Annual activity of two endemic beetles (Carabidae) at the edge between fell-field and moorland on a sub-Antarctic island (original) (raw)
Related papers
Biological Communities Of Keller Peninsula, King George Island - Antarctica
To carry out this work, we surveyed all the ice free areas on the Keller Peninsula, King George Island – Antarctica in 15 years visiting the area. The plant communities were mapped and identified during the field activities of the Brazilian Antarctic Program. In the vegetated areas, quadrats (20 x 20cm) were studied in order to identify the communities and describe the structure. The study of the vegetal communities followed the usual methodology for the Antarctic studies, based mainly on the structure, the fauna and flora species found in the communities. We identified six (6) areas of special scientific interest, with the objective to have them better preserved in order to ensure the biodiversity richness of the region, within Antarctic standards. It was possible to observe that the most interesting communities were located mainly on coastal areas, being basically represented by mat-type moss formations. Towards the interior of the peninsula, stretching for about 600 meters, there...
Polar Biology, 1999
On the sub-Antarctic island of South Georgia two species of predatory beetle, Trechisibus antarcticus and Oopterus soledadinus (Coleoptera, Carabidae), were accidentally introduced. The colonisation process oers unique opportunities for testing ecological hypotheses in the ®eld. As a basis for such studies, the spatial dynamics of the two species in the coastal lowland around Stromness Bay and Cumberland Bay were monitored during the period 1988±1996. Data are presented on the expansion of the two species and on the thermal characteristics of the tussock-forming grass Parodiochloā abellata, which dominates the coastal lowlands. The largest expansion was shown by T. antarcticus, occurring as two populations in the Stromness Bay area. The origin of one of the populations, discovered in 1982, is Husvik Harbour, from where the species has colonised the central part of Stromness Bay. The second population, discovered in 1988 at Harbour Point, is invading the northern part of the area around Stromness Bay. Up to the present, three populations of O. soledadinus have been discovered. One population was found in 1988 at Husvik Harbour, co-existing with T. antarcticus, from where it is slowly expanding its distribution into the coastal zone. A second, very small, population of O. soledadinus was found in 1996 at Jason Harbour (Cumberland West Bay). The largest population of O. soledadinus, ®rst reported in 1963, inhabits the area around Grytviken and King Edward Point (Cumberland East Bay), where it is the sole carabid species. The tussock grass vegetation oers a highly stable thermal environment compared with the more variable surroundings. Together with an ample food supply in the form of small arthropods and beetle larvae, and a vacant niche for arthropod predators, the benign microclimate of the tussock vegetation may explain the success of these predator introductions. Results of ®eld observations on population parameters of the carabids, and laboratory measurement of egg production indicate the potential for large-scale co-existence.
Kerguelen Islands: a living laboratory to understand the benthic biodiversity of the Antarctic
The high proportion of brooding (50 to 70% depending on phyla) compared with broadcaster species among invertebrates living along the coast of the Southern Ocean has been traditionally interpreted as an adaptation to local environmental conditions. Currently, however, species with a planktotrophic developmental mode are ecologically dominant along coastal areas, in terms of abundance of individuals. The fact that Kerguelen Island is inhabited by such species and that the French base Port-aux-Français, with its equipped marine laboratory, made it possible to address questions as to why are there so many brooders in the coastal waters of the Southern Ocean and if the apparent ecological success of broadcasters related to their developmental mode. We argue that the present shallow Antarctic benthic invertebrate fauna is the result of two processes acting at different temporal scales. First, the high proportion of brooding species compared with coastal communities elsewhere corresponds ...
Polar Biology, 2017
Barrientos Island is a small islet in the South Shetland archipelago frequently visited by Antarctic tourists. Collembola were recently used in another study developed in this site to assess the environmental conditions of two paths used by visitors, showing the importance of this soil faunal community. This motivated the realization of the first comprehensive census of Collembola from Barrientos Island. Fifty-six samples were recorded over three seasons, 2011-2013, from eight different substrate types. During the last campaign, 39 soil samples were also taken to analyze different physical, chemical, biological, microbiological, and biochemical variables in order to put into relation all these environmental conditions with abundance and richness of Collembola species. A total of ten species were recorded, all of them previously cited from Antarctica. The native species Cryptopygus antarcticus antarcticus Willem (Collembola: Isotomidae) is the most abundant in the island. Two cosmopolitan species-Hypogastrura viatica (Tullberg) (Hypogastruridae) and Mesaphorura macrochaeta Rusek (Tullbergiidae)-were also identified. Many of the species on this island can be considered as eurytopic, appearing in most of the analyzed substrate types. Collembola distribution was found to be influenced by elevation and, to a lesser extent, by phosphorous content and slope. Other variables that are usually cited in the specialized literature did not significantly influence the Collembola distribution in this island. Our results show that the distribution and abundance of Collembola in Antarctic locations is not directly dependent on a single factor. The environmental characteristics of each studied site will determine what factors are driving the composition and structure of this soil community.