Abstract: In the years 2004 and 2005 we collected samples of phytoplankton, zooplankton and macroinvertebrates in an artificial small pond in Budapest. We set up a simulation model predicting the abundance of the cyclopoids, Eudiaptomus zachariasi and Ischnura pumilio by considering only temperature as it affects the abundance of population of the previous day. Phytoplankton abundance was simulated by considering not only temperature, but the abundance of the three mentioned groups. This discrete-deterministic model could generate similar patterns like the observed one and testing it on historical data was successful. However, because the model was overpredicting the abundances of Ischnura pumilio and Cyclopoida at the end of the year, these results were not considered. Running the model with the data series of climate change scenarios, we had an opportunity to predict the individual numbers for the period around 2050. If the model is run with the data series of the two scenarios UKHI and UKLO, which predict drastic global warming, then we can observe a decrease in abundance and shift in the date of the maximum abundance occurring (excluding Ischnura pumilio, where the maximum abundance increases and it occurs later), whereas under unchanged climatic conditions (BASE scenario) the change in abundance is negligible. According to the scenarios GFDL 2535, GFDL 5564 and UKTR, a transition could be noticed.

Keywords: hydrobiology, community, ecosystem, climate change

Abstract: Cell-size here refers to mean length, as only the lengths of bacterial cells were measured in this study. Cell breadths were not measured, hence calculation of biovolume and biomass was not possible. In this study, the mean cell-lengths of heterotrophic bacterioplankton as well as their relation with environmental (water-quality) variables were analyzed for two years in the main river Cauvery and its four important upstream tributaries from February 2000 to January 2002. The initial hypothesis that all the five water courses have similar bacterial mean cell-lengths was rejected, because mean cell-lengths of free living and particle bound planktonic bacteria was more and was also significantly different in the river Lakshmanatheertha, when compared to the other four water courses studied. Season-wise grouped data revealed that, the mean cell-length of free-living bacteria was significantly less in winter season as compared to rainy and summer seasons during the second year of study only in the river Lakshmanatheertha. A correlation (r) analysis between the mean cell-lengths of heterotrophic bacteria and environmental (water-quality) variables revealed significant relations. Also with the help of regression analysis (r2) the effect of some important environmental variables on the mean cell-length of heterotrophic bacteria has been discussed in the light of recent investigations in the field of fresh water microbial ecology.

Keywords: bacterial cell length, planktonic food web, environmental factors, bacterial production

Abstract: The flow of organisms in lotic environments is known as Macroinvertebrate Stream Drift: a phenomenon that has long fascinated freshwater ecologists. Stream-dwelling organisms are often transported downstream in the water column in substantial numbers. Because they have limited swimming ability and the movement is apparently passive, the process is referred to as drift. This study assesses drift fauna in a lotic environment upstream from the Australian inland city of Wagga Wagga, looking at the abundance and diversity of invertebrates over sampling times spanning daytime, dusk and nighttime. Not only did the abundance of individual macroinvertebrates increase from daytime to nighttime, but the diversity of taxa also increased. Although not as sharp as the increase in individual numbers, the diversity of taxa however did more than double from the dusk sampling period to the first night sampling period.

Keywords: lotic; macroinvertebrate; drift; taxa

Abstract: Cochin backwaters, a micro tidal estuary, undergo a characteristic transformation from a riverdominated system during summer monsoon to a tide-dominant system during pre-monsoon season. The present study observes that as the river flow weakens after monsoon, the flushing of the estuary diminishes and the nitrogen and phosphorous loadings through anthropogenic activities (industries) and sediment re-suspension alter the nutrient stoichiometry substantially. The increased tidal activity during pre-monsoon changes the estuary into a vertically mixed, eutrophic and flow-restricted system supporting an enhanced organic production. This implies that monsoon-induced hydrology plays an important role in regulating the nutrients, secondary production and even the migrant fauna of the estuary. The system is delicately poised, as continuous release of pollutants including nutrients into this estuary would suppress fish and shell fish production, where only pollution tolerant species can exist.

