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1.
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.  相似文献   

2.
Harvestman communities inhabiting plots treated differently for grassland restoration were investigated at the Vyzkum site near Malá Vrbka village (Bílé Karpaty Protected Landscape Area). Harvestman were sampled by pitfall trapping from 1999 to 2003 on plots sown with native haymeadow seed mixture, also on plots where narrow strips of regional seed mixtures were sown either within a matrix of commercial grass mixture or within vegetation cover in natural regeneration state and on plots in a natural regeneration state. Additionally, harvestman were collected in a field under permanent crop rotation and in a neighbouring xerothermic deciduous forest. In total, 5,086 individuals of harvestman representing 15 species from three families were obtained. Phalangium opilio was dominant (78%) and P. opilio, Rilaena triangularis and Zachaeus crista were the most frequent species. The results confirmed colonisation and subsequent development of harvestman communities on meadows in various state of restoration, including plots with spontaneous plant succession. Nevertheless, biotope character and successive formation of plant cover evidently influenced the structure of harvestman communities. The highest number of taxa (12) was recorded on plots with natural regeneration; the lowest one (9) was recorded in the field with permanent crop rotation. The highest values of diversity and equitability indices of harvestman communities were found in neighbouring forest habitats representing possible sources of harvestman migration.  相似文献   

3.
A faunal record of chironomid remains was analyzed in the upper 280 cm of a 543 cm long sediment core from Ple?né jezero (Ple?né Lake), the Bohemian Forest (?umava, Böhmerwald), Czech Republic. The chronology of the sediment was established by means of 5 AMS-dated plant macroremains. The resolution of individual 3-cm sediment layers is ~115 years and the analyzed upper 280 cm of the sediment core represent 10.4 cal. ka BP. As the results of DCA show, two marked changes were recorded in the otherwise relatively stable Holocene chironomid composition: (1) at the beginning of the Holocene (ca. 10.4-10.1 cal. ka BP) only oligotrophic and cold-adapted taxa (Diamesa sp., M. insignilobus-type, H. grimshawi-type) were present in the chironomid assemblages, clearly reflecting a cool climate oscillation during the Preboreal period, and (2) during an event dated in the interval 1540–1771 AD, when most taxa vanished entirely and only Zavrelimyia sp. and Procladius sp. were alternately present accompanied by Tanytarsus sp. Although, the age of this event is in agreement with the dating of the Little Ice Age, the most probable reason for the elimination of many chironomid taxa was very low sums recorded in this part of the sediment, rather than cool conditions connected with the LIA. Variations in the chironomid fauna after the Preboreal period were reflected mainly by changes in abundances of dominant taxa rather than by changes in species composition. These variations could be explained by: (1) climatic changes, namely temperature and amount of rainfall resulting in oscillations in lake level, with changes in the occurrence of macrophytes in the littoral and (2) increasingly dense afforestation which led to a considerable input of organic material into the lake and a subsequent increase in the trophic status of the lake water.  相似文献   

4.
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.  相似文献   

5.
Characteristics of the growth and performance ofPhragmites australis as well as sediment characteristics were investigated along the western shore of Ro?mberk fishpond. The reed performance decreased toward the southern end of the shore, proximate to outlets of wastewater effluent and untreated sewage. While the reed stand was closed and looked healthy at the northern end, gaps occurred within the flooded part of the reed belt further southwards; reed was absent in water along the southernmost part of the shore, though dead shoot stubble indicated its presence in earlier times. In the latter site, the surface layer of sediment consisted of fine mud with a high organic matter content and a high oxygen demand. To a smaller extent, patches of partly decomposed reed litter inside the gaps showed the same properties. It is suggested that organic matter accumulating within the flooded part of the reed belt may have reduced plant performance which ultimately lead to the formation of gaps. At a later stage, the lakeside fringe of the reed belt collapsed, thus completing the retreat of reed from water. A protective effect of calcium against the adverse effects of organic matter is suggested.  相似文献   

