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1.
Heliyon ; 9(8): e18597, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37560701

RESUMO

In small Alpine catchments, floods are mostly triggered by surface runoff generation during convective heavy precipitation events. Their magnitude also depends on the antecedent soil moisture content, which was shown in several previous studies. This study aims at understanding (a) which sites change their surface runoff response to rainfall events with high precipitation intensity under very moist pre-conditions to what extent and (b) on which site characteristics this depends on. Therefore, we conducted repeated rainfall simulation experiments (40-80 m2, 1 h, 100 mm h-1) at 20 sites in five Eastern Alpine areas and analyzed their results on the basis of soil-physical parameters derived from collected soil samples. The hay meadow sites reacted with a strong increase in surface runoff to reduced saturation deficits, the pasture sites showed a smaller but visible response. The forest sites had the highest water retention capacities. The change in the surface runoff response is a function of the saturation deficit at the beginning of the initial experiment (r = -0.58). The soil physical parameters, especially the fine pore fraction (r = 0.56), correlate with the difference of the total surface runoff coefficient between the initial and the repeated experiment. The fine pore fraction also shows a high correlation (r = -0.78) with the saturation deficit at the beginning of the initial experiment, although pores of this fraction were saturated during all experiments. (Non-quantifiable) Land use effects, which in turn influence the soil physical parameters, play an important role in explaining how the surface runoff response in the repeated rainfall simulation experiment differs from the initial experiment. The information on land use and soil characteristics allowed the sites to be categorized into four types in terms of surface runoff disposition and the increase in total surface runoff coefficient in the second rainfall simulation experiment.

2.
Sci Total Environ ; 742: 140588, 2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-32629267

RESUMO

Forests have an important regulating function on water runoff and the occurrence of shallow landslides. Their structure and composition directly influence the risk of hydrogeomorphic processes, like floods with high sediment transport or debris flows. Climate change is substantially altering forest ecosystems, and for Central Europe an increase in natural disturbances from wind and insect outbreaks is expected for the future. How such changes impact the regulating function of forest ecosystems remains unclear. By combining methods from forestry, hydrology and geotechnical engineering we investigated possible effects of changing climate and disturbance regimes on shallow landslides. We simulated forest landscapes in two headwater catchments in the Eastern Alps of Austria under four different future climate scenarios over 200 years. Our results indicate that climate-mediated changes in forest dynamics can substantially alter the protective function of forest ecosystems. Climate change generally increased landslide risk in our simulations. Only when future warming coincided with drying landslide risk decreased relative to historic conditions. In depth analyses showed that an important driver of future landslide risk was the simulated vegetation composition. Trajectories away from flat rooting Norway spruce (Picea abies (L.) Karst.) forests currently dominating the system towards an increasing proportion of tree species with heart and taproot systems, increased root cohesion and reduced the soil volume mobilized in landslides. Natural disturbances generally reduced landslide risk in our simulations, with the positive effect of accelerated tree species change and increasing root cohesion outweighing a potential negative effect of disturbances on the water cycle. We conclude that while the efficacy of green infrastructure such as protective forests could be substantially reduced by climate change, such systems also have a strong inherent ability to adapt to changing conditions. Forest management should foster this adaptive capacity to strengthen the protective function of forests also under changing environmental conditions.


Assuntos
Mudança Climática , Deslizamentos de Terra , Áustria , Ecossistema , Europa (Continente) , Florestas , Noruega , Árvores
3.
Antimicrob Agents Chemother ; 53(4): 1645-7, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19164153

RESUMO

We evaluated the MICs of isavuconazole (ISAV) against 96 isolates of Aspergillus species and 36 zygomycetes according to the methodology of the European Committee on Antimicrobial Susceptibility Testing. In addition, the in vitro activity was obtained for hyphal inocula. ISAV exhibited good antifungal activity against the tested isolates with the exception of Aspergillus niger and Mucorales. The in vitro activity of ISAV was comparable to that of voriconazole aside from Mucorales.


Assuntos
Antifúngicos/farmacologia , Aspergillus/efeitos dos fármacos , Testes de Sensibilidade Microbiana/métodos , Mucorales/efeitos dos fármacos , Nitrilas/farmacologia , Piridinas/farmacologia , Triazóis/farmacologia
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