Land use legacies in post-agricultural forests in the Doupovské Mountains,Czech Republic

Questions: Do differences in previous land use cause long-lasting changes in soil chemistry? Is vegetation composition affected by the previous land use after 50 years of secondary succession? Is the effect of previous land use caused by pre-existing differences in environmental conditions or mediated through changes in soil chemistry? How important is the effect of previous land use in relation to other factors? Location: Doupovské Mountains, Czech Republic. Methods: A stratified random sampling design was used to collect 91 vegetation relevés with accompanying soil samples. The effects of previous land use (arable field, meadow, pasture) on soil pH, organic carbon (C), total nitrogen (N), C:N ratio and available phosphorus were tested by an analysis of covariance. A canonical correspondence analysis and variation partitioning procedure were used to reveal relationships among previous land use, environmental factors and species composition. Results: Organic C, total N and C:N ratio were significantly influenced by previous land use, while available phosphorus and soil pH were not. Previous land use explained a significant part of the variation in species composition and its effects only partly overlapped with the effects of soil chemistry and terrain attributes. However, the species composition of post-agricultural forests was mostly determined by environmental factors not modified by previous land use. Conclusions: Forest communities that originate on abandoned agricultural land are primarily determined by natural environmental conditions. Nevertheless, the type of previous land use also modifies the species assemblages of these forests and needs to be considered as an important determinant of their composition.     

Use of human buildings by Eurasian badgers in the Moravskoslezské Beskydy Mountains,Czech Republic

An inspection of human buildings used by Eurasian badgersMeles meles (Linnaeus, 1758) in 28 sites in the Moravskoslezské Beskydy Mountains, Czech Republic, was carried out in 2001. The buildings inhabited or visited by badgers were as follows: wooden barns (18 cases), masonry buildings used for residential purposes (4), abandoned buildings (1), wooden sheds (2), wooden beehouses (2) and a non-residential part of a house (1). In three sites, female badgers with their cubs inhabited buildings. Badgers use the buildings more frequently in winter than in summer. Use of human buildings and the occurrence of badgers in setts in the wild in these mountains was observed in detail on a study area of 950 ha around the village of Lubno. In total, 12 setts were discovered. Eight of them were in the wild: two setts were located closer than 50 m, five between 100 m and 300 m, and one 700 m from human buildings. In four sites badgers inhabited human buildings.     

Vegetation changes in blown-down and scorched forests 10–26 years after the eruption of Mount St. Helens,Washington, USA

We examine patterns of vegetative change in blown-down and scorched forests in the blast zone of Mount St. Helens (USA), 10–26 years after the eruption. We compare trends in community attributes in four post-eruption environments, or site types, defined by severity of disturbance, presence/absence of a protective snowpack at the time of eruption, and seral state (previously clearcut vs. mature/old forests). Permanent plots established in 1980 at 16 sites were sampled at 5- to 6-year intervals between 1989 and 2005. Data on species presence and abundance were used to characterize changes in total plant cover, life-form spectra, species diversity, species turnover, and community composition. Due to the magnitude and heterogeneity of disturbance, vegetation re-establishment was gradual and highly variable among sites. Total plant cover averaged 36–70% after 26 years. Early-seral forbs were dominant except in snow-protected sites, where surviving shrubs were most common. Tree regeneration remained sparse after 26 years (<?6% cover in all but two sites). Species richness increased in all site types, reflecting greater species gain than loss, although rates of gain declined with time. Species heterogeneity, integrating the number and abundance of taxa, did not increase. Successional trajectories were distinct, but parallel among sites, reflecting legacies of pre-eruption composition, variation in disturbance severity, and differences in composition of early-seral colonists. Slow re-colonization by forest herbs and trees likely reflects seed limitations and abiotic stress rather than competition from early-seral species. Succession following this major eruption is both slow and contingent on pre-conditions, nuances of the disturbance, and species’ life histories.     

Long-term changes in numbers and distribution of wintering waterbirds in the Czech Republic, 1966–2008

Capsule?Of 26 species of wintering waterbirds, 18 showed an increase in numbers, five showed a decrease and two showed no change.

Aim?To assess long-term trends in the numbers and distribution of the 26 most abundant wintering waterbird species in the Czech Republic.

