Environmental variation and seasonal changes as determinants of the spatial distribution of scorpions (Arachnida: Scorpiones) in Neotropical forests

2018 ◽  
Vol 96 (9) ◽  
pp. 963-972 ◽  
Author(s):  
A.F.A. Lira ◽  
A.M. DeSouza ◽  
C.M.R. Albuquerque

Habitat selection and seasonal changes are key drivers of the population dynamics of many species. We analyzed how the environmental structure influences species establishment in an area by comparing microhabitat preference and functional richness of scorpions (Arachnida: Scorpiones) in wet (Atlantic forest) and semiarid (Caatinga) areas. Variations in superficial foraging activity and microhabitat colonization during dry and rainy seasons were evaluated as an indication of the climatic impact on population dynamics. We collected 12 scorpion species using ultraviolet light lamps. We found that differential patterns in spatial distribution were independent of forest type, and we provide evidence for partial niche partitioning among scorpion species based on age class and climatic conditions. Foraging activity was also seasonally influenced. Functional richness was higher in wet forests than in dry forests, whereas taxonomical richness exhibited an opposite pattern. We conclude that spatiotemporal resource partitioning and refuge sharing are important drivers of the population dynamics and spatial distribution of scorpion species in Neotropical forests.

1997 ◽  
Vol 13 (4) ◽  
pp. 595-616 ◽  
Author(s):  
Carlos A. Peres ◽  
Claudia Baider

ABSTRACTSeeds of the Brazilnut tree (Bertholletia excelsa Humb. & Bonpl., Lecythidaceae) sustain one of the most important extractive industries in neotropical forests. Yet little is known about the demography and seed dispersal ecology of Bertholletia, particularly in natural stands which have not been previously harvested. This study presents data on the population density, spatial distribution, and seed dispersal ecology of Brazilnut trees at a pristine stand located within the Kayapó Indian Area of southeastern Amazonia, Pará, Brazil. Brazilnut trees were primarily found within groves (castanhais) of 75 to 149 trees, with a few isolated trees in between. Although the density of trees ≥ 10 cm in diameter at breast height (hereafter, dbh) at two groves was 4.8 to 5.1 trees ha–1, the overall density for the entire study area of c. 950 ha was estimated at 1.3 tree ha–1. Within-grove nearest neighbour distances averaged 21 m and were markedly skewed towards even shorter distances. Seed dispersal experiments using 709 marked seeds indicated that this pattern can be largely explained by the highly restricted seed shadows imparted by the main seed dispersal agents of Bertholletia at this site, the red-rumped agouti (Dasyprocta leporina). Agoutis on average scatterhoard Bertholletia seeds to an average distance of 5 m, and rarely beyond 20 m, from seed stations. We suggest that, once edaphic and climatic conditions are suitable, the highly contagious spatial distribution of Bertholletia trees at the landscape level can be largely accounted for by the quantitatively dominant effect of short-distance dispersal by caviomorph rodents, and rare events of long-distance dispersal provided by other vectors. This mechanism of grove formation need not resort to untested conjectures of human dispersal and intentional planting in prehistoric and historic times as it has often been suggested in the literature.


2019 ◽  
Vol 11 (14) ◽  
pp. 186 ◽  
Author(s):  
Lucas Faro Bastos ◽  
Artur Vinícius Ferreira dos Santos ◽  
Fernanda Valente Penner ◽  
Lizandra Maria Maciel Siqueira ◽  
Anderson Gonçalves da Silva ◽  
...  

Haplaxius crudus is the primary vector of the phytoplasma that causes the Lethal Yellowing of Coconut, a disease that has become a barrier to the establishment of large coconut plantations in the world. The objective of this study was to determine the spatial distribution pattern and population dynamics of H. crudus adults by correlating them with the abiotic factors, such as temperature and rainfall in commercial dwarf coconut palm plantations. Collection of American palm cixiid was carried out using yellow sticky traps fixed to the abaxial part of the coconut leaves. The sampled plants were georeferenced to obtain the geographic coordinates and geostatistical analysis, besides the planialtimetric survey of the experimental plot for the preparation of the map that shows the topographic conformation of the terrain. Insects were found at the study site throughout the year, showing greater abundance in months when the average monthly temperatures and rainfall were not significant. The climatic factors showed a correlation with the total of insects, positive for the temperature, with 0.733 and negative for the precipitation with -0.606. The spatial distribution of H. crudus displayed an aggregate pattern, explained by the spherical model. The infestation focus occurred in the periphery of the plot, near a Brachiaria humidicola pasture. It was concluded that the infestation of the H. crudus showed a behavior directly related to the local climatic conditions and the aggregate spatial distribution explained by the spherical model, therefore, forming shrubs with a radius of 154 to 190 m, with areas of influence between 7.45 and 17.80 ha, which coincide with the lower part of the terrain.


