Springtail (Hexapoda: Collembola) functional group composition varies between different biotopes in Russian rice growing systems

Regular flooding during rice cultivation adversely affects soil animals in agroecosystems and may disrupt ecological functions that they deliver. Alternation of upland crops and flooded rice potentially has a positive effect on soil fauna. However, this aspect has not yet been studied outside the tropics. We focused on the influence of interannual crop rotation accompanied by long periods of paddy drainage in Russian rice growing systems on the total abundance, species richness and abundance of functional groups of springtails (Hexapoda: Collembola) with respect to their vertical stratification. In three rice-growing regions of Russia (Krasnodarsky Krai, the Republic of Kalmykia and Primorsky Krai), we collected soil in four different biotope types: flooded rice paddies, drained paddies seeded with upland crops, paddy bunds and a control of semi-natural grasslands. We found that the total abundance and total species richness of Collembola were consistently higher in upland crops (21100 ± 12700 ind. m−2; 4 ± 0.7 species plot−1) than that in flooded rice (340 ± 190; 1 ± 0.4, respectively) across all regions. The abundance of euedaphic springtails in upland crops and flooded rice paddies (700 ± 350 and 150 ± 150 ind. m−2, respectively) remained significantly lower than that in bunds or control grassland sites (5600 ± 1900 and 6100 ± 2100, respectively). In contrast, the abundance of epiedaphic springtails was higher in upland crops (18900 ± 12500 ind. m−2) than that in flooded rice paddies (170 ± 100) but did not differ from that in control grasslands and bunds. We conclude that interannual alternation of flooded rice and upland crops in Russian rice paddies implies opportunities for soil microarthropods to rebuild their diversity and functional group composition before the next period of flooding mainly due to quicker dispersing surface-dwelling species.