Beech seeds dispersed by animals fail to germinate

The trees do not benefit when wood mice and edible dormice spread their seeds through the forest, as Viennese biologists demonstrate in a study.

They located hundreds of beechnuts carried off by the rodents in a forest in Lower Austria. Not a single one of them was able to germinate, they report in the Royal Society's journal «Biology Letters».

Four Years of Research in the Rothwald

A team led by Frederik Sachser from the Federal Research Centre for Forests in Vienna set out bowls of beechnuts marked with flags or radio transmitters in the Rothwald over a period of four years.

Camera traps revealed to the researchers who visited the food caches: various wood mice, bank voles and edible dormice. Such studies show how complex the relationships within ecosystems can be.

Not a Single Carried-Off Seed Germinated

The rodents ate some of the nuts immediately. However, the animals carried off between 20 and 70 percent of them to hoard in a hiding place.

During their weekly searches, the researchers were able to find 536 marked beechnuts again. “Not a single seed that was no longer at its original location germinated,” they wrote in the scientific article.

That only happened with the nuts that were not transported by the rodents. The relationship between rodents and beeches is thus not one of mutual benefit, as had previously been assumed. Accordingly, the animals feast on the trees' fruit without giving anything in return. How wild animals act as landscape architects thus depends heavily on the particular species and interaction involved.