Keywords: nutrient stoichiometry, Cochin backwaters, Southwest coast of India

Abstract: A biomonitoring study was carried out at Kanewal reservoir, an internationally important wetland listed in Asian Directory of Wetlands, designated as a “Wetland of National Importance” and a proposed community reserve of Gujarat State, India, to ascertain the degree of trace element contamination. The study focused on assessment of trace element contamination in certain aquatic macrophytes to be used as biomonitors, in comparison with water and sediments (abiotic monitor) for heavy metal pollution. Good information was provided by analyzing the roots, stems and leaves of native aquatic plants (biomonitors) represented by seven species: Eichhornia crassipes, Echinochloa colonum, Hydrilla verticillata, Ipomoea aquatica, Nelumbo nucifera, Typha angustata and Vallisneria spiralis, along with surface sediments and water, were analyzed for Cd, Co, Cu, Ni, Pb and Zn contamination. The highest concentrations of the trace elements were measured in Eichhornia crassipes and the lowest in Nelumbo nucifera. Based on the concentration and toxicity status observed in the lake's vegetation, the six metals are arranged in the following decreasing order: Zn > Cu > Ni > Cd > Co > Pb. Compared with the standard, normal and critical toxicity range in plants, the detected value of Pb falls within normal range, while that of other elements were within the critical range. However, Zn and Cu showed the highest concentration and alarming toxicity levels, which are considered as one of the most hazardous pollutants in Kanewal reservoir. Certain species of aquatic macrophytes are also proposed as biomonitors (and/or biofilters) such as Eichhornia crassipes and Typha angustata, which are the two most useful species in biomonitoring studies due to their ability to accumulate elements in high concentration in the roots and its availability throughout the year. The results showed the significant difference in accumulation of metals like Zn, Cu and Ni in different plant organs, which showed more accumulation in roots than that of stems and leaves. High positive correlation between combinations of different metal pairs in plant’s root, stem or leaf system was established.

Keywords: aquatic macrophytes, trace elements, lake contamination, Kanewal, Community Reserve (KCR)

Abstract: In view of the environmental problems generated by large-scale production of fly ash, increasing attention is now being paid to the recycling of fly ash as a good source of nutrients. Because availability of many nutrients is very low in fly ash, available ranges of such nutrients must be improved to increase the effectiveness of fly ash as a soil amendment. In our experiment, we assessed the possibility of increasing total nitrogen, total phosphorus, total potassium and micronutrients in fly ash through vermicomposting. Fly ash was mixed with cow dung at 1:3, 1:1, and 3:1 ratios and incubated with Eudrilus eugeniae for 60 days. The concentration of above said macro and micronutrient was found to increase in the earthworm-treated series of fly ash and cow dung combinations compared with the fly ash alone. This helped to transform considerable amounts of total nitrogen, total phosphorus, total potassium and micronutrients from fly ash into more soluble forms and thus resulted in increased bioavailability of the nutrients in the vermicomposted series. Among different combinations of fly ash and cow dung, nutrient availability was significantly higher in the 1:3 fly ash to cow dung treatment compared with the other treatments.

Keywords: mass reduction, nutrient, fly ash

Abstract: Higher atmospheric CO2 concentration may influence positively plant production once the substrate for photosynthesis and gradient increase between the ambient air and mesophyll cells. Plants respond not only to change in surrounding CO2 concentration, but to modifications of their microenvironment. Modelling approach was applied to investigate the relation of plants and some elements of microclimate to increased CO2 levels. Other influences of global warming included in the study indirectly by running warmer and dryer sample days than the average measured locally during the past decades. Depending on growth in CO2 concentration increases in inside canopy air temperatures were between 0.12 and 0.37°C. The warmer plants could have less effective transpiration cooling resulted from higher stomatal resistances. It decreased the water vapour pressure of the air inside the plant stand. In spite of partly stomatal closure, abundant carbon-dioxide concentration raised the intensity of photosynthesis. However if elevated CO2 concentration takes place, the other additional influencing factors as warming, change in precipitation amount and its distribution, plant adaptation processes etc. may offset the production benefits of increasing level of CO2. More detailed investigations are needed to complete our imaginations about future consequences of possible climate variations, mainly in local level.

Keywords: global warming, simulation, microclimate, physiology of maize

Abstract: The main aim of this research was to determine the susceptibility of Lithuanian selection potato cultivars to late blight. Late blight infection was different in potato groups with various maturities. In early potatoes disease spread was more intensive, and slower in late maturity cultivars. The intensity of potato blight spread in various maturity potato cultivars depends not only on their earliness, but their biologic traits as well. Late blight research has been conducted in the potato breeding program – for the creation of biological-mathematical prognosis models of late blight. Potato cultivar ‘Aista’ has high resistance to P. infestans. ‘Aista’ is recommended for growing on ecologic farms.

Keywords: potato, cultivars, late blight, resistance, ecologic farms

Abstract: Trace metal contents in zooplankton samples were estimated as a part of Marine Research- Living Resource Programme (MRLR) programme at 24 stations to establish the importance of these metals in the Bay of Bengal. The average concentration of Fe, Co, Ni, Cu, Zn, Cd and Pb in zooplankton from the Bay of Bengal indicates that it is slightly enriched in coastal samples than offshore samples. The heavy river discharge in the east coast of India might be related to the increased metal bioavailabilities in seawater and hence an increased uptake of metals by zooplankton from coastal areas than offshore areas. The zooplankton species examined showed great accumulations of metals, with bioaccumulation factors in the range >15,000 to 40,000,000 with respect to the concentrations (soluble fractions) in marine waters. Metal concentrations recorded in the Bay of Bengal zooplankton may be used as background levels for future studies, a body of water about which information is still very scarce.

