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Effect of flooding régime on the growth of Carex acuta in a mesocosm experiment
JANUŠ, Vojtěch
This MCs thesis is part of the Grant Agency of Czech Republic GACR P504/11/1151 The role of plants in bilance of greenhouse gases in Carex fens. The results of this project will serve as a basis for another analyses of greenhouse gases in natural wetland biotops. Growth and morphological changes of Carex acuta were monitored in mesocosm experiment durig the growing seson. Carex acuta has already been the subjekt of numerous studies. The aim of this study is to compare the growth rate of plants C. acuta grown under controlled conditions, simulating different regimes of flooding habitat. Number of shoots and maximum plant height were observed during the growing season. Destructive method has been used to fall aboveground and belowground biomass in autumn. Elevated water levels in the middle of the growing season caused a slowdown in growth in height and the creation of new shoots. Reduced water level of the mid-growing season seemed to faster growth of plants in height. Underground biomass significantly negatively affected by increased water level in the middle of the growing season.
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Dynamics of aboveground biomass of a sedge fen
HAŠEK, Ladislav
This thesis is part of Project of the Grant Agency of the Czech Republic No P504/11/1151, focused on the role of plants in the balance of carbon dioxide and the other greenhouse gases produced in the ecosystem of a sedge fen, which is situated on the study site Wet Meadows near Třeboň. The thesis deals with the growth dynamics of the dominant sedge, Carex acuta. The samples were taken using the method of successive harvests near the automatic meteorological station of Czech Globe, Academy of Sciences of the Czech Republic. During the growing season nine harvests were accomplished on 25.3, 15.4, 6.5, 5.6., 9.7., 5.8., 9.9., 21.10., 25.11.. On each date eight replicates were taken, i.e., a total of 72 samples within the vegetation season. The seasonal dynamic of the above ground biomass was compared between C. acuta and the other plant species on the experimental area. Both live and dead biomass, was harvested and subsequently sorted to single botanic species, dried, weighed and the values were processed using the MS Excel tables. The seasonal maximum of aboveground biomass of all plant species (both live and dead parts) was found on 9.7. (1452,72 g.m-2). Among plant species the highest values of aboveground biomass were attained by Calamagrostis canescens (1257,93 g.m-2) and C. acuta (1163,49 g.m-2). C. acuta displayed the highest density of all shoots on 15.4 (300 m-2),and the highest average weight of one shoot. The maximum length of the longest live shoot of Carex acuta was very consistent among the measurememnts.
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Dynamics of aboveground biomass of a sedge fen
HOVORKA, František
This thesis is part of Project of the Grant Agency of the Czech Republic No P504/11/1151, focused on the role of plants in the greenhouse gas budget of a sedge fen. The thesis deals with the growth dynamics of the dominant sedge, Carex acuta L., on the study site, Wet Meadows near Třeboň, Czech Republic. The seasonal changes in aboveground biomass were followed using successive harvests during vegetation seasons of 2010 and 2011. The seasonal maximum of aboveground biomass of Carex acuta L. (both live and dead parts) was 321,44 g.m-2 and 357,97 g.m-2 in 2010 and 2011, respectively. The seasonal maximum of total aboveground biomas sof all species was 558,22 g.m-2 and 522,38 g.m-2 in 2010 and 2011, respectively. The seasonal maximum of shoot density was 485 ks.m-2 and 435 ks.m-2 in 2010 and 2011, respectively.
