Abstract Conservation of rare habitats and species are central elements in the management of semi-natural grasslands of high biodiversity. Understanding the impacts of various abiotic and biotic interactions and management methods on threatened species is fundamental to their conservation. In the present study, effects of competition, plant parasitism, grazing and mowing were studied at the community level in Bothnian Bay coastal meadows and in greenhouse. This was the first time when the impacts of various biotic interactions on the critically endangered creeping alkali grass (Puccinellia phryganodes) have been explored in detail in one of its rare occurrences in the boreal vegetation zone in Europe. In addition, questions related to ecological and economical sustainability of cattle grazing on coastal meadows were examined. Puccinellia phryganodes was found to suffer severely from competition with taller graminoids. Simulated and actual grazing by greylag goose, Anser anser, as well as infection by a hemiparasitic plant, Odontites litoralis, were found to indirectly benefit P. phryganodes by decreasing the competitive advantage of its competitors. In spite of the relatively intensive grazing by greylag goose in the field, P. phryganodes experienced a drastic decrease during four years in the grazed experimental quadrats and simultaneously the proportion of the taller graminoids increased substantially. Primary succession of coastal meadow vegetation was found to progress rapidly and continuous formation of suitable open habitats is therefore crucial for the subordinate species. Mowing was found to be an effective management method for some threatened plant species in coastal meadows, but not for P. phryganodes, which would probably benefit more, for example, from livestock grazing. Both lightly and rather intensively managed large open meadows could provide optimal habitats for the critically endangered lesser white fronted goose (Anser erythropus) as well as for the greylag goose. The relatively low and variable yield of the coastal meadow vegetation compared to that of cultivated grasslands sets limits how management by cattle grazing can be implemented. Key factors for both the biodiversity management and livestock production in coastal meadows are timing of the grazing season, intensity of grazing and selection of suitable types of animals.

Meadows are crucial components to larger river watersheds because of their unique hydrologic and ecological functions. Due to climate change, over grazing, and fire suppression, conifer encroachment into meadows has accelerated. In some western regions, nearly half of all meadow habitat has been loss due to conifer encroachment. Restoration of these hydrologic systems requires tree removal. Many studies exist that address the issue of conifer encroachment in montane meadows, however, few studies focus on the role that conifer removal plays on the encroaching meadow. Furthermore, few studies exist that document the hydrologic change from conifer removal and further restoration steps, if any, to take after the removal. The overall research goal is to understand the efficacy of removal of encroached conifers from an encroached meadow (Marian Meadow) for successful meadow restoration. The objectives of this study are to determine (i) quantify the meadow hydrology following removal of encroached conifers, (ii) determine if forest tree removal adjacent to the meadow influences the meadow’s hydrology, and (iii) test three common revegetation techniques for a formerly encroached montane meadow.. Marian Meadow is in Plumas County, CA at an elevation of 4,900 feet. This 45-acre meadow enhancement project is part of a 2,046-acre timber harvest plan implemented by the Collins Pine Company. Soil moisture sensors at one foot below the ground and water table depth sensors at four feet below ground were installed in Marian Meadow and a control meadow in September 2013, with additional soil moisture sensors at three-foot depth installed August 2015. The removal of encroaching conifers from Marian Meadow occurred in June 2015. Electrical Resistivity Tomography (ERT) was used to determine maximum water table depths and climatic variables were measured from a weather station as inputs for the water budget. A groundwater recession curve equation was used to model water table depths between water table depth sensor measurements and ERT measurements. A general linear model was used to determine any statistical significant difference in soil moisture and water table depths prior to and after conifer removal. Revegetation plots were installed at the start of the 2017 growing season to determine the establishment rate for three different techniques (BARE, WOOD, and EXISTING) and three different species of meadow plant. Technique BARE, which removes approximately 10 cm of top soil and disperses seed was statistically significant, yielding the highest population count. Another growing season data collection and control plot is required to draw further conclusions and recommendations. The water balance indicated that the majority of Marian Meadow and the Control Meadow’s water storage can be attributed to precipitation and not upland sources. This hydrologic characteristic is common in dry meadows. The statistical analysis indicated that measured water table depths increased on average by 0.62 feet following conifer removal. The first year following restoration and the second year following restoration yielded statistically significantly different water levels than pre-restoration water levels. The third year following restoration is inconclusive until the end of the 2018 WY data set is available. On average, soil moisture increased by 6.43% following conifer removal and was statistically significantly different in all three post restoration years when compared to pre-restoration volumetric soil moisture content. Additionally, growing season (April through September) water table depths indicated that meadow vegetation communities could be supported in Marian Meadow following conifer removal. The removal of conifers from an encroached meadow appears to promote soil moisture and water table depth conditions indicative of a meadow and meadow plant community types.

