Lipid composition of Collembola and their food resources in deciduous forest stands—Implications for feeding strategies |
| |
Authors: | Liliane Ruess Kirsten Schütz Sonja Migge-Kleian Ellen Kandeler |
| |
Institution: | a Institute of Soil Science, University of Hohenheim, Emil-Wolff-Str. 27, 70599 Stuttgart, Germany b Institute of Zoology, TU Darmstadt, Schnittspahnstr. 3, 64287 Darmstadt, Germany c Institute of Zoology II, Georg-August-University Göttingen, Berlinerstr. 28, 37073 Göttingen, Germany d Department of Biochemistry and Microbiology, Rutgers University, 76 Lipman Drive, New Brunswick, NJ 08901-8525, USA |
| |
Abstract: | The lipid composition of Collembola and their potential food resources was assessed in three deciduous forest stands, in order to gain insight into food web linkages under field conditions. Fatty acids (FAs) previously assigned as trophic markers in laboratory experiments were used to investigate feeding strategies in situ. As potential food sources soil microbiota and plant debris were characterised by their phospholipid fatty acid (PLFA) composition. Both the amount and the pattern of PLFAs differed between sites and soil depth, in particular the bacterial and plant marker FAs in the upper soil layer. Thus, the availability of resources for micro-detritivores varied due to forest and soil layer. The lipid composition of vital and senescent beech leaves was predominantly influenced by metabolic status and represented a quite homogenous FA resource across forest stands. Comparing Folsomia quadrioculata, Lepidocyrtus lignorum, Neanura muscorum and Pogonognathellus longicornis between the different forests revealed FA profiles to be predominantly affected by site, suggesting a diet shift depending on resources at hand. However, species-specific differences in individual FAs occurred, likely related to feeding strategy and physiological activity. Lipids of Collembola comprised low amounts of bacterial marker FAs, and bacterial consumption may occur to some extent, particularly on Gram-positives. The marker FA for predatory feeding, 20:1ω9, was found in several species, although in low amounts. This contradicts known feeding habits and caution is advisable in using 20:1ω9 as trophic marker. Overall, as indicated by high proportions of oleic (18:1ω9) or linoleic (18:2ω6,9) acid, most species were either plant litter or fungal feeders, with some transitions. The ratio 18:1ω9/18:2ω6,9 is proposed as a tool to distinguish between these two major feeding strategies in Collembola. |
| |
Keywords: | Fatty acids Trophic biomarker Soil fauna Microorganisms Plant litter |
本文献已被 ScienceDirect 等数据库收录! |
|