National Repository of Grey Literature 17 records found  1 - 10next  jump to record: Search took 0.01 seconds. 
Natural regeneration of Norway spruce in mountain forests and at disturbed plots
Urbanová, Renáta ; Hadincová, Věroslava (advisor) ; Brůna, Josef (referee)
The natural regeneration of Picea abies in undisturbed mountain spruce forests as well as in disturbed areas formed by windstorms and overgrowth of bark beetles, especially spruce bark beetle (Ips typographus), takes place primarily through seed germination from a transitional soil seed bank. The quality of the soil seed bank depends on the amount of seeds available, which varies significantly throughout years, and on environment conditions. Interannual changes in the amount of seeds produced are caused by the irregular occurrence of seed years, which reflects weather changes in the context of ongoing climate change. Increased average air temperature and unevenly distributed rainfalls throughout the year have a positive effect on the spruce phenology, seed abundance and quality and results in increasing frequency of seed years. The large amount of seeds during seed years induces increased abundance of granivores for which the seeds are the source of nutrients and environment for their development. Seed predators of invertebrates and, small vertebrates groups and fungal pathogens significantly reduce the proportion of seeds needed for spruce natural regeneration. This bachelor thesis summarizes up to now knowledge explaining mechanisms and interactions associated with the soil seed bank of Picea...
Use of remote sensing data for monitoring of long-term vegetation dynamics on the landscape scale
Brůna, Josef
This thesis deals with the use of remote sensing data for studying and monitoring vegetation changes. Thanks to archival materials, we can now make extensive studies at the landscape and global level without the need for large-scale old field data. From the Middle Ages, we can rely on different types of maps, for vegetation studies, these are mainly forestry maps. Since the 1930's, aerial photographs have been available in Europe, and satellite imagery was available since the 1970's. Availability and quality of satellite imagery had increased rapidly during my study. The most recent data source are unmanned aerial systems and methods of processing their data, which allow inexpensive detailed mapping of large areas. The presented publications do not only solve ecological research questions, but also contribute to solving current environmental problems in the Czech Republic, from nature conservation in National Parks and protected areas to monitoring of plant invasions. I have used archival forest maps for the reconstruction and analysis of large disturbances (windthrow and subsequent gradations of bark beetle) in forests of Šumava and the Bavarian Forest in 1868-1870. Species composition, as well as environmental factors derived from digital elevation model, were analyzed. The same topic was also...
Use of remote sensing data for monitoring of long-term vegetation dynamics on the landscape scale
Brůna, Josef ; Wild, Jan (advisor) ; Romportl, Dušan (referee) ; Kropáček, Jan (referee)
This thesis deals with the use of remote sensing data for studying and monitoring vegetation changes. Thanks to archival materials, we can now make extensive studies at the landscape and global level without the need for large-scale old field data. From the Middle Ages, we can rely on different types of maps, for vegetation studies, these are mainly forestry maps. Since the 1930's, aerial photographs have been available in Europe, and satellite imagery was available since the 1970's. Availability and quality of satellite imagery had increased rapidly during my study. The most recent data source are unmanned aerial systems and methods of processing their data, which allow inexpensive detailed mapping of large areas. The presented publications do not only solve ecological research questions, but also contribute to solving current environmental problems in the Czech Republic, from nature conservation in National Parks and protected areas to monitoring of plant invasions. I have used archival forest maps for the reconstruction and analysis of large disturbances (windthrow and subsequent gradations of bark beetle) in forests of Šumava and the Bavarian Forest in 1868-1870. Species composition, as well as environmental factors derived from digital elevation model, were analyzed. The same topic was also...
Using of satellite imagery in environmental research for urban heat islands identification and its relationship with surrounding environment with case study in Prague locality
Houdová, Dominika ; Matějíček, Luboš (advisor) ; Brůna, Josef (referee)
The thesis is divided into two parts: literature review and case study. The aim of recherche part is an introduction to issue of urban heat islands and summarization of knowledge of relationship between urban heat islands and surrounding environment. It describes effect of urban heat islands in different biomes and with different land cover. Second part solves detection of urban heat island in city of Prague in the Czech republic locality and its relationship to vegetation indices by using satellite data Landsat 8. The aim of case study is to find a relationship between land surface temperature and its impact on vegetation. The study proves linear correlation between Normalized Difference Water Index (NDWI) and measured land surface temperature in areas with Normalized Difference Vegetation Index (NDVI) above a threshold. It was found city area vegetation to be in worse condition as compared to rural area vegetation. Key words: remote sensing, environmental research, urban heat islands, vegetation indices, Prague
The state of the Natural Regeneration in Bavarian Forest National Park, 10 Years after the Total Death Parent Stands
Červenka, J. ; Wild, Jan ; Svoboda, M. ; Kopecký, Martin ; Macek, Martin ; Brůna, Josef ; Zenáhlíková, J.
