Asphaltic Concrete Pavement Strength and the Impact of Rainfall

Studies have shown that moisture impacts on the strength of flexible pavement surface of asphaltic concrete. Several investigations and relevant researches treated the effect of subsurface and surface water sources, on the durability of flexible pavements. This study is focused on the surface water sources, as a result of precipitation (rainfall), on the surface of flexible pavements. To conduct this experiment, the considerations made include (i) the continuous exposure of the pavement surface to annual rainfall (ii) application of pavement exposure to moisture in the field. This study considered the amount of rainfall each day, as the duration (age) of pavement exposure to moisture (being under water during rainfall). For the purpose of this experiment, the Owerri to Onitsha about 90km of dual carriage way in south east of Nigeria, was considered. This is a flexible pavement that traverses through the rain forest belt, characterized with high amount of annual rainfall values. Flexible pavement specimens from this road were obtained, cleaned and immersed in water after weighing, to keep vital records of the necessary parameters, before further tests at 7days intervals. Values of strength obtained after days in water, that approximated to the appropriate field situation of exposure to rainfall, showed a consistent loss of strength, from the crushing strength results.

Lupemban

The Lupemban is an industry of the Middle Stone Age (MSA) that is found across the Congo Basin and on its plateau margins in central Africa. It takes its name from the site of Lupemba that was discovered in 1944 in the Democratic Republic of Congo (DRC, then the Belgian Congo). The Lupemban’s distinctive toolkit of elongated lanceolate bifaces, core-axes, points, blades, and other small tools coincides with the equatorial forest belt and is suitable for constructing hafted implements, which has led to speculation it was a special and specific prehistoric adaptation to rainforest foraging. Although poorly dated across most of its geographic range, radiometric dates for the Lupemban at Twin Rivers (Zambia) show it is at least ~265 ka years old, placing it among the oldest known expressions of the regional MSA. As such, the Lupemban bears on 21st-century debates about the evolution of complex cognitive abilities and behaviors that characterize the emergence of Homo sapiens at or before 300 ka bp. In spite of the Lupemban’s potential importance for understanding the evolution of technology, human–environment interactions, and cognition in early Homo sapiens, the industry remains enigmatic and poorly understood. Logistical, ecological, and political challenges continue to impede fieldwork in central Africa. Moreover, at sites including Gombe Point (DRC), severe soil bioturbation by tree roots has caused the vertical displacement of buried artifacts, which corrupts the basic integrity of stratigraphic sequences. This problem is known to be widespread and means that after 100 years of research, central Africa still lacks a refined Stone Age cultural sequence. Consequently, very little is known about spatiotemporal variability within the Lupemban, or its specific environmental or cultural adaptations. At the site of Kalambo Falls (Zambia), the industry is found in secondary but stratified context, which, as of the early 21st century, offers the best glimpse into Lupemban technology and its potential evolutionary significance.

Productivity of mountain bows of the carpathians depending on surface improvement measures

Purpose. To determine the peculiarities of formation of productivity, as well as the chemical composition, nutritional value and energy intensity of grass forage, depending on the measures of surface improvement of the meadows of the Carpathian mountain forest zone. Methods. Field works, laboratory, mathematical-statistical. Results. Productivity of haymaking and perennial mowing fluctuated on the range of 2.15–4.77 t/ha and 1.95–4.11 t/ha during the 3-year research of dry mass yield. Compared to the variants without additional sowing of grasses and fertilizer use, the highest productivity of haymaking was upon the additional sowing of cereal grass mixtures and applying of N60P30K60 – 12 % and 85 %, respectively. Productivity of perennial mowing increased upon the additional sowing of Trifolium repens and applying of P30K60 on 85 % and 111 % respectively. The best uniformity of distribution of biomass crop by slopes was obtained by the use of multifaceted use of creeping clover with the introduction of P30K60, when the proportion of 1st slope was 39%, 2nd - 33 and 3rd – 28% with unevenness, which is expressed by the coefficient variation - 18%. Among the measures of surface improvement on the quality of feed by chemical composition, increasing, first of all, the content of crude protein, influenced by the introduction of N60P30K60 or 15 t / ha of manure, and in the case of multi-grade use - the sowing of clover on the background P30K60. Irrespective of the measures of surface improvement, higher crude protein content, better energy consumption and nutritious nutritional value of feed were characterized by a multi-use (pasture imitation) mode of use than hay. Conclusions. For surface improvement of the meadows of the Carpathian mountain forest belt with natural herbage, the annual application of N60P30K60, or 15 t / ha of manure, or – N60P30K60 + sowing of a mixture of grass meadows and sapwood with sapwood, on the grass meadows, is a factor of increasing their productivity and improving the quality of herbage. use or – P30K60 + clover seeding for high quality use. The best positive effect is the application of mineral fertilizers in combination with sowing of perennial grasses.