The distinct ecological requirements of Microtus xanthognathus (yellow-cheeked vole or taiga vole) and M. pennsylvanicus (meadow vole) warrant accurate discrimination of their remains in studies of paleoecology and past biogeographical shifts. An occlusal length of the lower 1st molars (ml) that is >3.2 mm for M. xanthognathus is the method most frequently used to separate these 2 taxa in archaeological and paleontological samples. However, these measurements alone are unreliable because some specimens of M. pennsylvanicus overlap smaller individuals of M. xanthognathus in size. Therefore, I created and tested a morphometric technique that discriminates Recent lower 1st molars (mis) of M. pennsylvanicus from those of M. xanthognathus, and is applicable to other taxa (both modern and fossil). Despite overlapping occlusal length, my discriminant function based on landmark data correctly classified 100% (n = 53) of Recent m1s from the 2 taxa and 97.7% (43 of 44) of (assumed) m1s of M. pennsylvanicus from an archaeological site from about AD 1200 in central Nebraska. This landmark scheme is applicable to fossil and modern Microtus worldwide. © 2006 American Society of Mammalogists.

Sediment and nutrient retention are important ecosystem functions floodplain meadows fulfil. While it is known that the inundated floodplain vegetation purifies the water during floods, little is known about the processes behind. I investigated the effect of the vegetation structure on sedimentation at three hierarchical scales, leaf, patch, and floodplain scale and used two approaches, experiments and an in situ field study. In the leaf experiment (study 1) I inundated single leaves into sediment rich water. The results showed that leaf pubescence increased sedimentation on leaf surfaces and that for leaves without hairs, the sedimentation increased with decreasing leaf area. In the flume experiment (study 2) I investigated the effects of community characteristics of vegetation patches regarding their capacity to capture sediment. I manipulated the leaf pubescence, the community density, the community height and the structural diversity (high-high vs high-low growing species) of the patches. The results show that all four investigated community characteristics increased the sediment retention. In the second flume experiment (study 3), I investigated the effect of species richness of vegetation patches on sediment retention. The results showed the importance of the vegetation biomass and identity effects of single species, but no clear effect of species richness. For the in situ field measurements (study 4), I measured sedimentation during a real flood event along the Mulde River in Germany. With sediment traps and biomass harvests I quantified the sedimentation underneath as well as on the vegetation. The results showed that besides the vegetation biomass, the topographical parameter ‘hydrological distance’ (pathway of lowest elevation the water travels to the site) is important for sediment and especially nutrient retention. Even though sediment retention is highest close by the river, sedimentation is still reasonably high far insight the floodplain and especially nutrient retention (C, N and P) increase with hydrological distance. From the sum of results I can derive four management strategies for floodplains to increase the sediment retention. First, reduced mowing for more standing biomass during flood season, wherefore trade-offs with other ecosystem functions need to be evaluated carefully. Second, promotion of structural diversity, possible via species diversity. Third, promotion of species with characteristics that increase sediment, such as pubescent leaves. Forth, preserving or recreating topographic complexity in the floodplain. Overall, I showed that the specific structures of herbaceous vegetation are highly beneficial for sediment and nutrient retention on floodplains.:Table of contents 1. General introduction 6 1.1 The Mulde River and the “Wilde Mulde” project 7 1.2 Sediment retention on floodplains 8 1.3 Vegetation causes fine sedimentation 11 1.4 Structural characteristics 12 1.4.1 Structural identity of species 13 1.4.2 Structural identity of communities 14 1.4.3 Structural diversity of communities 15 1.5 Links between studies 17 2. Methodological features 19 2.1 Study area “Wilde Mulde” 19 2.2 Leaf roughness measurement 22 2.3 Experimental set up of the flume experiment 24 3. Original contributions 26 3.1 Paper 1 - Leaf area and pubescence drive sedimentation on leaves surfaces during flooding 26 3.2 Paper 2 – Plant structural diversity alters sediment retention on and underneath herbaceous vegetation in a flume experiment 44 3.3 Paper 3 – Effects of plant species identity overrides diversity effects in explaining sedimentation within vegetation in a flume experiment 65 3.4 Paper 4 – Vegetation characteristics control sediment and nutrient retention on but not underneath vegetation in floodplain meadows 77 4. Discussion 107 4.1 Mechanistic parallels among scales 109 4.2 Effects of species diversity in relation to species identity 112 4.3 Transferability and its limitations 113 4.4 The ecosystem function of sediment retention 114 4.4.1 Floodplain management for sediment retention 115 4.4.2 Sediment retention in the context of other ecosystem functions 117 4.4.3 Floodplain management for sediment retention along the Lower Mulde River 119 5. Outlook 122 5.1 Leaf roughness 122 5.2 Diversity experiment 123 5.3 Approaches for new management strategies 124 5.4 Extrapolation with remote sensing 125 5.5 Sediment budget 126 6. Conclusion 128 7. References 130 8. Summary 143 9. Zusammenfassung 149 Acknowledgements 155 Author contribution statement 156 Curriculum vitae 164 List of publications 166 Selbstständigkeitserklärung 169

