12 research outputs found
Effects of TemperatureâClimate Patterns on the Production of Some Competitive Species on Grounds of Modelling
Climate change has serious effects on the setting
up and the operation of natural ecosystems. Small increase
in temperature could cause rise in the amount of some
species or potential disappearance of others. During our
researches, the dispersion of the species and biomass
production of a theoretical ecosystem were examined on
the effect of the temperatureâclimate change. The answers
of the ecosystems which are given to the climate change
could be described by means of global climate modelling
and dynamic vegetation models. The examination of the
operation of the ecosystems is only possible in huge centres
on supercomputers because of the number and the
complexity of the calculation. The number of the calculation
could be decreased to the level of a PC by considering
the temperature and the reproduction during modelling a
theoretical ecosystem, and several important theoretical
questions could be answered
Comparative Assessment of Climate Change Scenarios Based on Aquatic Food Web Modeling
In the years 2004 and 2005, we collected samples of phytoplankton, zooplankton, and macroinvertebrates in an artificial small pond in Budapest (Hungary). We set up a simulation model predicting the abundances of the cyclopoids, Eudiaptomus zachariasi, and Ischnura pumilio by considering only temperature and the abundance of population of the previous day. Phytoplankton abundance was simulated by considering not only temperature but the abundances of the three mentioned groups. When we ran the model with the data series of internationally accepted climate change scenarios, the different outcomes were discussed. Comparative assessment of the alternative climate change scenarios was also carried out with statistical methods
Effect of sampling effort and sampling frequency on the composition of the planktonic crustacean assemblage: a case study of the river Danube
Although numerous studies have focused
on the seasonal dynamics of riverine zooplankton,
little is known about its short-term
variation. In order to examine the effects of sampling
frequency and sampling effort, microcrustacean
samples were collected at daily intervals
between 13 June and 21 July of 2007 in a parapotamal
side arm of the river Danube, Hungary.
Samples were also taken at biweekly intervals
from November 2006 to May 2008. After presenting
the community dynamics, the effect of
sampling effort was evaluated with two different
methods; the minimal sample size was also estimated.
We introduced a single index (potential
dynamic information loss; to determine the potential
loss of information when sampling frequency
is reduced. The formula was calculated for the total abundance, densities of the dominant taxa, adult/larva ratios of copepods and for two different diversity measures. Results suggest that abundances may experience notable fluctuations even within 1 week, as do diversities and adult/larva ratios
Climate change and freshwater zooplankton: what does it boil down to?
Recently, major advances in the climateâzooplankton interface have been made some of which appeared to receive much attention in a broader audience of ecologists as well. In contrast to the marine realm, however, we still lack a more holistic summary of recent knowledge in freshwater. We
discuss climate change-related variation in physical and biological attributes of lakes and running waters, high-order ecological functions, and subsequent alteration
in zooplankton abundance, phenology, distribution, body size, community structure, life history parameters, and behavior by focusing on community level responses. The adequacy of large-scale climatic indices in ecology has received considerable support and provided a framework for the interpretation of community and species level responses in freshwater zooplankton. Modeling perspectives deserve particular consideration, since this promising stream of
ecology is of particular applicability in climate change
research owing to the inherently predictive nature of
this field. In the future, ecologists should expand their
research on species beyond daphnids, should address
questions as to how different intrinsic and extrinsic
drivers interact, should move beyond correlative
approaches toward more mechanistic explanations,
and last but not least, should facilitate transfer of
biological data both across space and time
Water velocity modeling can delineate nearshore and main channel plankton environments in a large river
Increasing water temperature triggers dominance of freshwater picoplankton
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