Reconciling pest control, nature conservation, and recreation in coniferous forests

Jonas Hagge,Martin Plechinger,Simon Thorn,João Gonçalo Soutinho,Franz Leibl,Jörg Müller

doi:10.1111/conl.12615

Abstract

AbstractProtected areas are not only crucial for biodiversity and natural processes but also for recreation. Although a benign neglect strategy of dealing with natural disturbances in protected areas is beneficial for nature, public debate on avoiding increased pest population growth has intensified. We evaluated the effect of mechanical pest control measures in decreasing populations of insect pests, maintaining nontarget biodiversity, retaining high recreational value, and keeping economic costs low. Debarking and bark scratching or gouging effectively prevented infestation of felled trees by European spruce bark beetles (Ips typographus) and controlled the beetles in recently infested trees. Bark scratching or gouging retained biodiversity at natural levels, whereas debarking decreased biodiversity by 54% with higher economic costs. The public rated bark‐gouged trees more positively than debarked trees. We thus urge authorities to promote bark scratching or gouging in the control of bark beetles in protected areas instead of salvage logging and debarking.

Highlights

Coniferous forests are prone to an increasing number and frequency of large-scale stand-replacing disturbances such as severe wildfires and windstorms (Kurz et al, 2008; Seidl, Schelhaas, Rammer, & Verkerk, 2014)
Our study was conducted in the Bavarian Forest National Park, a region that has been heavily affected by outbreaks of the European spruce bark beetle (I. typographus) and windstorms during the last three decades (Thorn, Bässler, Svoboda, & Müller, 2017)
Bark gouging with our new device was an efficient preventive method of pest control and it is as effective as debarking (Figure 2a, Supporting Information Table S4.1)

Summary

Introduction

Coniferous forests are prone to an increasing number and frequency of large-scale stand-replacing disturbances such as severe wildfires and windstorms (Kurz et al, 2008; Seidl, Schelhaas, Rammer, & Verkerk, 2014). Pest control has become a main argument for removing trees affected by disturbances, that is, salvage logging, in protected areas worldwide (Müller et al, 2018). Salvage logging in the ancient Białowieża Forest in Poland (Schiermeier, 2017) and management of overwintering reserves of the monarch butterfly in Mexico (Leverkus, Jaramillo-López, Brower, Lindenmayer, & Williams, 2018) have recently caused substantial public debates. Scientists are increasingly calling for alternative management strategies to handle naturally disturbed forests in protected areas (Thorn et al, 2018). The debate on how to best manage naturally disturbed forests is intense in protected areas, as for example, in national parks, where pest management has

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Conclusion