The temperate forest phyllosphere and rhizosphere microbiome: a case study of sugar maple
To prevent sugar maple from declining in the face of global change, it will be crucial to gain a better understanding (1) of its capacity to shift north in pace with climatic changes and (2) of the contributions of surrounding microbial communities in this process. ... sugar maple assembles diverse and species-specific root and leaf microbiomes, with potential impacts on tree growth, immunity, and survival. First, the origin of the soil on which sugar maple grows appears to play a key role. Despite improved regeneration under colder temperatures, which corresponds to current northern range limit climatic conditions, sugar maple survival and biomass after transplants are up to 50% higher on soil from the center of its range. This suggests that this tree species is highly dependent on root biotic interactions (e.g., in the rhizosphere with arbuscular mycorrhizae) for successful establishment in a newly available niche or in adaptation to climate change, irrespective of the physico-chemical properties of the soil. Second, sugar maple leaves have also been the focus of several studies on tree-microbe interactions in the phyllosphere, demonstrating that the local abiotic environment of trees drives leaf microbial colonization (Laforest-Lapointe et al., 2016a; Wallace et al., 2018).
Tonia De Bellis, Isabelle Laforest-Lapointe, Kevin A. Solarik, Dominique Gravel, Steven W. Kembel - Ecology - 12 April 2022
We collected sugar maple seeds from across the species current range, then planted them in temperate and mixedwood/transitional forests (current range) and in the boreal region (beyond range but predicted future range in response to climate change). ... Variation among sites and regions were the main drivers of the differences in host microbial communities, whereas seed provenance did not play a large role .... Along the latitudinal gradient, we (1) observed reductions in mycorrhizal diversity that can negatively impact maple establishment; (2) and revealed reductions in fungal leaf pathogens that can have opposite effects. Our results highlight the need for an integrated approach including the examination of various microbial taxa on different plant compartments to improve our understanding of plant range shifts and plant–microbe interactions.