2019 ◽  
Vol 49 (4) ◽  
pp. 101-105 ◽  
Author(s):  
G. M. Shkyratova ◽  
B. Z. Bazaron ◽  
T. N. Khamiruev ◽  
S. M. Dashinimaev

The seasonal changes in the skin thickness and structure of the horses’ coat, as signs of adaptation to environmental factors, were studied. The experiment was carried out with the livestock kept in a herd using winter-grazing technology without additional feedings in the climatic conditions of the Trans-Baikal Territory. The objects of the research were adult mares of Zabaikalsky breed of horses of the same age, class and fatness. The studies were carried out in the middle of each season (May, July, October, February). The length of the coat was measured with a caliper, the coat itself with the determination of the ratio of hair (fl uffy hair, heterotype hair and coarse hair) and the thickness of the skin fold were measured in accordance with the approved methodological recommendations. The minimum skin thickness in winter was detected in mares on the back and shoulder blade – 4.3 and 4.4 mm, the maximum – on the side and thigh – 4.5 4.6 mm. When compared with the summer period, the increase on the side was 0.8 mm, whereas on the back, shoulder blade and thigh – 0.4 mm (p ≤ 0,001). In spring, thickening of the skin was noted within 0.1-0.3 mm in the same topographic areas, compared to autumn. The quantitative indicators of the coat changed depending on the season of the year. In winter, the coat contained more fl uffy hair (23.10%), and less coarse hair (68.24%), in summer there was a lower content of fl uffy hair (4.33%), but more coarse hair (94.01%.) Sharp seasonal changes were noted with regard to the length of the hair. The longest hair was found in winter and spring – 4.96 and 4.26 cm, whereas the shortest – in summer and autumn – 0.94 and 1.90 cm, respectively.


2021 ◽  
Vol 24 (3) ◽  
pp. 301-310
Author(s):  
N. V. Harbachova ◽  
N. D. Kuzmina ◽  
N. V. Kulich ◽  
S. N. Yatsko ◽  
J. A. Korchova

In this paper, natural (geological and hydrological) and climatic impact conditions on the influence zone for two different sites of radioactive waste disposals have been studied. Probabilistic approach to assessment of the groundwater vulnerability from radionuclide contamination during disposal of radioactive waste is developed. As to climatic conditions, an effective numerical and analytical methods for annual precipitation rates assessment of rare recurrence have been proposed which allow to take into account uncertainties of rare events as well.


2020 ◽  
Vol 23 (3-4) ◽  
pp. 91-102
Author(s):  
Ivana Pajač Živković ◽  
Irena Brlić Puškarić ◽  
Darija Lemić

The invasive species Drosophila suzukii (Matsumura, 1931), the spotted wing drosophila, was first recorded in Croatia in 2010. Since then, it has spread on Croatian territory but its presence has not yet been confirmed in the City of Zagreb. In this research population dynamics of D. suzukii was investigated in three orchards in Zagreb (Maksimir, Jelenovac, Zelenjak) in the period from 20th of March to 27th of November 2017. Feeding traps with apple vinegar were used for catching D. suzukii. The flight began in the period from 27th of June to 11th of July and lasted until 27th of November. The total pest catches were 874 specimens (Jelenovac 187, Maksimir 232 and Zelenjak 455). From September to November there was a continuous flight and a large increase in the number of caught flies, suggesting the presence of more overlapping generations. Besides the host plants, the development of the pest in this area is also enabled by suitable climatic conditions. The present population in the City of Zagreb County poses a danger to fruit producers in the Zagreb County. The results of this research are a contribution to better understanding of the population and the spread of the pest in Croatia.


2018 ◽  
Vol 97 (5) ◽  
pp. 418-423
Author(s):  
L. V. Veremchuk ◽  
E. E. Mineeva ◽  
Tatyana I. Vitkina ◽  
T. A. Gvozdenko

Introduction. The climatic factors affect the mucous membrane of the respiratory tract contacting with the environment. The investigation of pulmonary ventilation plays a leading role in the diagnosis of bronchial obstruction in response to an external stimulus. Material and methods. The study included a healthy population of the city and patients with chronic catarrhal nonobstructive bronchitis (CCNB), controlled and uncontrolled asthma (131 people). The respiratory function (RF) was estimated by spirography and body plethysmography. Meteorological conditions were evaluated from the point of view of contrasting weather changes (on the survey day, on 1st and 2nd days before the survey). The degree of the climatic impact on RF was determined by the statistical module “Discriminant analysis”, used to a group of RF indices relatively adverse levels of impact of the monsoon climate. Results. The low level of the responsiveness in a healthy urban population was identified. The negative impact of climatic indices on the respiratory system in CCNB patients was observed mainly in extreme weather conditions. The influence of climatic conditions on patients with asthma depends on the level of the disease control. Discussion. The influence of climatic conditions was found to be within the adaptive and compensatory responses in a group of healthy people and CCNB patients. We assumed the use of basic drugs in patients with asthma without signs of bronchial obstruction to reduce the susceptibility of the receptors of the bronchi to the negative climatic impact. The greatest negative RF response to the impact of monsoon climate manifested both in static and in dynamic weather conditions, was observed in patients with uncontrolled asthma. It was associated with the impaired pulmonary ventilation. Conclusion. The results indicate the Far East monsoon climate to be an important risk factor for the exacerbation in patients with respiratory diseases.


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