1. elektronické vydání 1 online zdroj (256 stran)
Kniha předkládá přehled problémů z oblastí výzkumu životního prostředí s ohledem na jejich aktuálnost a potenciální rizika, která do budoucna mohou daná témata skýtat. Zahrnuje kapitoly z oblasti dopadů a aspektů globálních změn, problémy týkající se nových typů znečištění životního prostředí a jejich expozice a rovněž témata týkající se změn v chování populace ve vztahu k přírodě a komunikace environmentálních otázek ve vztahu k veřejnosti. Publikace se dotýká rovněž problematiky očkování a věnuje se i legislativní stránce ochrany životního prostředí.
Many of the world's peatlands have been affected by water table drawdown and subsequent loss of organic matter. Rewetting has been proposed as a measure to restore peatland functioning and to halt carbon loss, but its effectiveness is subject to debate. An important prerequisite for peatland recovery is a return of typical microbial communities, which drive key processes. To evaluate the effect of rewetting, we investigated 13 fen peatland areas across a wide (>1500 km) longitudinal gradient in Europe, in which we compared microbial communities between drained, undrained, and rewetted sites. There was a clear difference in microbial communities between drained and undrained fens, regardless of location. Community recovery upon rewetting was substantial in the majority of sites, and predictive functional profiling suggested a concomitant recovery of biogeochemical peatland functioning. However, communities in rewetted sites were only similar to those of undrained sites when soil organic matter quality (as expressed by cellulose fractions) and quantity were still sufficiently high. We estimate that a minimum organic matter content of ca. 70% is required to enable microbial recovery. We conclude that peatland recovery after rewetting is conditional on the level of drainage-induced degradation: severely altered physicochemical peat properties may preclude complete recovery for decades.
- MeSH
- mikrobiota * MeSH
- mokřady * MeSH
- půda MeSH
- uhlík analýza MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Evropa MeSH
Geodiversity plays an important role in species establishment during spontaneous succession. At post-mining sites in the Czech Republic in 2003, we established plots in which the surface of the heaped overburden was either kept wave-like or leveled. Based on surveys conducted from 2006 to 2015, leveled plots were increasingly dominated by grasses and herbs (and especially by the grass Calamagrostis epigejos) while the wave-like plots were increasingly dominated by the trees Salix caprea and Betula pendula. In 2015, a detailed survey was conducted of the dominant species. Both S. caprea and B. pendula occurred more often in wave-like plots than in leveled plots; this was particularly true for trees taller than 1 m, which were absent in leveled plots. In wave-like plots, leaf and root biomasses of both woody species were higher on the wave slopes than on the wave depressions. Nitrogen content was higher but content stress indicating proline in leaves of S. caprea was lower in wave-like plots than in leveled plots. In wave-like plots, both woody species occurred mainly on wave slopes but C. epigejos occurred mainly in the depressions. We speculate that trees were more abundant in wave-like plots than in leveled plots because the waves trapped tree seeds and snow and because the soil porosity was greater in wave-like than in leveled plots. Grasses may have preferred the leveled plots because soil porosity was lower and clay content was higher in leveled than in wave-like plots.
- MeSH
- dřevo MeSH
- lipnicovité * MeSH
- půda MeSH
- stromy MeSH
- životní prostředí * MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
1. elektronické vydání 1 online zdroj (96 stran)
Tato knížka představuje úvod do světa odborné literatury v environmentálních vědách a je určena zejména studentům vysokých škol v bakalářském, magisterském i doktorském stupni studia. První část knihy se věnuje různým druhům odborných publikací − proč vůbec vznikají, jakou mají strukturu a jak bychom měli přistupovat k jejich četbě. Ve druhé části poskytují autoři praktické rady pro přípravu a psaní odborného textu, ať už se jedná o literární rešerši, nebo o odborný článek popisující empirický výzkum. Hlavní text knihy doprovázejí samostatné boxy, ve kterých jsou detailněji vysvětleny některé aspekty vědecké práce a literatury (např. statistika, tvorba a interpretace grafů a tabulek, pravidla citování, použití citačních manažerů, správa dat aj.).
