Grid Mapping of Flora and Its Employment at Various Spatial Scales

Katedra botanikyDepartment of BotanyPřírodovědecká fakultaFaculty of Scienc

Loss factor estimation of the layered panels

The loss factor identification is the effective way to get the proper acoustic analysis in the virtual environment. Using the predictive model is a necessary part of the virtual development. The detection of the inappropriate materials or malfunction designs in the early phase of product development and can dramatically save the cost and development time. The loss factor is the nonlinear parameter for the material modeling of the noise suppression during acoustic analysis. The identification of the loss factor is necessary to perform on the real specimen. The Decay Rate Method is the effective methodology to get accurate results by using standard measuring equipment and is ideal to use in-situ environment. The article describes loss factor identification for plywood material and applications for the automotive industry for glass materials. The complete results analysis is confidential, but the overall procedure of the method is described in specimen analysis

Loss factor estimation of the plywood materials

The acoustic analysis in virtual environment enables the design optimization in the earlier phase of the new product development in term of the noise suppression of the structure. The structural material damping behavior is the most important parameter for the predictive acoustic simulations. The method for the damping loss factor identification involves the measurement of the real specimen and post-processing analysis. The result of the estimation is the structural damping behavior of plywood materials needed for the virtual acoustic analysis

Dark side of the fence: ornamental plants as a source of wild-growing flora in the Czech Republic

Ornamental plants constitute an important source of alien, and potentially invasive species, but also include a substantial part of native flora and consist of taxa that occur both in the wild and in cultivation; yet garden floras are largely ignored in ecological studies.We studied ornamental plants in the Czech Republic in order to provide detailed information, based on field sampling, on the diversity of taxa grown in cultivation in private gardens. Sampling was done in accessible public areas, private gardens and private areas in villages, town- and city neighbourhoods, garden allotments, cemeteries, areas of dispersed farmhouse settlements not accessible to the public, and in new urban sprawl. The data can be used to estimate the propagule pressure of individual taxa, measured in terms of the frequency with which they are planted in the gardens. To make the data comparable across sites, we adopted a two-level approach that resulted in producing a detailed list (including all the taxa recorded) and an aggregated list (merging closely related and similar taxa, which was necessary in order to assess the frequency of planting across sites). Each species on the detailed list was assigned an origin, status, life history and cultivation requirements. Comparing the field records with national checklists of both native and alien vascular plants we quantified particular components of the ornamental flora. The floristic inventories for 174 sites yielded 1842 taxa on the detailed list, consisting of 1642 species (standard binomials), 9 cultivars assigned to genera, 147 hybrids and hybridogenous taxa, and 44 taxa identified at higher than species level. Of these taxa 1417 (76.9%) were alien and 420 (22.8%) native. The ornamental flora consisted of not-escaping aliens, escaping aliens and cultivated natives. Of the recorded taxa, 841 (45.6%) occur both in cultivation and the wild. The aggregated list comprised 1514 taxa and resulted from merging 533 taxa from the detailed list into 205 taxa. Most alien ornamentals are native to Asia and Americas. The proportion of escaped and not-escaping aliens significantly differed from wild aliens in the spontaneous flora with underrepresentation of escaped, which originated from Australia, Africa and the Mediterranean area. Taxa from Africa and anecophytes were overrepresented and those from Australia, the Mediterranean and other parts of Europe underrepresented among not escaping aliens. The assessment of planting frequency revealed that 270 taxa were found at more than 25% of the sites, while 584 (40%) occurred at only one or two sites.Winter annuals and shrubs are most represented among the commonly planted aliens; the only native species with comparably high planting frequencies among the aliens, are Vinca minor, Hedera helix and Aquilegia vulgaris. Related to the invasion potential of ornamental garden flora we analysed the recorded taxa with respect to the transient/persistent character of their occurrence. The core (persistent) part of the flora comprised 599 taxa (32% of the total number of taxa) and the transient 240 (13%) taxa. The “grey zone” between the two included 1003 taxa (55%). The results reported here provide quantitative insights into the role of horticulture as a major pathway of plant invasions

