Structure and function of two Antarctic terrestrial moss communities

first_imgTwo bryophyte—dominated communities in the maritime Antarctic are analyzed in terms of the transfer and standing crops of organic matter within them. A moss turf dominated by Polytrichum alpestre and Chorisodontium aciphyllum and a moss carpet composed of Calliergon sarmentosum, Calliergidium austro—stramineum, and Drepanocladus uncinatus with the liverwort Cephaloziella varians were investigated at Signy Island, South Orkney Islands. Biomass, respiration, and production data for the primary producers (mosses, lichens, liverworts, and algae), for the fauna (Protozoa, Rotifera, Tardigrada, Nematoda, Acari, and Collembola), and for the microflora were synthesized, and annual rates of consumption, egestion, assimilation, and production were derived. The two communities showed similar levels of productivity, trophic structure, and efficiencies of organic matter transfer, but different Collembola and Acari standing crops, turnover of mosses, and accumulation of dead organic matter. These features are discussed in relation to the role of biotic and abiotic variables in determining community structure and function.last_img read more

Factors causing the limitation of growth of terrestrial algae in maritime Antarctica during late summer

first_imgThe factors causing the cessation of growth and decline of microalgal communities on Antarctic fell-field soils during late summer were investigated. Physical and chemical amendments were applied within small enclosures and the size and taxonomic composition of the communities assessed. Most treatments had no effect on the microalgal communities or individual taxa. The addition of calcium nitrate to the soil either singly or as part of a complete growth medium promoted growth of all taxa studied on most sites. As the cation was naturally present in excess in the soil it is concluded that growth of the microalgal communities during late summer was nitrogen-limited.last_img

Modeling the formation and deposition of frazil ice beneath Filchner-Ronne Ice Shelf

first_imgLarge areas of the Filchner-Ronne Ice Shelf are underlain by layers of marine ice, which form when supercooled seawater circulating beneath the ice shelf freezes. The freezing process initially produces a suspension of disc-shaped frazil ice crystals, and these are subs quently deposited onto the ice shelf base in areas where the flow of water is slack enough. This has been modeled assuming that the freezing takes place within buoyant plumes of Ice Shelf Water ascending the ice shelf base from source regions near the grounding lines of the major inlet glaciers. The deposition of the majority of the suspended frazil ice is found to occur in spatially discrete bursts, where peak rates of accumulation at the ice shelf base exceed 1 m yr−1 of solid ice. There is a good correlation between the location of the zones of crystal deposition and the position of the upstream limits of the marine ice layers. The high rates of localized accumulation account for the rapid buildup observed in the layer thickness, which then gradually declines as the marine ice is carried downstream with the flow of the ice shelf. Model results also suggest an origin for the ice platelets observed at depth in the water column near the Filchner Ice Shelf.last_img read more

Antarctic clouds

first_imgSensitivity studies with global climate models show that, by their influence on the radiation balance, Antarctic clouds play a major role in the climate system, both directly at high southern latitudes and indirectly globally, as the local circulation changes lead to global teleconnections. Unfortunately, observations of cloud distribution in the Antarctic are limited and often of low quality because of the practical difficulty in observing clouds in the harsh Antarctic environment. The best surface observations suggest that the fractional cloud cover at the South Pole is around 50-60% in all seasons, whereas the cloud cover rises to around 80-90% close to the coast of the continent. Microphysical observations of cloud parameters are also very sparse in the Antarctic. However, the few measurements that do exist show predominantly ice-crystal clouds across the interior, with mixed-phase clouds close to the coasts. Crystal sizes vary from 5 to 30 mm (effective radius) in the interior to somewhat larger ice crystals and water drops near the coast. A wide range of crystal shapes is observed at all sites. This review considers the available cloud observations and highlights the importance of Antarctic clouds and the need for better observations in the future.last_img read more

Migration timing and routes, and wintering areas of Flammulated Owls

first_imgDetermining patterns in annual movements of animals is an important component of population ecology, particularly for migratory birds where migration timing and routes, and wintering habitats have key bearing on population dynamics. From 2009 to 2011, we used light-level geolocators to document the migratory movements of Flammulated Owls (Psiloscops flammeolus). Four males departed from breeding areas in Colorado for fall migration between ≤5 and 21 October, arrived in wintering areas in Mexico between 11 October and 3 November, departed from wintering areas from ≤6 to 21 April, and returned to Colorado between 15 and 21 May. Core wintering areas for three males were located in the Trans-Mexican Volcanic Belt Mountains in the states of Jalisco, Michoacán, and Puebla in central and east-central Mexico, and the core area for the other male was in the Sierra Madre Oriental Mountains in Tamaulipas. The mean distance from breeding to wintering centroids was 2057 ± 128 km (SE). During fall migration, two males took a southeastern path to eastern Mexico, and two males took a path due south to central Mexico. In contrast, during spring migration, all four males traveled north from Mexico along the Sierra Madre Oriental Mountains to the Rio Grande Valley and north through New Mexico. The first stopovers in fall and last stopovers in spring were the longest in duration for all males and located 300–400 km from breeding areas. Final spring stopovers may have allowed male Flammulated Owls to fine tune the timing of their return to high-elevation breeding areas where late snows are not uncommon. One male tracked in both years had similar migration routes, timing, and wintering areas each year. Core wintering and final stopover areas were located primarily in coniferous forests and woodlands, particularly pine-oak forests, suggesting that these are important habitats for Flammulated Owls throughout their annual cycle.last_img read more

