Large-scale habitat model reveals a key role of large trees and protected areas in the metapopulation survival of the saproxylic specialist Cucujus cinnaberinus

Michał Bełcik,Michał Ciach,Jakub Goczał

doi:10.1007/s10531-019-01854-0

Abstract

Deforestation for agricultural purposes and logging over centuries has resulted in a significant loss of forest cover and the deep structural and functional simplification of persistent European woodlands, which has led to a large-scale decline in biodiversity. Despite recent reforestation efforts in many regions of Europe, populations of numerous forest species remain unrecovered. Due to the loss of ecological continuity and the simplification of the ecosystem structure and functionality, the value of secondary forests in sustaining habitat specialists is being questioned. Here, we build a large-scale habitat suitability model to predict the current potential of forests to host populations of the flagship European saproxylic beetle Cucujus cinnaberinus. Our maximum entropy model revealed that the distribution of suitable habitats strongly corresponds to the occurrence of large and well-preserved forest complexes that are characterized by an ecological continuity of the stands. Among the analysed environmental variables, the mean tree diameter and distance to protected areas were the most important suitable habitat contributors. The optimum habitats were identified almost exclusively within some parts of the Carpathians and the northeastern part of the country, particularly in the Białowieża Forest, which include the best preserved European forests. Although a large number of small habitat patches was revealed across the country, these patches were highly scattered and had low predicted suitability. This study demonstrates that most woodlands are unsuitable for C. cinnaberinus, which points to the limited value of secondary forests for habitat specialists. Our findings emphasize the importance of large and intact forests with undisrupted ecological continuity as key areas for the persistence of the rare saproxylic beetle, which provokes questions about the effectiveness of reforestation as a tool for the conservation of forest habitat specialists.

Highlights

In recent centuries, human agricultural activity has led to the deforestation of the temperate region (Hanski et al 1994; Glatzel 1999; Paillet et al 2010)
Large parts of central and western Poland revealed no suitable habitats for C. cinnaberinus despite their relatively extensive forest coverage
Our large-scale study revealed that the optimal habitats for the flagship saproxylic specialist C. cinnaberinus included large forest complexes located mostly in the southeastern and northeastern parts of Poland (Fig. 2)

Summary

Introduction

Human agricultural activity has led to the deforestation of the temperate region (Hanski et al 1994; Glatzel 1999; Paillet et al 2010). Forest management policies have been subject to a major paradigm shift through decades of intensive forest utilization to more sustainable and multifunctional forestry (Gamborg and Larsen 2003; Rametsteiner and Mayer 2004; Siry et al 2005) Despite these positive trends, secondary growth forests still differ significantly from primeval conditions in terms of ecological complexity and biodiversity (Kuuluvainen et al 1996; Weslien and Schroeder 1999; Grove 2002; Liira et al 2007; Brumelis et al 2011; Bouget and Parmain 2016). Such differences are a consequence of the disruption of ecological continuity and limitations of dead wood resources

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Conclusion