- Klíčová slova
- Přírodní vědy,
- MeSH
- čtení MeSH
- ekologie MeSH
- jazykové techniky MeSH
- psaní MeSH
- redakční směrnice MeSH
- vzdělávání odborné metody MeSH
- NLK Obory
- humanitní vědy a umění
Small twigs represent a substantial input of organic carbon into forest soils, but potential influencing factors on their decomposition have rarely been investigated. Here, we studied potential effects of twig size on decomposition and associated composition and activity of microbial communities during decomposition. Because the surface area for microbial colonization and the volume of accessible substrate increases with decreasing twig size, we hypothesized that twig size affects both microbial community and decomposition rate. Litterbags with twigs (Salix caprea) of two different diameters were placed within the litter layer and consecutively collected over a seven-year period. We determined the mass loss and microbial measures after each sampling event. The observed microbial parameters suggested a faster microbial colonization of thin twigs, where the proportion of bacteria was higher than in thick twigs. The development of the microbial community in thick twigs was more gradual and the proportion of fungi was higher. Despite this differential and successional development of microbial communities (and against our hypothesis), the mass loss among different twig diameters did not differ after our seven-year experiment, indicating that surface-to-volume ratios, though a primary control on microbial succession, may have limited predictive power for twig decomposition rates.
Heterogeneity of environmental conditions is the crucial factor supporting biodiversity in various habitats, including post-mining sites. The effects of micro-topographic heterogeneity on biodiversity and conservation potential of arthropod communities in post-industrial habitats had not been studied before now. At one of the largest European brown coal spoil heaps, we sampled eight groups of terrestrial arthropods with different life strategies (moths, spiders, ground beetles, ants, orthopteroids, centipedes, millipedes, and woodlice), in successionally young plots (5-18 y), with a heterogeneous wavy surface after heaping, and compared the communities with plots flattened by dozing. A combination of the standardized quantitative sampling, using two different methods, and a paired design of the plot selection enabled a robust analysis. Altogether, we recorded 380 species of the focal arthropods, 15 of them nationally threatened. We revealed the importance of the micro-topographic heterogeneity for the formation of the biodiversity of arthropods in their secondary refuges. The communities with higher biodiversity and conservation value were detected in the plots with heterogeneous surfaces; exceptions were ground beetles and millipedes. The surface flattening, often the first step of technical reclamation projects, thus suppress biodiversity of most terrestrial arthropods during the restoration of post-mining sites. Since the communities of both surface types differed, the proportional presence on both surfaces could be more efficient in supporting the local biodiversity. We suggest reducing the surface dozing for the cases with other concerns only, to achieve a proportional representation of both surface types. Such a combination of different restoration approaches would, thus, efficiently support high biodiversity of groups with various needs.
- MeSH
- biodiverzita * MeSH
- brouci MeSH
- členovci * MeSH
- ekosystém MeSH
- regenerace a remediace životního prostředí MeSH
- uhlí * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Reclamation of post-mining sites commonly results in rapid accrual of carbon (C) and nitrogen (N) contents due to increasing plant inputs over time. However, little information is available on the distribution of C and N contents with respect to differently stabilized soil organic matter (SOM) fractions during succession or as a result of different reclamation practice. Hence, it remains widely unknown how stable or labile these newly formed C and N pools are. Gaining a deeper understanding of the state of these pools may provide important implications for reclamation practices with respect to C sequestration. We thus investigated C, N, and plant-derived compounds in bulk soil and SOM fractions during succession in post-mining chronosequences (reclaimed with overburden or salvaged topsoil) located along a northwest to southeast transect across the USA. Our results indicate that current reclamation practices perform well with respect to rapid recovery of soil aggregates and the partitioning of C and N to different SOM fractions, these measures being similar to those of natural climax vegetation sites already 2-5 years after reclamation. A general applicability of our results to other post-mining sites with similar reclamation practices may be inferred from the fact that the observed patterns were consistent along the investigated transect, covering different climates and vegetation across the USA. However, regarding SOM stability, the use of salvaged topsoil may be beneficial as compared to that of overburden material because C and N in the fraction regarded as most stable was by 26 and 35% lower at sites restored with overburden as compared to those restored with salvaged topsoil. Plant-derived compounds appeared to be mainly related to bio-available particulate organic matter and particulate organic matter partly stabilized within aggregates, challenging the long-term persistence of plant input C in post-mining soils.
