45 research outputs found
Landscape typology of the Czech republic
29 number of framework was set expertly. The next step affected by author of classification is the choice of training objects. For each of the classes 5 objects were considered that cover the range of variability of natural conditions. However, their selection was also a affected by author's choice. Verification and comparison of the results of object-oriented analysis with traditional methods of pixel-based classification showed differences in the of classification methods. In the case of object- oriented analysis spectral information are evaluated for the whole object. The highly heterogeneous objects such information may be averaged out and the object is thus classified as atypical representative of a certain class. Pixel classification methods, however, assess the quality of each pixel of the raster, so that any heterogeneous objects are divided into several classes. Using the results of the supervised classification the accuracy of object-oriented classification has been confirmed, considering a few exceptions. 4.1 THEORETICAL ISSUES Serious question of developing comprehensive landscape typology is the purpose and reason for such action. Pedroli et al. (2006) points to a general demand for accurate, highly detailed and high quality representative spatial information on the status and development of...15 klasifikace, je volba trénovacích objektů. Pro každou z uvažovaných tříd bylo zvoleno vždy 5 objektů, které nejvhodněji postihují spektrum podmínek dílčích typů. Jejich výběr byl však rovněž zatížen osobou zpracovatele. Ověření a porovnání výsledků objektově orientované analýzy s výstupy tradičních pixelových metod ukázalo rozdíly ve způsobu klasifikace obou typů metod. V případě objektově orientované analýzy jsou hodnoceny spektrální informace za celý objekt. V rámci vysoce heterogenních objektů mohou být tyto informace zprůměrovány a objekt je tak zařazen jako netypický zástupce do určité třídy. Pixelové metody klasifikace naproti tomu hodnotí kvalitu jednotlivých polí rastru, případné heterogenní objekty jsou tak touto metodou rozděleny do více tříd. Pomocí výsledků řízené klasifikace byla až na několik výjimek potvrzena správnost objektově orientované klasifikace. 4.1. TEORETICKÉ OTÁZKY Závažnou otázkou zpracování komplexních typologií současné krajiny je samotný smysl a důvod takového konání. Pedroli et al. (2006) upozorňuje na všeobecnou poptávku po přesných, vysoce podrobných a zároveň srozumitelných prostorových informacích o stavu a vývoji krajiny, jejích složek a funkcí. Groom et al. (2006) a Jongman et al. (2006) na konkrétních příkladech uvádí možnosti využívání stále kvalitnějších...Department of Physical Geography and GeoecologyKatedra fyzické geografie a geoekologieFaculty of SciencePřírodovědecká fakult
Determinants of Orchid Occurrence: A Czech Example
Orchids are an endangered plant group, protected in the whole world. Questions of their conservation are therefore highly discussed, but not all factors affecting their survival and distribution are known so far. The purpose of this study was to determine the environmental factors influencing the existence of certain orchid species in their localities in our model area—South Bohemia. Our data were analyzed using the MaxEnt program, which produces species distribution models (SDMs) and allows predicting potential occurrence of orchids in yet unknown localities. This program also determines the environmental factors affecting species presence. This is important for better protection of orchids, because only by knowing these factors, we can find new localities or improve management plans. We studied two orchid species growing in South Bohemia: Dactylorhiza majalis and Platanthera bifolia. The main factors affecting their occurrence were the consolidated layer of ecosystems, habitat heterogeneity, cover of arable land, and vertical heterogeneity. We determined areas, where new sites are most likely to be discovered and show them in the maps of the area. This approach can help in finding new localities of orchids and in understanding, which environmental factors influence the occurrence of these endangered orchid species
The declining occurrence of moose (Alces alces) at the southernmost edge of its range raise conservation concerns
