History and Productivity Determine the Spatial Distribution of Key Habitats for Biodiversity in Norwegian Forest Landscapes

Einar Heegaard,Ivar Gjerde,Jan Nilsen,Magne Sætersdal,Fride Schei

doi:10.3390/f7010011

Einar Heegaard, Ivar Gjerde + Show 3 more

Open Access

https://doi.org/10.3390/f7010011

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Abstract

Retention forestry, including the retention of woodland key habitats (WKH) at the forest stand scale, has become an essential management practice in boreal forests. Here, we investigate the spatial distribution of 9470 habitat patches, mapped according to the Complementary Habitat Inventory method (CHI habitats), as potential WKHs in 10 sample areas in Norway. We ask whether there are parts of the forest landscapes that have consistently low or high density of CHI habitats compared to the surveyed landscape as a whole, and therefore have a low or high degree of conflict with harvesting, respectively. We found that there was a general pattern of clumped distribution of CHI habitats at distances up to a few kilometres. Furthermore, results showed that most types of CHI habitats were approximately two to three times as common in the 25% steepest slopes, lowest altitudes and highest site indices. CHI habitats that are most common in old-growth forests were found at longer distances from roads, whereas habitats rich in deciduous trees were found at shorter distances from roads than expected. Both environmental factors and the history of human impact are needed to explain the spatial distribution of CHI habitats. The overrepresentation of WKHs in parts of the forest landscapes represents a good starting point to develop more efficient inventory methods.

Highlights

Forest area reduction and degradation are among the most important factors threatening biodiversity
Rock wall and Stream gorge were excluded because they are topographically defined habitat types and their qualities defined by presence of other CHI habitat types
This is the first study investigating the spatial distribution of woodland key habitat (WKH) in forest landscapes

Summary

Introduction

Forest area reduction and degradation are among the most important factors threatening biodiversity. Forests amount to 30% of global terrestrial land area, and up to three quarters of terrestrial species are found in forests [2]. It is of vital importance to the conservation of biodiversity that forests are managed in a sustainable way. Conservation actions in forests were primarily to set aside forest areas as protected land. To date, this constitutes only 13% of global forest area, which is not supposed to be sufficient to stop the loss of biodiversity [1]. We have seen the development of approaches where environmental, economic, and cultural values are managed on the same areas simultaneously [3]. Production of ecological and economic values in the same areas is challenging because of conflicts that potentially exist between these two objectives

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