latitudinal gradient
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2022 ◽  
Author(s):  
Manuela Velazquez ◽  
Adam M M Stuckert ◽  
Rafael Vivero ◽  
Daniel R Matute

Sandflies are vector species of Leishmania, among many other pathogens, with a global distribution and a variety of ecological niches. Previous samplings have found that karstic formations (i.e., caves and folds formed by the erosion of limestone) serve as a natural habitat to sandfly species. The majority of samplings of cave sandfly diversity have occurred in Brazil and to date none have studied the species composition in a cave in the Northern Andes. We collected sandflies in the Cave-Los Guacharos-, in the state of Antioquia, Colombia. The sampling was carried out during two consecutive nights in September 2019. CDC-type light traps were installed inside the cavern and in other surrounding karst systems (caves and folds). In total, we identified 18 species of sandfly from the cave and surrounding karst systems, including three new records for Colombia (Bichromomyia olmeca nociva, Brumptomyia brumpti, and Warileya leponti), and provide the first karstic reports for four other species (Lutzomyia gomezi, Lutzomyia hartmanni, Pintomyia ovallesi, and Psychodopygus panamensis). We then used the results of our survey and published literature to test two hypotheses. First, that sandfly diversity in Neotropical caves is richest nearer to the equator and second that there is a phylogenetic signal of karstic habitat use in sandflies. Counter to our predictions, we found no evidence that diversity follows a latitudinal gradient. Further, we find no evidence of a phylogenetic signal of karstic habitat use, instead finding that the use of caves likely evolved multiple times across several genera. Our results highlight the importance of a wide sampling to understand the natural habitat of sandflies and other disease vectors.


MAUSAM ◽  
2021 ◽  
Vol 43 (4) ◽  
pp. 385-394
Author(s):  
P.N. PATHAK ◽  
N. GAUTAM

The main purpose of the present work is to establish the reliability of the SAMIR-derived water vapour (WV) data over the Arabian Sea and the Bay of Bengal for the entire 18-month from January 1982 to June 1983 period of the in-orbit operation of the SAMIR system. The average latitudinal distributions of WV over the Arabian Sea and Bay of Bengal for different months, derived from the SAMJR data were found to be broadly consistent with the climatological data on WV from the coastal and island radiosonde stations.   A significant latitudinal gradient in WV has been found during the northern winter months (Dec-Feb) with the highest value of 4-5 gm/cm2 near the equator and thc lowest value of about 2 gm/cm2 at about 20oN over the Indian seas. This gradient gradually decreases during the subsequent months and almost vanishes during the southwest monsoon months (Jun-Sep) when the WV has nearly uniform value of 4-5 gm/cm2 in the entire latitude range from the equator to 20oN over the Indian seas. Finally, it has been found that WV values over the Bay of Bengal are generally higher than those over the Arabian Sea at co-latitudinal positions. The implications of this result are discussed in the light of other considerations.


Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2811
Author(s):  
Rodrigo A. Chorbadjian ◽  
María I. Ahumada ◽  
Francisco Urra ◽  
Mario Elgueta ◽  
Todd M. Gilligan

Identifying the particular guilds of herbivore arthropods that affect the production of crops is key to developing sustainable pest-management strategies; however, there is incomplete information about the identity of herbivore arthropods that could potentially damage the production of both highland and lowland quinoa landraces grown in Chile. By both reviewing the literature and conducting field collections across a large latitudinal gradient, we generated an updated list of 43 herbivore arthropods associated with quinoa production in Chile. In general, most species are polyphagous feeders, and only seven are specialists. The number and identity of species varied in relation with the latitude, such that four distinctive assemblages of herbivores were identified, each containing 32, 27, 34, and 22 species between latitudes 18–26, 26–32, 32–40, and 40–44° S, respectively. The most northern production area (18–26° S) is affected by nine unique species, including the major quinoa pest Eurysacca quinoae Povolný (Lepidoptera: Gelechiidae). Similarly, the central area (32–40° S) contains four unique species, including Eurysacca media Povolný (Lepidoptera: Gelechiidae) and Orthotylus flavosparsus (Sahlberg) (Hemiptera: Miridae). The particular species assemblages described here will help further development of local pest-management practices.


