Endozoochory by European bison influences the build-up of the soil seed bank in subcontinental coniferous forest

Bogdan Jaroszewicz

doi:10.1007/s10342-013-0683-4

Abstract

The faeces of large herbivores include viable seeds of many plant species. With dung decomposition, some seeds migrate into the soil and influence seed bank build-up. However, only a few papers report evidence of this process, and only from grasslands. In forest studies, this subject has so far been neglected. Therefore, I ask in this paper whether seeds present in the dung of European bison migrate to the forest soil seed bank and influence its build-up. I sampled soil from underneath European bison dung pats and from surrounding areas (control samples). Samples were divided into shallow (0–5 cm) and deep (5–10 cm) series. Soil seed bank content was studied in the greenhouse for 2 years. The shallow seed bank under dung pats was characterized by the highest species richness (49 species) and seed density (>2,000 m−2). Urtica dioica, Juncus effusus and Carex remota showed a demonstrable increase in seed density in the shallow seed bank underneath dung. Three years after dung deposition, seeds of endozoochoric origin influenced the soil seed bank of coniferous forest. U. dioica, J. effusus, C. remota and other species of deciduous forests and grasslands (Agrostis capillaris, Milium effusum, Polygonum hydropiper, Polygonum mite, Scrophularia nodosa, Stachys sylvatica, Veronica chamaedrys) caused an increase in seed density (by 61 %) and species richness (by 33 %) of the shallow soil seed bank underneath dung in comparison with the control soil seed bank.

Highlights

The soil seed bank is defined as a pool of seeds with germinating potential present in the soil
The number of plant species (49) and the abundance of viable seeds (2,041.1 m-2) recorded for S0–5 were over two times higher than that recorded for corresponding control series C0–5 (22 and 796.7 m-2, respectively)
In deeper layers of soil, the highest numbers of seeds belonged to Calluna vulgaris, a species typical for subcontinental coniferous forest (28 and 59 % of all seeds in S5–10 and C5–10, respectively; Appendix A1 in ESM)

Summary

Introduction

The soil seed bank is defined as a pool of seeds with germinating potential present in the soil. It is a type of ‘plant community memory’, storing past events (Harper 1977). It needs to be emphasized that the dung of large herbivores contains vast numbers of viable seeds of many vascular plant species Bruun and Poschlod 2006; Cosyns et al 2006; Gower 2008; Pakeman and Small 2009; D’hondt and Hoffmann 2011) and for some wild species (e.g. Malo et al 1995; Heinken et al 2002; Myers et al 2004; Eycott et al 2007).

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Conclusion