Evaluation of seed-dispersal services by ants at a temperate pasture: Results of direct observations in an ant suppression experiment

Ant dispersal
Ants disperse seeds of many plant species adapted to myrmecochory. While advantages of this ant–plant mutualism for myrmecochorous plants (myrmecochores) have been previously studied in temperate region mostly in forests, our study system was a pasture. Moreover, we used a unique combination of observing the effect of ant‐activity suppression on ant dispersal and comparison of the contribution of ant and unassisted dispersal to the distance from mother plant. We established plots without and with ant‐activity suppression (enclosures). We offered diaspores of a myrmecochorous (Knautia arvensis), and a non‐myrmecochorous (Plantago lanceolata) species in a choice test and followed ants carrying diaspores during days and nights (focus of previous studies was on diurnal dispersal). We measured frequency and distances of ant dispersal and compared them with unassisted dispersal recorded using sticky trap method. The dispersal frequency was lower in enclosures (3.16 times). Ants ..., In cafeteria experiments, we compared the frequency and distance of seed dispersal between enclosures and controls and between the myrmecochorous and the non‐myrmecochorous species. The cafeteria experiment took place at eight observational days in two periods—4 days with favorable weather between July 1 and 7 and August 22–292,019. Each day, 50 diaspores of each species were exposed to ants on a bait station (cardboard squares 6 cm × 6 cm) placed in the center of each of the 16 plots. Diaspores of the two species were placed in a mixture in a single layer so ants were able to choose among them (between and within species) according to their attractiveness.
After the start of the experiment, approximately noon, we repeatedly checked the position of seeds during dispersal and placed a marker where it was found (so the diaspore can be carried farther by the same or different ant). Diaspores were covered with fluorescent powder and approximately four people rotated among plots (time spent ..., , # Dispersal distances: ant and unassisted dispersal

[https://doi.org/10.5061/dryad.s4mw6m9cf](https://doi.org/10.5061/dryad.s4mw6m9cf)
The dataset contains dispersal distances gained by one myrmecochorous (*Knautia arvensis*) and one non-myrmecochorous (*Plantago lanceolata*) species. We distinguished two types of dispersal events: unique dispersal events with the seed present (i.e., found on the ground or seen to be carried into the anthill) and second type with seed absent at the last observation at the time of collection. These data we named ongoing dispersal events as one seed might be recorded repeatedly as more dispersal events during the dispersal process. The ongoing dispersal events mean that seeds were later dispersed to their final destination with a greater (often unknown) distance where they were either not found (e.g., inside the anthill) or found and counted as unique dispersal events, thus one seed can be counted multiple times in the ongoing dispersal events. The dispe...