Nitrogen enrichment of plant communities is known to have big impact on declines in plant diversity and increase of biomass production. Though nitrogen is an important nutrient in the life cycle of a plant it is also problematic when the availability of nitrogen is continually high. When enrichment of nitrogen is continual, the increase in biomass and height from competitive plant species result in shading, which contribute to diversity loss in plant communities. Some nitrogen-favoured plants are long-lived and have the possibility to store seed banks in the ground until conditions are more favourable. Little is known about what role historic fertilization have on plant communities that are being re-fertilized. The aim with this study was to re-fertilize vegetation plots and compare those with vegetation plots that have not been fertilized before. The study site was vegetation plots on a meadow in Strycksele, Västerbotten, Sweden. Some plots had been fertilized from year 1996 until 2000 and scientific studies with re-fertilization started in 2019 and is ongoing. The vegetation response from re-fertilization and newly fertilization was assessed by investigating species diversity and biomass. The results showed no significant difference between re-fertilized and newly fertilized plots in either species diversity or biomass, but there was significant higher biomass in newly fertilized plots than control plots which had not been fertilized 2019-2021. For future studies there would be of high interest to look at potential differences in functional group composition in plant communities that are being re-fertilized compared to newly fertilized plant communities.

Solution of complex of school buildings in Ostrava-Black Meadow. The area is located by the river Ostravice. The whole complex is designed as crossing a line between the city and the river. River should be an element which attracts people to stayand relax. My goal is thus to access the Ostravice river - create an attractive waterfront and get city closer to it.

This diploma project deals with a problematic area called Black Meadow in Ostrava. It proposes a school building which is located on the edge between the city centre and the greenery by the river. The shape of the building creates two courtyards. The entrance courtyard is open to the park and the second courtyard is oriented to the city.

