RESULTS OF THE EXPLORATION OF A SMALL WATCH FORTRESS OF THE SCYTHIAN ERA

The article presents the results of the first studies of the defensive line of the hillfort located on the cape of the right bank of the river Don near the village 1st Storozhevoe in the Voronezh region. On a plot of 124 sq. m, a rampart, a moat and the adjacent territory were researched. Ceramic fragments were discovered that remained from an unfortified settlement of the Bronze Age. In the embankment of the rampart, four Sarmatian burials of the 1st - 2nd centuries AD were discovered. The fortifications themselves, according to the characteristic ceramic materialls of the beginning of the Scythian era, are dated to the second half of the 6th - beginning of the 5th centuries BC. At an early stage, they apparently consisted of a ground structure that had a defensive and residential purpose. At some distance from the building, there was also an outer wall. These structures are traced along three parallel grooves deepened into the clay. After the fire destroyed the structure, a rampart and a moat were erected in the settlement. In its present state, the embankment of the rampart has a width of about 6 m at the base, and a height above the mainland - more than 0.7 m. It consists mainly of dark gray loam, including lumps of red clay and burnt soil. The moat, now almost completely flooded by ground, is 1.5-1.9 m wide and up to 0.8 m deep.

Impact of Bush Burning on Chemical Properties of Some Soil in Igboora, Oyo State, Nigeria

Soil is used in agriculture as an anchor and primary nutrient base for plants, and the types of soil and available moisture determine the species of plants that can be cultivated. Bush burning, whether as result of a wildfire or a controlled burning, affects not only the appearance of the landscape, but the quality of the soil. Bush burning method of land clearing is a traditional farming system used as a means of land clearing for crop production. This method of land clearing has both beneficial and detrimental effects on soil physical and chemical properties. Therefore, this study investigated the effects of bush burning on soil chemical properties at different soil depth of 0-30 cm and 30-60 cm respectively base on the rooting depth of crop planted. The experiment was carried out in six selected farms in Igboora, Ibarapa central Local Governmental, Oyo State. The soil sampled were collected from burnt and unburnt experimental soil and analyzed using USDA standard methods for soil analysis for the selected chemical characteristics (pH, Ca2+, Mg2+ Na+. TN and P). Two samples were taken from each burnt and un-burnt locations at depth of 0-30 and 30-60 cm. Paired t-test was used to compare means value of soil chemical properties determined from burnt and un-burnt soil. ANOVA was used for significance difference between soil from burnt and un-burnt soil. pH increased from moderately acidic to slightly acidic, phosphorus content of the soil increased greatly from un-burnt soil to burnt soil at 0-30 cm and 30-60 cm depths from 6.64 to 22.21 ppm and 3.53 to 24.95 ppm, respectively. Similarly, potassium increased from 0.27 to 0.40ppm at 0-30cm depth but decreased from 0.23 to 0.17 ppm at 30-60 cm depth. Nitrogen reduced at both depths from 0.80 to 0.76% and 0.72 to 0.68% respectively. Magnesium also increased from 1.3 cmol/kg to 2.00 cmol/kg and 1.65 to 1.75 cmol/kg at both 0-30 cm and 30-60 cm depth respectively. Whereas calcium showed a reduction from 3.17 to 2.85 cmol/kg and 1.65 to 1.45 cmol/kg at both depths. The variations observed between burnt and un-burnt soil for Ca, Mg, exchangeable acidity, pH, Nitrogen, potassium was significant at p<0.05 probability level. This indicates that bush burning has an impact on soil physical and chemical properties which may affect the suitability of the soil for crop production. Based on this, there is need for environmental education for farmers in the area in order to know the implications of bush burning on soil properties for soil sustainability which will boost food production.

