Hartel T.,Mihai Eminescu Trust |
Hartel T.,Ovidius University |
Hartel T.,Netherlands Center for Biodiversity Naturalis |
Bancila R.,Ovidius University |
And 2 more authors.
Freshwater Biology | Year: 2011
1.Habitat loss is a major driver of biodiversity decline worldwide. Temporary waterbodies are especially vulnerable because they are sensitive both to human impact and to climatic variations. Pond-breeding amphibians are often dependent on temporary waterbodies for their reproduction, and hence are sensitive to loss of temporary ponds. 2.Here we present the results of a 5-year study regarding the use of temporary aquatic habitats by amphibians in a hydrologically modified area of Eastern Europe (Romania). The annual number of aquatic habitats varied between 30 and ~120. Each aquatic habitat was characterised by a number of variables such as: 'type' (pond, drainage ditch and archaeological ditch), 'hydroperiod' (number of weeks the ponds were filled in a given year), 'depth' (cm), 'area' (m2) and the density of predatory insects ('predation'). The turnover rate for each amphibian species for each wetland was calculated based on the pond occupancy. 3.Eight amphibian species were recorded from the aquatic habitats. Hydroperiod was the most important variable, positively influencing wetland use by amphibians and their reproductive success. Most species preferred drainage ditches for reproduction, and the reproductive success was highest in this habitat type every year. For most of the species, the local extinction rate was higher than the colonisation rate in the first 4years, but the situation reversed in the last year of the study when wetland use by amphibians sharply increased because of high rainfall. 4.This study confirms the importance for amphibians of maintaining and managing aquatic habitat diversity at small spatial scales. Man-made aquatic habitats such as drainage ditches may be important habitats for amphibians, and this should be considered in restoration activities. © 2011 Blackwell Publishing Ltd.
Dogaru D.,National Commission for Nuclear Activities Control |
Niculae O.,National Agency for Radioactive Waste |
Terente M.,Institute of Speleology Emil Racovita |
Jinescu G.,Polytechnic University of Bucharest |
Duliu O.G.,University of Bucharest
Romanian Reports in Physics | Year: 2010
This paper aims at presenting the geological aspects of the Saligny site necessary for developing the conceptual model of the repository as well as the associated mathematical model which describe the transfer of radio-nuclides from radioactive waste disposal system to the aquifer. The transfer time of some important radio-nuclides through the geological layers of the Saligny site, as a complementary safety indicator, is herein calculated. The transfer time of 137Cs, 90Sr 63Ni, 59Ni and 99Nb is derived from the time difference when a radionuclide reaches the highest value of concentration into two adjacent compartments. It is compared with the half-life of radio-nuclides in order to assess the role of geological layers of the site to delay the transfer of radio-nuclides in the surrounding environment.
Sandor M.S.,University of Agricultural Sciences and Veterinary Medicine, Cluj-Napoca |
Brad T.,Institute of Speleology Emil Racovita |
Maxim A.,University of Agricultural Sciences and Veterinary Medicine, Cluj-Napoca |
Toader C.,University of Agricultural Sciences and Veterinary Medicine, Cluj-Napoca
Notulae Botanicae Horti Agrobotanici Cluj-Napoca | Year: 2011
A mesocosm study was conducted in order to evaluate the effects of short-term rainfall and temperature variation on soil microbial biomass and bacteria to fungi ratio. In addition, the relation between the decomposition process of two organic fertilizers, cattle manure and barley straw, and the activity of soil microbial biomass was also studied. In order to assess the effect of biological activity on soil fertility the dynamics of soil pH, N-NO3-, N-NH4+, Corg and Nt during plant growing season was measured. The results suggest that short-term variation of climate had a significant effect on microbial biomass with dry periods distinguished by a reduced microbial biomass compared to wet periods. The ratio bacteria to fungi seems also to be sensitive to variations in rainfall and temperature regime, however further studies are required to draw a definitive conclusion. Regarding the type of fertilizer used, the straw treatments showed higher microbial biomass than the manure treatments, but higher decomposition rate was observed in manure fertilized soil. The effect of soil biological activity on soil pH was limited for both manure and straw treatments while the changes of the soil nitrate amounts are related to the microbial biomass. The study indicates that nitrate immobilization and mineralization processes are influenced by meteorological conditions and microbial biomass dynamics. In contrast, soil organic carbon and total nitrogen did not seem to be affected by variations in temperature, rainfall and microbial activity.
Kumaresan D.,University of East Anglia |
Wischer D.,University of East Anglia |
Stephenson J.,University of Warwick |
Hillebrand-Voiculescu A.,Institute of Speleology Emil Racovita |
Murrell J.C.,University of East Anglia
Geomicrobiology Journal | Year: 2014
Discovered in 1986, Movile Cave is an unusual cave ecosystem sustained by in situ chemoautotrophic primary production. The cave is completely isolated from the surface and the primary energy sources are hydrogen sulfide and methane released from hydrothermal fluids. Both condensation and acid corrosion processes contribute to the formation of Movile Cave. Invertebrates, many of which are endemic to Movile Cave, are isotopically lighter in both carbon and nitrogen than surface organisms, indicating that they derive nutrition from chemoautotrophic primary producers within the cave. Here we review work on the microbiology of the Movile Cave ecosystem, with particular emphasis on the functional diversity of microbes involved in sulfur, carbon and nitrogen cycling, and discuss their role in chemosynthetic primary production. © 2014 Copyright Taylor and Francis Group, LLC.
Bancila R.,Institute of Speleology Emil Racovita |
Bancila R.,Ovidius University |
Bancila R.,Netherlands Center for Biodiversity Naturalis |
Van Gelder I.,Netherlands Center for Biodiversity Naturalis |
And 3 more authors.
Journal of Zoology | Year: 2010
We measured the level of fluctuating asymmetry (FA) in head shape, head scalation and femoral pores in two lizard species (Podarcis bocagei and Podarcis hispanica) from 13 islands and 15 mainland localities in the Ria de Arosa archipelago of north-western Spain. Given the recent geological history of the region, the degree of isolation to which lizard populations have been subjected can be ordered along a spatio-temporal gradient, yielding the following hypotheses to be tested: FA will be higher (1) in island populations than in mainland populations; (2) on remote islands than on islands close to the mainland; (3) on small islands than on large islands. Molecular genetic data suggest that P. hispanica is autochthonous in the Ria de Arosa, whereas P. bocagei is a more recent arrival. Therefore, we predict also (4) a higher level of FA in P. hispanica than in P. bocagei. Statistically significant results were obtained for head-shape asymmetry, supporting the second and the fourth hypotheses. With an overall meristic asymmetry index, none of the hypotheses were corroborated, whereas for certain independent meristic traits, the first, the third and the fourth hypotheses were partially supported. Both head shape and meristic traits constitute precise measures of FA, but FA is more convincingly expressed in head shape and in single meristic traits than in overall meristic traits asymmetry. We conclude that FA reflects population isolation and may be a good indicator of developmental instability. It seems worthwhile to test for FA in a landlocked system under environmental and genetic stress, for the purpose of conservation biological assessments. © 2010 The Authors. Journal of Zoology © 2010 The Zoological Society of London.