Abstract The overuse of synthetic fertilizers has been associated with negative environmental consequences. The use of biochar in this regard has been recommended as a win–win strategy. However, our understanding on the comparative influences of biochar prepared from various feedstocks mixed with other bulking agents on soil health and crop performance remained limited. Therefore, in the present study, three types of biochar produced from sewage sludge, food, and agricultural waste were analyzed and compared for their effects on soil enzymes (dehydrogenase, DHA; β-glucosidase, GLU; phosphatase, PHOS; urease, URE; N-acetyl-β-D-glucosaminidase, NAG; and arylsulphatase, ARS), soil basal, as well as substrate-induced respirations and plant growth and physiology characters. The results revealed that food waste-derived biochar co-pyrolyzed with zeolite and/or sawdust was more effective in improving soil physicochemical properties and carbon and phosphorous cycling enzyme (DHA, GLU, and PHOS) activities in addition to soil basal respiration. While the influence of wastewater sewage sludge-derived biochar was more pronounced on urease, N-acetyl-β-D-glucosaminidase, and arylsulphatase enzymes as well as plant biomass accumulation and physiological attributes. Moreover, agricultural waste-derived biochar was found to be effective in enhancing substrate-induced respirations. This study thus concluded that biochar derived from various feedstocks has the tendency to improve soil health and plant growth attributes which further depend on the type of modification prior to pyrolysis.
The impact of global warming on plant phenology is the subject of a growing number of studies. However, most of these do not focus on woody species, and few examine the entire annual phenological cycle of woody species. In this paper, we explore the phenological pattern of seven woody species native to Europe under ex situ conditions for 3 years, in two urban areas with different mesoclimates. The average temperature differs by 1.81 °C between the two sites. The investigated plants were clonally identical for each species, and the exact same care protocol was kept at both sites. Despite the large variation in the phenological pattern between years, during the study, spring phenophases occurred earlier, while the examined autumn phenophases were delayed at the site observing a higher average temperature. The phenological sensitivity of flowering was significantly higher than that of leaf bud burst. The growing season was 14.8 days longer at the site with a higher average temperature. In most cases, a significant correlation was obtained between the examined phenophases and climatic factors at both sites. Among the autumn phenophases, the strongest correlation was found between the maximum temperature between July and October and the beginning of leaf coloring.
Environmental contamination caused by uranium mining is becoming a worldwide issue due to its negative impact on the environment. The aim of this study is to evaluate the contamination levels of riparian forest stands and their interaction with pollutants on the example of two localities with long and short-term uranium mining closure. Notably high Cu content, which exceeded the lower range of the toxicity limit in 50–75% of the cases, was detected in the leaves. Increased U content also represents a potential risk. As both of the elements have a negative effect particularly on the root system, it can be assumed that the soil-stabilizing and water erosion-reducing functions of the stands may be reduced. Extremely high U content (51.8 mg/kg DA) in the leaves of Aesculus hippocastanum L. indicates its potential for phytoremediation. Significantly higher U content determined at the locality with the long-term closure of mining was probably caused by the instauration of the shallow hydrogeological circulation after mine inundation. Strong correlation between U and Pb suggests identical trend of their uptake and accumulation by plants. A significant dependence of the level of contamination on the distance from its source was not demonstrated. Therefore, the management of mining areas should focus on the protection of riparian forest, which can through its stabilizing and erosion-reducing functions and through suitable species composition effectively prevent spreading of contamination.
Many climatic models predict significant temperature rises in mountainous regions, which may influence the distribution of montane species. Thermophilization observed or predicted in mountainous areas to date may accelerate the shift of forest-forming trees to higher areas. Our aim was to detect how the health status of Norway spruce (Picea abies [L.] Karst) and dwarf mountain pine (Pinus mugo (Turra)) changes along an altitudinal transect, and to what extent the health status of trees depends on the studied environmental variables. Field measurements were performed in the Alps with an acoustic tomograph, which is able to determine the extent and exact location of rotten parts without damage. In the case of P. abies, the stands are currently considered to be the healthiest between 1000 and 1500 m, while they show the greatest deterioration near the lower limit of their distribution. At the lower limit of the vertical distribution of the species, a retreat of 50–100 m is expected. We observed a different trend in the relationship between deterioration values and altitude depending on the extent of the P. mugo belt. It seems the extent and speed of the upper movement may be different in different mountains, depending on environmental parameters.
