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Intraspecific trait variability of herbaceous plants in organic and conventional olive plantations in region at desertification risk
MIGLIORINO, Michele
This thesis is an ecological study in an agricultural context (agroecological research). It is carried out in olive plantations in south Italy, Apulia, a region at strong desertification risk. The effect of agricultural management (organic vs. conventional) is investigated on i) the herbaceous species composition ii) intraspecific trait variability of five selected herbaceous plants iii) soil conditions. Herbaceous plants are here considered as "indicators" of olive plantations' health. Studying if and how species traits and soil parameters vary with management, should reveal how olive understory grasslands are responding to increasing drought conditions and other desertification constraints. Management of grasslands and soils is critical to maintain high ecological functionality and services of olive agroecosystems.
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Sublethal effect of agrochemicals on \kur{Pardosa} sp.
KRIŠTOFOVÁ, Lucie
In the last decades, there has been a growing interest in studying particular those arthropods who have an important role in agroecosystems. For example, they are natural enemies of pests and therefore they are considered to be beneficial organisms. However, these beneficial arthropods may be negatively affected by the application of chemicals under the management of agroecosystems and their potential to inhibit pests can be significantly reduced. Such organisms certainly include spiders which occure in abundant numbers practically in all types of terrestrial habitats including agricultural ecosystems where they have a role of very important predators. Therefore, the thesis focused on current issues of pesticides, especially from the view of their negative effects on behavioral modification of beneficial invertebrate organisms in agricultural crops. The theoretical part is devoted to a brief characteristics of pesticides, their sublethal effects on non-target organisms and the importance of spiders as natural regulators of pests in agroecosystems. The practical part describes the experiment whereconventionally used agrochemicals were tested the influence of the herbicide and desiccant Basta 15, the Arrest preparation and their combination (mixture Basta 15 + Arrest) on spiders genus Pardosa. I focused on the side effects of these solutions, specifically on the modification of predatory behavior and on the mortality of spiders. It has been shown that agrochemicals affect the predation successfulness of spiders. From the short term and the long term point of view, it has been shown that spiders treated with the tested preparations killed less prey than the individuals in the control group which were treated only with distilled water. The dependence of mortality and the number of killed prey on the size and sex has not been proved. Preparations Basta 15 and the mixture caused significantly higher mortality of spiders. The Arrest preparation did not increase the mortality.
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Chemical parameters of surface waters in selected model ecosystems of the cultural landscape.
STRNADOVÁ, Johana
The aim of this study was to determine and compare the concentration of chemical parameters in five streams in Novohradské hory. Individual sampling points were different with their types of ecosystem, management practices, vegetation composition of growth and subsoil. Monitored parameters in forest ecosystems were: conductivity, pH, sulfate and calcium. In agrosystems observed parameters: electrical conductivity, pH, calcium, chloride and nitrate. The collected data generated graphs for the years 2005 - 2010. Based on the results we can say that natural mixed forest resists concentrations of sulphates and prevents the acidification of surface water. In contrast with spruce monoculture where surface water has the lowest pH because the sprice forest captures haigher quantitty of sulphates. Chemistry of water in agroecosystems corresponds to the flow through the landscape, which is used for economic activity. This was most evident in the stream, which in the upper sampling point flows through spruce monoculture and conductivity there was only 65 ?S.cm-1. On the contrary conductivity was substantially higher 175 ?S.cm -1 in the lower sampling point. Conductivity value of stream flowing through wet meadows, was 191 ?S. cm1. The measurement results confirmed that the water reaches the higher conductivity in the managed landscape.
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