Skip to main content
SLU publication database (SLUpub)
Research article - Peer-reviewed, 2016

Are long-term changes in plant species composition related to asymmetric growth dominance in the pristine Bialowieza Forest?

Pommerening, Arne; Brzeziecki, Bogdan; Binkley, Daniel

Abstract

Bialowieza Virgin Forest in northeastern Poland is one of the greatest treasures of the international conservation community for its high degree of naturalness, large area and long status of protection. Over seven decades of intensive measurements revealed substantial changes in tree species composition. In the early 20th century, Bialowieza Forest was dominated by Norway spruce, Scots pine and pedunculate oak, The densities of these species declined in subsequent decades, while those of hornbeam and small-leaved lime increased. We applied a recently developed concept of growth dominance to explore how the changes in species abundance and size structure may have influenced growth processes. Growth dominance is a statistical characteristic that is based on the Lorenz curve and combines cumulative sizes of trees with the corresponding cumulative growth rates. Despite the substantial changes in size distributions and growth dominance curves, the species populations remained in the phase of "reverse growth dominance" throughout the long monitoring period. This is a state typical of undisturbed, old-growth forests, where small trees grow disproportionately more for their size than large trees. The two formerly dominant species Norway spruce and pedunculate oak showed symmetric growth dominance, while the two increasing species hornbeam and small-leaved lime exhibited asymmetric growth dominance. Interestingly we also observed much larger variation in the growth dominance patterns of hornbeam and lime compared to spruce and oak. The findings seem to suggest that the unusual growth dominance patterns are related to the changing species composition.

Keywords

Plant growth analysis; Relative growth rates; Lorenz curve; Cumulative size distribution; Mixed-species forest; Uniform growth

Published in

Basic and Applied Ecology
2016, Volume: 17, number: 5, pages: 408-417