National Repository of Grey Literature 5 records found  Search took 0.00 seconds. 
Modeling the recovery of antropogenically acidified mountain waters
Hardekopf, David ; Stuchlík, Evžen (advisor) ; Krám, Pavel (referee) ; Marchetto, Aldo (referee)
11 Abstract In order for an economic system to function and produce goods and services necessary for meeting human needs, it behaves similarly to a living organism. It absorbs materials from the surrounding environment and transforms them into products, but ultimately all the materials are transformed into some kind of waste and emitted back into the environment. This flow of materials is referred to as industrial or socio-economic metabolism (Baccini and Brunner, 1991; Fischer-Kowalski and Haberl, 1993; Ayres and Simonis, 1994). Extraction of resources, consumption of materials and related emissions exert some pressure on the environment. So far, there has been a positive relation between meeting human needs and this pressure. The overall goal of developed countries within their strategies of sustainable development is to break the relation between pressure exerted on the environment and economic growth, which represents meeting of human needs and improvements in the standard of living. This phenomenon is called decoupling (EC, 2002, 2005, 2006; OECD, 2002; UN, 2002). One of the methods for assessing environmental pressure related to extraction and consumption of resources and materials is material flow analysis. In the case of economy- wide material flow analysis (EW-MFA), this method aims at...
An acidification of fresh waters is not over
Beneš, Filip ; Tátosová, Jolana (advisor) ; Hardekopf, David (referee)
Acidification of freshwaters is a problem of many areas over the northern hemisphere from the half of the 20th century. It has been caused by industrial factories discharging emissions of sulfur and nitrogen oxides, from which originate acids by the photochemical reactions in the atmosphere. Acidic atmospheric deposition has caused disappearance of fish and the most aquatic organisms in streams and lakes. Acidic atmospheric deposition has also washed up not only the buffering basic cations (Ca2+ , Mg2+ , Na+ , K+ ), but also toxic aluminium (Al3+ ) ions from soils into the freshwaters. The maximum levels of emissions of sulfur and nitrogen oxides were observed in 1980s and since that time the emissions of sulfur and nitrogen oxides significantly dropped down. However, the recovery from acidification is not as fast as it could be expected. It is impeding by several processes. One of them is hysteresis or saturation of soils by sulfur and nitrogen, which are slowly washing up into the freshwaters in forms of sulfates and nitrates now. Another process is the oligotrophication of lakes, when the important nutrient - phosphorus - is precipitating by aluminium. There is the lack of food for organisms after that. Another processes slowing down the recovery from acidification could be bad forest management...
Modeling the recovery of anthropogenically acidified mountain waters
Hardekopf, David
Thesis Summary The five chapters of this thesis consist of manuscripts published in peer-reviewed journals, focused on the effects of anthropogenic acidification on freshwater ecosystems in the Czech Republic and Slovakia, and an attempt to understand the processes and time-frame of recovery using modeling. In the Tatra Mountains in Slovakia and the Bohemian Forest in the Czech Republic, high mountain lakes have been the focus of long-term studies on both the biological and chemical impacts of acidification. The effects of anthropogenic acidification on headwater streams in the mountains and highlands of the Czech Republic have been recognized more recently, and the resulting changes to the biological community and trends in chemical changes are less well- known. Dynamic modeling, combined with the incorporation of scenarios of possible climate change, is used to investigate the present status and future trends in recovery of these ecosystems after recent reductions in atmospheric acid deposition. The first chapter is a paper on the macroinvertebrate biota in atmospherically acidified streams in the Czech Republic. This paper shows the effect of low pH on the taxonomic composition in these streams. The second chapter is focused on the current (2004) chemical composition of 91 lakes in the Tatra Mountains,...
Indicators of ecosystem recovery after heavy disturbances
Hermová, Markéta ; Hardekopf, David (referee) ; Frouz, Jan (advisor)
Minerals mining have huge impacts on the coutrryside and fundamentally change its character. The restoration of the habitats can be done basically in two ways. The mine can be either abandoned and left to natural succession or recultivated. In order to decide how to proceed on actual site, we have to carefully consider all the surroundings and set the objective we want to reach. Naturally, we are not able to monitor all the characteristics present in given locality and their changes. Therefore it is highly convenient to use a set of indicators, which can cover majority of these characteristics and will sensitively respond to development of the whole ecosystem. I decided to use three types of indicators in this study. These are physiochemical environment, ecosystem production and diversity. Through these indicators I have analysed the restoration possibilities of degraded ecosystems in localities used for coal mining in former times. I have chosen coal because it is an important commodity in Czech Republic.

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