Influence of Bison bonasus on flora and vegetation change in Krasnikovsky forestry of “Orlovskoe Polesie” national park

The purpose of the study is to reveal the influence of European bison (Bison bonasus) on flora and vegetation change in Krasnikovsky forestry of “Orlovskoe Polesie” national park. In August-September of 2019, floristic and geobotanical studies of flora and vegetation were carried out at self-feeding stations, in the locations of salt licks, as well as in the bisons’ passage points in Krasnikovsky forestry of “Orlovskoe Polesie” national park. There were identified 142 species of vascular plants of 9 phytocenotic formations according to G. Zozulin’s classification: nemoral, birch forest, helobious grass, alder, boreal-willow, boreal forest, pine forest, meadow and anthropogenic. The number of phytocenotic groups and the percentage of species in each of them varied. A direct relationship was established between the time of self-feeding stations formation and the participation of non-forest species in the corresponding phytocenoses: the earlier self-feeding station was formed, the higher the participation percentage in the coen of non-forest species. When assessing geobotanical descriptions according to the Ramensky’s pasture digression ecological scale it was revealed that the greatest digression degree is observed in the locations of self-feeding stations: from a moderate influence of grazing (semi-pasture stage, 5 points) to a weak influence of grazing (hay stage, 4.5 points). In places adjacent to feeding self-feeding stations, or bisons’ passages, a weak influence of grazing was noted, a haying stage (3.7-4.0 points). In the places solonetzic soil locations, the influence of grazing does not affect (2 points) or there is a weak influence of grazing, haying stage (3-4 points).

BIOMELIORANT APPLICATION FOR INCREASING THE PRODUCTIVITY OF SLIGHTLY HUMIC SOILS

Purpose: to study physical-chemical parameters of sludge and the possibility of its application as a biomeliorant for increasing soil fertility in Volgograd region. Materials and methods. The object of research is light chestnut solonetzic soil of heavy loamy granulometric texture, silt sludge of domestic waste water. The analysis of soil samples was carried out according to generally accepted methods. Results and discussion. Comparative data of various sludge sediments in terms of physical-chemical parameters allow for the conclusion that the sewage sludge processed by the enzymatic-cavitation method has optimal moisture content (11 %), contains the main nutrients: nitrogen (3.3 %), phosphorus (4.27 %), potassium (0.31 %). The content of organic matter in the sludge was 32 %, which fully complies with the specifications of GOST R 54651-2011. The data of the water extract analysis show that in the variant with the processed sludge sediment there is a higher content of sulfate anions (5.40 mmol/100 g soil) in comparison with the variant of light chestnut soil (0.30 mmol/100 g soil), and increased content of calcium cations (8.40 mmol/100 g soil) and magnesium (5.10 mmol/100 g soil). As a result of the study of soil samples, it was found that after the introduction of sewage sludge in soil, the content of organic matter was 2.28 %, while in soil samples without the introduction of sediment it was 1.67 %. The content of nitrate nitrogen ranged from 8.3 to 30.9 mg/kg, ammonia nitrogen from 4.1 to 5.7 mg/kg, mobile phosphorus from 82.0 to 102.0 mg/kg, exchangeable potassium from 385 to 392 mg/kg according to the variants of the experiment. The conducted studies of the content of heavy metals in soil show that no excess was found for all standardized indicators. Conclusions: it is advisable to use sewage sludge after its biological treatment as a biomeliorant for increasing the productivity of slightly humic soils.

Long-term changes in soil salinity as influenced by subsoil thickness in a reclaimed coal mine in east-central Alberta

Olatuyi, S. O. and Leskiw, L. A. 2014. Long-term changes in soil salinity as influenced by subsoil thickness in a reclaimed coal mine in east-central Alberta. Can. J. Soil Sci. 94: 605–620. Elevated salinity and sodicity are major challenges to reclamation of surface-mined coal sites in the Alberta Plains region. Research plots were established in 1981 at the Battle River Coal Mine near Forestburg, AB, to determine an optimum depth of subsoil replacement over sodic mine spoil required to sustain agricultural capability. Subsoil thickness was varied at 0, 25, 65, 135, 165 and 335 cm, overlain with 15 cm topsoil. The plots were monitored annually from 1982 to 1986 and were seeded to forage from 1987. Plots were resampled in 2013 to examine long-term changes in soil quality by comparing the results with the historical means for the 1980s. Key soil parameters measured are pH, electrical conductivity (EC), total dissolved salts (TDS), sodium adsorption ratio (SAR) and soluble Na. The soil quality of the root zone (0–40 cm) improved over time in all treatments as EC, TDS, SAR and concentration of Na decreased significantly between the 1980s and 2013. Amounts of EC and soluble Na consistently increased with depth, suggesting salt accumulation was predominantly by downward leaching, but with contribution by upward migration of Na from the underlying spoil. Relative to the native soils in 2013, the root zone quality ratings for EC and SAR in the topsoil/spoil treatment were better than in the shallow-bedrock Solonetzic soil. Ratings for the 25-cm subsoil treatment were also comparable with the local Chernozemic soil, but better than the fine till Solonetzic soil. This study demonstrates that a minimum of 25 cm subsoil and 15 cm topsoil are required for mitigating salinity and sodicity in these reconstructed soils. The resampling in 2013 demonstrates that long-term monitoring is essential to obtain a better understanding of reclamation outcomes.

Terrestrial algae of hypersaline environments of the Central Syvash islands (Kherson Region, Ukraine)

In hypersaline environments of the Churiuk and Kuyuk-Tuk islands located in Central Syvash lagoon (Ukraine) 93 species of oxygenic phototrophs (49 Cyanoprokaryota, 29 Chlorophyta, 12 Bacillariophyta, 2 Xanthophyta, 1 Streptophyta, 1 Eustigmatophyta) are recorded. The sites studied represent four basic types of habitats: semi-terrestrial ecotone (littoral heavy-loam solonchak free of vascular plants), wet gleyic solonchak covered by sparce halophytic vegetation, gleyic solonetz under saline meadow vegetation, and chestnut solonetzic soil with Steppa salsuginosa formation. They differ in the taxonomic composition and species diversity of algae. The highest species diversity is observed at sites of wet gleyic solonchaks (71 species of five divisions), the lowest diversity (23 species belonging to three divisions) in the harsh littoral ecotone. The distribution and abundance of species in the four habitats are discussed with reference to their ecology. Descriptions and original drawings of noteworthy taxa of Chlorophyta and Xanthophyta are presented.