Czech

Fluvial archives are a rich source of information about the environmental impact of the local industry in the past. This research is focused on Holocene fluvial sediments that were excavated in the area of Křenová street in Brno, Czech Republic. The area was researched during the rescue archaeological excavations, which unearthed the defunct river Svitava channel and its banks together with wooden constructions and archaeological artifacts from the 13th to the 16th century. Three profiles were documented and lithostratigraphically described. Samples for the palaeoecological and chemical analyses and granulometry were taken from the excavated probe S11. The finding of the rivers´ point bar and the shape of the riverbed allowed us to determine that the river was meandering. Analysed pollen profile of the medieval riverbed shows species-rich vegetation in the close proximity od the medieval town and progressing urbanization. Results from chemical analyses shows that the area was not significantly polluted. The source of most of the probable contamination were surrounding sumps, as is indicated by slightly elevated concentrations of phosphorus in the sediments

Impacts of native and alien plant dominants at different spatial scales

Plant invasion science has made a substantial progress in documenting the impacts of aliens, but comparisons with the impacts of native dominants are still rare. Further, the impacts on larger spatial scales remain poorly understood. We recorded the impacts of 10 native and nine invasive dominant plants in the Czech Republic on species richness and Shannon diversity by comparing communities with high vs. low cover of the dominant species. To estimate the impacts at the (i) population level and (ii) between-population level, we compared the Jaccard dissimilarity, nestedness and turnover of high- and low-dominance plots. Further, we calculated the Jaccard dissimilarity, nestedness and turnover between the high- and low-dominance plots within each population to express the impacts on species composition. We tested whether (i) native and invasive dominants affect the population- and between population levels of diversity by making the vegetation more homogenous; (ii) whether these effects differ between the native and alien dominants; and (iii) whether the impacts at different spatial levels are related. At the population level, high-dominance plots (with both native and alien dominants) showed higher nestedness and lower turnover compared to the low-dominance plots. Further, all plots with native dominants, both with high- and low dominance, showed higher similarity but lower nestedness than plots with alien dominants. Most importantly, high-dominance plots with native dominants were more similar to each other but showed marginally significantly lower nestedness compared to high-dominance plots with alien dominants. At the between-population level, high-dominance plots with native dominants showed a marginally significantly lower turnover compared to high-dominance plots with alien dominants. The differences in Jaccard dissimilarity, nestedness and turnover between the low- and high-dominance plots at the population level showed strong positive relations to low- and high-dominance differences at the between-populations level. Further, compositional impacts, expressed as the dissimilarity between high- vs. low-dominance plots, positively related to the plot-level impacts on Shannon diversity. Our results show that (i) both native and invasive dominants tend to reduce the diversity over larger areas and that the effect of native dominants may be even stronger, and (ii) the effects on plot-level richness and diversity cannot be easily extrapolated to larger scales but the impacts at the population- and between-populations levels are positively related

Paleomeander at the Northern bailey of the archaeological site Pohansko near Břeclav

