Species faced with rapidly shifting environments must be able to move, adapt, or acclimate in order to survive. One mechanism to meet this challenge is phenotypic plasticity: altering phenotype in response to environmental change. Here, we investigated the magnitude, direction, and consequences of changes in two key phenology traits (fall bud set and spring bud flush) in a widespread riparian tree species, Populus fremontii. Using replicated genotypes from 16 populations from throughout the species’ thermal range, and reciprocal common gardens at hot, warm, and cool sites, we identified four major findings: (a) There are significant genetic (G), environmental (E), and GxE components of variation for both traits across three common gardens; (b) The magnitude of phenotypic plasticity is correlated with provenance climate, where trees from hotter, southern populations exhibited up to four times greater plasticity compared to the northern, frost‐adapted populations; (c) Phenological mismatches are correlated with higher mortality as the transfer distances between provenance and garden increase; and (d) The relationship between plasticity and survival depends not only on the magnitude and direction of environmental transfer, but also on the type of environmental stress (i.e., heat or freezing), and how particular traits have evolved in response to that stress. Trees transferred to warmer climates generally showed small to moderate shifts in an adaptive direction, a hopeful result for climate change. Trees experiencing cooler climates exhibited large, non‐adaptive changes, suggesting smaller transfer distances for assisted migration. This study is especially important as it deconstructs trait responses to environmental cues that are rapidly changing (e.g., temperature and spring onset) and those that are fixed (photoperiod), and that vary across the species’ range. Understanding the magnitude and adaptive nature of phenotypic plasticity of multiple traits responding to multiple environmental cues is key to guiding restoration management decisions as climate continues to change.
1. The type of mycorrhizal associations (i.e. ectomycorrhizal [EM] or arbuscular mycorrhizal [AM]) formed by trees is of fundamental importance for a range of soil properties and processes in forests, yet their importance for the distribution of other important soil biota such as bacteria is largely unknown.2. We used an experimental common garden and amplicon sequencing to assess how abiotic and biotic variation differentially influenced bacterial communities associated with 13 climax tree species (8 EM members of the Dipterocarpaceae and 5 AM species from different families) planted into a secondary tropical forest in Borneo.3. Rhizosphere bacterial (RB) communities differed significantly between EM and AM trees but not among EM species and only marginally among AM species. 4. RB communities were related to the density and size of neighbouring EM but not AM trees. Diversity of RB on AM trees responded positively to AM neighbours and negatively to EM neighbours but RB diversity associated with EM trees was unaffected by neighbourhood. Plant-growth-promoting taxa of RB assorted similarly to total RB but more strongly. 5. Synthesis. Our results suggest that the distribution of RB communities is associated with plant mycorrhizal type and plant neighbourhood. Because rhizosphere bacteria alter nutrient cycling and influence plant species composition, their distributions are likely important for understanding ecosystem processes and plant demographics in forest ecosystems.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.