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1. 50. let existence České (Československé) demografické společnosti

Creator:
Zdeněk Pavlík
Format:
print, bez média, and svazek
Type:
article, zprávy, model:article, and TEXT
Subject:
Demografie. Populace, Česká demografická společnost, Československá demografická společnost, 20.-21. století, výročí, demografie, instituce a organizace, anniversaries, demography, institutions and organizations, Česko, Czechia, 18, and 314
Language:
Czech
Description:
Zdeněk Pavlík.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

2. Adult demography, spatial distribution and movements of Zerynthia polyxena (Lepidoptera: Papilionidae) in a dense network of permanent habitats

Creator:
Čelik, Tatjana
Type:
article, články, model:article, and TEXT
Subject:
Zoologie, zoologie, entomologie, Lepidoptera, Papilionidae, Zerynthia polyxena, Southern Festoon, mark-release-recapture, demography, resource distribution, movement, home range, butterfly conservation, 2, and 59
Language:
English
Description:
1_The adult demographic parameters, mobility, nectar choice and how the spatial distribution of males and females of Z. polyxena is affected by the distribution and abundance of host-plants, and adults of the opposite sex was studied in a population of this species inhabiting a dense network of permanent habitats (totalling 8.7 ha). The population size was estimated to be ca. 300 individuals. The average adult lifespan was 4.4 days and the maximum 23 (male) and 20 (female) days. The capture probability was higher for males than females due to the more conspicuous behaviour and bounded area of activity of males. A slow increase was followed by a slow decrease in the sex specific parabolic recruitment curve, indicating slight protandry and long emergence period, probably due to habitat heterogeneity. The spatial distribution of host plants (Aristolochia lutea) is the key factor determining the spatial distribution of adults. There was a strong positive correlation between male and female density at each patch, both of which were dependent on the cover of host plants growing in sunny conditions. In searching for A. lutea plants suitable for oviposition, females fly greater distances and move more frequently between patches than males. The size, shape and orientation of the male home range were influenced by the size, shape and orientation of stands of host-plants in sunny positions, but not by patch area. Such adult fidelity to stands of host-plants in sunny positions indicates that the spatial distributions of oviposition sites, mate-locating sites and larval habitats of Z. polyxena overlap. The better statistical fit and much lower probabilities for long-distance movements generated by a negative exponential function than an inverse power function are probably due to the small size and high habitat connectivity of the site studied. Adults were opportunistic in their use of nectar plants., 2_Traditional management is the key factor for maintaining permanent habitats for this species in a grassland biotope., Tatjana Čelik., and Obsahuje seznam literatury
Rights:
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3. Demography of adults of the Marsh fritillary butterfly, Euphydryas aurinia (Lepidoptera: Nymphalidae) in the Czech Republic: Patterns across sites and seasons

Creator:
Kamil Zimmermann, Blažková, Pavla, Čížek, Oldřich, Frič, Zdeněk, Hůla, Vladimír, Kepka, Pavel, Novotný, David, Slámová, Irena, and Martin Konvička
Type:
article, články, model:article, and TEXT
Subject:
Zoologie, entomologie, Česko, Czechia, Lepidoptera, Nymphalidae, Euphydryas aurinia, Marsh fritillary, butterfly conservation, demography, density dependence, grasslands, local dynamics, metapopulation, 2, and 59
Language:
English
Description:
The Marsh fritillary (Euphydryas aurinia) (Lepidoptera: Nymphalidae) has declined across Europe, including the Czech Republic. Current conservation strategies rely on prevention of habitat loss and degradation, and increase in habitat quality and connectivity via promoting traditional grassland management. The population structure and adult demography parameters of a single population was investigated for eight years (single system), and of all the known Czech populations (multiple populations) for a single year, using mark-recapture. There was substantial variation in the patterns of adult demography, both among years in the single system and among the multiple populations in a single year. In the single system, the date of the first flight of an adult varied by 18 days over the 8 years and total annual numbers varied with a coefficient of variation of 0.40 (females fluctuating more than males). The average density was ca 80 adults/ha. The population size displayed density-dependence, i.e. decreased following years with high adult numbers, with an equilibrium density of 90 individuals/ha. The average density of the multiple populations was ca 120 individuals/ha. The estimated total population for the Czech Republic was 25,000 individuals (17,000 males / 8,000 females) in 2007, which does not indicate an imminent threat of extinction. The regional persistence of E. aurinia is likely to depend on re-colonisation of temporarily vacant sites by dispersing individuals, facilitated by local shifts in adult flight phenology to that better adapted to local conditions. and Kamil Zimmermann, Pavla Blazkova, Oldrich Cizek, Zdenek Fric, Vladimir Hula, Pavel Kepka, David Novotny, Irena Slamova, Martin Konvicka.
Rights:
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4. Demography of the endangered butterfly Euphydryas aurinia (Lepidoptera: Nymphalidae): A case study of populations in sub-Mediterranean dry calcareous grasslands

