Sammanfattning

Boreal forests receive nitrogen-(N)-enrichment via atmospheric deposition and industrial fertilization. While it is known that N-enrichment can intensify interactions with natural antagonists, it remains poorly understood how genetic variability in plant defense chemistry can affect biotic interactions and height growth in N-enriched environments. We grew replicates of five low-and high-tannin Populus tremula genotypes, respectively, under three N-treatments (ambient, 15, and 150 kg N ha(-1) yr(-1)). We assessed shoot blight occurrence (i.e. symptoms caused by Venturia fungi) during four growing seasons, and tree height growth during the same period. Damage by Venturia spp. increased with N-addition during all years, likely due to enhanced foliar quality. Low-tannin plants showed higher incidences of Venturia infection than high-tannin plants, regardless of the N-input-level. Height responded to an N-by-tannin-group interaction, which occurred because high-tannin plants grew taller than low-tannin plants at the high N-treatment, but not under the other N-levels. This pattern indicates that innate resource investment into tannin production yields a positive effect on growth under N-enriched conditions. Given that N-deposition is increasing globally, our research suggests that further studies are needed to investigate how N-enrichment interacts with plant defense traits globally. Moreover, our research suggests that N-deposition may provide an advantage for well-defended, high-tannin plants; and further, that genetic diversity in plant defense may be a key mechanism by which plant populations respond to this change.

Nyckelord

European aspen; Condensed tannins; Genotypic variation; Growth; Nitrogen deposition; Venturia

Publicerad i

Forest Ecology and Management
2021, Volym: 487, artikelnummer: 118985
Utgivare: ELSEVIER

SLU författare

• Gundale, Michael

  • Institutionen för skogens ekologi och skötsel, Sveriges lantbruksuniversitet
    

Associerade SLU-program

SLU Nätverk växtskydd


UKÄ forskningsämne

Skogsvetenskap


Publikationens identifierare

DOI: https://doi.org/10.1016/j.foreco.2021.118985

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/111453