Comparative study on windbreak effects of two different configuration shelterbelts

Pinus sylvestris, Artemisia ordosica, Tamarix chinensis Lour, Elaeagnus angustifolia and Salix matsudana Koidz were selected to design the models of forest belts. Through wind tunnel experiments, we analyzed the wind speed frequency, wind speed flow field and wind protection efficiency of two different configuration shelterbelts. The results showed the wind speed frequency of mixed shelterbelts was generally lower than that of single shelterbelts with the same configuration. The similarity of the average wind speed between No.1 A3 and No.2 C3 indicates that the windbreak effect of low-density arbor-shrub mixed shelterbelt was similar to that of high-density single shelterbelt. The average wind protection efficiency of No.1 A1 was similar to that of No.1 C2, indicating that the influence of density of pinus sylvestrison of wind protection efficiency is greater than the height of forest belt. the average wind protection efficiency of No. 2 A2 was 57.64%, which was similar to that of No. 2 B3, indicating that the height of the forest belt increased, and the influence of density on the protection effect of the forest belt decreased.Therefore, the wind protection ability of multi-species and highly hierarchical mixed forests was higher than that of single shelterbelt.

Growth Layers and Its Complex Structure in a Common Species Under Uncommon Conditions: Pelophylax ridibundus in the Talysh Mountains

In the Talysh Mountains, the marsh frog, Pelophylax ridibundus (Pallas, 1771), increases its distribution due to human activity. In the mountain forest belt, frogs inhabit flowing ponds with cold spring water. These reservoirs are characterized by a stable temperature regime: the water in them is kept at the level of 10 – 12°C in winter and does not fall below 6°C, and in summer does not rise above 18°C. Probably, the cold flow water of ponds in the mountain-forest belt of Talysh can cause some features of growth and maturation for P. ridibundus. The aim of our work was to study the features of the structure of growth layers including the variation in degree of expression of lines of arrested growth (LAGs) of the marsh frogs in ponds with cold flow water. Frogs were collected in the upper part of the Tangeru River gorge in Sym village of Astara District of Azerbaijan (480 m a.s.l.) in August 2018. In total, we studied skeletochronologically 8 females and 9 males. In contrast to the results of the tubular bones studies in the marsh frog presented in earlier works, the studied individuals are characterized by a more complex and diverse structure in the cross section of shin bones. All the revealed diversity of this structure can be divided into three groups. To the first group are relatively rare cases in which there are growth layers with wintering LAGs and additional growth layers but without additional LAGs. The second group includes more frequent cases in which there are growth layers not only with wintering LAGs but with additional LAGs differing discretely from wintering LAGs. The third group includes the rarest cases where there are growth layers with wintering LAGs and with additional LAGs without discrete difference from wintering LAGs. The revealed high variable structure of growth layers and distinctiveness of LAGs in P. ridibundus can be explained by unusual temperature regime in habitat of studied population and the existence of several activity period during a year. The most continuous period of low temperatures (February and March) corresponds to formation hibernation LAGs and dark rings in growth layers. Besides, period from early December to late January may be so cold that frog growth retard sufficiently or stop completely. The formation of more dark parts of growth layers or even several additional LAGs can correspond to this period.