Creator:
Jugovic, Jure, Uboni, Costanza, Zupan, Sara, and Lužnik, Martina
Format:
print, počítač, and online zdroj
Type:
model:article and TEXT
Subject:
motýli, babočkovití, demografie, grasslands, butterflies, Nymphalidae, demography, Slovinsko, Slovenia, Euphydryas aurinia, mark-release-recapture, movement, nectar plants, metapopulation, 2, and 59
Language:
English
Description:
We studied a population of the regionally endangered marsh fritillary butterfly Euphydryas aurinia inhabiting a system of loosely connected dry calcareous grasslands in sub-Mediterranean Slovenia. Our goal was to set the basis for a long-term monitoring of this butterfly in four meadows using mark-release-recapture (MRR). We determined its demographic parameters, dispersal, behaviour and utilization of nectar plants in different quality patches. Total population size was estimated to be approximately 347 males (95% confidence interval: 262-432) and 326 females (95% confidence interval: 250-402), with an unbiased sex ratio. The average lifespans were 6.3 and 8.6 days, respectively. Daily population sizes followed a parabola with marked protandry. Both sexes were relatively highly mobile with both occasionally moving over half a kilometre. The spatial distribution of animals seemed to be associated with patch size, host plant densities and nectar sources, resulting in much higher population densities in the largest patch. Adult behaviour differed between the sexes, with females resting more and flying less than males. Behaviour also changed during daytime and with the progression of the season. Adults were confirmed to be opportunistic feeders, since as many as ten nectar sources were detected. We conclude that demographic parameters differ greatly among regions and habitats, thus conservation aims should be planned accordingly. Although the population studied is apparently in good condition, there are threats that may hamper the long-term persistence of the species in this area: succession, intensification of mowing and overgrazing., Jure Jugovic, Costanza Uboni, Sara Zupan, Martina Lužnik., and Obsahuje bibliografii
Rights:
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5. Effect of grassland management on the age and reproduction structure of Helianthemum nummularium and Lotus corniculatus populations

Creator:
Poschlod, Peter, Hoffmann, John, and Bernhardt-Römermann, Markus
Type:
article and TEXT
Subject:
abandonment, ageing of plant populations, burning, calcareous grassland, clonality, conservation, demography, grazing, mowing, mulching, population structure, population viability, and seasonal germination niche
Language:
English
Description:
Dry calcareous grasslands are among the most species-rich and endangered ecosystems in the Central- European landscape. They are of anthropogenic origin and mainly a result of grazing by domestic animals. Due to land-use changes in the last century, particularly in the 1960s, they were often abandoned or afforested. Therefore, in 1975 long-term experiments were started in the southwestern Germany (Baden-Württemberg) to determine the effectiveness of alternative management treatments in maintaining grasslands and their species composition. The aim of this study was to assess the effect of grazing (reference management treatment), mowing once a year, mulching twice a year, mulching every second year, burning once a year and succession (abandonment) on the population structure (in terms of density, age structure, reproduction mode) and seasonal germination niche of a dwarf shrub, Helianthemum nummularium, and a herbaceous plant, Lotus corniculatus. To study the age structure, annual ring analyses were applied. The classification of the reproduction mode, either by seed or vegetatively, was carried out by differentiating the central under-ground organ either as a root (in this case the individual has established from seed) or rhizome (the individual has developed from clonal multiplication). The seasonal germination niche was derived from the age structure. Management clearly affected population density and age structure. Highest density of individuals was found in the grazing and the lowest in the succession treatment. In the mulching every second year and succession treatments populations were senescent. Management also affected reproduction mode in H. nummularium. Regeneration by seed was especially enhanced by mowing and burning but was inhibited by mulching twice and succession. In the latter treatments H. nummularium reproduced only clonally. Helianthemum nummularium germinated mainly in autumn but burning by breaking the dormancy of seeds initiated germination in spring. A similar pattern was detected in L. corniculatus: burning increased germination rate in spring. Comparing population characters (density, age, reproduction mode) to the traditionally used grazing treatment, mowing was most similar and for L. corniculatus additionally burning. This is in contrast to the assessment of the vegetation of the management treatments where mowing and mulching twice per year maintain a similar floristic composition. Finally, the analysis of the population structure revealed important mechanisms behind population and vegetation dynamics.
Rights:
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6. Effects of aluminium toxicity and low pH on the early development of Isoëtes echinospora

Creator:
Čtvrtlíková, Martina, Vrba, Jaroslav, Znachor, Petr, and Hekera, Petr
Type:
article and TEXT
Subject:
acidification, demography, Isoëtes echinospora, quillwort, recovery, reproduction, and sporeling
Language:
English
Description:
A relict population of Isoëtes echinospora Durieu survived a thirty-year period of severe acidification and high concentrations of phytotoxic aluminium (Al) in Plešné Lake (Bohemian Forest, Czech Republic). The population consisted of only adult plants. Sporeling survival and age structure were examined during the population recovery in 2004–2008. Laboratory experiments were conducted to assess the effect of various pH values (4–8) and Al concentrations (0–1000 µg·l–1) on sporeling development. The responses of the sporelings to the experimental treatments were evaluated and compared with those observed in the lake. The experiments showed that an Al concentration higher than 300 µg·l–1, and high acidity (pH 4), inhibit sporeling growth, in particular resulted in a pronounced reduction in absorptive organs (macrogametophyte rhizoids, roots and root hairs). With increasing concentrations of Al and at pH 4, the ratio of the below-ground to above-ground sporeling biomass decreased to less than 1. The responses of the lake sporelings, rooting in the upper sediment layer, were similar to those exposed to 100–300 µg·l–1 of Al in the laboratory, and reflected the Al toxicity of the lake water. The quillworts at Plešné Lake survived because adult plants can tolerate these adverse conditions and are very long-lived. The population recovered when the pH of the water increased to over 5 and the Al concentration decreased to below 300 µg·l–1.
Rights:
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8. Genet longevity and population age structure of the clonal pioneer species Geum reptans based on demographic field data and projection matrix modelling

