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Second-generation biofuel crop miscanthus is one of the most promising plants tested for phytomanagement of contaminated sites. In this preliminary pot case study, the most used hybrid Miscanthus x giganteus was cultivated in three different real contaminated soils: agricultural soil contaminated with Cd, post-military soil slightly contaminated with Zn, Pb and Cd, and soil contaminated by petroleum industry with metals and hydrocarbons. The stress response of plants and soil microbial communities was monitored to receive data that are important for successful phytomanagement application. With metals only, the plant grew well, and chlorophyll fluorescence measurement proved their good vitality. Changes in leaf anatomy (leaf thickness and sclerenchyma cells area) were additionally determined in post-military soil compared to agricultural. On the contrary, in petroleum-contaminated soil, the biomass yield was too reduced and also physiological parameters were significantly decreased. The response of microbial communities also differed. In agricultural soil, no microbial stress was determined. In post-military soil, it became reduced during the experiment, and in petroleum contamination, it increased year-on-year. It could be concluded that miscanthus is suitable for cultivation in metals contaminated soils with potential for microbial communities support, but in soil contaminated by the petroleum industry, its application did not seem meaningful.

Bioenergy crops such as Miscanthus x giganteus are foreseeable as an alternative source to replace fossil fuel and reduce greenhouse gas emissions. They are also assessed as an environment-friendly solution for polluted, marginal and low-quality agricultural soils. Several studies had been launched on soil organic carbon sequestration potentials of miscanthus culture along with its impacts on restoring soil functionality, most of which focus on the long-term basis of the plant’s cultivation. Nevertheless, information concerning the short term impacts as well as the situation in Czechia is still scarce. In this context, a field experiment was launched in 2017 in a poor-quality agricultural land in the city of Chomutov (North-Western Czechia) to compare the impacts of the perennial C4 miscanthus with an annual C3 forage crop (wheat) on the soil carbon stocks as well as enhancing its functionality. Results through the 0–30 cm soil profile examination showed that miscanthus plants played a role in improving the studied soil physico-chemical (bulk density and soil organic carbon concentrations) and biological (Phospholipid fatty acids stress indicator, basal respiration and fluorescein diacetate hydrolytic activity) parameters. The naturally occurring δ13C concentrations were used to evaluate the direct plant contribution to the total soil organic carbon (SOC) stocks and revealed considerable miscanthus contribution all over the detected soil layers (1.98 ± 0.21 Mg C. ha−1 yr−1) after only 3 growing seasons. It is thus suggested that the C4 perennial miscanthus possess remarkable prospects for SOC sequestration and restoring degraded lands.

Soil is a key part of a biotope and microorganisms are dominant components contributing to soil functions. Conversely, established methods for valuation of biotopes according to Natura 2000 rely predominantly on the communities living on the surface. Here, we aimed to assess soil microbial biomass and community structure on five localities with range of biotope values by means of phospholipid fatty acid (PLFA) profiling. PLFA figures were affected both by sampling season (spring vs. autumn) and locality. In spring, the living microbial biomass (estimated by PLFAtot) exhibited poor correlation to biotope values. These were, on the contrary, correlated to trans/cis PLFA, an indicator of microbial stress, (i.e., lower stress in higher-rated biotopes), and fungal/bacterial PLFA (i.e., higher-rated biotopes contained more fungi). The attempt to model biotope values from microbial characteristics explained a maximum of ~50% of the variability; the best predictors were the trans/cis stress indicator, percentage of actinobacterial PLFA, and ratio of PLFA of Gram-positive to Gram-negative bacteria. These results show that soil microbial characteristics present partly new information and indicate the need to amend the procedures of biotope assessment. Soil PLFA profiling could serve as suitable methods for this purpose.

In the Protected Landscape Area “Labské pískovce” (Czech Republic), there are many sandstone caves accessible by permission only and where climbing equipment is commonly required. The tradition of visiting the caves dates back to turn of the 19th and 20th centuries, and visitors traditionally record their visits in log-books. We have gathered attendance data from 12 caves from log-books and via survey (2-year form collection period). The attendance varied from less than 10 to ~650 visitors annually. Signs of inadequate behavior of visitors were observed, especially waste disposal and smoking in the caves. Sediment step-compression increased significantly the ratios of fungi/bacteria and gram-positive to gram-negative (G+/G−) phospholipid fatty acids (PLFA) as well as PLFA of actinobacteria and activities of sediment phosphatases, glucosidases, and peroxidases. The number of visitors was correlated positively with the G+/G− ratio and sediment nutrients but negatively with sediment moisture and the activity of peroxidases. The results indicate a significant effect of attendance on sediment microbial communities, most likely caused by the import of nutrients into caves. Hence, reconsideration of the cave attendance policy is recommended.