Journal of Ecological Engineering Received: 2020.02.27 Revised: 2020.04.15 Volume 21, Issue 5, July 2020, pages 137–147 Accepted: 2020.05.06 Available online: 2020.05.25 https://doi.org/10.12911/22998993/122375 Effect of Soil Moisture on the Epigeic Arthropods Diversity in Steppe Landscape Marina Kirichenko-Babko1*, Yaroslav Danko2, Małgorzata Franus3, Witold Stępniewski4 1 Schmalhausen Institute of Zoology NAS of Ukraine, B. Khmelnitsky Str. 15, 01030 Kyiv, Ukraine 2 Sumy Makarenko State Pedagogical University, Romenska Str. 87, 40002 Sumy, Ukraine 3 Lublin University of Technology, Faculty of Civil Engineering and Architecture, Nadbystrzycka 40, 20-618 Lublin, Poland 4 Lublin University of Technology, Faculty of Environmental Engineering, Nadbystrzycka 40B, 20-618 Lublin, Poland * Corresponding author’s e-mail: [email protected] ABSTRACT The consequences of global climate change are a decrease in precipitation as well as an increase in the length of the period with high temperatures from spring to autumn. The climate change intensified the negative consequences of land reclamation and regulation of rivers by dams in Ukraine in the 20th century. The modern landscape of the Circum-Pontic and Circum-Azov regions in Ukraine has undergone desertification, and a multiple reduction in the freshwater runoff has manifested itself in a violation of the water balance of soils and their salinization. In addition to the climate change and anthropic landscape transformations, most upland areas in southern Ukraine have been converted into farmland, systematically fertilized and treated with pesticides and herbicides. Total plowing of the territory also led to soil erosion and degradation. The global climate change and the impact of human activity have affected the diversity of the steppe fauna as well. The questions of the influence of soil humidity on the diversity of epigeic arthropods were considered on the example of ground beetles (Coleoptera, Carabidae). Soil moisture is one of the key factors that determines their diversity. Keywords: steppe, humidity, ground-dwelling beetle, distribution, south-western Ukraine INTRODUCTION the extinction of species indicates the violation of important environmental parameters common The current issues of conservation of biologi- to many species. In this context, two aspects are cal diversity have gone far beyond the conserva- particularly important today. First of all, these are tion of species populations [Myers et al. 2000]. negative anthropic factors operating on the local Today, it is obvious that the problem of species scale, the effects of which are often unpredict- conservation is the problem of preserving their able. Apart from that it is a phenomenon of global habitats on the one hand and preserving the com- warming, the causes of which are also associ- ponent composition of ecosystems on the other ated with the human activities. Global warming [Van Drop 1987; Berg et al. 1994]. Often, the dis- is accompanied by large-scale climate changes in appearance of one species entails the disappear- entire regions and even continents. Distinct eco- ance of a number of other species that most often systems described in detail in the 20th century, did not have any visible interconnections (tro- e.g. on the Eurasian continent – steppe, forest- phic, topical, edaphic, etc.) and were not in com- steppe, woodland, etc. were the result of pro- petitive relations. On the one hand, this proves longed co-evolution of animals and plants under that our ideas about the structure and interactions fairly stable conditions, in which the amplitude of individual ecosystem components are quite of deviations of individual factors remained, as a incomplete, and on the other hand it shows that rule, within the ranges of ecological tolerance of 137 Journal of Ecological Engineering Vol. 21(5), 2020 most species. This predetermined the pronounced to it are included in the territory of the Tiligul Re- physiognomy of the composition of these eco- gional Park (nature reserve) (Ukraine, Mykolaiv systems, their recognizability. However, the pro- Oblast). The study area is located at an altitude of cesses triggered by the climatic changes in com- 117 to 290 m above sea level. The climate of this bination with such forms of human activity as, for region is continental with an average temperature example, land reclamation, caused a significant of -18°C in January and +30°C in July. The po- change in the conditions, which led to a reduction tential evaporation rate is 600–900 mm. in the abundance of species populations and it has Most of the flat interfluve areas are plowed already become obvious that we are witnessing a and used as farmland. The steppe vegetation on mass extinction of the flora and fauna represen- the plateau has been preserved only along the tatives [Wilson, MacLean 2011; Ceballos et al. edges and the slopes of ravines. Previously, the 2015; Kirichenko-Babko et al. 2017]. A manifes- Tsarega River was