Structural peculiarities of forest litter in water protective pine stands in wet sites of Zhytomyr Polissia

The results of the study of the fractional composition, structure and formation of forest litter in water protection pine plantations, which grow in the predominant moist forest vegetation conditions of Zhytomyr Polissia, are presented. The age range of stands varies between 18 and 85 years. It is established that water-protected pine stands in wet hygrotopes accumulate significant reserves of forest litter, which ranges from 33.0 t/ha in young plantations 77.0 t/ha in mature stands. The distribution of forest litter throughout area in most stands is uniform, although in young plantations its greater share is accumulated between rows. In terms of composition, the forest litter of pure pines is characterized by a medium dense structure, and in pines with an admixture of deciduous species, the litter is usually loose, due to the presence of annual fallen leaves in its upper horizon. The thickness of forest litter between rows of young plantations varies within and 2.6-2.9 cm without its clear distribution on the horizons. In medieval plantations, the horizons of the litter are already clearly distinguished. The total thickness of the litter is 4.0–4.3 cm. In the pre mature and mature pine stands the thickness of the forest litter profile varies between 6.0–6.3 cm. In the stands of older age groups the forest litter has mainly a three-layer structure. The trend of intensive accumulation of forest litter in the conditions of wet boreal and sub boreal conditions with the age of maturity is revealed. In pre mature plantations, the accumulation of litter slows down and in mature plantations; the processes of accumulation and decomposition of litter are leveled. The tendency of predominance of the active part and, accordingly, reduction of the inactive fraction of litter in the pre mature and mature plantations of wet sub boreal site compared to boreal conditions is indicated, which indicates more active processes of mineralization of litter in wet subboreal conditions.

THE INFLUENCE OF RECREATIONAL IMPACT IN FOREST COMMUNITIES ON THE ALLELOPATHIC REGIME OF TREE EDIFICATORS

The allelopathic regime of the phytogenic field of model middle-aged trees of seven forest formations in the zone of humid subtropics of the Sochi Black Sea region was evaluated with an admissible range of stages of recreational digression. The method of biotesting of water extracts from forest litter, soil and roots was used to determine the spatial gradient of allelopathic activity of the phytogenic field environ-ment. The share of participation of the allelopathic factor in the formation of the phytogenic field at certain stages of recreational digression was established. It was determined that the value of allelopathic intensity of the phytogenic field, depending on the stage of recreational digression, field zones and edifi-cator species, can characterize the degree of resistance to the introduction of new species, recreational resistance and community stability.

Structure of forest litter in larch forests of Middle and Southern Siberia

Forest litter plays a significant role in the functioning of forest ecosystems. As a product of forest and soil interaction, forest litter participates actively in the processes of soil formation and plant nutrition. We measured the total stock and analyzed difference in structure of forest litter formed in permafrost larch forests growing in the different climatic zones: in northern taiga of Central Siberia and in the mountain taiga of the Eastern Baikal region. The forest-forming species in both regions is Gmelin larch (Larix gmelinii (Rupr.) Rupr.), but climatic conditions and soil cover in these regions differ. It was found that average stock of forest litter is higher in mountain larch forests of the Eastern Baikal region in comparison with northern boreal forests. The litter composition in these larch forests is characterized by a relatively larger contribution of soft fractions (needles and leaves) in contrast to the larch forests in the northern taiga, where a higher contribution of hardly decomposable components (branches, cones, bark, semi-decomposed wood, thick roots, and moss residues) was observed. Higher stock of fermented plant residues in comparison with humified ones indicated the accumulation of incompletely decomposed plant residues on the soil surface of these northern forests.