The analysis of splash erosion depending on the degree of soil wettability - a preliminary study

&lt;p&gt;The soil splash phenomenon is the initial stage of the water erosion process. It occurs when a rain drop hits the soil surface and causes a few processes e.g. i) detachment of soil particles and their transport over different distances, ii) breakdown of soil aggregates, iii) surface runoff or iv) formation of a crusted surface.&lt;/p&gt;&lt;p&gt;The aim of the study was to carry out an analysis of the splash erosion in mineral soil in 4 variants of sample preparation: a) dry natural soil, b) wet natural soil, c) dry burnt soil, d) wet burnt soil.&lt;/p&gt;&lt;p&gt;In both cases (natural soil and soil modified with high temperature), full moistening was achieved by capillary rise. Fire simulation was carried out in several variants at varying temperature and duration. Variant that affected soil wettability to the greatest extent was selected for the splash analyses. &quot;Natural&quot; and &quot;modified&quot; wettability were measured using the water drop penetration time (WDPT) method. &quot;Natural&quot; wettability classified soil into the &quot;wettable&quot; group (WDPT &lt; 5s), while the modification of the surface properties by high temperature changed the wettability group of the analyzed soil into &quot;slightly to moderately repellent&quot; (5 s &gt; WDPT &lt; 60s).&lt;/p&gt;&lt;p&gt;Each time, the soil material was placed in aluminum rings with an internal diameter of 36mm and a height of 10mm, and the surface was leveled without excessive compaction of the sample.&lt;/p&gt;&lt;p&gt;A single drop of distilled water with a diameter of 4.2 mm fell on the sample prepared in this way from a height of 1.5m. The drops were dosed with a peristaltic pump and reached the final velocity of 4.98 m/s.&lt;/p&gt;&lt;p&gt;Three synchronized Phantom Miro M310 cameras (Vision Research, USA) were used to register the splash phenomenon. The recorded films were used to analyze the splash phenomenon through measurements of the velocity, angle and distance of ejected particles.&lt;/p&gt;&lt;p&gt;A Scan3D UNIVERSE 10 MPiX structural light scanner (Smarttech 3d, Poland) was used to determine the magnitude of the surface deformation caused by the drops. The analyses made it possible to determine e.g. the depth, diameter, and volume of craters and the height of surrounding rims.&lt;/p&gt;&lt;p&gt;The analysis of the results showed significant differences in the size and dynamics of the emerging splash depending on the degree of soil wettability.&lt;/p&gt;&lt;p&gt;The study was partially funded by the National Science Centre, Poland, as part of project no. 2017/26/D/ST10/01026.&lt;/p&gt;

Assessing the Ecotoxicity of Soil Affected by Wildfire

This study was carried out to assess the ecotoxicity of soil affected by wildfire using two laboratory toxicity tests, and to investigate the possibility of application of selected soil amendment into the burnt soil in order to improve its properties for faster post-fire reclamation. A phytotoxicity test is a fast-indicative test for revealing acute toxicity and was performed on quickly growing plant species Sinapis alba L. and Lepidium sativum L., while a pot experiment is a standardized toxicity test with a longer experiment duration and was carried out with Lolium perenne L., Festuca rubra L., Brassica juncea L. Diatomite, bentonite, compost, and biochar were supplemented to the soil. Regarding the phytotoxicity test only 3% w/w of biochar stimulated the growth of Lepidium sativum L. Pot experiment confirmed that effect of soil application amendments on biomass yield is more significant than the plant species. The average highest biomass yields were achieved in treatments with bentonite and diatomite. Subsequent research should focus on investigating possible combinations of soil amendments for burnt soil reclamation and complementing the experiments with chemical analysis.

Effects of different vegetation types on burnt soil properties and microbial communities

The intensive wildfires recurring in the Mediterranean area modify soil physico-chemical properties, in turn inducing changes in soil microbial abundance and activity. Soils were sampled from burnt and adjacent unburnt sites within Vesuvius National Park 1 year after a large wildfire occurred in summer 2017. The aims of the present study were to evaluate the effects of fires on soil characteristics and to investigate whether different plant types contribute to mitigating or enhancing these effects. The results showed lower organic matter and water content and a higher C/N ratio in burnt than in unburnt soils. In particular, this trend was the same for all the plant types investigated, with the exception of soils covered by black locust tree and holm oak, which showed a higher C/N ratio in unburnt than in burnt soils. In soils covered by holm oaks, a shift in the bacterial and fungal fractions occurred between burnt and unburnt soils, whereas the amount of ammonia oxidisers was notably higher in burnt than in unburnt soils covered by black locusts; the highest N concentration was also measured in burnt soils covered by black locusts. The burnt soils showed a lower metabolic quotient and a higher rate of organic carbon mineralisation compared with unburnt soils, and this trend was particularly evident in soils under herbaceous plants. The findings suggest that soils covered by herbaceous species are more sensitive to fire effects and less able to restore their functionality compared with soils covered by trees.

