European aspen with high compared to low constitutive tannin defenses grow taller in response to anthropogenic nitrogen enrichment

FOREST ECOLOGY AND MANAGEMENT

卷:487

Article

Bandau, Franziska¹  Albrectsen, Benedicte Riber¹  Robinson, Kathryn M.¹  Gundale, Michael J.² 

[1] Umea Univ, Umea Plant Sci Ctr, Dept Plant Physiol, SE-90187 Umea, Sweden

[2] Swedish Univ Agr Sci, Dept Forest Ecol & Management, SE-90183 Umea, Sweden

关键词: European aspen;    Condensed tannins;    Genotypic variation;    Growth;    Nitrogen deposition;    Venturia;   

DOI  :  10.1016/j.foreco.2021.118985

来源: Elsevier

【 摘 要 】

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.

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