The arbuscular mycorrhizal (AM) grass Calamagrostis epigejos and predominantly ectomycorrhizal (EcM) tree Salix caprea co-occur at post-mining sites spontaneously colonized by vegetation. During succession, AM herbaceous vegetation is replaced by predominantly EcM woody species. To better understand the interaction of AM and EcM plants during vegetation transition, we studied the reciprocal effects of these species' coexistence on their root-associated fungi (RAF). We collected root and soil samples from three different microenvironments: stand of C. epigejos, under S. caprea canopy, and contact zone where roots of the two species interacted. RAF communities and mycorrhizal colonization were determined in sampled roots, and the soil was tested for EcM and AM inoculation potentials. Although the microenvironment significantly affected composition of the RAF communities in both plant species, the effect was greater in the case of C. epigejos RAF communities than in that of S. caprea RAF communities. The presence of S. caprea also significantly decreased AM fungal abundance in soil as well as AM colonization and richness of AM fungi in C. epigejos roots. Changes observed in the abundance and community composition of AM fungi might constitute an important factor in transition from AM-dominated to EcM-dominated vegetation during succession.
- MeSH
- ekosystém * MeSH
- lipnicovité mikrobiologie MeSH
- mykorhiza fyziologie MeSH
- půdní mikrobiologie * MeSH
- Salix mikrobiologie MeSH
- stromy mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
Temperature plays crucial roles in microbial interactions that affect the stability and performance of anaerobic digestion. In this study, the microbial interactions and their succession in the anaerobic digestion process were investigated at three levels, represented by (1) present and (2) active micro-organisms, and (3) gene expressions under a temperature gradient from 25 to 55 °C. Network topological features indicated a global variation in microbial interactions at different temperatures. The variations of microbial interactions in terms of network modularity and deterministic processes based on topological features, corresponded well with the variations of methane productions, but not with temperatures. A common successional pattern of microbial interactions was observed at different temperatures, which showed that both deterministic processes and network modularity increased over time during the digestion process. It was concluded that the increase in temperature-mediated network modularity and deterministic processes on shaping the microbial interactions improved the stability and efficiency of anaerobic digestion process.
- MeSH
- anaerobióza MeSH
- bioreaktory * MeSH
- methan MeSH
- mikrobiální interakce * MeSH
- teplota * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
In early spring, red wood ants Formica polyctena are often observed clustering on the nest surface in large numbers basking in the sun. It has been hypothesized that sun-basking behaviour may contribute to nest heating because of both heat carriage into the nest by sun-basking workers, and catabolic heat production from the mobilization of the workers' lipid reserves. We investigated sun-basking behaviour in laboratory colonies of F. polyctena exposed to an artificial heat source. Observations on identified individuals revealed that not all ants bask in the sun. Sun-basking and non-sun-basking workers did not differ in body size nor in respiration rates. The number of sun-basking ants and the number of their visits to the hot spot depended on the temperature of both the air and the hot spot. To investigate whether sun basking leads to a physiological activation linked with increased lipolysis, we measured respiration rates of individual workers as a function of temperature, and compared respiration rates of sun-basking workers before and two days after they were allowed to expose themselves to a heat source over 10 days, at self-determined intervals. As expected for ectothermic animals, respiration rates increased with increasing temperatures in the range 5 to 35°C. However, the respiration rates of sun-basking workers measured two days after a long-term exposure to the heat source were similar to those before sun basking, providing no evidence for a sustained increase of the basal metabolic rates after prolonged sun basking. Based on our measurements, we argue that self-heating of the nest mound in early spring has therefore to rely on alternative heat sources, and speculate that physical transport of heat in the ant bodies may have a significant effect.
- MeSH
- dechová frekvence * MeSH
- Formicidae fyziologie MeSH
- lipolýza MeSH
- sluneční záření * MeSH
- teplota MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
