Abstract

Increased nitrogen (N) input in boreal forests has previously been shown to induce a shift from Vaccinium myrtillus L. to Deschampsia flexuosa (L.) Trin. as the dominant understory species. We investigated the relative importance of increased light and N for this shift, in a field experiment. We increased light availability, that is, we reduced aboveground competition from V myrtillus, and increased N by adding 50 kg N.ha(-1). Increased light availability had a positive effect on both the growth rate and final biomass of D. flexuosa. Although N addition increased the uptake of fertilizer N by both species, it had no effect on the growth or biomass of either species. Thus, aboveground competition from V myrtillus prevented expansion of D. flexuosa, regardless of N treatment. The results suggest that aboveground competition may be more important than belowground competition for structuring understory boreal forest communities. As light availability is important, both the structure and total amount of standing crop will be important for the outcome of species interactions

Published in

Canadian Journal of Botany
2004, Volume: 82, number: 4, pages: 430-435
Publisher: NATL RESEARCH COUNCIL CANADA

SLU Authors

• Näsholm, Torgny

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Forest Science


Publication identifier

DOI: https://doi.org/10.1139/B04-017

Permanent link to this page (URI)

https://res.slu.se/id/publ/3152