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Effect of mineral nutrient availability and flooding on the growth of Carex acuta in a mesocosm experiment
SYCHROVÁ, Jana
This MSc thesis is part of the project GACR 526/09/1545 Importance of newly assimilated carbon for the plant-soil interactions in wet grassland ecosystems in varying environmental conditions, which focuses on the effects of eutrophication on selected wet meadows with mineral or organic soil in the Trebon Biosphere Reserve. The results of this project will serve as a basis for developing a suitable ecosystem management for wet meadows, especially for sites registered as nature reserves. Pot experiments were carried out with Carex acuta, a dominant species of wet meadows that has already been subject of many studies. The aim of this work was to find out how C. acuta responds to different levels of fertilization and soil flooding under controlled conditions. The growth of the generative shoots of C. acuta was significantly affected by fertilization. The growth of vegetative shoots was significantly influenced by the soil organic matter content and fertilizer addition. The vegetative shoots reached greater length than the generative shoots. The pot experiment indicates that fertilization has not a large influence on the growth of C. acuta. This finding may explain field observations that C. acuta is gradually replaced in eutrophic habitats by stronger competitors, especially Phalaris arundinacea.
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Aboveground production of an unmown wetland stand
HOVORKA, František
The bachelor thesis is part of the project of The Ministry of Environment no. SP/2d1/9307 (Czech Terra). The aim of this project is evaluation of the carbon budget in main ecosystem types in the Czech Republic. The thesis is focused on the production of aboveground biomass of a stand dominated by Carex acuta. Thje seasonal dynamics oc the aboveground biomass was estimated by repeated destructive harvests. The highest value of Carex acuta biomass (alive and dead) was 364,63 g.m-2 on 13 August. The maximum total aboveground biomass in m2 (alive and dead biomass of Carex acuta and other plant species) was 506,76 g.m-2. The highest value of the numer of C. acuta tillers was 424 pieces/m2.
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Study of light microclimate in a chosen vegetation type during vegetation season
STOLIČKOVÁ, Martina
The aim of Bachelor thesis is the analysis of light microclimate depending on the production profile of sedge vegetation ( Carex acuta L. ) during the growing season. The light transmission of the growth of sedge and its changes during the growing season were examined. Then the seasonal cycle of the incoming and reflected solar radiation, including the albedo was evaluated.The seasonal changes in increase of aboveground live biomass, the amount of dry matter in the vertical vegetation profile, the distribution of leaf covering and the extinction coefficient changes during the growing season were assessed. The study of light microclimate and the biomass sampling was conducted in Mokré Louky near Třeboň close to pond Rožmberk. The largest representation of plant species has got Slender sedge ? Carex acuta L. there. The findings of relative insolation and light transmission was measured by pyranometer and the sampling of aboveground part was conducted by destructive method. These results show that the transmission is the highest at the vegetation surface and it decreases with the declining height. In August there was a radical decrease in the impact and the reflection of solar radiation due to the higher concentracion of water in the soil and air and this led to a reduction in albedo. Live biomass was measured: in July 1820g, in August 1670g and in September 1789g.The values of LAI and dry matter, recorded from July to September,were gradually decreasing and with the growing measured layer of growth there was a reduction in amount of dry matter and value of leaf area index.The extinction coefficient value varies depending on the age of stand. With the vegetation age the extintion coefficient increased up to 200,38. The Bachelor Thesis was developed within the research project of Faculty of Agriculture MSM 6007665806 ? The sustainable methods of farming in the foothills and mountainous areas,aiming to create harmony between their production and non-production application?.
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Effect of mineral fertilization on photosynthetic characteristics of Carex acuta
LESKOVCOVÁ, Martina
The MSc. thesis "Effect of mineral fertilization on photosynthetic characteristics of Carex acuta" deals with photosynthetic characteristics of plants subjected to different nutrient regimes. Stands dominated with Carex acuta were studied din two localities: Záblatské louky with organic soil and Hamr with mineral soil. The experimental treament was subjected to high fertilization, while the control treatment received no nutrient addition. The net assimilation was measured using Licor 6400. The aim was to find out whether the net assimilation was higher in fertilized plants as compared with non-fertilized plants. In spring the fertilized plants did not have higher photosynthetic rates at either locality, probably because of water limitation. The positive effect of fertilization was proved only at Hamerské louky after the second cut.
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