Methods?We used International Waterbird Census data from between 48 and 639 wetland sites which had been counted annually in the Czech Republic from 1966 to 2008. From these data long-term changes in numbers and distributions were determined. Log-linear Poisson regression analysis was used to estimate missing data using trim software. The distribution of each species was described as the ratio of the number of sites occupied by that species to the total number of sites investigated.

Results?Increasing trends were found for 18 species, five species were found to be declining, one species was stable and two species were found with uncertain trends. Wintering distributions (the ratio of sites occupied by a given species to the total number of sites counted) increased in 16 species and decreased in two species, broadly correlated with the species changes in numbers.

Conclusion?In most species changes in numbers as well as changes in distribution followed the Western Palearctic population trends. Those species which increased were mainly piscivores and included geese, ducks and gulls. Scarcer species also exhibited an increase in numbers. The changes in numbers (both positive and negative) were more frequent among species associated with running water, whereas species which showed uncertain trends were more frequently recorded on standing water, which is more affected by variable weather conditions.     

Palaeolimnological evidence of environmental change over the last 400 years in the Rwenzori Mountains of Uganda

Tropical alpine areas may be highly sensitive to climate change. Yet, because high-resolution palaeoenvironmental studies in these regions are scant, patterns of environmental change over the last few centuries, and linkages with regional changes, remain poorly resolved. This article presents a 400-year palaeolimnological record from Lower Kitandara Lake (3,989 m above m.a.s.l.), located in the Rwenzori Mountains of Uganda, where marked glacial recession has been recorded over much of the twentieth century. An age model is produced for a 57.5 cm sediment core based on ²¹⁰Pb and ¹⁴C dating, suggesting a basal date of approximately 1600 AD. Diatom and organic geochemistry (%TOC, C/N ratios, δ¹³C) analyses are carried out at an approximately decadal resolution. Twentieth-century glacial recession does not appear to have significantly impacted either the diatom or geochemical records. However, large ecological changes have occurred during the past 400 years, particularly shown by the diatom fluxes and geochemical data. Throughout the core, the diatom record reveals only minor changes in assemblage composition, which may be related to the dominance of Staurosira construens var. venter in the lake’s diatom flora, a tychoplanktonic taxon which is highly adaptive to environmental change. Geochemical analyses, however, reveal a marked change at around the end of the eighteenth century, when C/N ratios suggest an increase in the dominance of algal aquatic sources to lacustrine organic matter, concomitant with a stabilisation of catchment inputs and increased diatom productivity, which may have been caused by reduced glacial inputs. The relationship between these changes at Lower Kitandara Lake and wider regional climate change that occurred at the end of the eighteenth century is not well understood, but this study highlights the need for additional research to link drivers of alpine ecosystem change with those operating at low altitudes.     

Relationships between sudden weather changes in summer and mortality in the Czech Republic, 1986–2005

The study examines the relationship between sudden changes in weather conditions in summer, represented by (1) sudden air temperature changes, (2) sudden atmospheric pressure changes, and (3) passages of strong atmospheric fronts; and variations in daily mortality in the population of the Czech Republic. The events are selected from data covering 1986–2005 and compared with the database of daily excess all-cause mortality for the whole population and persons aged 70 years and above. Relative deviations of mortality, i.e., ratios of the excess mortality to the expected number of deaths, were averaged over the selected events for days D−2 (2 days before a change) up to D+7 (7 days after), and their statistical significance was tested by means of the Monte Carlo method. We find that the periods around weather changes are associated with pronounced patterns in mortality: a significant increase in mortality is found after large temperature increases and on days of large pressure drops; a decrease in mortality (partly due to a harvesting effect) occurs after large temperature drops, pressure increases, and passages of strong cold fronts. The relationship to variations in excess mortality is better expressed for sudden air temperature/pressure changes than for passages of atmospheric fronts. The mortality effects are usually more pronounced in the age group 70 years and above. The impacts associated with large negative changes of pressure are statistically independent of the effects of temperature; the corresponding dummy variable is found to be a significant predictor in the ARIMA model for relative deviations of mortality. This suggests that sudden weather changes should be tested also in time series models for predicting excess mortality as they may enhance their performance.     