The presented research is focused on the state of natural regeneration (Norway spruce and Rowan), 10 years after total death of parent stands in the core untouched part Bavarian Forest National Park. The 16 permanent plots 40m x 40m are located on the southeast of Bavaria. We determined exact height, size of the last height increment, condition and species of trees. Number of saplings were counted and classified by heights. These number ranged from 53 to 17276 saplings per hectare. The spruce species composition was 96.7%. The height structure of spruce shows that almost 73% found spruce trees reached heights greater than 0.5 m. The average height increment increased with increasing height of saplings. This paper presents state of natural regeneration in mountain spruce forests in Bavarian Forest National Park without the human influence in summer 2010, 10 years after total death of parent stands.
Methodology of invasive species mapping using remote sensing approach
Müllerová, Jana ; Bartaloš, T. ; Brůna, Josef ; Dvořák, P. ; Vítková, Michaela
The manual provides instructions on monitoring of four problematic invasive species based on remote sensing. It focuses on low cost and operational unmanned aircraft solution. The manual provides bases for understanding of the problematic, specifies the requirements for the data type and quality in respect to the species phenophases, and describes the data processing and quality assessment. Described methods are particularly suitable for targeted monitoring (in case of unmanned aircraft solution), still can be used at regional scale as well (in case of satellite imagery). Methodology is intended mainly for environmental agencies and other land managers, such as regional authorities and owners due to prevent and manage the introduction and spread of invasive alien species.
Use of unmanned aerial vehicles for precision agriculture
Fialová, Kateřina ; Matějíček, Luboš (advisor) ; Brůna, Josef (referee)
6 Abstract This bachelor thesis deals with the use of unmanned aerial vehicles (UAV) in precision agriculture. UAVs are one of the many tools used in Earth remote sensing (RS), their task is to monitor object without physical contact. Over the past 20 years, UAVs have been expanding in a wide variety of areas, massively in precision agriculture. This thesis compares the UAV with the classical means of RS and through demonstrations of real UAV deployment in selected case studies - Applications of Low Altitude Remote Sensing in Agriculture, Weed Mapping using Object-Based Analysis of UAV images, Low-altitude, high- resolution aerial imaging systems for row and field crop phenotyping and Estimating Biomass using Crop Surface Models show wide possibilities of data collection, processing and evaluation, covering the full spectrum of important information usable in precision agriculture. UAVs and their use in precision agriculture is an area that is expected to expand dynamically and which, compared to standard data collection, only positives. The greatest advantage is immense flexibility in terms of both deployment and sensor layout, high accuracy of data acquisition, ease of operation, affordability and, consequently, the availability of software specialized in processing such data. The only possible...
Using satellite data of the Copernicus program for environmental research with a case study focused on assessment of REP reclaimed land in the neighbourhood of the lake Medard
Hernová, Jana ; Matějíček, Luboš (advisor) ; Brůna, Josef (referee)
Using satellite data of the Copernicus program for environmental research with a case study focused on assessment of REP reclaimed land in the neighbourhood of the lake Medard Abstract The thesis is divided into two parts on theoretical part and case study. The first deals is focused on description satellites of the Copernicus program and using for environmental research. The work is supplemented with examples of studies and projects that use satellite data of Sentinel with a focus on Sentinel-2. The second part deals with the use of the vegetation index REP of Sentinel-2 for the evaluation of vegetation in the landscape recultivation and evaluation of spatial resolution REP Sentinel-2. The area of interest is in the neighbourhood of the lake Medard. Keywords: satellite data, Copernicus, environmental research, REP, Medard
Model of spontaneous vegetation development in post-mining heap
Vodička, Jan ; Frouz, Jan (advisor) ; Brůna, Josef (referee)
Predictability of primary succession in post-mining sites is needed for choosing appropriate restoration method. This study models 18 years of spontaneous succession on a post mining heap in Sokolov in the Czech republic with using historical aerial photographs and spatially - analytical methods. Each photograph has been georeferenced and classified manually into several categories based on the tree density. Three spatial models that applied different population growth equations and seed diffusion from the near neighbourhood has been developed. All models were able to predict spatial distribution of trees with solid accuracy, however, predictability were decreasing with time. The best results corresponded with 40% agreement on average from all years and more than 50% for some individual years. Keywords: spontaneous succession, spatial models, post-mining sites

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See also: similar author names
4 BRUNA, Jaroslav
4 Bruna, Jaroslav
3 Bruna, Jiří
1 Brůna, Jan
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