Ecological and Agrochemical Assessment of the Kamennaya Steppe Soils under Forest Cenosis

A set of parameters of soils under forest belts was studied. The objects of research were old-growth (65–68 yrs) ravine and shelterbelt forest plantations of the Kamennaya Steppe. The results allow assessing the trends of changes in soil characteristics over a long period of time. Key plots of 100×100 m were laid out using a regular sampling grid. The sampling interval is 15–25 m. A positive effect of forest shelterbelts on the properties of chernozems was found. There is an increase in thickness of the humus horizon from 42.3 cm (arable land on the slope) to 72.6±5.1 cm (under forest). The maximum values are typical for chernozems of watershed areas: 59.6±2.4 cm (arable land) and 85.6±3.9 cm (forest belt). Chernozems leached due to the activation of migration processes of carbonates into the underlying soil horizons have the maximum depth of soil effervescence. Chernozems zooturbated due to mechanical transport and mixing of accumulative-carbonate horizon have the lowest depth of soil effervescence. A general trend to decrease the depth of soil effervescence under the forest cenosis was found. The highest humus content is observed in watershed areas: 7.14±0.24 % (arable land) and 8.56±0.18 % (forest belt). A ravine forest belt reduces the risk of erosion processes. A fairly strong humus profile with a high content of organic matter: 7.03±0.27% (under forest) and 6.10±0.10% (on arable land), was possible to preserve on arable lands in the zone of the belt’s influence. The planting of forest belts causes a change in the nature of vegetation. The influence of acidic products of litter decomposition formed soil horizons with a moderately acidic reaction of the environment in the humus layer. Despite the leading position of calcium, an increased content of magnesium was found in the composition of exchange-absorbed cations. Forest belts have become especially important in recent decades due to changing climatic conditions. In the steppe regions of Russia, such plantations are a powerful soil conservation factor that helps stabilize and increase soil fertility. It is necessary to intensify the planting of artificial forest stands in the steppe regions of Russia. For citation: Cheverdin Yu.I., Bespalov V.A., Sautkina M.Yu., Titova T.V. Ecological and Agrochemical Assessment of the Kamennaya Steppe Soils under Forest Cenosis. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 5, pp. 76–91. DOI: 10.37482/0536-1036-2021-5-76-91

Decoding of forest belts using satellite images

The paper presents the results of decoding the current condition of protective forest plantations of the Volgograd region and their digital inventory mapping on the basis of remote sensing methods and GIS technologies. We have applied a three-level analysis of the system of forest belts located within an administrative district, a farmstead, and a single forest belt. The laboratory visual interpretation of space images has allowed us to analyze the horizontal projection of the forest belts canopy and crowns, their placement in the canopy, as well as pattern and structure. We have also deciphered the signs of the prevailing patterns of tree species mixing. As a result of the research, we have created digital cartographic models of forest belts, compiled digital standards of elm stands in a given age period, assesse taxation and reclamation features of the current state of plantations. The results obtained can be used to monitor the state of plantings and create a local agroforestry GIS.

Features of the migration of heavy metals in the forest landscapes of the ’Kamennaya Steppe’

The article examines the influence of woody vegetation on the change in some soil properties. Numerous studies have confirmed the change in the water regime under forest belts. Such dynamics entails the transformation of morphological characteristics and the following basic soil properties: pH of the soil solution, carbon of organic compounds. The evolution of properties causes changes in the total content of heavy metals: nickel (Ni), lead (Pb), cadmium (Cd) and their exchange compounds. The features of the profile distribution of Ni, Pb and Cd in the chernozems of the forest belt have been studied. Elements were determined by atomic absorption spectrophotometry. Carbon of organic compounds - by titrimetric method, pH of soil solution - by potentiometric method. Wood species affect the profile distribution of heavy metals. Correlation analysis revealed a close relationship in the profile distribution of carbon of organic compounds, pH, Ni, Pb. Variational analysis of spatial heterogeneity showed the differences in the studied indicators between arable land and forest belt. A decrease in the coefficient of variation from the forest belt to arable land is noted. The phenomenon is explained by plowing, mixing the soil mass and leveling out spatial differences in the content of carbon of organic compounds, pH, heavy metals.