6.
The presence of the thermophilic species Anopheles hyrcanus in the lower Dyje River basin has been regularly monitored since 2008. Mosquito trapping has been conducted mainly in summer using EVS traps with CO2 as attractant. Anopheles hyrcanus and Culex modestus were studied in a group of ponds near the Czech–Austrian border. At the Sedlec location, occurrence of An. hyrcanus was low during 2008–2011, with around 1–9 individuals/trap/collection day. At the Lednice location on the edge of Mlýnský Pond, the first capture of An. hyrcanus occurred in 2010. In 2013, there was a sudden increase in the An. hyrcanus mosquito at all monitored locations. The largest presence was recorded at Sedlec and reached 524.4 individuals/trap/collection day. Culex modestus was one of the predominant species throughout the period. At Sedlec, the smallest finding was in 2009 (at 9.6 individuals) while the greatest was in 2010 (at 988.6 individuals/trap/collection day). At Lednice, the smallest finding was in 2011 (at 56.3 individuals) while the largest was in 2013 (at 3850 individuals/trap/collection day).  相似文献   

7.
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.  相似文献   

8.
A slightly crushed but otherwise nearly complete specimen of the recently described rhombiferan echinoderm genus Vizcainoia Zamora and Smith, 2012 is documented from the “Middle” Cambrian Jince Formation of the P?íbram–Jince Basin of the Czech Republic. Isolated thecal plates, earlier determined as calyx plates of the eocrinoid Acanthocystites briareus Barrande, 1887 and/or as eocrinoid sp., occurring in diverse levels of the Jince Formation are reassigned to Dibrachicystidae gen. et sp. indet. Similarly, isolated thecal plates collected from the Buchava Formation of the Skryje–Tý?ovice Basin could be classified as Dibrachicystidae gen. et sp. indet. Specimens from the Barrandian area are the first records of the family Dibrachicystidae outside of southwestern Europe, of the family otherwise known only from the Languedocian of Montagne Noire of France and from the Caesaraugustian and Languedocian of Iberian Chains of northern Spain.  相似文献   

9.
The species composition of the family Anthomyiidae in six peat-bogs in the Šumava Mts is analysed with regards to dominance, constancy, seasonal occurrence and type of distribution of each species. Anthomyiid communities in all sites are compared based on the number of species, species richness, diversity and equitability indices, as well as coefficients of similarity and Principal Components Analysis (PCA). Three collecting methods are compared: yellow pan water traps (439 specimens/43 species), sweeping (93/18) and Malaise traps (97/22). Three species, Pegoplata aestiva (24.17%), Delia platura (14.47%), and Hylemya nigrimana (11.29%) were eudominant, two further species were dominant: Delia cardui (8.74%) and Botanophila fugax (8.27%). Two species, Botanophilia fugax and Delia platura, were found in all study sites. These species, together with those collected in five sites (Delia cardui, Heterostylodes nominabilis and Hylemya vagans), had a constancy rate higher than 75% and belonged to the category of euconstant species.  相似文献   

10.
Variation in the number of species was studied in a subthermophilous grassland at a scale of 0.05 ×0.05 m during a 5-year period. The observed variance of species richness (VSR) was compared with a null model based on random distribution of species over a set of squares. It was found that distribution of species richness had more values than, expected around the mean and less values at the “shoulders”. Both tails fell within the predicted limits. Application of the procedures removing spatial dependence (random shifts, rotation/reflection method byPalmer & van der Maarel 1995) and environmental heterogeneity (patch model byWatkins & Wilson 1992) did not change the observed pattern. Using simulations in which the number of clumps and clumping intensity were manipulated it was found that the effect of the clumped spatial pattern, on VSR results in a wide range of variances. Both variance excess and variance deficit were found more frequently than expected under the null model. To test the effect of the limitation to the number of individuals per square, a null model was developed which included that observed number of plant shoots per square, the observed distribution of the number of shoots belonging to individual species per square and the observed spatial distribution of the shoots. The observed VSR was still lower than that produced by the null model. Therefore, it is concluded that at a scale of 0.05×0.05 m plant species combine in a non-random way in the studied grassland. It is suggested that the shape of left and right “shoulders” of the species richness distribution may be caused by different factors, such as positive and negative covariance between species, respectively. Their simultaneous impact can generate the observed pattern in species richness.  相似文献   

