Ungulate responses to the addition of silicate rock powder in acidified oak (Quercus robur) forests at the Veluwe, the Netherlands

Abstract

Introduction: Addition of silicate rock powder (SRP) is an increasingly used measure to restore vegetation and fauna on acidified mineral-poor soils in protected areas. In theory, however, the positive effects of SRP addition on vegetation may be offset by grazing and browsing ungulates attracted to higher-quality forage. Objectives: This study aimed to determine whether SRP addition to acidified old oak (Quercus robur) forests attracts foraging ungulates in the short term. Methods: We measured wildlife activity within an SRP-addition experiment established at nine Quercus robur forests at the Veluwe, the Netherlands, 3 years after SRP application. Each site had three 0.5-ha plots: one with addition of volcanic SRP, one with addition of metamorphic SRP, and one control. We used camera trapping to quantify foraging by four ungulate species: wild boar (Sus scrofa), red deer (Cervus elaphus), roe deer (Capreolus capreolus), and European fallow deer (Dama dama). Results: While SRP addition increased mineral concentrations in tree leaves within 3 years after treatment, we found no significant differences between treatments in the frequency and duration of ungulate foraging. Conclusion: Our study yields no evidence for the attraction of foraging ungulates to oak forests treated with SRP within 3 years after application.