Introducing Intensively Managed Spruce Plantations in Swedish Forest Landscapes will Impair Biodiversity Decline

Joachim Strengbom,Artur Larsson,Jonas Sandström,Lena Gustafsson,Olof Widenfalk,Åke Lindelöw,Anders Dahlberg

doi:10.3390/f2030610

Abstract

Due to pressure to raise forest productivity in Sweden, there are proposals to apply more intensive forestry methods, but they could have potentially large effects on biodiversity. Here we report a compilation and evaluation of the extent and significance of such effects. We evaluated potential effects on biodiversity by introducing intensively fertilized Norway spruce plantations as a management option in Swedish forests with low conservation values on insects, vascular plants, lichens, bryophytes, and red-listed species. Due to a lack of specific studies addressing this question, we based the evaluation on a combination of available and appropriate empiric and anecdotic knowledge; literature data, and expert judgments largely available in species data bases. Our evaluations suggest that such forests will only harbor species that are common and widespread in conventionally managed stands and that species of conservation interest will be lacking, due to the low heterogeneity and light intensity of even-aged monocultures with dense canopies, short rotation times and low availability of coarse woody debris. Effects at the landscape scale are more difficult to evaluate, but will be dependent on the area utilized and the conservation value of sites used. We conclude that negative effects on biodiversity can be reduced if: (1) only land with the lowest conservational value is utilized; (2) plantations are spatially arranged to minimize fragmentation of the landscape; (3) the quality and quantity of key structural elements (e.g., coarse woody debris, old living trees and snags) are maintained at the landscape level; and (4) management intensity is relaxed on other land. For effective implementation of these measures, legislative frameworks and policy instruments need to be adjusted and new models for planning and monitoring need to be developed.

Highlights

The growth of human populations, climate change concerns and increasing interest in replacing fossil fuels with biofuels are raising pressure to increase the productivity of agricultural and forest land in many parts of the world [1,2,3,4,5,6]
Brockerhoff et al [11] suggested that plantation forests may promote biodiversity by: (1) providing a supplementary feeding habitat for species that are otherwise confined to small pockets of remnant intact forests; (2) increasing landscape connectivity and facilitating dispersal among otherwise isolated pockets of pristine forests; and (3) providing buffer zones, thereby reducing the edge effects of fragments of intact forest zones
More adverse effects on biodiversity were indicated by this assessment compared with the majority of cases presented by Brockerhoff et al [11]

Summary

Introduction

The growth of human populations, climate change concerns and increasing interest in replacing fossil fuels with biofuels are raising pressure to increase the productivity of agricultural and forest land in many parts of the world [1,2,3,4,5,6]. This has raised concern about potential conflicts between global food and timber production and preservation of biodiversity [3,4]. A potential solution may be to utilize designated parts of the land for plantation forestry [8], i.e., establishment of forests or other wooded land of introduced species (characterized by few tree species) and in some cases native species, through planting or seeding, mainly for production of wood or non-wood goods [9]

Methods

Results

Conclusion