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Opis: Subterranean habitats are known for their rich endemic fauna and high vulnerability to disturbance. Many methods and techniques are used to sample the biodiversity of terrestrial invertebrate fauna in caves, among which pitfall trapping remains one of the most frequently used and effective ones. However, this method has turned out to be harmful to subterranean communities if applied inappropriately. Traditionally, pitfall traps have been placed in caves solely on the ground. Here we present an optimized technique of pitfall trapping to achieve a balance between sampling completeness and minimal disturbance of the fauna in the cave. Monthly we placed traps for two days in two parallel sets, a ground trap and an upper one−just below the ceiling−along the cave. In the upper set, about 10% additional species were recorded compared to the ground set. Greater species diversity in the cave was the consequence of both the increased sampling effort and the amplified heterogeneity of sampled microhabitats. In caves sampled by traditional pitfall trapping, overlooked species may be a consequence of methodological biases, leading to lower biodiversity estimates. In our research, incidence-based estimations mostly surpassed abundance-based ones and predicted 95% coverage of the species richness within about two years of sampling. The sampling used contributes at the same time to both the more effective and less invasive inventory of the subterranean fauna. Thus, it may serve as an optional sampling to achieve optimal balance between required data for biodiversity and ecological studies, and nature conservation goals.
Ključne besede: biodiversity estimators, microhabitats, sampling effort, sampling techniques, biological inventories
Objavljeno v DKUM: 30.10.2017; Ogledov: 1014; Prenosov: 372
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Opis: Most organisms are able to survive shorter or longer exposure to sub-zero temperatures. Hypothetically, trogloxenes characterized as not adapted, and troglophiles as not completely adapted to thermally stable subterranean environment, have retained or partially retained their ability to withstand freezing, while most troglobionts have not. We tested this hypothesis experimentally on 37 species inhabiting caves in Slovenia, analyzing their lower lethal temperatures in summer and winter, or for one season, if the species was not present in caves during both seasons. Specimens were exposed for 12 hrs to 1°C-stepwise descending temperatures with 48 hr breaks. In general, the resistance to freezing was in agreement with the hypothesis, decreasing from trogloxenes over troglophiles to troglobionts. However, weak resistance was preserved in nearly all troglobionts, which responded in two ways. One group, withstanding freezing to a limited degree, and increasing freezing tolerance in winter, belong to the troglobionts inhabiting the superficial subterranean habitats. The other group, which equally withstand freezing in summer and winter, inhabit deep subterranean or other thermally buffered subterranean habitats. Data on cold resistance can thus serve as an efficient additional measure of adaptation to particular hypogean environments.
Ključne besede: endemites, superficial subterranean habitats, trogloxenes, troglophiles, troglobionts
Objavljeno v DKUM: 04.08.2017; Ogledov: 1106; Prenosov: 342
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Opis: Kratki priročnik uspešnega študija; napotki za načrtovanje in ocenjevanje uspešnosti lastnega študija
Ključne besede: visoko šolstvo, študij, priročniki
Objavljeno v DKUM: 30.12.2015; Ogledov: 773; Prenosov: 46
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Opis: Eleven of the most important terrestrial invertebrate species in Slovenian caves were analyzed for differences in their fresh and dry biomass, energy content and carbon bulk during winter. These data were combined with the species abundance in 54 caves and adits in order to estimate their organic carbon bulk and carbon input into these habitats. In Central European caves, Troglophilus cavicola, T. neglectus, Faustina illyrica, Amilenus aurantiacus and Scoliopteryx libatrix are the most important vectors of carbon between the epigean and hypogean habitats. In contrast to the general assumption, carbon total contribution to caves via dead bodies is only 0.15% of total migratory biomass, and it is not directly available to troglobionts because of infection with entomopathogenic fungi. In winter, together with predated migratory specimens, carbon input does not exceed 0.3% of the total migratory biomass. This situation should be carefully examined in every karstic region inhabited by distinctive fauna.
Ključne besede: biomass, carbon flux, caves, non-troglobiotic species, organic carbon, respiration
Objavljeno v DKUM: 21.12.2015; Ogledov: 1308; Prenosov: 83
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Opis: In the present paper, further findings of harvestmen in the Sub Mediterranean region of Slovenia are presented, and comments on some actual problems with the species are added. With the exception of the possible discovery of a troglobitic species in the region, all species living there have presumptively been recorded. With the exclusion of Trogulus gr. nepaeformis and T. gr. tricarinatus, where more species are expected, 34 species and one subspecies have been found in the region. About 20 opilionid species are typical of the region; the others occur in the marginal habitats bordering other zoogeographical regions.
Ključne besede: zoologija, biogeografija, pajkovci, suhe južine, Opiliones, Arachnida, suhe južine, Slovenija, submediteran, zoology, biogeography, Opiliones, arachnids, harvestmen, Slovenia, Sub Mediterranean
Objavljeno v DKUM: 10.07.2015; Ogledov: 1503; Prenosov: 48
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