Population dynamics of ramets Allium ursinum l. in south-western Slovakia

Allium ursinum (Liliaceae) is bulbiferous spring ephemeroid and geophyte with underground organs bulbs. Population dynamics of Allium ursinum ramets were studied in woodland communities (with Acer campestre, Acer pseudoplatanus. Fraxinus excelsior) in park in Hlohovec (SW Slovakia) on four permanent plots (025 x 025 m) during growing seasons (2001- 2003) in 14-days interval. Field measurements we realized with usual methods of population biology (Harper, 1977). Analyzed plots were selected by random selection. Observed characteristics were - density of populations (individual, lm'2 ) and size structure of population. Self-infilling was observed to second census (in March) and than decrease density ramet between 5. and 6. census (in May). In April 2003 we observed the highest average densities (720 i.). Maximum average plant size was observed in 2002 (275 mm), this years was externally humid and minimum in 2003 (229 mm). In April 2003 we noted 53% seedling of total number ramets (1056 i) on fourth permanent research plots

Hodnotenie vybraných genotypov Miscanthus na produkciu bioplynu ako možného riešenia regionálnej bioenergie

Plantations of fast-growing crops represent local agroecosystems providing provisioning services in the form of phytomass that can be utilized for energy and/or non-energy purposes. Permanent grasses such as Miscanthus are identified as potentially suitable sources of raw materials for the output of second-generation biofuels. The experiments focused on the production ability of the perennial energy grass Miscanthus were performed in the region of SW Slovakia. It was confirmed that the studied genotypes (Miscanthus sinensis Tatai and Miscanthus × giganteus) exceeded the costefficient level of biomass production. The above-ground biomass of the studied genotypes was ensiled and afterwards fed to the experimental fermenters to evaluate the biogas production. The experiments with individual silage mixtures lasted 600 hours. The total amount of biogas produced from M. × giganteus and M. sinensis Tatai silage mixture was 273 dm3 and 328 dm3, respectively. The average share of methane in the biogas of both studied samples of silage mixtures was 51%. On the basis of the 10-year average yields of the studied Miscanthus genotypes achieved in our conditions, it is possible to produce 8 181 m3/ha (M. × giganteus) and 11 248 m3/ha (M. sinensis Tatai) of biogas from the silage mixtures. The achieved production represents sufficient and stable amount of biogas and its use can be economically efficient and sustainable in the long run in SW Slovakia.Plantáže rýchlorastúcich rastlín predstavujú lokálne agroekosystémy poskytujúce zásobovacie služby vo forme fytomasy využiteľnej na energetické a/alebo neenergetické účely. Trvalé trávy ako Miscanthus sú identifikované ako potenciálne vhodné zdroje surovín na výrobu biopalív druhej generácie. Experimenty zamerané na produkčnú schopnosť trvácej energetickej trávy Miscanthus boli realizované v regióne JZ Slovenska. Potvrdilo sa, že študované genotypy (Miscanthus sinensis Tatai a Miscanthus × giganteus) prekročili ekonomicky efektívnu úroveň produkcie biomasy. Nadzemná biomasa študovaných genotypov bola silážovaná a následne privedená do experimentálnych na vyhodnotenie produkcie bioplynu. Pokusy s jednotlivými silážnymi zmesami trvali 600 hodín. Celkový objem vyprodukovaného bioplynu zo silážnej zmesi M. × giganteus a M. sinensis Tatai bol 273 dm3 a 328 dm3. Priemerný obsah metánu v bioplyne oboch študovaných vzoriek silážnych zmesí bol 51%. Na základe 10-ročných priemerných výnosov študovaných genotypov Miscanthus dosiahnutých v našich podmienkach je možné vyrobiť 8 181 m3/ha (M. × giganteus) a 11 248 m3/ha (M. sinensis Tatai) bioplynu z tzv. silážne zmesi. Dosiahnutá produkcia predstavuje dostatočné a stabilné množstvo bioplynu a jeho využitie môže byť na JZ Slovenska ekonomicky efektívne a dlhodobo udržateľné

THE CURRENT SPREAD OF INVASIVE NEOPHYTES OF GENUS FALLOPIA IN TOWN HLOHOVEC (SW SLOVAKIA) AFTER TEN YEARS

In this paper, we compare the current spread of invasive populations of neophytes, the genus Fallopia (Polygonaceae) in town Hlohovec (SW Slovakia) in intensively farmed agricultural landscape after ten years. F. × bohemica has been the most successfully spreading hybrid. In 2001, it had colonized the area of 1 520 m2 on 54 localities and in 2011 by 120 % more (3 338 m2, 63 localities). The total surface area occupied by F. japonica was small