USU-Eastern Utah’s Namdar Signs With Division II Hawaii Pacific

first_img Brad James Tags: Hawaii Pacific Sharks/Neema Namdar/SUU Men’s Basketball/USU Eastern Utah Men’s Basketball Written by FacebookTwitterLinkedInEmailPRICE, Utah-Tuesday, per an announcement from the USU Eastern Utah athletics department, former Eagles guard Neema Namdar has signed with the Division II Hawaii Pacific Sharks.The native of Sandy, Utah will head out to Oahu to continue his collegiate career after averaging 11.3 points, 3 rebounds and 1.6 assists per game in his sole season with the Eagles.The former member of the Southern Utah University’s men’s squad also shot a torrid 44.9 percent behind the arc and broke the USU-Eastern school record for made 3-pointers in a game with 10 in a 124-111 triple-overtime loss to SLCC last January 6.Namdar confirmed that spending a season in Price helped him improve his game and compete against “some of the best basketball talent in the country.” August 7, 2018 /Sports News – Local USU-Eastern Utah’s Namdar Signs With Division II Hawaii Pacificlast_img read more

Surfer rides mesmerizing 68-foot wave, sets world record for largest wave rode by a woman

first_imgOctober 3, 2018 /Sports News – National Surfer rides mesmerizing 68-foot wave, sets world record for largest wave rode by a woman Written by Beau Lundcenter_img FacebookTwitterLinkedInEmailiStock/Thinkstock(NEW YORK) — A Brazilian surfer set a world record for the largest wave ever surfed by a woman when she successfully glided through a terrifyingly enormous 68-foot wave off the coast of Portugal.Mesmerizing video of Maya Gabeira, 31, flying through the ginormous wave from trough to crest was captured by the World Surf League (WSL) videographers at their competition earlier this year in Nazare.On Monday, Gabeira was awarded the Guinness World Record for the largest wave surfed by a woman.Gabeira’s history-making ride is especially incredible after the surfer suffered a serious injury in 2013 while surfing at the same spot where she went on to break a world record.MORE: This fearless skateboarder has landed Tony Hawk’s infamous loop and she’s the 1st woman to do it“To set the world record has been a dream of mine for many years,” Gabeira said in a statement released by the WSL. “But of course, after the accident in Nazare 2013, it felt like a very distant dream.”“It’s been quite a journey,” Gabeira added, reflecting on how her “life changed like never before” after she first came to Nazare.Instead of running away from the surfing spot where she was injured five years ago, “I dedicated most of my time to the spot and I had years to focus on improving, on safety and on being around the best people to get where I wanted to be,” Gabeira said.“That time was priceless,” she added. “It taught me a lot and slowly I got back to my feet.”Sophie Goldschmidt, the WSL CEO said in a statement that Gabeira “exemplifies the courage, commitment, and progression of female athletes around the world,” adding that they were so proud to celebrate her Guinness World Record achievement.Copyright © 2018, ABC Radio. All rights reserved.last_img read more

St. Louis Blues capture first ever Stanley Cup title

first_imgYour #stlblues are champions!!! Celebrate with us Saturday at the 2019 Blues Championship Parade & Rally!The parade will start at noon at 18th St. & Market St., and end at Broadway & Market St. The rally will take place after at the Gateway Arch.More details to come. pic.twitter.com/zHu7lzT6XR— St. Louis Blues (@StLouisBlues) June 13, 2019Copyright © 2019, ABC Radio. All rights reserved. FacebookTwitterLinkedInEmailBruce Bennett/Getty Images(BOSTON) — It may have taken 52 years, but the St. Louis Blues finally did it.The team beat the Boston Bruins 4-1 in Game 7 of the Stanley Cup Final Wednesday night to take home their first championship in franchise history.The Blues’ victory will be celebrated back home in St. Louis, Missouri, where a parade is scheduled for the team on Saturday.“The parade will start at noon at 18th St. & Market St., and end at Broadway & Market St. The rally will take place after at the Gateway Arch,” the team tweeted Thursday morning. Written by June 13, 2019 /Sports News – National St. Louis Blues capture first ever Stanley Cup title Beau Lundlast_img read more

Davis Heslington Tied For 55th After First Day of Competition At Midwestern State

first_img Written by October 14, 2019 /Sports News – Local Davis Heslington Tied For 55th After First Day of Competition At Midwestern State Brad James FacebookTwitterLinkedInEmailWICHITA FALLS, Texas-Monday, Dixie State men’s golf returned to action at the Midwestern State Invitational at the Wichita Falls Country Club with Beaver High School product Davis Heslington representing the Trailblazers.Through Day 1 of competition, Heslington is tied for 55th place at +10 with Parker Doan of Texas-Permian Basin, Troy Lopez of Texas-Permian Basin, Harris Butler of Texas @ Tyler and Max Mitchell of Lubbock Christian.The individual leader through Day 1 is Jake Doggett of Midwestern State on his home course with a score of -8. The Trailblazers’ leader is Spencer Wallace, who is tied for 12th at even.Dixie State is 6th place overall at +14 and the host Midwestern State Mustangs are in first place in the team standings at -8. Tags: Davis Heslington/Dixie State Men’s Golf/Midwestern Statelast_img read more

Prep Sports Roundup: 8-10

first_img FacebookTwitterLinkedInEmailGirls SoccerNon-RegionPRICE, Utah-Allie Bridges and Jayci Jolley each scored as the Manti Templars blanked Carbon 2-0 Monday in non-region girls soccer action. Katie Larsen earned the shutout for the Templars. Tags: Prep Roundup Brad James August 11, 2020 /Sports News – Local Prep Sports Roundup: 8-10 Written bylast_img