Influence of environmental factors on the occurrence of Ixodes ricinus ticks in the urban locality of Brno - Pisárky, Czech Republic.

The occurrence of Ixodes ricinus ticks was observed in the suburban locality of Brno-Pisárky (South Moravia, Czech Republic) from March to November, 1996 to 2002. A total of 2,813 ticks was collected. Statistical tests divided the activity of ticks into three periods during the year. The curve of seasonality had two peaks with a maximum in May and August, with a significantly larger number of specimens collected during this period compared to other months. The abundance of ticks during Spring and Autumn months was comparable. All developmental stadia of ticks were found in this locality. The number of larvae, males, and females was not significantly different, but the occurrence of nymphs was significantly greater. Except for the year 2000, there were no statistically significant differences in tick abundance. Tick activity was not dependent on humidity but did vary directly with temperature. This relation had a linear character and could be described by the equation y = 8.3 + 1.8x.     

Vegetation changes during the Holocene in the North Ibersá, Corrientes, Argentina

Vegetation changes during the Holocene in the North Iberá, Corrientes, Argentina. Wetlands are very important sites for palynological studies, since they represent one of the most suitable environments for fossil pollen preservation. The aim of this work was to determine, by palynological analysis of lacustrine sediments, the vegetal communities and the predominant environment during the Holocene in NW of Iberá. Two lagoons were studied: San Sebastián and San Juan Poriahú. Sediment samples were obtained with witness using a "Levingstone square-rod sampler", processed with Faegri e Iversen techniques and dated with C14. The palynological graphs were divided in zones using the Tilia program. The palynological analysis allowed visualizing diverse changes in the vegetation: from 6 140 +/- 50 to 5 170 +/- 100 a. C., the NW of Iberá was characterized by marsh-herbaceous vegetation and arboreal vegetation typical of dry vegetation. From 5 170 +/- 100 to 3 460 +/- 60 a. C., a decrease in the species frequency, typical of wet environments, is produced, and the clogging of the waterbody, from 3460 +/- 60 a. C. onwards, while continuing the dominance of herbaceous vegetation typical of these environments, the arboreal pollen, indicates the beginning of a hygrophilous forest development.     

Bird community changes associated with cattle raising management in the delta forests of the Paraná River

Riparian forests and environments close to watercourses support high biodiversity, which may be modified by human activities. In the Paraná River Delta region, cattle raising is one of the activities with the greatest impact, altering vegetation structure. These changes are reflected in bird communities that inhabit these environments. We hypothesize that the absence of large herbivores (whether cows or native deer) will produce an increase in the vegetation cover of the lower strata of forests, due to the greater height of the herbaceous stratum and greater coverage of the shrub stratum, and that these changes mainly affect the species of birds that use resources associated with these strata. Our objective was to understand the changes in richness and abundance of the bird community among different types of cattle management using a functional aggregation approach of bird species. In the areas with cattle, we found less coverage of the shrub layer, lower height of the herbaceous layer and fewer climbing vines. We found that changes in richness and abundance of bird community were strongly related to species associated with the lower vegetation strata (ground-feeding guild, shrub guild and low canopy guild), and that the responses of the different guilds were not homogeneous. Understanding the direction of changes in bird communities occurring in response to modifications of the environment, allows us to optimize conservation efforts. If these efforts are based on conservation of the environment in its natural state, we should adjust the management of the herbivory to the pristine conditions of the environment. On the other hand, if conservation efforts are based on particular species or groups of species associated with certain resources, the correct management of herbivory by cattle can be essential to obtain successful results.     