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

Litterfall and Element Return in an Abies faxoniana Forest in Tibet—A Five-Year Study

Forest litter is the main contributor to soil fertility and the main carrier of circulating material and energy in forest ecosystems. Abies faxoniana (Minjiang fir) is one of the dominant species in alpine forest ecosystems. Its litter input plays important roles in soil organic matter formation and biogeochemical cycles in these ecosystems, but the annual litterfall pattern and its components remain largely unknown. To determine the litter input and nutrient return of A. faxoniana, we measured the litterfall and element (carbon (C), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), sodium (Na), magnesium (Mg), aluminium (Al), iron (Fe), and manganese (Mn)) contents of different litter components (branches, leaves and epiphytes) from 2016 to 2020. The results showed that the annual litterfall in the A. faxoniana forest ranged from 2055.96 to 5384.15 kg·ha−1·a−1, and the average mass proportions of branches, leaves and epiphytes were 30.12%, 62.18% and 7.7%, respectively. The litterfall yield varied significantly with time and component; not only was the yield of litter in the nongrowing season higher than that in the growing season, but it also exhibited dramatic interannual variations. We also found that time had significant effects on the contents of all elements except for Ca in the litter. The return and input amounts of each element followed the same dynamics, which closely resembled a bimodal pattern. Moreover, there was significant interannual variability in the returned amounts of each element. The ranges of annual returns of C, N and P were 744.80~2275.12, 19.80~59.00 and 1.03~2.81 kg·ha−1·a−1, respectively. The ranges of annual returns of K, Ca, Na, Mg, Al, Fe and Mn were 0.91~2.00, 7.04~18.88, 0.13~0.58, 0.33~1.20, 0.55~2.29, 0.41~1.37 and 0.16~0.48 kg·ha−1·a−1, respectively, reflecting a seasonal double-peak pattern. These results have important implications for understanding the biogeochemical cycles and material migration processes in alpine forest ecosystems.

Assessment of regulating ecosystem functions/services of the urban forests in the Angara region (Eastern Siberia, Russia)

The studies of urban forests were carried out on the territory of the Angara region in cities with a high air pollution index (up to 20) and with a high recreational load. The state of forest biogeocenoses was assessed by the parameters of trees, forest litter, and soil. Morphostructural, physicochemical, biochemical, and toxicological indicators were analysed. It was found that the selected biogeochemical parameters of trees and soils have a high level of correlation relationships under conditions of negative anthropogenic impact. The biogeochemical redistribution of technogenic pollutants in urban forests connects with the accumulating capacity of the soil cover and the regulatory function of trees, namely the ability to purify atmospheric air by accumulating toxicants in the needles and leaves. Regulatory function/service of pollutant absorption and air purification depends not only on the condition of urban forests, it is unequal for forests of different cities and, even more, for different forested territories.

Keanekaragaman jamur makroskopik di Hutan Wisata Desa Tiang Tarah Kabupaten Bangka

Jamur merupakan salah satu komponen ekosistem yang berperan penting dalam mendukung keberlangsungan siklus kehidupan di dalam hutan. Penelitian ini dilakukan untuk mengidentifikasi jenis jamur makroskopik pada kawasan hutan wisata di Desa Tiang Tarah, Kabupaten Bangka. Penelitian dilakukan secara eksploratif dengan menelusuri jalur wisata yang terdapat dalam kawasan hutan. Hasil penelitian diperoleh sebanyak 44 jenis jamur makroskopik berbeda yang termasuk ke dalam sepuluh ordo dari filum Basidiomycota dan Ascomycota. Keseluruhan jamur tersebut termasuk ke dalam Basidiomycota dan Ascomycota. Genus Marasmius merupakan jamur yang paling beragam pada lokasi penelitian. Jamur ini merupakan salah satu jenis jamur yang banyak ditemukan pada daun mati dan serasah hutan. Keberadaan jamur makroskopik di hutan sangat penting sebagai komponen ekosistem tersebut. Kata kunci: Bangka; fungi makroskopik; hutan; keanekaragaman; Marasmius ABSTRACTDiversity of macroscopic mushrooms in the tourism forest of Tiang Tarah Village, Bangka Regency. Fungi is one of the ecosystem components that plays an important role in supporting the sustainability of the life cycle in the forest. This research aimed to identify the species of macroscopic fungi in the tourism forest area in Tiang Tarah Village, Bangka Regency. The research was conducted in an exploratory manner by tracing the tourist route in the forest area. The results found as many of 44 different macroscopic fungus belongs to ten orders from the phyllum of Basidiomycota and Ascomycota. The whole fungus were belong to Basidiomycota and Ascomycota. The genus Marasmius was the most diverse fungi in the study area. This fungus is a type of fungus that is commonly found in dead leaves and forest litter. The presence of macroscopic fungi in the forest is very important as a component of the ecosystem. Keywords: Bangka; diversity; forest, macroscopic fungi; Marasmius