11.
To determine the best date for patients in the southern part of the Netherlands to begin treatment for pollinosis, an attempt was made to predict the start of the grass pollen season at Helmond as accurately as possible, as was previously done at Leiden. The start of the grass pollen season was defined as the date when at a given location the accumulated total (from 1 Jan.) of 24 h average grass pollen concentrations (No./m3) reaches 100 (the so-called Σ100-method). Using the phenological method over the years 1981 through 1985, with the birch (Σ125=x) as the indicator plant, the start of the grass pollen period (Σ100=z) could be predicted much more accurately than would have been possible solely on the basis of the mean starting dates in the preceding years. The predicted starting date (z) can be calculated with the equation z=0.44x+95.46 (x and z as day-of-year numbers), SD=3.6 days, r=0.83, n=5). The SD of the Σ100-method of grasses being 5.6 days, the effectivity of the prediction is 35.7%. The difference in results between Helmond and Leiden is discussed.  相似文献   

12.
Hédl  Radim 《Plant Ecology》2004,170(2):243-265
From 1941–;1944 nearly 30 phytosociological relevés were completed by F. K. Hartmann in the Rychlebské Mountains, a typical mountainous area in northeastern Czech Republic. Of the original plots still covered with adult grown beech (Fagus sylvatica) forest, 22 were resampled in 1998 and 1999. In order to describe the recent vegetation variability of the sites 57 relevés were recorded. Changes in vegetation were estimated using relative changes in species density and ordinations (PCA, RDA). Environmental changes were assessed using Ellenberg indicator values when no direct measurements were available. A decline in species diversity has been documented, particularly, many species occurring frequently in deciduous forests with nutrient and moisture well-supplied soils around neutral have decreased. In contrast, several light-demanding, acid- and soil desiccation-tolerant species have increased. Natural succession, quantified as forest age, contributed slightly to these changes. In Ellenberg indicator values, a decline in F (soil moisture), R (soil calcium) and N (ecosystem productivity), and an increase in L (understorey light) were shown. This is interpreted as the influence of modified forestry management and of airborne pollutants. Intensified logging caused the canopy to open and soil conditions to worsen. The latter is most likely also due to acid leaching of soil cations (Ca, K, Na). This caused a decline in soil productivity, thus the effect of nitrification could not be detected. The original relevés may have differed in size influencing the results. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

13.

Biofilm formation is a typical life strategy used by microorganisms populating acidic water systems. The same strategy might be used by microbes in highly acidic soils that are, however, neglected in this regard. In the present study, the microbial community in such highly acidic soil in the Soos National Nature Reserve (Czech Republic) has been investigated using high-throughput DNA sequencing and the organisms associated with biofilm life mode and those preferring planktonic life were distinguished using the biofilm trap technique. Our data show the differences between biofilm and planktonic microbiota fraction, although the majority of the organisms were capable of using both life modes. The by far most abundant prokaryotic genus was Acidiphilium and fungi were identified among the most abundant eukaryotic elements in biofilm formations. On the other hand, small flagellates from diverse taxonomical groups predominated in plankton. The application of cellulose amendment as well as the depth of sampling significantly influenced the composition of the detected microbial community.

  相似文献   

14.
15.
The occurrence of toxigenic fungi producing aflatoxins and ochratoxin A in foodstuffs was studied in the Czech Republic. Twenty five commodities were collected at twelve collection places in the Czech Republic (300 food samples). The presence of potentially toxigenicAspergillus flavus was observed in 28% of the sampled foods (black pepper, caraway seeds, fruit tea, black tea, oat flakes, fine flour, rolled oat flakes and semolina) in the year 1999, and in 25% of the sampled foods (black pepper, black tea, fine flour) in the year 2000.A tamarii (aflatoxins producer) was found in 3 black pepper samples (25%) in both years. Aflatoxins were detected in black pepper and caraway seed samples in the year 1999 and in sweet red pepper in the year 2000.A parasiticus andA nomius were not isolated. Aspergillus section Nigri (potential producer of ochratoxin A) was detected in some foodstuffs. Ochratoxin A was detected in raisins.Penicillium verrucosum andA ochraceus were not isolated from foodstuffs.  相似文献   

