25 research outputs found
Long-term fertilizer regimes have both direct and indirect effects on arthropod community composition and feeding guilds
Ecological segregation drives fine-scale cytotype distribution of Senecio carniolicus in the Eastern Alps
In order to uncover patterns and processes of segregation of co-existing cytotypes, we investigated a zone in the eastern Alps (Austria) where diploid and hexaploid individuals of the alpine herb Senecio carniolicusWilld. (Asteraceae) co-occur. Linking the fine-scale distribution of cytotypes to environmental and spatial factors revealed segregation along an ecological gradient, which was also reflected in the cytotype-associated plant assemblages. Compared to diploids, hexaploids are found in more species-rich and denser communities. This may be due to their better competitive ability and lower tolerance of abiotic stress compared to the diploids. The lack of any intermediate cytotypes suggests the presence of strong reproductive isolation mechanisms, whose nature is, however, elusive
Different temperature perception in high-elevation plants: new insight into phenological development and implications for climate change in the alpine tundra
Intraseasonal climate and habitat-specific variability controls the flowering phenology of high alpine plant species
The Response of the Alpine Dwarf Shrub Salix herbacea to Altered Snowmelt Timing: Lessons from a Multi-Site Transplant Experiment
Snow redistribution for the hydrological modeling of alpine catchments
Modeling snow redistribution by wind and avalanches in hydrological studies in alpine catchments is important, as the spatial variability of the snow cover has an impact on timing and magnitude of the snowmelt runoff. Disregarding snow redistribution in models can lead to the formation of ‘snow towers,’ i.e., multi-year accumulation of snow at high elevations and an incorrect water balance. The reviewed approaches to deal with snow redistribution in hydrological models were first broadly grouped by the represented physical processes: (1) the correction of the precipitation input data to account mainly for preferential deposition, (2) the description of all wind-driven processes based on wind field data, (3) the description of gravitational transports and/or wind-driven processes based on topographic information, and (4) the statistical description of the variability of the snow water equivalent (SWE) to account for all types of snow redistribution. The review further assessed the implementation of these approaches in physically based and bucket-type hydrological models. Generally, snow redistribution consideration has improved the simulation of snow patterns and SWE and consequently the prediction of discharge in mountain catchments worldwide. Snow redistribution approaches still have some limitations and a large gap exists between the knowledge and processes in highly detailed physically based snow models and the widely used bucket-type hydrological models used for water resources and climate change studies. There is a real need to bridge this gap using the knowledge earned by snow redistribution modeling with established physically based models to develop more conceptual approaches for the application in bucket-type models
Long-term geobotanical observations of climate change impacts in the Scandes of West-Central Sweden
Responses of flowering phenology of snowbed plants to an experimentally imposed extreme advanced snowmelt
In snowbed habitats, characterized by a
long-lasting snow cover, the timing of snowmelt can
be included among the major factors controlling plant
phenology. Nevertheless, only a few ecological studies
have tested the responses of flowering phenology
of species growing in very late snow-free habitats to an
advanced snowmelt (AS) date. The aim of this study
was to determine the impacts of an extremely earlier
melt-out of snow on flowering phenology of vascular
plant species inhabiting an alpine snowbed. The study
was conducted in the high Gavia Valley (Italy,
2,700 m a.s.l.). On 30th May 2012, we removed
manually the snow cover and set up an experiment
with 5 AS and 5 control plots. Phenological observations
of the most abundant vascular species were
conducted every 4–6 days. Moreover, we calculated
cumulative soil temperature and recorded the mortality
of reproductive structures of three species. For
several species flowering occurred earlier, and the
prefloration period was extended in the AS treatment
in comparison with the control. For the majority of
species, cumulative soil temperatures in the AS
treatment and the control were comparable, confirming
that temperature exerts the main control on the
flowering of the species inhabiting snowbeds. Earlier
flowering species resulted more affected by an AS date
in comparison with later flowering species. The
mortality of reproductive structures did not increase
in the AS treatments in comparison with the control
suggesting that few and weak frost events in late
spring do not affect the survival of reproductive
structures of the species studied