Keywords: Bay of Bengal, zooplankton, trace metals, bioaccumulation

Abstract: In this paper we study the stability of the spatial structure of demersal assemblages of the Moroccan southern Atlantic zone, ranging between Cap Boujdor (26°N) and Cap Blanc (20°50 'N). The data used are the frequencies of demersal species captured during trawling surveys along the continental shelf to less than 120 meters of depth; the samplings were undertaken during October and April of the years 2002 and 2003. The data collected during December 2003 was retained for the comparison results. The processing of these data was carried out by multi-tables method (STATIS version AFC), used for the stability study of the capture structure. The analysis indicates the existence of three types of stable associations, presenting a gradient from inshore towards offshore. Each structure represents an assemblage of species tending to cohabit in the same environment. In contrast, other species (Rajah asteria, Serranus cabrilla, Arnoglossus imperialis, Pagrus auriga and Sepia orbignyana) were characterized by a very strong spatio-temporal variability.

Keywords: fish association, trawl surveys, multitable analysis, Atlantic Ocean, stability, spatial structure

Abstract: Desertification involves many countries featuring different ecological, economic, and social conditions. In Mediterranean Europe, high human pressure, economic development, and climatic changes combine to produce land consumption, soil erosion, salinization, and fire risk, all considered as key factors to start desertification processes. For many years the term desertification has been strictly associated to geo-physical conditions, but in very complex ecosystems the study of the interaction of physical patterns with population and social characteristics is necessary to better delineate areas at risk. The aims of this paper are therefore (i) to review recent findings in term of desertification processes and risk assessment in the Mediterranean basin, (ii) to illustrate a simplified model in which social and economic variables may significantly accelerate land degradation leading to desertification, (iii) to suggest a set of demographic, economic, and institutional indicators suitable to contribute to the assessment of desertification risk in the Mediterranean basin, (iv) to built a synthetic index based on a multivariate approach and, finally, (v) to compare such index with a standard index of desertification risk only referring to geo-physical conditions. As a conclusion, new findings to be achieved in the context of human impact on environment as an original contribution to the study of desertification were delineated.

Keywords: desertification risk, indicators, demography, economy, Italy

Abstract: Aerial extent and distribution pattern of seagrass meadows in the Mandapam group of islands viz. Pamban area of Rameshwaram, Krusadai, Pullivasal and Pumarichan Island of the Gulf of Mannar Biosphere Reserve were studied. Visual interpretation and digital analysis of satellite data viz. IRS 1D LISS III (2000 and 2002) and IRS P6 LISS III (2004) showed the presence of extensive seagrass beds in these areas. Present study has recorded 3289.14 ha of reef area, 794.45 ha of reef vegetation, 726.15 ha of dense and 601.00 ha of sparse seagrass beds in this part of the Gulf during the year 2004. Further, spread and changes in seagrass cover in this region have been classified and loss has been estimated. In addition, drastic reduction in the seagrass resources of the Gulf of Mannar in certain places was identified and management plans to conserve this resource have been suggested.

Keywords: seagrass, assessment, remote sensing, anthropogenic

Abstract: In agriculture we face several decision problems in which, among proficiency and sustainability, the risk aspects have to be investigated more and more seriously. In Hungary the risk of production is especially meaningful as it has considerably been increased in the last few decades. In this paper we review those risk analysis methods which are very useful in climate change impact research. We give a case study of the application of the described methods in which we prove that the risk of corn and wheat production has increased between 1951 and 1990 in four Hungarian regions (Hajdú-Bihar, Bács- Kiskun, Fejér and Győr-Moson-Sopron), independently to the rate of absolute risk aversion. In some regions the rate of increase became even quicker.

Keywords: risk of production, Phillips-method, efficiency criteria, climate change, decision analysis

Abstract: Several methods have been worked out by now to present the changes of weather and its elements. In this article we present a graphic method where the changes of the different elements of the weather can be analised with the help of 3D figures. The tendency of changes can be seen well from the expressive, spatial plots.During the execution of the task several models to prepare the spatial surfaces (moving average, kriging, spline, inverse distance weighting, and artificial neural network) have been used and compared. Here the daily amount of precipitation measured at the meteorological station of Szeged has been analised. For the sake of better demonstration the measurement data with the help of a digital surface model has been illustrated. In connection with this a graphic display method, with which the presentation of the tendencies in the changes of precipitation are more expressive then the ones quoted in the literature has been presented earlier. Our method is presented with displaying time series, consisting of the daily amount of precipitation of 100 years, which has meant a separate challenge, as the precipitation data show significant deviation. We have already used the presented method for the demonstration of temperature and evaporation data as well.

Keywords: digital surface model, precipitation change, artificial neural network, moving average