Mechanical traits as drivers of trophic interaction between macrodetritivores and leaf litter

In ecosystems, the rates of resource consumption by animals drive the flows of matter and energy. Consumption rates are known to vary according to consumer energy requirements, resource nutrient content and mechanical properties. The aim of our study is to determine how mechanical constraints, compared to energetic and nutritional constraints, explain the variation in leaf litter consumption rates by macrodetritivores. In particular, we focus on the impact of litter toughness. To this end, we propose a non-linear model describing leaf litter consumption rates of detritivore as a function of litter toughness. We also investigate a possible match between bite force and litter toughness, since consumer-resource co-occurrence is thought to be driven by the match between invertebrate mandibular traits and resource toughness. Our study was designed as follows: leaf litter from oak and hornbeam was exposed to field physical and microbial decomposition in aquatic and terrestrial ecosystems for ..., Sites and experimental design
Our sampling sites were located south of Toulouse (France), in the Pyrenean Piedmont, an area characterized by a calcareous bedrock and continental climate. Leaf litter and detritivores were collected in oak-hornbeam forests. For each ecosystem type (low order streams and forest floors), we selected two sites, one dominated by oak (Quercus petraea) and the other by hornbeam (Carpinus betulus). Hornbeam sites were both located in a hornbeam coppice stand. The terrestrial oak site was a mature even-aged oak forest. As there was no stream crossing it, we selected a nearby stream running along a forest edge dominated by oak trees. Leaf litter was collected at the time of abscission and stored air-dried at room temperature. Leaf litter was also collected later, after various physical and microbial decomposition times, to produce litter with varying toughness values. In our feeding experiments, detritivore individuals collected at a site were only offered the loc..., , # Mechanical traits as drivers of trophic interaction between macrodetritivores and leaf litter

[https://doi.org/10.5061/dryad.ngf1vhj2j](https://doi.org/10.5061/dryad.ngf1vhj2j)

This table is the result of consumption tests aiming to quantify the consuption rate of leaf litter by different detritivore taxa.

Leaf litter (Hornbeam or Oak) was left to decompose in a forest stream or on a forested soil and collected (after 0 to 349 days). Detritivores comprise 3 aquatic and 5 terrestrial taxa. Consumption rates were measured at the laboratory in microcosms. We performed controls with leaf litter discs without detritivores to correct consumption rates.

We measured the mean litter toughness, softness, CN ratio, and N percent content for each litter batch.

We measured a mean index for detritivore mandible strength for each detritivore taxon. We measured or estimated (from individual fresh body mass) each individual dry body mass.

## Description of each data column

* Ecosystem: A=aqua...