Prodrssive soil succession after thinning in northern taiga bilberry spruce forest

Damage to the top soil layers during logging operations can be of various forms (compaction, mixing, pressing, etc.) and of a long-term character. The recovery of the morphological characters and the structure of the soil profile of the native soil can take decades or have irreversible effect. We have studied the soil damage during two-stage (1973 and 2002) conversion thinning operations in the spruce forest with blueberry cover in the northern taiga (tree-length log skidding, TDT-55 tractor). The types of damage that stay during the progressive succession for 50 years and have signs of disturbances due to the logging operations were identified. The mosaic structure of the mixed bedrocks still continues to exist. The forest litter pressed by the heavy machines is replaced by the newly formed one. And at the same time, the organic bedrock of the medium degree of decomposition, which is untypical for the native podzolic soil, is preserved. Mixing by tractor tracks and the formation of mixed bedrock is the most common disturbance of the upper bedrock during logging operations due to insufficient coverage of the skid roads by felling residues. The amount of such damage to the soil is 77 % and 79 % in the skid roads of 1973 and 2002, respectively. But the depth of damage is small, which is 10 cm on average, with fluctuations up to 22 cm. In nano- and micro-depressions, the processes of peat formation and gleying develop. The number of locations with the genesis of bog soils is gradually increasing. On the skid roads of 1973 the proportion of wetlands is 2,5 times higher than in the skid roads of 2002 (86,9 % and 37,3 %, respectively). The long-term soil disturbance in the structure of the soil profile makes it necessary to develop classification approaches to improve the analysis of anthropogenic disturbed soils in cutting areas. The classification units are suggested

INFLUENCE OF LONG-TERM APPLICATION OF FERTILIZERS ON BOTANICAL COMPOSITION OF HAYFIELD PHYTOCENOSIS AND THE QUALITY OF THE RECEIVED FODDER

In the Federal Williams Research Center of Forage Production and Agroecology in 1947 the study of the effectiveness of mineral and organic fertilizers was started. For 74 years of using the herbage without re-sowing, the features of succession variability have been revealed. There was a reformation of the seeded legume-grass herbage into two types: low grass-legume-motley grass against the background of the use of one- and two-component mineral fertilizers and manure (regressive succession) and grass-motley grass with the application of complete mineral fertilizer with high doses of nitrogen (progressive succession). On the herbage of the first type, the predominant species is the introduced species — red fescue (43.8–75.4%), on the herbage of the second type — high grasses (meadow foxtail, cocksfoot, awnless brome). The reformation of the herbage did not lead to a decrease in yield. Over the past 28 years (average for 1993–2020), the yield of herbage with regressive succession exceeded the control (3.3 t/ha dry matter) by 1.1–1.9 times, with progressive succession by 1.9–2.6 times. The annual consumption of nitrogen by grasses in the control was 54 kg, P2O5 — 14 kg, K2O — 46 kg. The application of one- and two-component mineral fertilizer and manure increases the consumption of nitrogen by 1.1–2.4 times, phos-phorus — by 1.3–3.1 times, potassium — by 1.3–3.6 times, the application of complete mineral fertilizer, respectively, in 2.3–3.5, 2.9–3.9 and 2.4–3.9 times. The quality of the received feed for the content of crude protein, crude fiber and crude ash on both types of herbage met the requirements of standard for the first and second class. The content of mineral elements also met the zootechnical standards.

