Chemical Characteristics of Precipitation and Cloud Water at High Elevation Site in Bulgaria

Author(s):  
Elena Hristova ◽  
Blagorodka Veleva ◽  
Krum Velchev ◽  
Emilia Georgieva
2012 ◽  
Vol 124 (2) ◽  
pp. 366-370 ◽  
Author(s):  
David F. Vogt ◽  
Mark E. Hopey ◽  
G. Rad Mayfield ◽  
Eric C. Soehren ◽  
Laura M. Lewis ◽  
...  

2010 ◽  
Vol 26 (5) ◽  
pp. 521-531 ◽  
Author(s):  
David Laurencio ◽  
Lee A. Fitzgerald

Abstract:Disentangling local and historical factors that determine species diversity patterns at multiple spatial scales is fundamental to elucidating processes that govern ecological communities. Here we investigated how environmental correlates may influence diversity at local and regional scales. Primarily utilizing published species lists, amphibian and reptile alpha and beta diversity were assessed at 17 well-surveyed sites distributed among ecoregions throughout Costa Rica. The degree to which regional species diversity patterns were related to environmental variables and geographic distance was determined using Canonical Correspondence Analysis and Mantel tests. Amphibian alpha diversity was highest in lowland Pacific sites (mean = 43.3 species) and lowest at the high elevation site (9 species). Reptile alpha diversity values were high for both lowland Atlantic (mean = 69.5 species) and lowland Pacific (mean = 67 species) sites and lowest for the high elevation site (8 species). We found high species turnover between local sites and ecoregions, demonstrating the importance of beta diversity in the determination of regional diversity. For both amphibians and reptiles, beta diversity was highest between the high-elevation site and all others, and lowest among lowland sites within the same ecoregion. The effect of geographic distance on beta diversity was minor. Ecologically significant climatic variables related to rain, temperature, sunshine and insolation were found to be important determinants of local and regional diversity for both amphibians and reptiles in Costa Rica.


2016 ◽  
Vol 13 (6) ◽  
pp. 1047-1055 ◽  
Author(s):  
Ana Mª M. Farrona ◽  
Fernando Domínguez-Castro ◽  
Mª Cruz Gallego ◽  
José M. Vaquero

2006 ◽  
Vol 42 (4) ◽  
pp. 399-409 ◽  
Author(s):  
S. K. YAU ◽  
M. NIMAH ◽  
I. TOUFEILI

Three different saffron strains (Crocus sativus, C. sativus var. ‘cashmerianus’ and C. cartwrightianus) were tested for two years in field experiments to study their red stigma yield and quality. The experiments were performed at a high-elevation (rainfed or irrigated) site and a coastal site in Lebanon. On average, the two C. sativus strains gave more flowers and stigma yield than C. cartwrightianus. The former was more productive in the more favourable environments, especially at the warmer coastal site, than the latter. C. sativus ‘cashmerianus’, which yielded better at the coastal site in 2004 and gave a stronger colour strength and aroma, appeared to be the better choice for the area. Mean yield at the coastal site was twice that at the non-irrigated high-elevation site. On average, saffron produced at the coastal site had more colouring strength and bitterness than that produced at the high-elevation site. Nevertheless, viable commercial saffron production may still be possible in the semi-arid, high-elevation Bekaa Valley if irrigation can be provided.


2009 ◽  
Vol 75 (15) ◽  
pp. 5121-5130 ◽  
Author(s):  
Robert M. Bowers ◽  
Christian L. Lauber ◽  
Christine Wiedinmyer ◽  
Micah Hamady ◽  
Anna G. Hallar ◽  
...  

ABSTRACT Bacteria and fungi are ubiquitous in the atmosphere. The diversity and abundance of airborne microbes may be strongly influenced by atmospheric conditions or even influence atmospheric conditions themselves by acting as ice nucleators. However, few comprehensive studies have described the diversity and dynamics of airborne bacteria and fungi based on culture-independent techniques. We document atmospheric microbial abundance, community composition, and ice nucleation at a high-elevation site in northwestern Colorado. We used a standard small-subunit rRNA gene Sanger sequencing approach for total microbial community analysis and a bacteria-specific 16S rRNA bar-coded pyrosequencing approach (4,864 sequences total). During the 2-week collection period, total microbial abundances were relatively constant, ranging from 9.6 × 105 to 6.6 × 106 cells m−3 of air, and the diversity and composition of the airborne microbial communities were also relatively static. Bacteria and fungi were nearly equivalent, and members of the proteobacterial groups Burkholderiales and Moraxellaceae (particularly the genus Psychrobacter) were dominant. These taxa were not always the most abundant in freshly fallen snow samples collected at this site. Although there was minimal variability in microbial abundances and composition within the atmosphere, the number of biological ice nuclei increased significantly during periods of high relative humidity. However, these changes in ice nuclei numbers were not associated with changes in the relative abundances of the most commonly studied ice-nucleating bacteria.


2010 ◽  
Vol 25 (1) ◽  
pp. 323-337 ◽  
Author(s):  
Trevor I. Alcott ◽  
W. James Steenburgh

Abstract Contemporary snowfall forecasting is a three-step process involving a quantitative precipitation forecast (QPF), determination of precipitation type, and application of a snow-to-liquid ratio (SLR). The final step is often performed using climatology or algorithms based primarily on temperature. Based on a record of consistent and professional daily snowfall measurements, this study 1) presents general characteristics of SLR at Alta, Utah, a high-elevation site in interior North America with frequent winter storms; 2) diagnoses relationships between SLR and atmospheric conditions using reanalysis data; and 3) develops a statistical method for predicting SLR at the study location. The mean SLR at Alta is similar to that observed at lower elevations in the surrounding region, with substantial variability throughout the winter season. Using data from the North American Regional Reanalysis, temperature, wind speed, and midlevel relative humidity are shown to be related to SLR, with the strongest correlation occurring between SLR and near-crest-level (650 hPa) temperature. A stepwise multiple linear regression (SMLR) equation is constructed that explains 68% of the SLR variance for all events, and 88% for a high snow-water equivalent (>25 mm) subset. To test predictive ability, the straightforward SMLR approach is applied to archived 12–36-h forecasts from the National Centers for Environmental Prediction Eta/North American Mesoscale (Eta/NAM) model, yielding an improvement over existing operational SLR prediction techniques. Errors in QPF over complex terrain, however, ultimately limit skill in forecasting snowfall amount.


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