The environmental impacts of air transport and air transportation systems have become increasingly important and are heavily debated. The aim of the study was to determine the degree of soil contamination by the potentially toxic elements (Cu, Ni, Pb, and Zn) in the vicinity of the airport runway and to evaluate whether airport traffic has had factual toxic effects on airport vegetation. The overall assessment of soil contamination by means of the Nemerow integrated pollution index indicated slight pollution; evaluation by the geoaccumulation index evinced moderate contamination by Zn and nonexistent to moderate contamination by Cu, Ni, and Pb. A significant difference between the take-off and landing sections of the runway was not statistically confirmed. The vegetation risk assessment by means of the potential ecological risk index (RI) showed the low ecological risk, while the phytotoxicity test revealed an inhibition of up to 33.7%, with a slight inhibition of 16.7% on average, and thus low toxic effects of airport traffic on airport vegetation. The results of the linear regression model between phytotoxicity and RI manifested no relation between the two. The outcomes from other studies suggest that the range of elements and the extent of contamination can be highly variable at different airports and frequently affected by car traffic. Therefore, further research on this issue is needed for the more precise determination of the elements emitted by air traffic at airports.
Though botanical gardens are an important and widely visited component of urban green spaces (UGS) worldwide, their pollution is rarely studied. The aim of this study was to assess botanical garden soil contamination and ecotoxicity and to evaluate whether urban botanical gardens are more contaminated than urban parks. Soil assessments showed serious contamination with Cd, Pb and Zn, emitted predominantly by traffic, agrochemicals and past construction and demolition waste. The discovery of hazardous historical ecological burden in the UGS calls for the necessity of detailed surveys of such areas. Despite prevailing moderate-to-heavy contamination, the soil was only slightly ecotoxic. Maximum immobilisation inhibition of Daphnia magna reached 15%. Growth of Sinapis alba L. was predominantly stimulated (73%), and Desmodesmus subspicatus Chodat was exclusively stimulated, possibly due to soil alkalinity and fertiliser-related nutrients. The hypothesis of a higher contamination of urban botanical gardens compared to urban parks was confirmed. However, urban parks can face a greater risk of soil ecotoxicity, hypothetically due to decreased activity of soil organisms resulting from adverse soil conditions caused by active recreation. The results highlight the need for an increased focus on botanical and ornamental gardens when assessing and managing UGS as areas potentially more burdened with contamination.
The results of numerous climatic models predict a significant increase in temperature, which co- upled with other factors could affect mountain species distribution and community composition. In addition, it can accelerate an upward shift of alpine treelines. However the number of field measurements focusing on the health status of dominant trees in temperate mountains are limited. Our measurements were carried out in the Stuhleck Mountains along an elevation gradient from 850 to 1750 metres. Health status analysis of Picea abies and Pinus mugo have been completed by using FAKOPP 3D acoustic tomography, which is able to detect the size and location of decayed regions in the trunk non-destructively. For modelling the relati- onship between the decay of tree and other factors simple linear regression models were used. The results showed that the individuals of Picea abies and Pinus mugo had the worst health status in the lowest and up- permost range of the taxa in the studied area. It could be a sign of the upward shift of their range. Positive significant correlation was found between the decay and the ratio of whole trunk/healthy wood both in case of Picea abies and Pinus mugo. It seems, that acoustic tomography measurements are adequate to indicate non-destructively the altitudinal optimum and upward shift of different taxa.
Objective: Biochar and a commercial humic acid-rich product, Humac (modified leonardite), represent soil amendments with the broad and beneficial effects on various soil properties. Their combination has been scarcely tested so far, although the positive impact of their interaction might be desirable. Materials and Methods: The dehydrogenase activity (DHA), microbial biomass carbon (Cmic), soil respiration (basal and substrate-induced), enzyme activities, total carbon (Ctot), and both shoot and root biomass yield were measured and compared in the short-term pot experiment with the lettuce seedlings. The following treatments were tested: the unamended soil (control), the Humac-amended soil (0.8 g·kg−1), the biochar-amended soil (low biochar 32 g·kg−1, high biochar 80 g·kg−1), and the soil-amended with biochar + Humac. Results: The effect of both amendments on the soil pH was insignificant. The highest average values of Ctot and Cmic were detected in high biochar treatment and the highest average values of basal and substrate-induced respiration (glucose, glucosamine, alanine) were detected in the low biochar treatment. The phosphatase activity and fresh and dry lettuce aboveground biomass were the highest in the low biochar + Humac treatment. Conclusions: Even though the combination of both biochar + Humac decreased the microbial activities in the amended soil (Cmic, DHA, enzymes, substrate-induced respiration) at the low biochar dose, they mitigated the detrimental effect of the high biochar dose on respiration (all the types) and the enzyme (phosphatase, arylsulphatase) activities. In contrast to the previously published research in this issue, the effects could not be attributed to the change of the soil pH.
'/%3e%3cpath fill='%23fff' d='m8.751-17.959 10.11 11.373L3.997-9.844l13.94-6.1-7.692 13.129z'/%3e%3c/svg%3e)