An assessment of orchids’ diversity in Penang Hill,Penang, Malaysia after 115 years

A comprehensive study on the orchid diversity in Penang Hill, Penang, Malaysia was conducted from 2004 to 2008 with the objective to evaluate the presence of orchid species listed by Curtis (J Strait Br R Asiat Soc 25:67–173, 1894) after more than 100 years. A total of 85 species were identified during this study, of which 52 are epiphytic or lithophytic and 33 are terrestrial orchids. This study identified 57 species or 64.8% were the same as those recorded by Curtis (1894), and 78 species or 66.1% of Turner’s (Gardens’ Bull Singap 47(2):599–620, 1995) checklist of 118 species for the state of Penang including 18 species which were not recorded by Curtis (1894) and the current study but are actually collected from Penang Hill. A comparison table of the current findings against Curtis (1894) and Turner (1995) is provided which shows only 56 species were the same in all three studies. The preferred account for comparison was Curtis’ (1894) list as his report was specifically for the areas around Penang Island especially Penang Hill, Georgetown and Ayer Itam areas. Our study reveals that about 50% of Curtis’ collection localities have been converted to residential areas and agricultural land, and this probably explains the decreasing numbers of species found in the current study especially for the terrestrial species as epiphytic species have better adaptation capabilities towards environmental changes. Seven species were identified as new records to Penang Hill as they were not recorded by Curtis (1894). None of the three species recorded as endemic to Penang by Turner (1995) was recollected during the current study, of which only Zeuxine rupestris was in Curtis’ (1894) list. Overall, we concluded that Penang hill harbours at least 136 species of orchids of which 78 species or 57.4% were recollected in this study. This also indicates that this area is still suitable for orchid growth even though it is surrounded by rapid development and mass conversion of forested land into fruit orchards and residential area. The designation of Penang Hill as a Permanent Forest Reserve would better guarantee the survival of some orchid species unless human interventions and climatic changes occur.     

Diversity of saproxylic bryophytes in old‐growth and managed beech forests in the central Balkans

Abstract

The diversity of saproxylic bryophyte species in beech forest stands from the wide region of the central Balkans (i.e. Serbia and Montenegro) was studied, and this study is the first of such a type in SE Europe. Comparison of preserved old‐growth and managed forests were made. Bryophyte species diversity is higher in primeval forest stands where the spectra of dead wood in various decaying stages of its dynamics are present. The ecological group of epixylic specialists is predominant among the bryophytes recorded. Threatened bryophyte species occur in old‐growth beech stands. The dead wood as habitat together with some other factors are extremely important for the surviving of epixylic bryophyte; so these species can be used as bioindicator bryophyte species of old‐growth or managed and structured forest ecosystems.     

Trends in stage-specific population-based survival of cancer patients in the Czech Republic in the period 2000–2008

BackgroundThe objective of this study was to assess trends in overall and in stage-specific 5-year relative survival rates of the Czech cancer patients between periods 2000–2004 and 2005–2008.MethodsAll Czech cancer patients diagnosed between 1995 and 2008 were included in the analysis. Period analysis was employed to calculate 5-year relative survival for 21 cancers.ResultsSignificant improvements in crude 5-year relative survival for 14 of 21 assessed types of cancer, including the most frequent diagnoses, such as, colorectal, prostate, breast, lung, kidney, pancreatic, and bladder cancer and melanoma, were identified. Moreover, in case of colorectal, lung, and prostate cancer, improvement in stage-specific 5-year relative survival was confirmed as statistically significant for all clinical stages. No diagnosis showed significant decrease in the 5-year relative survival. However, the 5-year relative survival remained poor in patients with metastatic cancers at diagnosis, particularly in case of liver, pancreatic, lung, and oesophageal cancer.ConclusionsThe cancer-specific outcomes in the Czech Republic are improving. Nevertheless, despite the overall significant improvement in 5-year relative survival of most of the cancer diagnoses, the high proportion of patients primarily diagnosed with metastatic cancer still represents a substantial challenge for prevention and early detection.     

A new species of the sleeper goby (Gobioidei,Eleotridae) from the České Středohoří Mountains (Czech Republic,Oligocene) and analysis of the validity of the family Pirskeniidae

A new species of gobioid fish Pirskenius Obrhelová, 1961 (P. radoni sp. nov.) is described from Oligocene strata of the ?eské St?edoho?í Mountains and compared with related species. The new species is characterized by a unique combination of characters that allow it to be separated from P. diatomaceus Obrhelová, 1961. The taxonomic position of the genus Pirskenius is discussed, and its affinity to the family Eleotridae is indicated. The new record documents, together with P. diatomaceus, the oldest known skeletal record of the Eleotridae.     