The border region between Austria, the Czech Republic, and Germany harbors the most south-western occurrence of moose in continental Europe. The population originated in Poland, where moose survived, immigrated from former Soviet Union or were reintroduced after the Second World War expanded west and southwards. In recent years, the distribution of the nonetheless small Central European population seems to have declined, necessitating an evaluation of its current status. In this study, existing datasets of moose observations from 1958 to 2019 collected in the three countries were combined to create a database totaling 771 records (observations and deaths). The database was then used to analyze the following: (a) changes in moose distribution, (b) the most important mortality factors, and (c) the availability of suitable habitat as determined using a maximum entropy approach. The results showed a progressive increase in the number of moose observations after 1958, with peaks in the 1990s and around 2010, followed by a relatively steep drop after 2013. Mortality within the moose population was mostly due to human interactions, including 13 deadly wildlife-vehicle collisions, particularly on minor roads, and four animals that were either legally culled or poached. Our habitat model suggested that higher altitudes (ca. 700–1,000 m a.s.l.), especially those offering wetlands, broad- leaved forests and natural grasslands, are the preferred habitats of moose whereas steep slopes and areas of human activity are avoided. The habitat model also revealed the availability of large core areas of suitable habitat beyond the current distribution, suggesting that habitat was not the limiting factor explaining the moose distribution in the study area. Our findings call for immediate transboundary conservation measures to sustain the moose population, such as those aimed at preventing wildlife-vehicle collisions and illegal killings. Infrastructure planning and development activities must take into account the habitat requirements of moose.publishedVersio
Ökológiai folyosók a Kárpátok-régiójában : A Connectgreen Projekt = Ecological Corridors In The Carpathians : The Connectgreen Project
Bird tolerance to humans in open tropical ecosystems
AbstractAnimal tolerance towards humans can be a key factor facilitating wildlife–human coexistence, yet traits predicting its direction and magnitude across tropical animals are poorly known. Using 10,249 observations for 842 bird species inhabiting open tropical ecosystems in Africa, South America, and Australia, we find that avian tolerance towards humans was lower (i.e., escape distance was longer) in rural rather than urban populations and in populations exposed to lower human disturbance (measured as human footprint index). In addition, larger species and species with larger clutches and enhanced flight ability are less tolerant to human approaches and escape distances increase when birds were approached during the wet season compared to the dry season and from longer starting distances. Identification of key factors affecting animal tolerance towards humans across large spatial and taxonomic scales may help us to better understand and predict the patterns of species distributions in the Anthropocene.</jats:p
Landscape typology of the Czech republic
29 number of framework was set expertly. The next step affected by author of classification is the choice of training objects. For each of the classes 5 objects were considered that cover the range of variability of natural conditions. However, their selection was also a affected by author's choice. Verification and comparison of the results of object-oriented analysis with traditional methods of pixel-based classification showed differences in the of classification methods. In the case of object- oriented analysis spectral information are evaluated for the whole object. The highly heterogeneous objects such information may be averaged out and the object is thus classified as atypical representative of a certain class. Pixel classification methods, however, assess the quality of each pixel of the raster, so that any heterogeneous objects are divided into several classes. Using the results of the supervised classification the accuracy of object-oriented classification has been confirmed, considering a few exceptions. 4.1 THEORETICAL ISSUES Serious question of developing comprehensive landscape typology is the purpose and reason for such action. Pedroli et al. (2006) points to a general demand for accurate, highly detailed and high quality representative spatial information on the status and development of..
Typologie krajiny v Česku a zahraničí: stav problematiky, metody a teoretická východiska
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Global Environmental Systems—A Spatial Framework for Better Understanding the Changing World
Purely natural land formations are increasingly rare in today’s world, as most areas have been shaped, to varying degrees, by human influence over time. To better understand ongoing changes in the natural environment, we adopted an approach that involves identifying global systems with a significant anthropogenic component. In this study, we developed a new classification of Global Environmental Systems based on over 20 high-resolution datasets, covering abiotic, biotic, and anthropogenic conditions. We created abiotic, biotic, and anthropogenic classifications, each with ten classes. The combinations of these classes result in 169 distinct classes of Global Environmental Systems. This classification provides a suitable spatial framework for monitoring land use dynamics, biodiversity changes, global climate change impacts, and various processes exhibiting complex spatial patterns