Occurrence and Spread after 18 Years of Invasion by Fallopia × bohemica (Slovakia)

At the global level, the invasion of alien organisms is considered the second largest threat to biodiversity. Hybrid Japanese Knotweed (Fallopia × bohemica) is an invasive alien species in Slovakia, which is indigenous to eastern Asia. Ragweed is a significant threat to agriculture in Central Europe. In this study, we compare the current occurrence and spread of invasive populations of hybrid Fallopia × bohemica (Polygonaceae) in Hlohovec town (SW Slovakia) in intensively farmed agricultural landscape after eighteen years. In 2001, it had colonized the area of 1 520 m2 on 54 localities and in 2011 it increased by 120% (3 338 m2, 63 localities); however, in 2018 it decreased by 9% (3 051 m2, 43 localities). Surprisingly, the research results in the period 2011-2018 showed that the further spread of hybrid in Hlohovec was not confirmed; even the total colonized area had decreased. The main reason for the reduction of surface area occupied by F. x bohemica is the management measures carried out on habitats railway communications, roads and extensively cultivated fields (home gardens). The size of the areas in 2018 was significantly dependent on the size of the areas in 2001 (r = 0.682) and in 2011 (r = 0.907)

Altitudinal occurrence of non-native plant species (neophytes) and their habitat affinity to anthropogenic biotopes in conditions of South-Western Slovakia

Many ecological studies showed that species density (the number of species per unit area) in nonnative organism groups of the mountain areas decreases with increasing altitude. The aim of the paper is to determine the variability in the incidence of non-native plant species (neophytes) associated with the change in altitude and links of the invading taxons to reference habitat types, as well as their links to three ecologically very similar, however in natural conditions, different areas. In general, the most invaded habitats are those which are highly influenced by human activities. Firstly, data collection was conducted through field mapping of build-up areas in South-western Slovakia. Subsequently, with the assistance of ordination methods, we evaluated the level of association of invasive neophytes according to the set objectives. We found that altitude was an important factor determining variability of invasive neophytes’ occurrence. Total amount of habitats with invasive neophytes’ occurrence showed a linear increase along the altitudinal gradient. Many invasive neophytes adapted to abandoned habitats of upland territory were also able to grow along roads, and vice versa, abandoned and unused habitats of lowland areas created conditions for many typical invasive neophytes occurring along roads and habitats of gardens and yards. Railways of lowland areas provided habitats and means of spread of invasive woody neophytes. Gardens and yards were important sources of alien neophytes in all observed territories. Invasive neophyte Aster novi-belgii can be described as a very variable species tolerant to a wide range of factors limiting the spread of species along the elevation gradient

Mapping of alien species of Asclepias syriaca and Fallopia japonica populations in the agricultural landscape

In recent years, Asclepias syriaca, a invasive neophyte, has spread aggressively in intensively farmed agricultural landscape in the Central Slovakia. In 2011, it had colonized the area of 100 654 m2 in abandonment vineyards and permanent grasslands in the district of Velký Krtíš (South Slovakia). We found the infiltration of these plants into the stands of Triticum aestivum and Helianthus annuus. No management measures were taken. In contrast, the second studied invasive plant Fallopia japonica had occupied area lower by 93% (7276 m2), but spread across higher number of sites (19) on the banks of the brooks and along the roads. Regulated populations accounted for only 11% of the total area occupied by F. japonica. Low correlation dependence was found between the size of the area and population density of A. syriaca (r = 0.50) and F. japonica (r = 0.56)

Response of soil organic carbon and water-stable aggregates to different biochar treatments including nitrogen fertilization

Recent studies show that biochar improves physical properties of soils and contributes to the carbon sequestration. In contrast to most other studies on biochar, the present study comprise a long-term field experiment with a special focus on the simultaneous impact of N-fertilizer to soil structure parameters and content of soil organic carbon (SOC) since SOC has been linked to improved aggregate stability. However, the question remains: how does the content of water-stable aggregates change with the content of organic matter? In this paper we investigate the effects of biochar alone and in a combination with N-fertilizer (i) on the content of water-stable macro- (WSAma) and micro-aggregates (WSAmi) as well as soil structure parameters; and (ii) on the contents of SOC and labile carbon (CL) in water-stable aggregates (WSA)