Effect of rotational and continuous grazing on vegetation of an upland grassland in the Jizerské hory Mts., Czech Republic

The effect of different grazing regimes on pasture vegetation was studied during the intensive grazing of heifers in the Jizerské hory mountains during 1993–1997. The vegetation was monitored in 3 pairs of permanent 1×1 m plots using a continuous grid of nine 0.33 × 0.33 m subplots. We applied continuous stocking and rotational grazing. Vegetation varied as a result of time and differences between treatments. Several prostrate dicotyledonous species (Trifolium repens, Taraxacum sp.,Bellis perennis andLeontodon autumnalis) increased under continuous stocking. This treatment also promoted the growth of the perennial grassLolium perenne, which was able to cope with frequent defoliation. Tall grasses sensitive to frequent defoliation (Poa trivialis, Holcus mollis, Alopecurus pratensis, Dactylis glomerata andElytrigia repens) were more abundant in rotationally grazed paddocks. Species diversity was not significantly influenced by the different grazing systems. The decrease in the potential sward height under continuous stocking revealed the replacing of tall dominants by lower species. Our results indicate that different grazing systems alter the composition and structure of grassland vegetation. Defining the intensity of grazing under continuous stocking or rotational grazing is complex due to the different stocking rates and the heights of sward during a grazing season. Information about pasture management should therefore involve not only grazing intensity but also the grazing system used.     

Effects of deforestation on structure and diversity of small mammal communities in the Moravskoslezské Beskydy Mts (Czech Republic)

During 1970s and 1980s, a large area of mountains in the Czech Republic was influenced by long-term industrial air pollution. Among the most degraded areas were the peaks of the Moravskoslezské Beskydy Mts, where vast clearings resulted from emissions and subsequent forest destruction. This study is aimed at determining the degree of deforestation that is necessary to cause changes in structure and species diversity of small mammal communities that were observed previously. Communities of rodents and insectivores were monitored for a minimum of 3 years at two mountain ranges of the Moravskoslezské Beskydy Mts (Czech Republic) by standard mouse snap-traps. The localities (Smrk and Kněhyně) differ by the degree of human disturbance. Clearings on Smrk Mt are very large (> 30 ha) with no remaining original forest growth as a result of intensive air pollution, unlike the same habitat type at Kněhyně Mt, where the clearings are minor (< 3 ha) and contain living solitary trees. Structure and diversity of small mammal communities in clearings were compared with those from original forests and other mountain habitats. Communities of small mammals at clearings in Smrk Mt (with dominatingMicrotus agrestis) are structurally very different from all other habitats, while structure of communities at Kněhyně clearings are very similar to those of original mountain forest (Complete linkage clustering based on Renkonen index). The community of the original mountain spruce forest at Kněhyně had the highest species diversity (according to Shannon-Weaver, Brillouin, and Simpson indices, Shannon evenness, and rarefaction), while species diversity at clearings of Smrk was the lowest. Shannon diversity of community at Kněhyně primeval forest is similar to that of Kněhyně clearings, while at Smrk Mt the forest diversity is higher than that of clearings. The species diversity of mountain forest and clearings at Kněhyně Mt was significantly higher than that in the same habitats at Smrk Mt. Our results obtained in disturbed habitats at Kněhyně and Smrk Mts suggest that the degree of deforestation may influence the presence and/or the degree of community changes. If the forest destruction is relatively small (clearings < 3 ha), the structure and diversity of small mammal communities do not differ from those of original forest.     

Vegetation changes in semi-natural meadows with unchanged management in southern Sweden, 1965–1990

Vegetation records from 1963–66 and 1990 were compared in eight semi-permanent plots from continuously managed, semi-natural hay-meadows from five sites in southern Sweden to find out whether changes in plant communities could be detected in these grasslands over a period of ca. 25 years in spite of unchanged management. It was found that species richness, α-diversity and species frequency distribution remained fairly constant over the period, while there was considerable species turnover. However, it was also found that the total cover of vascular plants increased as well as the proportion of graminoids, both in cover and in species number, with a corresponding decrease of forbs. The number of species favoured by mowing also decreased as well as the number of typical grassland species. The detected changes are interpreted partly as effects of increased loads of atmospheric nitrogen deposition, and partly related to small changes in management intensity (changed frequency of mowing and/or aftermath grazing). It is possible that the significant land use changes in adjacent areas resulting in large landscape changes (increase of forests and woodlands) might have negatively influenced the interchange of grassland species, leading to an increase in the number of non-typical grassland species in the meadows.     

