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Sipkay C.,Hungarian Academy of Sciences | Kiss-Keve T.,Hungarian Academy of Sciences | Vadadi-Fulop C.,Eötvös Loránd University | Homorodi R.,ALOKI Applied Ecological Research and Forensic Institute Ltd. | Hufnagel L.,Hungarian Academy of Sciences
Biologia | Year: 2012

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. © 2012 Versita Warsaw and Springer-Verlag Wien.

Ferenczy A.,Corvinus University of Budapest | Petranyi G.,Corvinus University of Budapest | Hirka A.,Forest Research Institute | Szaboki C.S.,Forest Research Institute | And 7 more authors.
Applied Ecology and Environmental Research | Year: 2010

Climate change is one of the biggest environmental problems of the 21st century. The most sensitive indicators of the effects of the climatic changes are phenological processes of the biota. The effects of climate change which were observed the earliest are the remarkable changes in the phenology (i.e. the timing of the phenophases) of the plants and animals, which have been systematically monitored later. In our research we searched for the answer: which meteorological factors show the strongest statistical relationships with phenological phenomena based on some chosen plant and insect species (in case of which large phenological databases are available). Our study was based on two large databases: one of them is the Lepidoptera database of the Hungarian Plant Protection and Forestry Light Trap Network, the other one is the Geophytes Phenology Database of the Botanical Garden of Eötvös Loránd University. In the case of butterflies, statistically defined phenological dates were determined based on the daily collection data, while in the case of plants, observation data on blooming were available. The same meteorological indicators were applied for both groups in our study. On the basis of the data series, analyses of correlation were carried out and a new indicator, the so-called G index was introduced, summing up the number of correlations which were found to be significant on the different levels of significance. In our present study we compare the significant meteorological factors and analyse the differences based on the correlation data on plants and butterflies. Data on butterflies are much more varied regarding the effectiveness of the meteorological factors. © 2010, ALÖKI Kft., Budapest, Hungary.

Gimesi L.,University of Pécs | Homorodi R.,ALOKI Applied Ecological Research and Forensic Institute Ltd | Hirka A.,Forest Research Institute | Szaboki C.,Forest Research Institute | Hufnagel L.,Hungarian Academy of Sciences
Applied Ecology and Environmental Research | Year: 2012

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. © 2012, ALÖKI Kft., Budapest, Hungary.

GergoCS V.,Corvinus University of Budapest | Garamvolgyi A.,Corvinus University of Budapest | Homorodi R.,ALOKI Applied Ecological Research and Forensic Institute Ltd | Hufnagel L.,Hungarian Academy of Sciences
Applied Ecology and Environmental Research | Year: 2011

Oribatid mites are one of the most abundant groups of the ground-dwelling mesofauna. They can be found in almost every terrestrial habitat all over the world and they are characterized by great species richness and great number of individuals. In spite of that not enough is known about their behaviour on community level and their spatial and temporal pattern in different habitats of the world. In our present study the seasonal behaviour of oribatid mite communities was analysed in three types of microhabitats in a temperate deciduous forest: in leaf litter, soil and moss. Samples were collected at a given site in a year and a half and the oribatid mite communities living there were studied on genus level along with the changes of meteorological factors characteristic of the area. The results show that corresponding to similar previous researches, the communities in our study do not have a seasonally changing, returning pattern either. Based on this, we can conclude that climatic differences and differences in other seasonally changing factors between the seasons do not have a significant role in the annual change of communities. Besides that we discovered that the communities of the three microhabitats are not completely the same. It is the oribatid mite community of the moss which differs mostly from communities in the leaf litter and in the soil. Our study calls attention among others to the fact that compositional changes of the oribatid mite communities living all over the world and their causes are unclear to date. © 2011, ALÖKI Kft., Budapest, Hungary.

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