No 8 (2023)

This issue of the journal is dedicated to Yuri Georgievich Puzachenko, an outstanding ecologist and geographer. In the presented message, we tried to trace the stages of Yuri Georgievich’s scientific path and highlight the key areas of his scientific interest: the organization and functioning of complex self-organizing non-equilibrium systems – biogeocenoses and landscapes, various aspects of biodiversity, relationships between species and environment. The research presented in the articles in this issue is devoted to these three directions.

One of the most important tasks in modern ecology theory is the formalization of the ecological niche. Advances in spatial analysis techniques and the availability of global databases on biodiversity and environmental parameters provide an unprecedented opportunity to integrate ecological niche components within a correlational modeling approach. The paper presents methods for formalizing biotic, spatial (environmental accessibility) and anthropogenic restrictions on the distribution of biological objects (components of an ecological niche) when constructing SDM (Species distribution modeling) and ENM (Ecological niche modeling) models.

Based on long-term (2010–2014) studies carried out in the forest ecosystems of the Central Forest Biosphere Reserve, two models of the spatial niche of the bank vole (Myodes glareolus Schreber, 1780) were constructed using factor analysis (ENFA). Models with a sufficient level of quality characterize the characteristics of the species’ niche. The modeling results make it possible to describe the structure of the optimal habitat for the bank vole in mosaic southern taiga forests at different levels (scales) of spatial organization.

Ecological conditions can influence the individual development of organisms and morphological variability at the population level. The dimensions and proportions of the skull and lower jaw of immature shrews (Sorex araneus, S. caecutiens, S. minutus) captured in August in overgrown clearings in the middle taiga of north-eastern Europe were dependent on the stage of abundance (“pikes” or “depressions”). For all three species belonging to the same taxocenosis, a statistically significant decrease in skull and jaw measurements was observed against a background of high abundance in captures, and multidimensional morphological niches corresponding to different stages were significantly separated. The parameters of morphological diversity - entropy and a measure of self-organisation were depended on the amplitude of fluctuations in species occurrence, but varied within limits characteristic of mammals. Together with Dehnel’s phenomenon, natural population fluctuations may be one of the main factors determining the nature of the dynamics of individual development and the spatio-temporal variability of morphological diversity in shrews.

The genetic and morphological variability of the southern form of the European chromosomal race of the small wood mouse Apodemus (Sylvaemus) uralensis (Pallas, 1811) in the North Caucasus was studied. The results of the sequence analysis of the cytochrome b gene fragment from 9 geographical samples from the western, central and eastern parts of the North Caucasus indicate a low degree of their genetic isolation with a relatively high diversity of haplotypes. Analysis of morphological variability revealed high variety: three morphological groups were identified. Representatives of all three or two groups were found in the same geographical samples, but their distribution did not conform to the hypothesis of random occurrence. Based on indirect evidence, hypotheses about possible causes of the observed features of regional small forest mouse biodiversity are formulated, which require verification in the course of future studies. In particular, we hypothesised that in the Late Pleistocene (130–11.7 thousand cal yr BP) there were several isolated populations in the region that could have been sources of species diversity in the Holocene.

The “hot spot analysis” was applied to materials from 51 Landsat satellite images using the example of the “Burtinskaya Steppe” area of the Orenburgsky Nature Reserve, to study the dynamics of areas of positive phytomass anomalies relative to a neighborhood with a radius of 300 m. The purpose of the study was to establish the dependence of the variability of areas of increased phytomass on the landscape structure and hydrothermal conditions. We concluded that the switching of phytocenoses in transition zones from steppe to meadow type of functioning is ensured by varying the ratio of xerophytes and mesophytes depending on fluctuations in hydrothermal conditions. The frequency and area of positive phytomass anomalies in the bottoms of gullies correlates with their area on partially forested slopes, which indicates the positive role of forest vegetation in the stabilization of moisture influx into the bottoms. In deforested catchment areas of the south-facing slopes, the area of positive phytomass anomalies is determined by the supply of snow moisture, and in the catchment areas of north-facing slopes, by warm-period precipitation. The binding factors for the most stable positive anomalies of phytomass are the moisture convergence and the landform concavity rather than the catchment area.

It is studied the representation of the texture and color of the soil on the Mansell scale, measured to a depth of 135 cm with an interval of 5 cm on the transect (length 6 km) with a step of 20 m, in hyperspectral data of the Hyperion instrument for 9 measurement periods from January to September. It was found that satellite image for May 24 is most closely related to all the characteristics under consideration. For the soil texture – the largest relationships are observed for depths of 7–15 cm, 45 cm, 75 cm and 120 cm; for color hue – 3–10 cm and 95–135 cm; for color value – 7–15 cm, 25–30 cm and 65–70 cm; for color chroma – 7–10 cm, 40–50 cm, 75 cm and 100 cm. The texture of soil is most related with wavelengths 579–702 nm and 529 nm, color hue – 641–691 nm, color value – 569–702 nm and 518–539 nm, color chroma – 569–702 nm, 508–529 nm and 732–763 nm.