Open AccessTrophic niche but not abundance of Collembola and Oribatida changes with drought and farming system
Author(s) -
Svenja Meyer,
Dominika Kundel,
Klaus Birkhofer,
Andreas Fließbach,
Stefan Scheu
Publication year - 2022
Publication title -
peerj
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.927
H-Index - 70
ISSN - 2167-8359
DOI - 10.7717/peerj.12777
Subject(s) - trophic level , oribatida , ecology , soil biology , biology , abundance (ecology) , ecological niche , soil food web , food web , agronomy , soil water , mite , habitat
Higher frequencies of summer droughts are predicted to change soil conditions in the future affecting soil fauna communities and their biotic interactions. In agroecosystems drought effects on soil biota may be modulated by different management practices that alter the availability of different food resources. Recent studies on the effect of drought on soil microarthropods focused on measures of abundance and diversity. We here additionally investigated shifts in trophic niches of Collembola and Oribatida as indicated by stable isotope analysis ( 13 C and 15 N). We simulated short-term summer drought by excluding 65% of the ambient precipitation in conventionally and organically managed winter wheat fields on the DOK trial in Switzerland. Stable isotope values suggest that plant litter and root exudates were the most important resources for Collembola ( Isotoma caerulea , Isotomurus maculatus and Orchesella villosa ) and older plant material and microorganisms for Oribatida ( Scheloribates laevigatus and Tectocepheus sarekensis ). Drought treatment and farming systems did not affect abundances of the studied species. However, isotope values of some species increased in organically managed fields indicating a higher proportion of microorganisms in their diet. Trophic niche size, a measure of both isotope values combined, decreased with drought and under organic farming in some species presumably due to favored use of plants as basal resource instead of algae and microorganisms. Overall, our results suggest that the flexible usage of resources may buffer effects of drought and management practices on the abundance of microarthropods in agricultural systems.