Ericaceous dwarf shrubs contribute a significant but drought‐sensitive fraction of soil respiration in a boreal pine forest

Boreal forests often have a dense understorey of ericaceous dwarf shrubs with ecological adaptations that contrast those the canopy-forming trees. It is therefore important to quantify contributions by ecosystem processes and disentangle shrub- tree-driven responses climatic factors. We quantified soil respiration driven pine canopy shrub over 3 years, using factorial root exclusion removal experiment in mature Pinus sylvestris forest. Soil temperature moisture-related attributed autotrophs (shrubs, roots) heterotrophs were compared. Additionally, we assessed effects interactions between these functional groups on nitrogen availability respiration. Understorey accounted for 22% ± 10% total autotrophic respiration, reflecting proportion fine production ecosystem. Heterotrophic constituted about half Shrub-driven was more susceptible drought than heterotrophic- pine-driven While remained additive, indicating no competitive release, plant guilds competed N. Synthesis. Ericaceous small, yet significant, share growing season Overlooking may lead erroneous partitioning modelling mediated contrasting moisture. A larger contribution root-associated organisms under conditions could implications organic matter accumulation decomposition as climate changes boreal forests.