Wildfire ignition from forestry machines in boreal Sweden

Several large Swedish wildfires during recent decades were caused by forestry machinery in operation, fires for which there is still no characterisation. We combined 18 years of data on dispatches, weather and fire danger and interviewed forestry workers to understand the spatial, temporal and weather distributions of these fires, and their underlying mechanisms. We estimate the average annual number of ignitions from forestry machinery in Sweden at 330–480 (2.0±0.4 ignitions per 1000ha clear-felling) of which 34.5 led to firefighter dispatches, constituting 2.2% of all forest fire dispatches and 40% of area burnt. Soil scarification causes the most ignitions and the main mechanism is likely high-inertia contact between discs and large stones, causing sparks igniting dry humus or moss, countering reports suggesting that such metal fragments cannot fulfil ignition requirements. We found a spatial relationship between forestry machine ignitions and abundance of large stones, represented by a Boulder Index generated from a nationwide dataset. Further, 75% of the dispatches occurred on days with relative humidity &lt;45%, Duff Moisture Code (Canadian system) &gt;26 and Fire Weather Index &gt;12. 75% of the area burned when Fire Weather Index was &gt;20. Results suggest machine-caused forest fires can be largely avoided by cancelling operations in stony terrain during high-risk weather.

Medium-term impact of post-fire emergency rehabilitation techniques on a shrubland ecosystem in Galicia (NW Spain)

The aim of this work was to study the effectiveness of two post-fire emergence<em> </em>rehabilitation techniques (seeding and mulching) for reducing soil erosion as well as their effects on the soil quality; therefore in the field, experimental plots of unburnt soil, burnt soil, burnt soil plus seeding and burnt soil plus mulching were established. Soil samples were collected from the A horizon and a wide range of physical, chemical and biological soil properties were analyzed to evaluate soil quality. The effect of fire on the vegetation cover was observed after one year and changes in soil properties persisted even after four years. The phospholipid fatty acids pattern showed that in the medium-term (8-48 months after the fire), the fire may modify the soil microbial communities by altering the plant community via plant-induced changes in the soil environment. No effect of seeding or mulching on the vegetation cover was observed. The mean efficiency in preventing soil erosion between 8 and 12 months after the fire and the application of the treatments was 11% for seeding and 65% for mulching. These stabilization treatments had a minor influence on the post-fire soil quality in the medium-term (48 months); therefore, taking into account its effectiveness for reducing soil erosion, the mulching treatment is recommended as the best post-fire stabilization technique.

Tell el-Farkha: archaeological fieldwork 2014–2015

The archaeological site of Tell el-Farkha is composed of three mounds excavated continuously by the Polish team since 1998. In the 2014 and 2015 seasons, covered in this report, investigations were carried out in already opened trenches in three sectors. On the Western Kom, another brewery was explored to add to the already existing set of investigated installations of this kind. It demonstrated three phases of use, the topmost separated from the middle one by a thick layer of burnt soil and ashes. The deposit attests to a conflagration that consumed the entire settlement. The study of a huge Naqadian building was continued on the Central Kom. Two occupation phases were distinguished: an older one at the beginning of the Naqada IIIA1 period and a younger one attributed to Naqada IIIA1–IIIA2. Remains of Lower Egyptian structures were unearthed below the foundations of this building. A big clay stamp-seal with hieroglyphs from the mid First Dynasty period was found associated with this feature. On the Eastern Kom, a big mud-brick edifice of unknown function was investigated. A further 17 graves, mostly from the second half of the First and the beginning of the Second Dynasty, were discovered as well.