Vegetation changes in forests of the Krkonoše Mts. over a period of air pollution stress (1980–1995)

Species composition of the understory of spruce (Picea abies (L.) Karsten) and beech (Fagus sylvatica L.) forests subjected to intense air pollution stress in the Krkonoe Mts., Czech Republic, showed directional changes over the last 15 years. The changes were documented with repeated observations of 29 permanent plots, initiated in 1980 and analysed with constrained ordination methods (Canonical Correspondence Analysis). Ground layer changes were mainly associated with the loss of canopy foliage from air pollution stress. The increased amount of the light at ground level resulted in increased herb cover. The initially dominant species (e.g., Calamagrostis villosa (Chaix) J. F. Gmelin, Deschampsia flexuosa (L.) P. B., Vaccinium myrtillus L., Athyrium distentifolium Tausch) were those that increased in cover. Moss cover, and moss and herb richness, declined over the course of the study. Thus, the changes in tree canopy are accompanied with changes in the forest understory, which in turn can affect the dynamics of these forests.     

Functional changes in the control of carbon fluxes after 3 years of increased drought in a Mediterranean evergreen forest?

Our objective was to test how a long‐term increased water limitation affects structural and functional properties of a Mediterranean ecosystem, and how these changes modify the response of the main carbon fluxes to climatic controls. In 2003, a 27% throughfall exclusion experiment was installed in a Quercus ilex L. forest in France. Gross primary production (GPP), ecosystem respiration (R_ECO) and net ecosystem exchange (NEE) were estimated in a control and a dry treatment. Decreasing throughfall decreased GPP by 14% and had a smaller effect on R_ECO (?12%), especially soil respiration R_S (?11%). Interannual variability of GPP (29%) was higher than for R_ECO (12%). Error propagation was used to estimates uncertainties in the NEE fluxes, which ranged from 3% to 10% in the control treatment but up to 167% for NEE in the dry treatment because more steps and data types were involved in the scaling. After 3 years of throughfall exclusion, we found no acclimation of R_S to climatic drivers. Functional properties of the response of R_S to soil water, temperature and rain pulse remained similar in the control and the dry treatments. A diurnal clockwise hysteresis in R_S was probably controlled by canopy photosynthesis with a 3 h lag. The proportion of diurnal variation of respiration due to photosynthesis was similar in all treatments (4–5%). Because of the characteristic of rain in Mediterranean climates, a continuous decrease of water input in these environments have an effect on topsoil water and consequently on R_S only during short periods when rainfall is characterized by infrequent and small events that does not allow the topsoil to reach field capacity and does not allow to dry completely. However, in the longer term, we expect a stronger decrease in R_S in the dry treatment driven by the decrease in GPP.     

Large-scale synchrony of gap dynamics and the distribution of understory tree species in maple–beech forests

Large-scale synchronous variations in community dynamics are well documented for a vast array of organisms, but are considerably less understood for forest trees. Because of temporal variations in canopy gap dynamics, forest communities—even old-growth ones—are never at equilibrium at the stand scale. This paucity of equilibrium may also be true at the regional scale. Our objectives were to determine (1) if nonequilibrium dynamics caused by temporal variations in the formation of canopy gaps are regionally synchronized, and (2) if spatiotemporal variations in canopy gap formation affect the relative abundance of tree species in the understory. We examined these questions by analyzing variations in the suppression and release history of Acer saccharum Marsh. and Fagus grandifolia Ehrh. from 481 growth series of understory saplings taken from 34 mature stands. We observed that (1) the proportion of stems in release as a function of time exhibited a U-shaped pattern over the last 35 years, with the lowest levels occurring during 1975–1985, and that (2) the response to this in terms of species composition was that A. saccharum became more abundant at sites that had the highest proportion of stems in release during 1975–1985. We concluded that the understory dynamics, typically thought of as a stand-scale process, may be regionally synchronized.