full-flowing and a number of tation of these processes is a universally observed tributaries flowed into it. Today, the valleys of the reduction in the diversity of natural ecosystems tributaries are turned into ravines, and the Tsarega [Butchart et al. 2019]. itself in the upper reaches is blocked by dams. As Especially noticeable reduction in diversity a result, on the territory of the park in the estuarine is observed among plants and invertebrates, both part of the river, the channel is shallow, swampy, aquatic and terrestrial [Dirzo et al. 2014]. For and the current is practically absent. At the con- most insects, one of the significant factors that fluence with the Tiligulsky estuary, the mouth of determined their evolution and their spatial dis- Tsarega is blocked by a dam. In the Tsarega valley tribution is humidity. Humidity was the key fac- and along the bottom of the ravines adjacent to it, tor in the high diversity of floodplain ecosystems the meadow vegetation is preserved. The steppe [Hammond 1998]. Humidity, combined with tem- vegetation is affected by salinization, present in perature and seasonal fluctuations of these fac- the area with alkali clay soils. tors, as well as their gradients in individual land- Traps were placed at three levels: flat inter- scape elements, determined a significant variety fluves, slopes and the bottom of ravines. At each of ecological niches. At present, the dry periods level, transects of 10 traps were set. The traps have been significantly extended, whereas the ar- (plastic cups of 8 cm diameter and 12 cm depth, eas of wet landscape elements have decreased, or partly filled with 40% ethylene glycol) were they even have disappeared completely. This is placed 5 m from each other. The samples were one of the reasons for the creation of Wetland In- taken once a week for three months (from June to ternational program and close attention to the wa- August in 2009–2011). In the places of sampling, terlogged ecosystems. In fact, against the back- the soil moisture level was recorded. The values ground of global warming, the xerophytic species of humidity ranging from 1 to 3 were considered are in an extremely favorable position and, as a as dry, from 4 to 7 as moist and from 8 to 10 as result, they are expanding to the previously wet wet. According to the humidity requirements, the landscape elements. carabid species were classified as xerophilic, me- The fact that family of Carabidae (Coleoptera) sophilic or hydrophilic, after Turin [2000]. is one group epigeic arthropods, the representa- In total, 30 locations were studied. In the tives which show the changes in the environmen- analysis, the points with an identical relief, be- tal conditions. This study is devoted to the analy- longing to the same habitat and having the same sis of the ground beetles distribution from various soil moisture level were interpreted as one loca- ecological groups, according to the elements of tion. Therefore, he data on the locations identical the steppe landscape with different humidity. in the indicated parameters were averaged; the result was 14 units for analysis. MATERIAL AND METHODS Statistical analysis Study area The data were processed using R version 3.6.1 [R Core Team 2019]. The employed R – soft- The valley of the Tsarega River and the system ware environment for statistical data curation of ravines (Velyka Zlodijka, Mala Zlodijka, Sazh- and graphics visualization is currently widely ap- neva and along left riverside of Tsarega) adjacent plied in ecology and environmental engineering 138 Journal of Ecological Engineering Vol. 21(5), 2020 [Majerek et al. 2017; Pliashechnyk et al. 2018; accessibility in the steppe landscape, is signifi- Babko et al. 2019; Łagod et al. 2019]. Hierarchi- cant. In the studied territory, the species composi- cal clustering was performed with hclust (func- tion of ground beetles is represented mainly by tion ward.D2) from core R package stats. Two common species, many of which are tolerant to types of p-values (AU and BP) for the nodes of a wide amplitude of humidity fluctuations. At the hierarchical clustering dendrograms were calcu- same time, the hygrophilous species: Carabus lated with R package pvclust. According to the clatratus, Elaphrus cupreus, Chlaenius nigricor- package documentation, “AU p-value, which is nis, Ch. vestitus, Demetrias imperialis did not computed by multiscale bootstrap resampling, is disappear from the ground beetle species assem- a better approximation to unbiased p-value than blage in the steppe. BP value computed by normal bootstrap resam- The results of fuzzy clustering essentially pling. Clusters with AU larger than 95% are high- coincide with the results of hierarchical cluster- lighted by rectangles, which are strongly sup- ing. These two groups of habitats superimposed ported by data” [Suzuki 2015]. Fuzzy clustering on the plane of the first two principal components was performed with function fanny from pack- of PCA (Fig.