|
|
Vegetation of old fields and its dynamics in relation to changes of arable land in Czech Banat (Romania)
Veselý, Adam ; Kovář, Pavel (advisor) ; Vojta, Jaroslav (referee)
- 4 - Abstract Recent abandonment of arable land close to the Czech villages originated in Romanian area called Banat during 19th century implies new variety of habitats representing old fields of different age. We can observe succesional stages of vegetation variable in plant diversity, in some cases significantly high with a number of plant species valuable from the viewpoint of nature protection. Some of these species were known as common in Czechlands as well, but nowadays are strongly endangered or completely extinct. Among others, the number of pieces of cattle in Banat has been reduced. This is the reason why traditional pastures have been grazed less intensively, especially those situated in hardly available localities (e.g. karst valleys and slopes) and often shared with neighborhood villages (including Romanian ones). The abandonment of arable fields thus facilitates the landuse by the way of more productive pastures with better availability from the villages. Next steps of secondary succession and the lost of traditional cycle of the land cultivation sparse shrubs are becoming an important part of the old field vegetation structure, which moreover have a strong influence on the potential restoration of forest ecosystems. The main aim of this thesis is to asses the process on the abandoning of...
|
|
|
The effect of agri-environmental schemes on biodiversity
Vodička, Jan ; Reif, Jiří (advisor) ; Kindlmann, Pavel (referee)
The aim of thesis is summary of current results of scientific publications evaluating effectiveness of agri-environmental measures in the relation to biodiversity. This work deals with this issue in Europe, characterizes the situation in selected European countries and evaluate the effectiveness of compensation schemes and individual measures on selected groups of organisms. It also deals with the factors influencing the effectiveness and methodical approaches of evaluation studies. Results of studies suggest a low to medium efficiency of allover measures for plants and invertebrates and low efficiency for birds. Conversely targeted measures had a high efficiency, but their overall significance was very low due to small proportion of land compared to the horizontal measures.The worst situation was in the Netherlands, in other countries the results were relatively similar.
|
|
|
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.
|
|
|
Species pool size and realized species richness affect productivity differently: A modeling study
RYCHTECKÁ, Terezie
Current and expected decline in biodiversity have motivated a number of experiments studying how biodiversity affects ecosystem functioning. The positive relationship is usually found in experiments where species pool is manipulated; the relationship between productivity and realized species richness does not show any single trend. We constructed a simple competition model for a plant community based on the classical LotkaVolterra equations, with randomly generated parameters. We varied the species pool size and intensity of competition (range of competition coefficients). Then, we compared two measures of diversity used as predictors of productivity: (1) the size of the species pool and (2) the realized species richness, i.e. the number of species that remained in the system after competitive exclusion. Simulation results showed that productivity was always positively affected by the size of the species pool. With increasing species pool, both the selection effect and complementarity increase. The relationship between realized species richness and productivity was extremely weak within a set of simulations with a fixed species pool (i.e.where the diversity gradient was caused only by differences in the randomly generated parameters). The relationship between realized species richness and productivity was slightly positive for small species pool sizes and slightly negative for larger species pools. A species with high carrying capacity within the generated set of species usually decreases the chance of other species to survive but increases the productivity of the mixture, leading to negative diversity productivity relationship. On the contrary, presence of highly complementary species (i.e. species with low mutual competition coefficients) increases both, the realized species richness and productivity, leading to positive diversity productivity relationship. These two effects mostly counterbalance each other. These trends are not affected by the competition intensity.
|
|
|
Structure of genetics resources and the actual use of spelta (\kur{Triticum spelta} L.) in the Czech Republic
HŮDA, Petr
The work is dealt with the analysis of the structure of genetic resources of spelt (\kur{Triticum spelta} L.), then the current state of cultivation and utilization of this cereal. The review of literature focuses on the orign, distribution, agricultural engineering and breending programmes of spelt. In the Czech Republic spelt is usually grown in organic farming. Data from the statistics of organic farming and data from the database EVIGEZ are used to present the results of this work. The results of this work show an obvious increase of production areas, spelt production and increased interest in products of this crop.
|
guest ::
