A következő címkéjű bejegyzések mutatása: climate change. Összes bejegyzés megjelenítése
A következő címkéjű bejegyzések mutatása: climate change. Összes bejegyzés megjelenítése

2013. március 4., hétfő

Gimesi et al. (2012) Applied Ecology and Environmental Research

 
 
Abstract
When examining the ecological effects of climate change those databases which contain monitoring results of long-term time series have a key role. We used the daily Lepidoptera data of the Hungarian Plant Protection and Forestry Light Trap Network between 1962 and 2006 to analyse the influence of the change of temperature on the ecological dynamics of Lepidoptera. Using the quantile regression analyses we concluded that in the examined period, for the total number of individuals, seasonal phenomena shifted forward, however the days with higher diversity occurred over a shorter period. The analysis of the heat sums shows that the spring warming started earlier, although, at the same time the low quantiles of the captured Lepidoptera occurred at lower and lower heat sums over the years, while the heat sums at which the high quantiles of the number of Lepidoptera occurred showed a steady increase, meaning that the active period of the Lepidoptera community has expanded. A strong correlation was observed between diversity and temperature.
 
 
Keywords
biodiversity, quantile regression, climate change, Lepidoptera, light trap

Szentes et al. (2012) Central European Journal of Biology



Abstract
This study investigates how yellow bluestem affects biodiversity in a typical Pannonian grassland. Beta diversity (i.e. the finescale spatial variability of species compositions), was estimated by the realized number of species combinations sampled at various scales. Sampling was performed by a standard protocol. Presences of plant species were recorded along 52.2 m long belt transect of 1044 units of 0.05x0.05 m contiguous microquadrats. According to the results the massive presence of tested C4 grass significantly reduced species richness of the grassland. Beta diversity assessment revealed that 90% of species combinations were lost due to yellow bluestem invasion. Fine-scale spatial pattern analyses showed complete local extinctions of other species from microsites dominated by yellow bluestem. This local extinction is enhanced by the specific clonal architecture of this species and by the accumulation of litter. Other dominant grasses had no effect on fine scale diversity, i.e. they could coexist well with other elements of the local flora. This study presents currently developed microhabitat types, forecasts and also draws attention to the danger that climate warming will probably enhance the spread of this detrimental C4 species.



Keywords
Dominant grass, Plant neighbourhood diversity, Litter, Spatial association, Climate change

Bartholy et al. (2012) Applied Ecology and Environmental Research

Bartholy, J., Pongrácz, R., Nagy, J., Pieczka, I., Hufnagel, L. (2012): Regional climate change impacts on wild animals’ living territory in Central Europe. Applied Ecology and Environmental Research 10(2): 107-120.


Abstract
In this paper the projected future impact of climate change has been analyzed for the quality of living conditions of the European terrestrial vertebrates (amphibians, reptiles, birds, mammals) in the Carpathian Basin. According to the climate scenarios, warmer and drier climatic conditions are likely to occur in the Carpathian Basin by end of this century. Simultaneous analysis of climate parameters, climate simulations and animal range datasets enables us to evaluate the vulnerability of different European species to regional warming and climate change. The spatial climate analogy technique is used to analyze the estimated rapid change of the wild animals’ habitats and their northward migration. For the reference climate data of Debrecen is considered, and three spatial analogue regions are compared. The results suggest that generally a significant decline in habitats is very likely for most of the analyzed animal groups by the end of the 21st century. The largest rate of decline is estimated for birds. However, living conditions for reptiles may improve in the future due to the warmer and drier climatic conditions, which are favourable for these species.


Keywords
spatial analogy, climate change, vertebrates species, ecology, area dynamics

Sipkay et al. (2012) Biologia

Csaba Sipkay, Tihamér Kiss-Keve, Csaba Vadadi-Fülöp, Réka Homoródi and Levente Hufnagel (2012): Simulation modeling of phytoplankton dynamics in a large eutrophic river, Hungary — Danubian Phytoplankton Growth Model (DPGM). Biologia(Bratislava) Section Botany, 67(2): 323-337. DOI: 10.2478/s11756-012-0004-2


Abstract
Ecological models have often been used in order to answer questions that are in the limelight of recent researches such as the possible effects of climate change. The methodology of tactical models is a very useful tool comparison to those complex models requiring relatively large set of input parameters. In this study, a theoretical strategic model (TEGM) was adapted to the field data on the basis of a 24-year long monitoring database of phytoplankton in the Danube River at the station of Göd, Hungary (at 1669 river kilometer - hereafter referred to as “rkm”). The Danubian Phytoplankton Growth Model (DPGM) is able to describe the seasonal dynamics of phytoplankton biomass (mg L−1) based on daily temperature, but takes the availability of light into consideration as well. In order to improve fitting, the 24-year long database was split in two parts in accordance with environmental sustainability. The period of 1979–1990 has a higher level of nutrient excess compared with that of the 1991–2002. The authors assume that, in the above-mentioned periods, phytoplankton responded to temperature in two different ways, thus two submodels were developed, DPGM-sA and DPGM-sB. Observed and simulated data correlated quite well. Findings suggest that linear temperature rise brings drastic change to phytoplankton only in case of high nutrient load and it is mostly realized through the increase of yearly total biomass.


Keywords
climate change, ecological model, nutrient load, tactical modeling