Stand age characteristics and soil properties affect species composition of vascular plants in short rotation coppice plantations

Martin Weih,Andreas Bolte,Sarah Baum

doi:10.3897/biorisk.7.2699

Abstract

Woody biomass plantations on agricultural sites are an attractive source of biomass for bioenergy, but their effects on local biodiversity are unclear. This study’s objective was to evaluate the influences of light availability, plantation age, and soil properties on phytodiversity in short rotation coppice (SRC) plantations. Ground vegetation mapping, irradiance measurement (PAR), and surface soil analyses were conducted in 15 willow and poplar SRC plantations in Central Sweden and Northern Germany. We performed different multivariate statistical methods like cluster analysis (CA), principal component analysis (PCA), and canonical correspondence analysis (CCA) in order to analyze species composition and the influence of irradiance, age, and soil properties on phytodiversity. CA revealed highest species composition similarities in SRC plantations in close proximity. PCA identified humus quality/essential plant nutrients, plantation age/irradiance effects, soil acidity and shoot age as the four principal components of the recorded parameters. The ground vegetation cover was negatively correlated with the plantation age component and positively with the nutrient component. With an increase in the plantation age component, a shift in species composition was proven towards more forest habitat species, more nutrient-demanding species, and increasing occurrence of indicator species for basic soils. Applying Ellenberg indicator values, basic soil indicator species corresponded in occurrence to increasing nutrient availability. However, species richness was not related to any of our studied site variables. Judged from CCA, species composition in SRC plantations was influenced by plantation age/irradiance, and nutrient availability; soil acidity and shoot age had no significant influence. Young poplar and willow SRC plantations showed greatest variation in photosynthetically active radiation (PAR). Our findings suggest that phytodiversity in SRC plantations depends mainly on plantation age and thus shifts over time.

Highlights

In the near future, bioenergy is predicted to be one of the key strategies for reducing greenhouse gas emissions and substituting fossil fuels (Faaij 2006, Cocco 2007)
Highest PAR values and variations were recorded in the poplar Short rotation coppice (SRC) plantations Cahnsdorf and Hamerstorf and in the willow SRC Bohndorf I
Our results show that species composition in SRC plantations was influenced by environmental parameters: the principal component analysis (PCA) resulted in four principal components standing for nutrients, plantation age effects, soil acidity, and shoot age

Summary

Introduction

Bioenergy is predicted to be one of the key strategies for reducing greenhouse gas emissions and substituting fossil fuels (Faaij 2006, Cocco 2007). Short rotation coppice (SRC) plantations are regarded as one of the most promising options for contributing towards the European targets to increase the amount of renewable energy (EEA 2006; Styles and Jones 2007). Due to the expected increase in demand for wood from SRC plantations, it is important to know how they affect the environment, and what factors influence the biodiversity in SRC plantations. Using this knowledge for the establishment and management of SRC plantations, environmental benefits and increased biodiversity may be achieved in agricultural areas. This is especially of interest given the significant role intensive agriculture plays in the world-wide loss of biological diversity (McLaughlin and Mineau 1995; Tilman et al 2001; Geiger et al 2010)

Methods

Results

Discussion

Conclusion