EARTHWORM COMMUNITIES (OLIGOCHAETA, LUMBRICIDAE) OF PINE FORESTS AND SMALL FOLIAGE FORESTS IN THE FOREST-STEPPE OB’ REGION

S.A Ermolov

doi:10.31509/2658-607x-202141d20

Abstract

Earthworms form an essential group of soil macrofauna that performs a number of ecosystem functions in forests. Studies of the species composition and population density of earthworms were conducted in many regions of Russia; however, the fauna of Lumbricidae of Novosibirsk area remained unexplored for a long time. The objective of this work is to carry out a comparative analysis of earthworm population in coniferous and small foliage forests of the forest-steppe Ob region (Novosibirsk area) and to identify the correlation between the fauna composition and the basic physical and chemical properties of the soil. The study was conducted in pine forests and birch-aspen forests. The main method of registration was layer-by-layer excavation of soil with hand sorting of soil samples and analysis of forest deadwood. Some soil parameters were also measured. Data of the species composition and population density of earthworms for each habitat are given. The studied habitats were classified according to the ratio of the earthworm living forms. It was found that soil humidity is the most significant factor for the group of epigeiс and epi-endogeiс species. The diversity of epigeiс and epi-endogeiс earthworm species in forests is largely supported by deadwood. The Asian subspecies Eisenia nordenskioldi nordenskioldi was subjected to morphometric analysis confirming its characteristic polymorphism.

Highlights

IntroductionStudies of the species composition and population density of earthworms were conducted in many regions of Russia; the fauna of Lumbricidae of Novosibirsk area remained unexplored for a long time
The highest density of earthworm population was observed in the Zael'covskij pine forest (174 individuals/m2), whereas it was the lowest in the pine forest in the vicinity of Baryshevo village (30 individuals/m2), where worms were not found in all pits, and some species were found only once (Table 1)
The most diverse species composition was found in the Kudrjashovskij pine forest (4 subspecies, 2 species; 172 individuals/m2 in total, some species were found only once), and the least diverse species composition was found in the pine forest in the vicinity of Sosnovka settlement (2 subspecies, 1 species; 124 individuals/m2 in total), where, with the exception of D. octaedra, there were no cosmopolitan species

Summary

Introduction

Studies of the species composition and population density of earthworms were conducted in many regions of Russia; the fauna of Lumbricidae of Novosibirsk area remained unexplored for a long time. The presence of various species and living forms of earthworms, as well as their estimated population density, indicate the state of forest soils (Chekanovskaja, 1960; Akkumuljacija..., 2018). Soil is not the only habitat for earthworms They inhabit forest litter, live in piles of animal dung, and are abundant in deadwood, contributing to its destruction. The latter is most important for forest ecosystems, where deadwood helps to maintain the species diversity, and the functional diversity of earthworms (Geraskina, 2016b, 2016c; Ashwood et al, 2019).

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