The site is situated in the bottomland near the confluence of Dyje and Morava rivers. The junction area is split by many sides and inactive channels. The human impact (settlement establishment, deforestation and landscape management) is also reflected in the bottomland development. Processes lead to erosion, accumulation of sediments in river beds and changes in vegetation. One of the peaks of the settlement of the studied area can be considered during existence of the Great Moravian Empire when the settlement agglomerations developed directly in the floodplain. The area has been intensively archaeologically studied for a long time. In the context of the ongoing climate change and increasing intensity of floods the relationship between climate, natural conditions and the functioning of the human settlements comes to the forefront of scientific interest. For the reconstruction of the complicated floodplain development a combination of different research methods was used. For direct determination of stratigraphy an excavated transect through the sediments connecting the edge of the settlement (in the area of the so called Northern bailey) on the sand elevation („hrúd“) and lower flood-plain step in the area of presumptive paleomeander has been studied. Direct field documentation and palynological and sedimentological studies and 14C dating method were utilized. These methods have been supplemented by remote sensing methods: Geophysics (ERT, DEMP), Lidar. On their basis a digital relief model (extend of measured area was 54 000 m2) was created as well as a map of conductivity anomalies. The study documented a sequence of extinct riverbeds (a series of fluvial point bars) of various ages at the northern edge of Pohansko. Their stratigraphic position proves the stage when the active channel was eroding the edge of the archaeological site. The sediments stored in previous periods were destroyed by erosion in this space. The aggradation of the floodplain occurred in 14th–16th century. Results of pollen analysis indicate the presence of a mosaic of forested and open landscape of mesophilous alluvial woodlands and open areas. The immediate vicinity of the sedimentary area was not too much affected by agricultural activity at that time. Compared to palynospectra from sediments of the Great Moravian settlement, the deforestation intensity and the proportion of anthropogenic indicators were noticeably lower.The site is situated in the bottomland near the confluence of Dyje and Morava rivers. The junction area is split by many sides and inactive channels. The human impact (settlement establishment, deforestation and landscape management) is also reflected in the bottomland development. Processes lead to erosion, accumulation of sediments in river beds and changes in vegetation. One of the peaks of the settlement of the studied area can be considered during existence of the Great Moravian Empire when the settlement agglomerations developed directly in the floodplain. The area has been intensively archaeologically studied for a long time. In the context of the ongoing climate change and increasing intensity of floods the relationship between climate, natural conditions and the functioning of the human settlements comes to the forefront of scientific interest. For the reconstruction of the complicated floodplain development a combination of different research methods was used. For direct determination of stratigraphy an excavated transect through the sediments connecting the edge of the settlement (in the area of the so called Northern bailey) on the sand elevation („hrúd“) and lower flood-plain step in the area of presumptive paleomeander has been studied. Direct field documentation and palynological and sedimentological studies and 14C dating method were utilized. These methods have been supplemented by remote sensing methods: Geophysics (ERT, DEMP), Lidar. On their basis a digital relief model (extend of measured area was 54 000 m2) was created as well as a map of conductivity anomalies. The study documented a sequence of extinct riverbeds (a series of fluvial point bars) of various ages at the northern edge of Pohansko. Their stratigraphic position proves the stage when the active channel was eroding the edge of the archaeological site. The sediments stored in previous periods were destroyed by erosion in this space. The aggradation of the floodplain occurred in 14th–16th century. Results of pollen analysis indicate the presence of a mosaic of forested and open landscape of mesophilous alluvial woodlands and open areas. The immediate vicinity of the sedimentary area was not too much affected by agricultural activity at that time. Compared to palynospectra from sediments of the Great Moravian settlement, the deforestation intensity and the proportion of anthropogenic indicators were noticeably lower

Technology and provenience of the oldest pottery in the northern Pannonian Basin indicates its affiliation to hunter-gatherers

Consensus holds that pottery technology came to Central Europe from the Northern Balkans with independent pottery traditions existing concurrently in Eastern Europe. An unusual grass-tempered pottery dating back to around 5800 cal BC found in lake sediments at Santovka, Slovakia, predated the earliest known Neolithic pottery in the region (~ 5500 cal BC), suggesting unexplored narratives of pottery introduction. Analyses of the pottery’s technology, origin, and grass temper shedding light on ceramic traditions' spread can unveil mobility patterns and community lifestyles. Our findings indicate a non-local provenance, low temperature firing, Festugc sp. grass temper and unique rectangular or cylindrical vessel shapes which align with Eastern European hunter-gatherer practices. Moreover, the pottery style and technology have no analogies in the contemporary Danubian pottery traditions and have more similarities to those of the Eastern traditions. The pottery's raw materials likely originated from distant areas, indicating extensive territorial access for its creators. Our findings imply late Mesolithic hunter-gatherers as the probable artisans and with implications for the site's significance in the late Mesolithic landscape

Responses of competitive understorey species to spatial environmental gradients inaccurately explain temporal changes

Understorey plant communities play a key role in the functioning of forest ecosystems. Under favourable environmental conditions, competitive understorey species may develop high abundances and influence important ecosystem processes such as tree regeneration. Thus, understanding and predicting the response of competitive understorey species as a function of changing environmental conditions is important for forest managers. In the absence of sufficient temporal data to quantify actual vegetation changes, space-for-time (SFT) substitution is often used, i.e. studies that use environmental gradients across space to infer vegetation responses to environmental change over time. Here we assess the validity of such SFT approaches and analysed 36 resurvey studies from ancient forests with low levels of recent disturbances across temperate Europe to assess how six competitive understorey plant species respond to gradients of overstorey cover, soil conditions, atmospheric N deposition and climatic conditions over space and time. The combination of historical and contemporary surveys allows (i) to test if observed contemporary patterns across space are consistent at the time of the historical survey, and, crucially, (ii) to assess whether changes in abundance over time given recorded environmental change match expectations from patterns recorded along environmental gradients in space. We found consistent spatial relationships at the two periods: local variation in soil variables and overstorey cover were the best predictors of individual species’ cover while interregional variation in coarse-scale variables, i.e. N deposition and climate, was less important. However, we found that our SFT approach could not accurately explain the large variation in abundance changes over time. We thus recommend to be cautious when using SFT substitution to infer species responses to temporal changes.</p