the dominant climate drivers had changed from temperature and solar radiation, solar radiation and precipitation, precipitation and solar radiation, solar radiation to precipitation and solar radiation, precipitation, precipitation and temperature, temperature and precipitation. The areas controlled by precipitation increased significantly, mainly distributed in arid, sub-arid, and sub-humid areas. The dominant climate drivers for vegetation growth in the plateau climate zone or high-altitude area changed from solar radiation to temperature and precipitation, and then to temperature, while in cold temperate zone, changed from temperature to solar radiation. These results are helpful to understand the climate dynamics of vegetation growth, and have important guiding significance for vegetation protection and restoration in the context of global climate change.


1970 ◽  
Vol 36 (2) ◽  
pp. 139-144 ◽  
Author(s):  
Fergan Karaer ◽  
Ferhat Celep

Scorzonera amasiana Hausskn. and Bornm. was described from type specimens collected by J.F.N. Bornmueller in 1889 but it was not collected again until 1993, when it was found near Amasya, Turkey. Populations of S. amasiana were quite small at that limited locations and were vulnerable to human impacts. Therefore, suitable conservation strategies should be developed immediately in order to protect the species from probable extinction. Here, an additional three small populations are reported. Brief history, morphology, habitat and ecology of this endemic species have been discussed. Its current conservation status was reevaluated with respect to the latest IUCN criteria. A key to distinguish it from the other closely related Turkish species is also provided and its distribution map is appended.   Key words: Endangered, Rediscovery, Scorzonera, Turkey DOI = 10.3329/bjb.v36i2.1502 Bangladesh J. Bot. 36(2): 139-144, 2007 (December)


MAUSAM ◽  
2021 ◽  
Vol 71 (4) ◽  
pp. 661-674
Author(s):  
HIMAYOUN DAR ◽  
ROSHNI THENDIYATH ◽  
MOHSIN FAROOQ

The present study investigated the spatio-temporal variations of precipitation and temperature for the projected period (2011-2100) in the Jhelum basin, India. The precipitation and temperature variables are projected under RCP 8.5 scenario using statistical down scaling techniques such as Artificial Neural Network (ANN) and Wavelet Artificial Neural Network (WANN) models. Firstly, the screened predictors were downscaled to predictand using ANN and WANN models for all the study stations. On the basis of the performance criteria, the WANN model is selected as an efficient model for downscaling of precipitation and temperature. The future screened predictor data pertaining to RCP 8.5 of CanESM2 model were downscaled to monthly temperature and precipitation for future periods (2011-2100) using WANN models. The investigation of the future projections revealed an average increase of 17-25% in the mean annual precipitation and 20-25% average increase in the monthly mean precipitation for all the selected stations towards the end of 21st century. The monthly mean temperature also showed an increase of 2-3 °C for all the study stations towards the end of 21st century. The mean seasonal temperature of the projected period is found to be increasing for all the four seasons in most parts of the basin.


2021 ◽  
Vol 42 ◽  
pp. e70549
Author(s):  
Jordi Bou ◽  
Lluís Vilar

The sessile oak forests found on the northeast of the Iberian Peninsula are ascribed to the Lathyro-Quercetumpetraeae association and play a key role in understanding the ecology of this habitat, as this region represents its xeric limit. For this reason, we analysed the biodiversity patterns and current conservation status of the sessile oak forests in the region. To do so, we collected Braun-Blanquet inventories of 34 plots randomly distributed throughout the sessile oak forests. The results showed a relationship between the climatic conditions and the biodiversity variables. While the richness of the community increased with decreasing temperatures, the characteristic species found within the community decreased at these same temperatures. This result was due to the presence of most companion species in the cool zones at high elevations.Sessile oaks are found close to other communities, such as silver birches and Scot pine forests.On the other hand, in the warm areas at low elevations, the sessile oak community was more established, with plants typical of this type of forest. These slightly warmer zones with sessile oaks are very important in terms of conservation and more vulnerable to climate change and the thermophilization of the community, as has been studied. As such, protecting and managing these forests is key to conserving this community. Nevertheless, as current protection measures do not safeguard most of these forests, it is essential to define a conservation strategy to preserve them. Using the conservation status, we have established criteria to improve the conservation strategy for sessile oak forest on the NE Iberian Peninsula.


<em>Abstract</em>.-Climate change can have an effect on species distributions. The 1900 distribution and potential future distribution of diadromous fish in Europe, North Africa, and the Middle East were explored using generalized additive models (GAMs) and selected habitat characteristics of 196 basins. Robust presence-absence models were built for 20 of the 28 diadromous species in the study area using longitude, annual temperature, drainage surface area, annual precipitation, and source elevation as explanatory variables. Inspection of the relationship between each variable and species presence-absence revealed that the GAMs were generally interpretable and plausible. Given the predicted rise in annual temperature in climate models ranging between 1°C and 7°C by 2100, the fish species were classified according to those losing suitable basins, those gaining suitable basins, and those showing little or no change. It was found that the climate envelopes based on temperature and precipitation for diadromous species would, in general, be shifted farther northeastwards by 2100, and these shifting ranges were comparable with those assessed in other studies. The uncertain future of some species was highlighted, and it was concluded that conservation policy and management plans will need to be revised in the face of climate change.


2012 ◽  
Vol 16 (2) ◽  
pp. 305-318 ◽  
Author(s):  
I. Haddeland ◽  
J. Heinke ◽  
F. Voß ◽  
S. Eisner ◽  
C. Chen ◽  
...  

Abstract. Due to biases in the output of climate models, a bias correction is often needed to make the output suitable for use in hydrological simulations. In most cases only the temperature and precipitation values are bias corrected. However, often there are also biases in other variables such as radiation, humidity and wind speed. In this study we tested to what extent it is also needed to bias correct these variables. Responses to radiation, humidity and wind estimates from two climate models for four large-scale hydrological models are analysed. For the period 1971–2000 these hydrological simulations are compared to simulations using meteorological data based on observations and reanalysis; i.e. the baseline simulation. In both forcing datasets originating from climate models precipitation and temperature are bias corrected to the baseline forcing dataset. Hence, it is only effects of radiation, humidity and wind estimates that are tested here. The direct use of climate model outputs result in substantial different evapotranspiration and runoff estimates, when compared to the baseline simulations. A simple bias correction method is implemented and tested by rerunning the hydrological models using bias corrected radiation, humidity and wind values. The results indicate that bias correction can successfully be used to match the baseline simulations. Finally, historical (1971–2000) and future (2071–2100) model simulations resulting from using bias corrected forcings are compared to the results using non-bias corrected forcings. The relative changes in simulated evapotranspiration and runoff are relatively similar for the bias corrected and non bias corrected hydrological projections, although the absolute evapotranspiration and runoff numbers are often very different. The simulated relative and absolute differences when using bias corrected and non bias corrected climate model radiation, humidity and wind values are, however, smaller than literature reported differences resulting from using bias corrected and non bias corrected climate model precipitation and temperature values.


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