Repeated mowing is considered as one of the effective control methods against species of the genus Solidago. This paper evaluates the impact of the repeated mowing on selected morphometric and productive characteristics of the invasive neophyte Solidago canadensis in the district of Rimavská Sobota in Central Slovakia. Permanent research plots (PRPs) were established within anthropogenic habitat on an abandoned land that was divided into two variants. In the first variant, the mechanical regulation - mowing was applied. The second variant was without the regulation. The mechanical regulation of the populations was carried out in June and August during the growing season 2011. The results showed that the mechanical regulation did not have a clear impact on the population density. The decreasing trend of the number of shoots within the mowed variant was found only in one research plot (PRP3). The other plots showed an increase in the number of individuals by 2.7 and 32.7% between the mowings. Statistically highly significant differences in terms of the mowing impact on the height of the individuals were found in all PRPs. The difference in the weight of dry aboveground biomass between the mowings was 221.87 g, which represents 36.41%. Double the difference (48.8%) was recorded in the dry weight of the underground biomass in the regulated stand compared with the unregulated stand (165.1 and 322.5 g/m2, respectively). Although there was a short-term success achieved by the application of the two mowings during the growing period, the pursued objective was not reached

The paper focuses on a research carried out during two consecutive growing seasons (2011 and 2012) in a willow tree stand (Salix schwerinii × S. viminalis, variety Tordis) and a grass stand of miscanthus (Miscanthus × giganteus Greef et Deuter). Both of the species can be used for energy production. The evaluation was carried out in a research centre located in Kolíňany (Nitra district area, SW Slovakia). Biodiversity of the ground flora within the two crops stands was jointly assessed through the multivariate statistical method of Principal Components Analysis (PCA). The results showed that almost all spontaneous vascular plant species have a weedy character, they have no specific environment requirements, they are stress tolerant, and their propagules are often present in agricultural ecosystems or in vegetation of rural landscape (field margins, strip boundaries, abandoned fields, orchards, etc.). Good examples of synanthropic species observed in the stands are Cirsium arvense, Equisetum arvense, Convolvulus arvensis etc., while several other typical species of usually non-synanthropic, habitats, e.g. Symphytum officinale, Persicaria lapathifolia, Calystegia sepium were also observed. Many juvenile shrub and wood species occurring in E1 and E2 layers also belonged to the semi-natural vegetation, e.g. Sambucus nigra, Rosa canina agg., Crataegus laevigata. The presence of potentially invasive and expansive plant species is evaluated as a negative factor.

Energy plantations create new habitats in agricultural landscapes with species compositions different from those in forests or farmlands. The purpose of our nine-year research project (2010–2018) was to evaluate the dependence of weed-species richness and their selected ecological aspects on stands of energy-plant species, and varieties in energy-tree and -grass plantations in conditions of Central Europe, on the basis of a case study. The permanent research plots were established in plantations containing two varieties of willow (Tordis and Inger), one poplar variety (Pegaso), and one clone of Miscanthus × giganteus. This evaluation included the species composition of understory flora, habitat preferences of different species, life cycle, life forms, ecological demands, and the harmfulness of these weed-species. The ground flora of energy plantations is predominantly composed of synanthropic plants of a weedy character with differences in species composition among different energy-tree and -grass species and varieties. The total number of vascular plant species was 98. The highest number of species (58) was recorded in the Tordis and Inger willow varieties, and the lowest was observed in the Pegaso poplar variety (45). Perennial species prevailed by their share, 10 of which were found in all four research plots. Therophytes and hemicryptophytes prevailed. Most species have high light requirements and are typical for mild-to-warm suboceanic areas, demanding freshly moist alkalic soils that are medium-to-rich in mineral nitrogen. Fifty percent of all observed species are considered weeds in Slovakia. The “very dangerous” category represented 46.94% of weeds, the “less dangerous” category 51.02%, and the “nondangerous” category represented 2.04% out of 49 species. The biggest share of “very dangerous weeds” was found in the poplar stand (38.78%), less in willow (32.65% and 28.57%), and the least in miscanthus stands (26.53%). The weeds of the Tordis variety were relatively poorly influenced by specific environmental conditions, and the weeds of the Inger variety were mainly defined by the soil reaction. Weeds in the undergrowth of both Miscanthus × giganteus and poplar trees (Pegaso) had the greatest affinity to mineral nitrogen content and temperature requirements.

The aim of this study is to investigate the effects of gas transit pipeline temperature on soil moisture, soil temperature and yield of harvest crops. The study area was located in the village Ivanka pri Nitre (Nitra District, Southwestern Slovakia). Soil type in the site is Orthic Brown Chernozem. Temperature of the transported gas increased the soil temperature in the range of 2.07°C to 3.4°C measured in a depth ranging from 250 mm to 350 mm above the gas lines. The temperature also reduced soil moisture by 1.27‒3.18 percentiles of weight. Yield of the winter wheat grown above the gas lines was higher by 9.40% in 2004 and by 13.06% in 2006. Yield of the sunflower grown above the gas lines was higher by 8.05% in 2005. In treatment 1, organic fertilisation in a dose of 50 t/ha affected the yield of the winter wheat above the gas pipeline and the yield increased by 13.95% in 2004.

This paper evaluates the potential and perspectives of wild plant species and macrofungi from short rotation coppice. The research was conducted during the years 2014 - 2018 in stands of short rotation coppice willow and miscanthus grass in southwest of Slovakia. Evaluated wild plant species and macrofungi were divided into four groups (green vegetables, fruits and seeds, flowers and nectar, subterranean parts). The results showed that ground flora of short rotation coppice consisted of 74 edible species from 34 botanical families. Asteraceae, Rosaceae, Poaceae, Polygonaceae and Cichoriaceae families were represented the most. From the evaluated categories the most species belonged to the category with consumable aerial parts like leaves and shoots (59 species). The similar representation of species was found in the category of wild fruits and seeds consumed in the raw or preserved state and in category of edible subterranean parts (27 species and 22 species respectively). Principal component analysis showed that the edible parts with the strongest effect on the functional group differentiation were the fruits, seeds and subterranean parts.

In experimental research plots in Kolíňany (SW Slovakia), ecological and socio-economic characteristics of weed vegetation were evaluated in the energy stands of Miscanthus × giganteus during three vegetation seasons (2010–2012). The spontaneous vegetation in the Miscanthus stand was dominated by annual therophytes (55.5 to 62%) and geophytes (17.2 to 22.2%). We identified two categories of herbaceous undergrowth in Miscanthus plantation: with potential positive (e.g. presence of medicinal plants and plants with melliferous potential) and potential negative impacts (e.g. invasive and toxic plants). Based on our observations, we can conclude that the species composition of spontaneous herbaceous vegetation is comparable with weed vegetation found on arable land.