Dynamic of Dominant Plant Communities in Kettle Holes (Northeast Germany) during a Five-Year Period of Extreme Weather Conditions

Understanding the ecosystem functions and services of central European kettle holes (small wetlands) requires knowledge about their spatiotemporal dynamics. A lot of existing research has been conducted on the wet–dry cycles of North American potholes, but much less is known about kettle holes. Based on the extreme weather conditions between 2015 and 2020, we aimed to quantify differences among dominant plant communities of kettle holes using unmanned aerial systems. Different dominant plant communities were differently affected by dry and wet intervals with a major increase in terrestrial plants. Multivariate analysis showed strong variability in plant community composition for permanent and semi-permanent kettle holes, where hydrophytes decreased and nitrophilous perennials increased. Although we cannot provide quantitative results in succession over a five-year observation period, we found indications of progressive succession towards irreversible alternative stable states with woody plants for some kettle holes, especially of the “storage type”. Therefore, we assume stronger changes in proportion of wetland types in kettle holes compared to potholes and we expect the proportion of wood-dominated kettle holes to increase in the central European landscape in the future, leading to enhanced homogenization of the landscape accompanied by a loss of ecosystem functions and services.

Historic and recent occurrences of Kievan nettle (Urtica kioviensis Rogow.) in Hungary

This paper presents occurrence data of Urtica kioviensis Rogow. in Hungary from the 20th century till today, based on a survey of six Hungarian public herbaria and the literature. Altogether 84 herbarium sheets from 9 counties, 83 literature records mentioned from 12 counties, and 57 flora mapping data were encountered. Based on these, we updated the distribution map of the species in Hungary. We found that the typical habitats of U. kioviensis in Hungary include marginal zones of bog forests, reeds, and old small watercourses. We report two newly discovered locations of the species in the Hanság area. Near Fehértó, in a peat-forming reed bordering a lake, approximately 150 plants were found, while in the vicinity of Dör, in a former open pit sand mine, approximately 300 plants were observed. The habitat at Dör is secondary, the current vegetation must be the result of progressive succession processes that started after the abandonment of sand mining. The integrity of Hungarian habitats has been threatened in recent decades by increasingly frequent climatic anomalies (mainly water shortages due to the lack of precipitation for long periods) and anthropogenic factors (fragmentation of biotopes, organic/inorganic substances washing into groundwater), which may cause a decrease in the number of plants. As a significant part of the distribution area of the species is located in Hungary, the protection of its populations and habitats is also of key importance.

To the question of the relationship between the diversity index and the saprobity index in algae and invertebrates

A description is given of the process of creating an empirical model of the functioning of aquatic ecosystems, its indicators, and the limits of the parameters related to progressive succession stages when considering the effects of pollution. In addition to the previously used data for autotrophs, the parameters of the diversity of consumers are included in the model. The overestimation of impact assessments based on the second trophic level is discussed. Based on the data of the private allotment of water bodies of Ukraine, a conclusion is drawn on the conformity of estimates regardless of the geographical location of water bodies and on the suitability of interpretations for water ecosystems of a wide ecological spectrum.

Dynamics of succession processes on sulphide-containing mine dumps as a result of their optimization

When optimizing the relief at the top of the trapezoidal sulfide-containing mine dump, young soil (embryozem) was formed as a result of abio- and biotic factors. In parallel with the formation of embryozems, primary succession processes are developing. As a result, the species composition of vegetation, the staging and intensity of progressive succession were studied depending on the mesorelief of dumps in accordance with the weathering and soil formation processes developing over time. The properties and indicators of young soil in depressions and sulfide rock (control) 25 years after the completion of the dumping of the rock pile were studied. As a result of optimization at the top of the dump, the processes of formation of embryozems in the depressions are significantly accelerated.

ESTIMATION OF VEGETATION ON THE FORAGE LANDS OF GORNYY ALTAI

The authors explored the situation in vegetation on hay harvesting areas and pastures in the mid mountain areas of Central and South-Eastern Altai in 2016-2017. The authors investigated 22 communities of various types of meadows and steppes; 8 cenoses were investigated twice. The vegetation of forage lands indicates moderate or high grazing of animals. 2016 was a wet year and it led to pasture degradation and progressive succession. 2017 was a dry year and grazing led to acute pasture degradation and reducing of surface phytomass in 2.2 – 3.6 times in comparison with the previous year. At the same time, the part of mortmass in the stand grass increases. The researchers investigated the perennial leguminous grasses of Astragalus austriacus, A. austrosibiricum, A. tibetanus, Hedysarum gmelinii, H. gmelinii subsp. setigerum and Oxytropis argentata and found out them to be preserved in grasslands and restored in many cenopopulations when grazing is reduced or stopped.