Exploring the Influencing Factors of the Recreational Utilization and Evaluation of Urban Ecological Protection Green Belts for Urban Renewal: A Case Study in Shanghai

With the continuous expansion of urban construction land, the green belts aiming for ecological protection have ensured a sustainable and effective function of regional ecosystem services. At the same time, these ecological green belts are expected to develop their compound service potentials with the development of cities. In order to meet the increasing demand of urban residents for the recreational utilization of urban green space, the primary function of the ecological green belts has transformed from being purely ecological to a combination of being ecological and recreational. Based on social media data, which has the characteristics of a large amount of accessible geographic information, this study used multiple regression models to analyze the recreational utilization intensity of ecological protection green belts with a case study in the green belt of Shanghai, China. The research results showed that the internal elements (total external area, water area, etc.) of the Shanghai green belt have positive correlations with its recreational utilization. The impact of external factors was inconclusive on the recreational utilization of the outer forest belt (the number of subway stations in accessibility factors was negatively correlated; the number of cultural facilities and the number of restaurants in the surrounding service facilities were positively related). Combined with the “Shanghai City Master Plan (2017–2035)”, this study suggests potential zones for the recreational transformation of the Shanghai green belt, provides a theoretical and practical basis for improving the recreational utilization of an urban ecological protection green belt and contributes to the sustainable development of ecological protection green belts in high-density cities.

Final Palaeolithic of Zhytomyr Polissia

Final Palaeolithic (Terminal Palaeolithic) — the last, final phase of the Upper Palaeolithic of Europe, dating from 13.5—10 kyr and has numerous paleogeographic equivalents — Dryas period, Late glacier, Late or Final glacial, Tardiglacial period, reindeer age. In Zhytomyr Polissia there are two main groups of different Final Palaeolithic monuments with different cultural and chronological characteristics. At the beginning of the epoch, Еpigravettian mammoth hunters lived in the region. In particular, on the Ovruch ridge at the beginning of the Final Paleolithic a separate variant of the Еpigravettian developed. The extinction of mammoths about 13 kyr and the onset of the reindeer era caused a change in population. During the Allerod warming about 12 kyr reindeer hunters of the Lyngby culture advanced from the South-Western Baltic region to Polissia. The spread of Lyngbian cultural traditions at the end of Allerod in the outwash plains from Jutland to the Neman, Prypiat, Upper Dnipro and Upper Volga laid the groundwork for the emergence 11 000 years ago areas of related cultures with arrowheads on blades. In addition to Lyngby, it includes the following cultures: Ahrensburg in Northern Germany, Swiderian in the Vistula, Prypiat and Neman basins, and Krasnosillia in the Prypiat, Neman and Upper Dnipro basins. The specificity of their flint inventory is the leading role of various tanged arrowheads on blades, while the cultural marker of Epigravettian complexes are a variety of micro-inserts with a backed edge. Genetically descended from the Lyngby culture population, Krasnosillian and Swiderian hunter groupes lived in the cold forest-tundra, hunting for herds of seasonally migrating reindeers. The sharp warming 10 kyr led to the migration of Krasnosillian and Swidrian groupes following the reindeer to the north of Eastern Europe, which they settled during the VIII millennium BC. On the Swiderian basis, the post-Swiderian Mesolithic was formed. It is Butovo and similar Mesolithic cultures of the forest belt of Eastern Europe from the Baltics to the Northern Ural. The Mesolithic Pisochnyi Riv culture of the Middle Desna, the Grensk culture of the Upper Dnipro, and the Ienevo culture of the Upper Volga were formed on the Krasnosillian basis. These Mesolithic communities of northern Eastern Europe in ethno-cultural terms were probably distant ancestors of the Finnish peoples.