Creator:
de Witte, Lucienne C., Scherrer, Daniel, and Stöcklin, Jürg
Type:
article and TEXT
Subject:
alpine vegetation, clonal reproduction, demography, genet age, glacier foreland, mortality risk, population persistence, recruitment, and Swiss Alps
Language:
English
Description:
Genet life span is a key demographic trait for understanding life history of plants. However, the longevity of clonal plants is hard to determine, especially when inter-ramet connections are short-lived and plants subsequently move independently of one another in space by means of an expansive growth strategy. In this study we estimated genet life span in the clonal pioneer species Geum reptans, living on glacier forelands, by using a projection matrix model based on demographic field data of ramets collected at two sites and in three subsequent years. We then calculated genet age structure at different population ages using multiple simulations, including a maximum carrying capacity and density-dependent mortality. Additionally, we estimated the age of the two field populations by comparing results from simulations with population structure recorded in the field. According to our simulations, more than half of the genets die within the first three decades. However, a considerable proportion survived more than 50 years and some genets even became immortal as they produced so many ramets that the risk of the entire genet becoming extinct was zero. Simulated genet age structures were strongly left skewed with many young and a few very old genets. The rather low carrying capacity was reached only after 350 years, after which density-dependent mortality started to influence genet age structure considerably. The age of the two field populations was estimated to be 250 and 450 years, respectively. Results indicate that in clonal plants, genet immortality can potentially lead to unlimited persistence of established populations. In the case of G. reptans, old populations may experience competition and increased mortality due to the ongoing succession in older parts of the glacier foreland that will prevent populations reaching their maximum carrying capacity. But due to the ability of this plant to colonize new sites and follow retreating ice on glacier forelands, populations of G. reptans can be very old as recorded here for the two field populations in the Swiss Alps.
Rights:
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9. Has the currently warming climate affected populations of the mountain ringlet butterfly, Erebia epiphron (Lepidoptera: Nymphalidae), in low-elevation mountains?

Creator:
Martin Konvička, Jiří Beneš, Oldřich Čížek, Tomáš Kuras, and Irena Klečková
Format:
print, počítač, and online zdroj
Type:
article, články, journal articles, model:article, and TEXT
Subject:
Zoologie, motýli, babočkovití, demografie, butterflies, Nymphalidae, demography, Erebia epiphron, alpine habitats, temperate mountains, climate warming, population structure, timberline, 2, and 59
Language:
English
Description:
Climate change scenarios predict losses of cold-adapted species from insular locations, such as middle high mountains at temperate latitudes, where alpine habitats extend for a few hundred meters above the timberline. However, there are very few studies following the fates of such species in the currently warming climate. We compared transect monitoring data on an alpine butterfly, Erebia epiphron (Nymphalidae: Satyrinae) from summit elevations of two such alpine islands (above 1300 m) in the Jeseník Mts and Krkonoše Mts, Czech Republic. We asked if population density, relative total population abundance and phenology recorded in the late 1990s (past) differs that recorded early in 2010s (present) and if the patterns are consistent in the two areas, which are separated by 150 km. We found that butterfly numbers recorded per transect walk decreased between the past and the present, but relative population abundances remained unchanged. This contradictory observation is due to an extension in the adult flight period, which currently begins ca 10 days earlier and lasts for longer, resulting in the same total abundances with less prominent peaks in abundance. We interpret this development as desynchronization of annual cohort development, which might be caused by milder winters with less predictable snow cover and more variable timing of larval diapause termination. Although both the Jeseník and Krkonoše populations of E. epiphron are abundant enough to withstand such desynchronization, decreased synchronicity of annual cohort development may be detrimental for innumerable small populations of relic species in mountains across the globe., Martin Konvička, Jiří Beneš, Oldřich Čížek, Tomáš Kuras, Irena Klečková., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

10. Hermann Zeitlhofer. Besitzwechsel und sozialer Wandel. Lebensläfe und sozioökonomische Entwicklungen im südlichen Böhmerwald, 1640-1840

Creator:
Josef Grulich
Format:
print, bez média, and svazek
Type:
article, recenze, model:article, and TEXT
Subject:
Demografie. Populace, 17.-19. století, demografie, obyvatelstvo, demography, population, Šumava (pohoří : oblast), Šumava Mountains Region, 18, and 314
Language:
Czech
Description:
[autor recenze] Josef Grulich. and Obsahuje bibliografii
Rights:
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