Seasonal Changes in the Photosynthetic Activity of Terrestrial Lichens and Mosses in the Lichen Scots Pine Forest Habitat

Photosynthetic activity is one of the most important metabolic processes that can be quickly and easily studied in the field. It can be used for identifying the environmental factors affecting ecosystem balance, as any stressor influencing metabolic and physiological processes will have a measurable effect on photosynthesis. The aim of this study was to measure the photosynthetic activity of selected lichens and mosses and investigate its changes resulted from diurnal and seasonal variability. We studied two lichens (Cladonia mitis Sandst and Cladonia uncialis (L.) Weber ex F.H. Wigg.) and two mosses (Pleurozium schreberi (Willd. ex Brid.) Mitt. and Dicranum scoparium (L.) Hedw.). Samples were collected in the area of lichen Scots pine forest of the “Bory Tucholskie” National Park. Our study revealed that the photosynthetic activity of cryptogams depended on species, season, time of the day, and water availability. Cladonia species, which are the main component of lichen Scots pine forests, have higher photosynthetic activity than Pleurozium schreberi, which represents species of fresh coniferous forests. Photosynthetic activity increased from spring through summer and reached the highest values in autumn. It was also higher in soaked samples collected in the morning and afternoon compared to noon. Despite the water access, noon samples still showed the lowest activity. This can result from natural changes in humidity during the day to which cryptogams are well-adapted.

Trends of Scots pine forest health and element flow changes in the ICP Forests monitoring sites in Latvia

Scots pine (Pinus sylvestris L.) is one of the most widespread and economically most important tree species in Latvia. Scots pine forest health and element flow changes have been monitored in Latvia within the International Cooperative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests) with assessment of crown condition and damaging agents at 115 Level I monitoring sites (mostly oligothrophic and mesotrophic Vacciniosa, Myrtillosa and Hylocomiosa forests) and with sampling and analyses of environmental samples at three Level II monitoring sites representing typical Scots pine forests (Myrtillosa) in hemiboreal conditions in Latvia. This study summarizes the background information and presents the trends of forest health, carbon turnover and environment condition in Scots pine forest since 2009. In general, defoliation rate in Scots pine stands remains stable for the studied period, with some yearly fluctuations, possibly related to regional insect outbreaks, especially well demonstrated in two Level II plots. The share of damaged trees varied by year from 12.8% to 19% of the total number; the main cause of damage was direct action of man. Chemical element flows in Scots pine forests in Level II monitoring plots have been relatively stable as well except the decreasing trend in total N concentration in deposition and SO4-S concentration in soil solution and increasing trends in DOC concentration in soil solution that is in line with common trends in Europe. Carbon input with above-ground litter was relatively stable during the whole period; however, interannual variations were rather wide.

The growth of geographical crops of Scots pine on drained lands

The research analyzes observation materials and condition assessment of 100-year geographical Scots pine forest cultures created in 1913 by professor Ogievsky V D on drained lands of the Okhta forestry territory to study the intensity of Scots pine trees growth depending on the seeds origin. The planting material was grown from seeds collected in the northern, southern, eastern, southwestern and central parts of Russia. The growth of Scots pine cultures was studied and changes in wood stock, trees amount, annual increments, influence of meteorological factors on radial increments were analyzed depending on the origin of the planting material. The results of research show that sustainable and highly productive cultures can be grown from seeds of northern and eastern regions of Russia.

An Evaluation of the Effects of UAS Flight Parameters on Digital Aerial Photogrammetry Processing and Dense-Cloud Production Quality in a Scots Pine Forest