Reclamation of Technogenic Disturbed Landscapes of the Far North

The peculiarity of progressive succession in the damaged territories of the Yamburg gas condensate field is considered. It is established that the reclamation of technogenic disturbed landscapes is accelerated by the use of a complex of agro technical measures, including the selection of species of perennial grasses and the optimization of mineral nutrition. Studies carried out in the Yamburg gas condensate field in areas lacking of the biologically active layer have developed elements for soil and vegetation reclamation.

The locality of Trapa natans L. within the region of Międzyodrze – dangers and protection perspective (the Lower Oder Valley, West Pomerania)

Research on a critically endangered and protected population of Trapa natans was carried out during growing season in 2016 at the site located on the Obnica channel within the region of Międzyodrze. It is a location that is close to the one indicated in historical sources by Winkelmann over 120 years ago. The post-war research did not confirm presence of this species within the region of Międzyodrze despite favourable biological conditions. The sites were declared relict and documented only in stratigraphy of peat deposits, detritus gyttja and bottom mineral sediments. Recently, an assessment of the population and habitat status were carried out. The appropriate indicators of the species status were examined according to the methodology of Chief Inspectorate of Environmental Protection. The floristic composition of Trapetum natantis association patches found within the researched site were analysed, reed bed associations belonging to the class of Phragmitetea and plant communities of pleustophytes, nymphaeids and elodeids belonging to the class Potametea and Lemnetea were recognised in the contact zone. On the basis of the collected data, particular attention was paid to the relevance of Trapa natans monitoring­ at the site located on the Obnica channel within the Międzyodrze region due to its indicative character. The conservation status of the population could be influenced by the change of water trophy within Międzyodrze channels caused by different forms of anthropopressure, including commercial use of this water body, hydromeliorative works, changes that are due to the progressive succession of water plants and reeds, which slow down the water flow rate within the area of Międzyodrze, favour accumulation of organic matter and increase of water trophy as well as fluctuations of surface water thermal activity caused by changing weather conditions.

Rehabilitation of Industrial Barren in Arctic Region Using Mining Wastes

Background: This work has explored the possibility of applying mining waste-based ameliorants for the remediation of soil that has been transformed by copper-nickel smelter emissions by means of forming artificial phytocenosis. Objective: The aim of our work was to propose, develop and approbate a technique for the preservation of dumps polluted by heavy metals and prevention of their erosion by creating dense grass covers with the use of wastes from mining and processing enterprises to form a supporting substrate for herbaceous plants. Methods: The vegetative cover was cultivated on a supporting medium, consisting of mining waste, with a hydroponic vermiculite substrate and a mix of graminaceous plant seeds, indigenous to the study area and resistant to heavy metal pollution. The mining wastes, used in the experiment, contained acid-neutralizing minerals such as calcium and magnesium carbonate and hydrous magnesium silicate. Results: It is shown that, due to a large pool of Ca and Mg, these mineral substrates are alkaline (pH 8.4 – 9.2) and can perform successfully in optimizing of edaphic conditions for the plant communities grown on industrial barrens. In a pilot experiment without a proposed supporting medium, the plants did not form a stable grass cover and had died out by the beginning of the third growing season, whereas the experimental plots with a proposed supporting medium (waste-based substrate) developed a high-quality grass cover by the end of second vegetation seasons. Conclusion: The resulting plant communities grown on a proposed supportive medium is find to be resistant to aerotechnogenic pollutants and capable of independent survival, representing the initial stage of progressive succession in the presence of on-going pollution.