No 5 (2023)

The perspectives of transition of the immature and virginal saplings of Quercus robur L. to the A1 and A2 canopy sublayers have been analyzed. The studies have been conducted in the different forest types within the Southern Moscow region. For the estimation of the phytosociological role an individual could claim we applied morphometric and architectural methods. We measured height, trunk diameter, crown projection, calendar age and lengths of five trunk increments in a row. We considered growth habit, configuration and branching of the trunk and of the branches themselves. Four degrees of an individual’s prospect have been identified. 0 – an individual will not go beyond the level of low shrubs. 1 – an individual will reach the level of high shrubs and can start fruiting. 2 – an individual will reach the A2 canopy sublayer. 3 – an individual will reach the A1 canopy sublayer. From the degree 0 to the degree 3 an increase in the values of the trunk increments and branching intensity was noted.

Modern global climate change manifests in an ever intensifying fashion, affecting anthropogenic and natural systems. Bioclimatic models predict significant shifts in biome boundaries, including a reduction in the forests’ proportion in the forest-steppe areas. This process can also affect carbon stocks. The aim of the work was to assess the impact of climate and its changes on the values and their changes of the phytomass’ carbon stocks of forest stands according to the data of repeated surveys of permanent sample plots. In the southern regions of the European Russia, 8 forests were selected and trial plots were set up. Repeated surveys were carried out on the test plots in 2010–2011, 2014–2015, 2019–2020. The carbon reserves of the living and the dead components of forest stands were calculated according to taxation characteristics. The litter carbon stocks were determined by the gravimetric method. The meteorological information analysis was carried out using data from the meteorological stations closest to the objects of study. Average annual temperature for 1991–2020 increased compared to 1961–1990. by 1.13°C, which is 2.5 times more than the global average. At the same time, annual precipitation decreased from 448.2 mm to 445.4 mm. The average value of the G.T. Selyaninov’s hydrothermal coefficient for May-September during the 1961–1990 period was 0.85, and 0.79 during the 1991–2020 period. The stock of the phytomass carbon in the studied forest stands varied from 38.5 ± 7.4 t C ha^–1 to 270.6 ± 52.8 t C ha^–1. Repeated surveys revealed both increases and decreases in phytomass carbon stocks, which ranged from –23.8 to 31.9 t C ha^–1 over a five-year interval. The phytomass carbon stocks and climatic characteristics analysis revealed a statistically significant correlation with the HTC for May-September. However, comparison of changes in phytomass with changes in the average annual temperature, annual precipitation and HTC for May-September did not reveal significant dependencies. The absence of significant correlations between changes in phytomass carbon and climatic parameters’ changes can be determined by the forest ecosystems’ stability, which ensures the preservation of their functions over several years intervals.

Within the framework of the multi-purpose forest management concept, the resource and economic potential of harvesting wild berries was analyzed under different forest management scenarios. As a tool for forecasting and analysis, scenario-based simulation was used to model the forest ecosystems dynamics under the clearcut and the selective felling management types. The object of research is the Pashe-Kapetskoe district forestry of the Leningrad Region, the calculation was carried out for a period of 120 years. Based on the forest condition types’, species composition and simulated illumination at the ground level data, the potential productivity of wild berries was calculated. The most productive resources on the territory were bilberry and lingonberries, the predicted yield of which reaches 25–48 t/ha and 7–15 t/ha respectively. Zoning of the territory was carried out according to the resources availability for industrial harvesting, taking into account the interests of the local population. 37–48% of the wild berries harvest was available for industrial harvesting, about 30% was allocated for the needs of the local population, and 27–36% of the resource remained in economically inaccessible areas. The most promising was the scenario with artificial restoration of 50% of the clearcut areas and a full maintenance cycle. For this scenario, the maximum profitability was predicted from both the food resources procurement (4.1–5.7 million rubles per year) and the harvesting of timber.

Deforestation and degradation of natural forests pose a challenge for the forest sector in Ethiopia. Gathering scientific data on the reproductive biology of selected timber species has now become important to develop seed production areas and establish forest management regimes. In this regard, this study is aimed at determining the reproductive phenology of three indigenous tree species. The time of leafing, flowering, and fruiting in the three indigenous timber tree species has been recorded for three years in South West Ethiopia. This study was conducted in natural forests of the Benchi-Maji zone (Debub Bench district). We selected three prioritized species, Milicia excelsa, Antiaris toxicaria, and Pouteria adolfi-friedericii, based on the severity of their depletion and relative timber values in the area and in the country at large. Over 20 reproductively healthy, mature, and average mother trees >10 cm wide in diameter at breast height and with easily visible crowns, located at a distance of 100 m from one another, were selected out of each species and marked with marking ink. We conducted continuous observations and recorded data on leafing, flowering, and fruiting every 15 days (twice every month). The data was then analyzed using descriptive statistics. The result of this study indicates that the actual season when the seeds of Milicia excelsa are available for collection is once a year, from January to February. The results also showed that, for Antiaris toxicaria, the fruiting time is seasonal, and seeds become available for collection from early January up to the end of February. The fruiting time or the actual season when seeds of Pouteria adolfi-friedericii become available for collection is from May to June. Low-cost technologies (to establish seed production areas and domesticate the species) are recommended to be used for seed/seedling acquisition and distribution and preferable to reduce the destruction of the selected indigenous tree species.

The paper presents the results of an ecological-geographical experiment on 4 species of hawthorn at two experimental bases of the Mountain Botanical Garden (1100 m and 1700 m a.s.l.). To identify intraspecific and interspecific variability of shoots and leaves, descriptive statistics, Student’s t-test, one- and two-way ANOVA and discriminant analyses were used, for which 10 quantitative signs of the annual shoot of individuals in the virginal period were analysed. The adaptive abilities and morphological features’ variability of annual shoots and leaves of hawthorn under different growing conditions were determined. At the age of five, the samples grown at an altitude of 1700 m a.s.l. have the largest average indicators values. Differences depending on the place of cultivation were most pronounced in C. pseudoheterophylla, for other samples, the effect of altitude is insignificant. One- and two-factor ANOVA in a hierarchical complex made it possible to determine the difference-defining traits, as well as the degree to which the ecotope affected the variability of traits. Having considered interspecific differences/similarities in terms of shoots’ and leaves’ traits under different growing conditions and using discriminant analysis, we were able to draw a preliminary conclusion: subsectional differences/similarities were most clearly manifested at an altitude of 1700 m, and interspecific differences – at an altitude of 1100 m. a.s.l. The work was carried out within the unique scientific installation “The System of Experimental Bases of the Mountain Botanical Garden”.