2021 ◽  
Author(s):  
Ian R. McFadden ◽  
Susanne A. Fritz ◽  
Niklaus E. Zimmermann ◽  
Loïc Pellissier ◽  
W. Daniel Kissling ◽  
...  

Species interactions are influenced by the trait structure of local multi-trophic communities. However, it remains unclear whether mutualistic interactions in particular can drive trait patterns at the global scale, where climatic constraints and biogeographic processes gain importance. Here we evaluate global relationships between traits of frugivorous birds and palms (Arecaceae), and how these relationships are affected, directly or indirectly, by assemblage richness, climate and biogeographic history. We leverage a new and expanded gape size dataset for nearly all avian frugivores, and find a positive relationship between gape size and fruit size, i.e., trait matching, which is influenced indirectly by palm richness and climate. We also uncover a latitudinal gradient in trait matching strength, which increases towards the tropics and varies among zoogeographic realms. Taken together, our results suggest trophic interactions have consistent influences on trait structure, but that abiotic, biogeographic and richness effects also play important, though sometimes indirect, roles in shaping the functional biogeography of mutualisms.


MAUSAM ◽  
2021 ◽  
Vol 47 (1) ◽  
pp. 53-58
Author(s):  
D. A. BEGUM

This article shows the analysis of total ozone and potential vorticity and also tropopause  pressure during winter period (December, January and February) over the area 20°-50°N, 90°.160oE (southeast Asia), This is done for three different latitude bands 20o-30oN, 30° -40° N and 40°S -50oN. Due to maximum, latitudinal gradient of ozone in the lower latitudinal band, high correlation is found with potential vorticity and also with tropopause level


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Monika Wagner ◽  
Georg Brunauer ◽  
Arne C. Bathke ◽  
S. Craig Cary ◽  
Roman Fuchs ◽  
...  

AbstractLecideoid lichens as dominant vegetation-forming organisms in the climatically harsh areas of the southern part of continental Antarctica show clear preferences in relation to environmental conditions (i.e. macroclimate). 306 lichen samples were included in the study, collected along the Ross Sea coast (78°S–85.5°S) at six climatically different sites. The species compositions as well as the associations of their two dominant symbiotic partners (myco- and photobiont) were set in context with environmental conditions along the latitudinal gradient. Diversity values were nonlinear with respect to latitude, with the highest alpha diversity in the milder areas of the McMurdo Dry Valleys (78°S) and the most southern areas (Durham Point, 85.5°S; Garden Spur, 84.5°S), and lowest in the especially arid and cold Darwin Area (~ 79.8°S). Furthermore, the specificity of mycobiont species towards their photobionts decreased under more severe climate conditions. The generalist lichen species Lecanora fuscobrunnea and Lecidea cancriformis were present in almost all habitats, but were dominant in climatically extreme areas. Carbonea vorticosa, Lecidella greenii and Rhizoplaca macleanii were confined to milder areas. In summary, the macroclimate is considered to be the main driver of species distribution, making certain species useful as bioindicators of climate conditions and, consequently, for assessing the consequences of climate change.


2021 ◽  
Vol 195 ◽  
pp. 104634
Author(s):  
Ana G. Pérez-Delgadillo ◽  
Rafael A. Lara-Resendiz ◽  
Jorge H. Valdez-Villavicencio ◽  
Diego M. Arenas-Moreno ◽  
Saúl F. Domínguez-Guerrero ◽  
...  

2021 ◽  
Vol 545 ◽  
pp. 151644
Author(s):  
Laura Regina Alvarez-Cerrillo ◽  
Francisco Benítez-Villalobos ◽  
Sergio Garcia-Ibañez ◽  
Omar Hernando Avila-Poveda

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