16.
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.  相似文献   

17.
Petr Pokorný 《Grana》2013,52(1):77-78
When studying house‐dust biology, one deals with a huge amount of data. In order to work on the data in an orderly and efficient way a computerized database has been developed for storing data found in field experiments. Six levels in this biological database characterize the home, the room and the substrate from which the sample has been taken, the sample taken from the substrate, the analyzed fraction taken from the sample and the arthropodal, fungal, guanine and mite antigen content of the fraction. In total thirteen files are being used for storing the data. As a database management system dBASE II is used. Interfaces with other computer programs are possible such as SPSS (Statistical Package for Social Sciences), BMDP (Biomedical Computer Programs), Wordstar, Basic interpreter and SIR (Scientific Information Retrieval). With the aid of this software it is possible to store, revise and retrieve the data easily and to draw conclusions in the field of ecology. An example shows some features of this database.  相似文献   

18.
Flow-like landslides are a dangerous landslide type. They often express gradual movement or seeming dormancy, but occasional reactivation can, in extreme cases, result in catastrophic events. To predict their future behaviour, knowledge of past spatio-temporal development and relationships with hydrometeorological triggers is crucial. Moreover, regional data are more robust than case studies. Dendrogeomorphic (tree-ring-based) methods are a very precise approach for reconstructing past landslide behaviour. Nevertheless, regional reconstructions are very rare, which is probably due to their time-consuming procedures. This paper presents the results of a regional tree-ring-based reconstruction of the spatio-temporal development of flow-like landslides in a selected region in the Outer Western Carpathians. Six selected landslides were studied via analysis of 614 increment cores that came from 307 disturbed trees. The reconstruction provided data for approximately 70 individual landslide reactivation phases that were distributed in 44 event years. Events with regional extension (at least half of the studied landslides were active) were detected in six years (1940, 1941, 1953, 1961, 1985, and 1997). Periods of increased (1950s, 1990s) as well as decreased (1940s, 1970s, 2010s) landslide activity were reconstructed. The use of tree-ring data enabled the construction of landslide probability maps. Based on this analysis, all studied landslides exhibit extremely high probabilities of reactivation during a temporal horizon of 100 years, but even over shorter periods (5 and 20 years), their probability of reactivation is very high. Finally, analysis of meteorological triggers suggests the positive effect of precipitation in May (and possibly in September) to activate landslides with regional extent. Extreme short-duration (1-day) precipitation events probably do not play a role in landslide triggering. Moreover, gradual increases in precipitation totals during periods of at least one-half year preceding the event years were detected.  相似文献   

19.
The Kellwasser Crisis represents one of the most severe extinction events in the Phanerozoic. The ?umbera section (Moravo-Silesian Basin, Moravian Karst) spans the Upper rhenana to Palmatolepis minuta minuta (or younger) conodont zones and corresponds to the upper part of a carbonate ramp with material derived from shallower areas. A rich association of calcareous algae, cyanobacteria, and microproblematica, comprising renalcids (Izhella), Girvanella, Rectangulina cf. tortuosa, Rothpletzella, “solenoporaceans”, “Keega”-like microfossils, udoteacean alga Paralitanaia, volvocean and radiospherid calcispheres, palaeoberesellids, Umbellina bella, and Wetheredella, is similar in diversity to associations known from China, Australia, Canada, and Belgium. The ?umbera section represents a unique locality where changes in shallow-water biota at the Frasnian-Famennian boundary are well calibrated by detailed conodont biostratigraphy. We track in detail the evolution of shallow-water biota and the features that are often discussed in the context of “anachronistic” facies, such as flourishing microbial structures, enhanced early marine cementation, and flat-pebble conglomerates. Some features which could be indicative of environmental stress such as flat-pebble conglomerates developed during the Frasnian part of the Kellwasser Crisis (Upper rhenana to linguiformis Zones), whereas a renalcid boom started at the Frasnian-Famennian boundary.  相似文献   

20.
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