The application of unmanned aerial systems (UAS) in forest research includes a wide range of equipment, systems, and flight settings, creating a need for enhancing data acquisition efficiency and quality. Thus, we assessed the effects of flying altitude and lateral and longitudinal overlaps on digital aerial photogrammetry (DAP) processing and the ability of its products to provide point clouds for forestry inventory. For this, we used 18 combinations of flight settings for data acquisition, and a nationwide airborne laser scanning (ALS) dataset as reference data. Linear regression was applied for modeling DAP quality indicators and model fitting quality as the function of flight settings; equivalence tests compared DAP- and ALS-products. Most of DAP-Digital Terrain Models (DTM) showed a moderate to high agreement (R2 > 0.70) when fitted to ALS-based models; nine models had a regression slope within the 1% region of equivalence. The best DAP-Canopy Height Model (CHM) was generated using ALS-DTM with an R2 = 0.42 when compared with ALS-CHM, indicating reduced similarity. Altogether, our results suggest that the optimal combination of flight settings should include a 90% lateral overlap, a 70% longitudinal overlap, and a minimum altitude of 120 m above ground level, independent of the availability of an ALS-derived DTM for height normalization. We also provided insights into the effects of flight settings on DAP outputs for future applications in similar forest stands, emphasizing the benefits of overlaps for comprehensive scene reconstruction and altitude for canopy surface detection.

PIONEERS OF FOREST BREEDING IN THE CENTRAL BLACK EARTH REGION

The article contains brief information from the life and scientific work of the founders of forest breeding, who worked in Voronezh. On the initiative of N.P. Kobranov in 1919, on the basis of Voronezh Agricultural Institute, a forestry department was opened, which was later transformed into the forestry faculty, and since 1930 Voronezh Forestry Institute (now VSUFT) was organized. The main scientific work of N.P. Kobranov is the country's first publication on forest selection - the monograph “Oak selection” (1925), which also outlined possible ways of selection development of forest woody plants in general. Further, his associates and colleagues were engaged in the introduction and selection of forest tree species in the pre-war period: O.G. Kapper ("Study of ecotypes of tree species", 1946; "Conifers", 1954, etc.) and S.A. Samofal (manuscript of his doctoral dissertation "Heredity and variability of forest species and their importance for forest growing", 1938, etc.). Then a huge contribution to the development of forest breeding in the country was made by M.M. Veresin ("Forest seed production", 1963; "Centennial experience of afforestation in the Savalsky forestry", 1963; "Forests of Voronezh", 1971; a new program for forest selection for universities, 1966, etc.). He is the author of grandiose experiments on the geographical planting of Scots pine on an area of about 40 hectares, including more than 350 origins. In addition, he created oak, nut, Karelian birch, seed plantations and collections of hybrids of different tree species. He developed a number of new highly productive poplar hybrids. The director of the Voronezh Forestry Institute V.I. Rubtsov, who himself laid large-scale experimental field facilities for Scots pine forest plantations. Vasily Ivanovich played an important role in the creation of Central Institute of Forest Genetics and Breeding in Voronezh. Among the well-known successors of forest selection work in the country is the director of All-Union Scientific Production Association "Soyuzlesselektsiya" A.I. Iroshnikov. Under him (together with Voronezh Forestry Institute and the Central Research Institute of Forest Genetics and Breeding), a department of forest selection was organized. All these scientists have shown an example of selfless service to the chosen cause

Soil successions of Carbic Podzols (Arenic) under Scots Pine plantations in Kursk region

Anthropogenic activities lead to significant transformations of natural landscapes. In this article, an attempt was made to describe the soil succession in the context of 100-year dynamics of Scots Pine forest stand in Kursk region. The morphological, physical, chemical and physical and chemical characteristics of sandy podzols in the chronological order of pine forests functioning 0 - 70 - 100 years were under analysis. It was revealed that monodominant forest stand of Scots Pine leads to the transformation of soils at the type level. It is noted that forest stand of Scots Pine on Umbric Podzols contribute to the development of the podzolic process at an average rate of formation of the podzolic horizon - 0.11 - 0.17 sm / year. During the time period of the soil succession (100 years), the thickness of the soil profile has increased and the humus reserves in the profile have increased by 47.1%, as well as a total decrease in the content of mineral nutrients is noted. The content of mobile forms of heavy metals (Cu, Zn, Ni, Mn and Co) in the genetic horizons of Carbic Podzols (Arenic) in the time interval of the succession 70 - 100 years decreases by 21.4 - 71.4%.