Fuel Briquettes from Sal (Shorea robusta) Forest Litter as an Alternative Cooking Fuel

Sal (Shorea robusta) forest leaf litter strongly influences seed germination and seedling survivorship. Therefore, it is crucial to open up the litter layer in such a forest with abundant leaf litter. Briquetting of Sal forest leaf litter can be an option for its management and meet the increasing energy demand. This research work is performed to quantify the amount of Sal forest litter and study the briquette’s combustion properties. The study was carried out in the Namuna Community Forest of Jhapa district. The average weight of leaf litter in the field was observed to be 851 g/m2 . Five varieties of briquettes were produced using different briquetting technologies. Proximate analysis results, calorific value and water boiling tests show these briquettes have good fuel characteristics and can be used as alternative cooking fuel.

Sheltering Role of Well-Decayed Conifer Logs for Forest Floor Fungi in Long-Term Polluted Boreal Forests

Coarse woody debris (CWD) provides food and shelter to a large proportion of forest biota and is considered vital for biodiversity during periods of harsh weather. However, its importance in long-term stressed ecosystems remains largely unknown. In this work, we explored the contribution of CWD to fungal diversity along the gradient of boreal forest degradation caused by 77 years of heavy industrial emissions. We analyzed the diversity and composition of fungi in 270 samples of well-decayed Picea abies and Abies sibirica logs, as well as forest litter both adjacent to and distant from the logs. Compared with forest litter, the wood had higher water content and possessed substantially lower concentrations of heavy metals, which suggests its potential favorability for biota in polluted areas. The pollution-induced loss of fungal diversity in forest litter reached 34% and was stronger in the microhabitats not influenced by CWD. Meanwhile, wood fungal communities lost less than 10% of their total richness and even increased in alpha diversity. These processes led to the diversity and compositional convergence of fungal communities from different microhabitats and substrates in polluted areas. Despite this, the importance of wood and CWD-influenced microhabitats for fungal diversity maintenance was low. Apart from wood-associated fungi, the taxa whose diversity increased in the wood of polluted areas were ectomycorrhizal fungi and eurytopic soil saprotrophs (Mucoromycota, Mortierellomycota, Eurotiomycetes, and Helotiales) that easily tolerate highly toxic litter. Within the majority of pollution-sensitive soil saprotrophic groups, only terricolous Tricholomataceae benefit from CWD as microrefugia. Upon considering the ecological variability within low-rank taxa, the importance of decayed logs as safe sites can be high for certain soil-inhabiting fungal groups in polluted areas.

DNA Damage in the Tissues of White Rats Exposed to Wildfire Smoke

Wildfire smoke affects the health of the population of the entire planet and each year the situation is getting worse. Fire smoke has mutagenic, carcinogenic and other long-term effects. The aim of this paper was to study the genotoxic effect of wildfire smoke on male white rats and the transgenerational effect of wildfire smoke on their offspring. Smoke exposure simulation was performed on 40 male white rats in 200-litre exposure chambers. Forest litter, branches, fallen bark, and the upper layer of soil served as a combustible substrate. The exposure was carried out for 4 hours 5 days a week in the course of 4 weeks. Offspring of both sexes were obtained from the exposed animals and intact females. We analysed DNA fragmentation and global DNA methylation in the gonadal tissue and blood cells of the exposed animals immediately after the exposure and global DNA methylation in the blood cells of the offspring upon reaching sexual maturity. The research was performed using the comet assay with modifications to study global DNA methylation with MspI and HpaII restriction enzymes. The exposed animals showed an increased level of global DNA methylation in their blood cells. In male offspring, a decrease in the level of global DNA methylation in the blood cells was revealed, compared with the controls, while females showed no differences from the controls. The established facts of changes in global DNA methylation after exposure to wildfire smoke require further in-depth research, since the mechanism of the development of this phenomenon remains rather unclear.