Urban design of the site called Black meadow in Ostrava is based on the winners’ design of urban planning competition for this place from the Dutch architectural studio Maxwan made in 2010. Changes in urban planning are influenced by changes of conditions, in which is the city Ostrava today. Nowadays it‘s important to find some additional function instead of just cultural cluster planned in 2010. The function, which is missing in the area and has potential to be realized in the future is sport and relax. It‘s nothing better, than develop different types of sport activities on the riverside and connect sport, relax and cultural activities at one place, to create living and attractive place. The major task was design of the school complex in this area. My school is located outside of Black meadow cluster, but in his very neighborhood, in connection with the sport playgrounds created along the river. Separated operational units are connected with common spaces like school library, canteen and hall and surround the common schoolyard with the view to the river and castle. Simple raster of classes is broken by common meeting and sport areas, which are extruded from the rectangular plan and creating view points, which communicate together and improve the orientation in the building.

Nutrient leakage into streams and rivers can lead to eutrophication, which negatively impact aquatic ecosystems. A commonly used tool to mitigate nutrient leakage is the implementation of wetlands into the polluted system. This study focuses on the levels of N and P in the river Fyris.n in Uppsala, Sweden, and the possible effects from restoration of a wetland near the river’s outlet. The results show a potential reduction of 41% and 45% for N and P respectively. The results point to a need for more wetlands further up in the catchment system to mitigate the nutrient load in the subcatchments, as the high nutrient levels there would not be affected by the proposed wetland. There are also several uncertainties due to the lack of reference material, and the results proves the need for further studies on this subject.

Mountain meadows in the western USA are experiencing increased rates of conifer encroachment due to climate change and land management practices. Past research has focused on conifer removal as a meadow restoration strategy, but there has been limited work on conifer transpiration in a pre-restoration state. Meadow restoration by conifer removal has the primary goal of recovering sufficient growing season soil moisture necessary for endemic, herbaceous meadow vegetation. Therefore, conifer water use represents an important hydrologic output toward evaluating the efficacy of this active management approach. This study quantified and evaluated transpiration of encroached conifers in a mountain meadow using sap flow prior to restoration by tree removal. We report results of lodgepole pine transpiration estimates for an approximate 1-year period and an evaluation of key environmental variables influencing water use during a dry growing season. The study was conducted at Rock Creek Meadow (RCM) in the southern Cascade Range near Chester, CA, USA. Sap flow data were collected in a sample of lodgepole pine and scaled on a per-plot basis to the larger meadow using tree survey data within a stratified random sampling design (simple scaling). These estimates were compared to a MODIS evapotranspiration (ET) estimate for the meadow. The 1-year period for transpiration estimates overlapped each of the 2019 and 2020 growing seasons partially. The response of lodgepole pine transpiration to solar radiation, air temperature, vapor pressure deficit, and volumetric soil water content was investigated by calibrating a modified Jarvis-Stewart (MJS) model to hourly sap flow data collected during the 2020 growing season, which experienced below average antecedent winter precipitation. The model was validated using spatially different sap flow data in the meadow from the 2021 growing season, also part of a dry year. Calibration and validation were completed using a MCMC approach via the DREAM(ZS) algorithm and a generalized likelihood (GL) function, enabling model parameter and total uncertainty assessment. We also used the model to inform transpiration scaling for the calibration period in select plots in the meadow, which allowed comparison with simple scaling transpiration estimates. Average total lodgepole pine transpiration at RCM was estimated between 220.57 ± 25.28 and 393.39 ± 45.65 mm for the entire campaign (mid-July 2019 to mid-August 2020) and between 100.22 ± 11.49 and 178.75 ± 20.74 mm for the 2020 partial growing season (April to mid-August). The magnitude and seasonal timing were similar to MODIS ET. The model showed good agreement between observed and predicted sap velocity for the 2020 partial growing season (RMSE = 1.25 cm h-1), with meteorological variables modulating early growing season sap flow and volumetric soil water content decline imposing transpiration decrease in the late growing season. The model validation performed similarly to calibration in terms of performance metrics and the influence of meteorological variables. The consistency of the declining volumetric soil water content effect during the late growing season between periods could not be evaluated due to an abridged validation period. Overall, the implementation GL-DREAM(ZS) showed promise for future use in MJS models. Lastly, the model derived transpiration estimates for the 2020 partial growing season showed some of the potential utility in using the MJS model to scale sap flow at the study locale. It also highlights some of the key limitations of this approach as it is executed in the present study.