Diversity of littoral zoobenthos in Lake Arakhley (Transbaikalia) during the arid phase

There is little data available on the zoobenthos of the Baikal region’s eastern periphery water bodies in low-water years. The taxonomic diversity of zoobenthos of the littoral zone of a deep lake (Arakhley, Transbaikalia) was studied in an extremely low-water year, 2017. The zoobenthos of the lake littoral zone was represented by 44 taxa. Chironomids accounted for 41% of the zoobenthos taxonomic diversity, 14% each – gastropods and leeches. The taxonomic diversity of the littoral zoobenthos in different parts of the lake varied from 19 to 24 taxa and averaged 22.3 ± 1.97 taxa. The relationship between taxonomic diversity and depth in Lake Arakhley is described by polynomial dependence. Deviations from the relationship identified at the periphery of vegetation thickets were due to the ecotone effect. Obtained data shows the state of zoobenthos taxonomic diversity under conditions of climate aridization and the reduction of littoral sandy habitats.

BURNING OF FORESTS IN SNNP «BURABAY» AND WAYS TO MINIMIZE IT

Аридизация климата, наблюдающаяся в последние десятилетия, обусловила увеличение опасности возникновения и развития лесных пожаров. Особенно это проявляется в южных районах, где лесные насаждения произрастают на границе со степью в экстремальных для них лесорастительных условиях. Уменьшение количества осадков, повышение летних температур и усиление ветра приводят к ускоренно- му высыханию напочвенных горючих материалов и, как следствие этого, повышают вероятность прихода в лесные массивы степных пожаров, а также перехода низовых лесных пожаров в верховые. Сосновые насаждения ГНПП «Бурабай» характеризуются повышенной пожарной опасностью. В них велика вероятность перехода низовых пожаров в верховые и создания угрозы населенным пунктам. В целях совершенствования охраны лесов от пожаров проанализированы показатели фактической горимости лесов ГНПП «Бурабай» за период с 2008 по 2019 гг., а также специфика развития указанных пожаров и причины их возникновения. На основе собранных материалов предпринята попытка разработки предложений по совершенствова- нию охраны лесов от пожаров и минимизации послепожарного ущерба. Climate aridization observed in recent decades has led to an increase in the risk of occurrence and development of forest risk. This is especially evident in the southern regions where forest stands grow on the border with the steppe in extreme for them forest growing conditions. A decrease in the amount of precipitation, an increase in summer temperatures and wind increasing leads to an accelerated drying on soil combustible materials and, as a consequence, increases probability of entering into forests steppe fi res as well as transition of ground forest fi res to crown ones. Pine stands in SNNP «Burabay» are characterized by an increased fi re hazard. They have a high probability of transition of ground fi res upper ones and creation of a threat to settlement. In order to improve the protection of forests from fi res the indicators of actual rate of forest burning in SNNP «Burabay» for the period 2009 to 2019, as well as specifi c of these fi res development and the causes of their occurrence were analyzed. On the basis of the collected materials an attempt was made to develop proposals for improving the protection of forests from fi res and minimizing fi re hazardous damage.

ASSESSMENT OF THE ARIDIZATION OF THE SOUTH-EAST TERRITORY ROSTOV REGION IN DYNAMICS

Based on the analysis of a long series of observations of meteorological parameters, a comparative assessment of the indicators of aridity in the South-East of the Rostov region in terms of time has been carried out. A general tendency for the increase in the degree of climate aridization was established.

The Impact of Climate Variations on the Structure of Ground Beetle (Coleoptera: Carabidae) Assemblage in Forests and Wetlands

We studied the effect of climate variations on the structure of the assemblage of ground beetles (Coleoptera: Carabidae) in a wetland and surrounding watershed forest. We analyzed the changes in the structure of the assemblage of ground beetles provoked by a two-year dry period against the background of studies carried out during the two-year wet period. Aridization influenced the structure of the assemblage of ground beetles more in wetlands than in forests. It was shown that despite the stabilizing effect of the forest on the structure of assemblages of terrestrial arthropods, the two-year dry period had a negative impact on the assemblage of ground beetles in the studied area. The Simpson dominance index of 4.9 during the wet season increased to 7.2 during the drought period. Although the total number of species during the dry period did not significantly decrease in comparison with the wet period—from 30 to 27 species—changes occurred in the trophic structure: during the drought period, the number of predators decreased. It is concluded that the resistance of forest habitats to climate aridization is somewhat exaggerated and, very likely, the structure of the community of arthropods in forests will change significantly.

THE IMPACT OF CLIMATE ARIDIZATION ON OAK STANDS IN THE REPUBLIC OF MOLDOVA (CASE STUDY)

The forests of the Republic of Moldova are composed predominantly by mesophilous deciduous tree species, the most valuable specie are oaks, located at the limit of their natural area. The growth and survival of forests, especially in the peripheral and transition areas of ecosystems, such as the oaks stands of country, also depend on the variety of the thermal and pluviometric regime, which has changed over the last decades in the context of climate aridization. The estimation of the mesophilic tree species exposure to regional climate aridization is shown by the simultaneous use of a set of eco-metric indices: Forest Aridity Index (FAI), De Martonne Index (IM), Ellenberg Coefficient (EQ), and Beech Tolerance Index (QBTI). For areas occupied by oaks (within 2 major natural reserves from central part of Moldova), have been indicated FAI values equal to 6.5-7.5; IM values between 30.0-35.0; EQ values ranging from 30.0-38.0; and QBTI values around 15.0 units, favourable for the mesophilic oak forests development. This fact indicates that during the vegetation period of mesophilic trees, in the central part of the Republic of Moldova, in more arid conditions of development, through modification of oak sensitivity to the water deficit, changes will occur in the compositional structure of ecosystems and the chorology of species. The study results are of particular interest in the sustainable management of the national forestry sector.

PREPARATION OF MEANS AND WINTER WHEAT SEEDS FOR CROPS IN DROUGHTY CONDITIONS

Sowing seeds in arid soil is accompanied by a delay in seedlings, their insufficient development by winter, and often the death of some crops, which leads to significant damage to the production of grain and an increase in their costs. In this regard, the directions of scientific research and constructive development to improve the technology and technical means of preparation and sowing of seeds of winter grain crops under conditions of climate aridization are a very urgent problem of agricultural production.

Evaluări privind impactul secetei asupra speciilor de stejari (Quercus Robur, Q. Petraea, Q.Pubescens) în condiții de aridizare a climei

The growth and survival of forests in the future, especially in the peripheral and transition areas of ecosystems, such as the Moldavian oak forests, depend directly on temperature changes and the amount of atmospheric precipitation. The purpose of this paper is to determine the potential impact of climate aridization on native species - oaks (Quercus robur, Q. petraea, Q.pubescens) in correlation with ecological niche for these species and identifying the vulnerability zones of forests versus the drought (reproduced by various values of the DeMartonne Index). It has been determined that mesophilic oak specie, during the vegetation period, in the central and southern part of the country, under more dry, more arid conditions of development, will feel changes in the sensitivity to water scarcity, changes in the compositional structure of the respective ecosystems and chorological displacements of the species (limiting the growth area of the Quercus robur, Q. petraea and advancing of Q.pubescens to the central part of country).