Changes in soil food web structure of the decomposer system with land use intensity in forest systems
Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
Final Report Abstract
The project investigated changes in soil food web structure with forest type / land-use intensity across the three Biodiversity Exploratories. Using quantitative sampling methodologies the density and biomass of soil invertebrates of soil animal communities was investigated in 25 of the Experimental Plots of the forest sites of each of the three Exploratories. Soil animal communities were investigated in a comprehensive way with most taxa studied at species level including earthworms, diplopods, centipedes, collembolans, and oribatid and gamasid mites. The results suggest that soil animal communities are rather resistant against changes in forest type / management, but change strongly in space and in part also in time. Using state-of-the-art technologies including stable isotope, fatty acid and molecular gut content analysis the structure and functioning of soil food webs have been investigated. The results showed that the thickness of the leaf litter layer drives food-web structures, and the leaf litter thickness increasingly decouples animal food webs from root-derived resources. Moreover, the isotopic signatures also indicated the lack of correlation between forest type / land-use intensity with food web structures. Rather the results demonstrate how predator and prey body size, soil pH and habitat structure determine predator feeding rates and variations in the prey spectrum of predators in forests. Major progress has been achieved in establishing and using molecular gut content analysis for analyzing the structure of soil food webs by establishing primers for analyzing the role of virtually all major prey groups of predators in soil food webs. Further, the results highlight the importance of root-derived resources for the nutrition of soil animal food webs in forest ecosystems. Overall, the project allowed understanding the structure of forest soil food webs, their variations in space and time, and their structuring forces in unprecedented detail, thereby forming an essential component of the variations in the structure and functioning of forest ecosystems with diversity and human impact as investigated in the framework of the Biodiversity Exploratories.
Publications
- (2014) Effects of prey quality and predator body size on prey DNA detection success in a centipede predator. Molecular Ecology 23:3767-3776
Eitzinger B, Unger EM, Traugott M, Scheu S
(See online at https://doi.org/10.1111/mec.12654) - (2014) Into darkness: Unravelling the structure of soil food webs. Oikos 123:1153-1156
Brose U, Scheu S
(See online at https://doi.org/10.1111/oik.01768) - (2014) Shifts in trophic interactions with forest type in soil generalist predators as indicated by complementary analyses of fatty acids and stable isotopes. Oikos 123, 1182- 1191
Ferlian O, Scheu S
(See online at https://doi.org/10.1111/j.1600-0706.2013.00848.x) - (2015) Temporal dynamics and variation with forest type of phospholipid fatty acids in litter and soil of temperate forests across regions. Soil Biology & Biochemistry 91, 248-257
Pollierer MM, Ferlian O, Scheu S
(See online at https://doi.org/10.1016/j.soilbio.2015.08.035) - (2015) Trophic niche differentiation and utilisation of food resources in collembolans based on complementary analyses of fatty acids and stable isotopes. Soil Biology and Biochemistry 82:28-35
Ferlian O, Klarner B, Langeneckert AE, Scheu S
(See online at https://doi.org/10.1016/j.soilbio.2014.12.012) - (2017) Driving factors and temporal fluctuation of Collembola communities and reproductive mode across forest types and regions. Ecology and Evolution 2017, 1-14
Pollierer MM, Scheu S
(See online at https://doi.org/10.1002/ece3.3035) - (2017) Root-derived carbon and nitrogen from beech and ash trees differentially fuel soil animal food webs of deciduous forests. PLoS One 12(12): e0189502
Zieger S, Ammerschubert S, Polle A, Scheu S
(See online at https://doi.org/10.1371/journal.pone.0189502)
