Trait–micro‐environment relationships of forest herb communities across Europe

• Published in: Global ecology and biogeography Vol. 33; no. 2; pp. 286 - 302
• Main Authors: Govaert, Sanne, Meeussen, Camille, Vanneste, Thomas, Bollmann, Kurt, Brunet, Jörg, Calders, Kim, Cousins, Sara A. O., De Pauw, Karen, Diekmann, Martin, Graae, Bente J., Hedwall, Per‐Ola, Iacopetti, Giovanni, Lenoir, Jonathan, Lindmo, Sigrid, Orczewska, Anna, Ponette, Quentin, Plue, Jan, Sanczuk, Pieter, Selvi, Federico, Spicher, Fabien, Verheyen, Kris, Vangansbeke, Pieter, De Frenne, Pieter
• Format: Journal Article
• Language: English
• Published: Oxford Wiley Subscription Services, Inc 01.02.2024; Wiley
• Subjects: Air temperature; Availability; biogeography; carbon; carbon nitrogen ratio; community-weighted mean; Deciduous forests; Environmental conditions; Environmental Sciences; Europe; Forest communities; Forest floor; forest litter; Forest management; Forest Science; forest understorey; Forests; functional trait; Fysisk geografi; herbaceous layer; Herbs; intraspecific variation; latitude; Leaf area; Light; light availability; Microclimate; Nitrogen; Physical Geography; plant height; plant nitrogen content; Plant species; Plants; Plants (botany); resource availability; Skogsvetenskap; Soil properties; Soil temperature; Soils; specific leaf area; Steering; Temperate forests; trait-environment; trees; understory; Variation; vascular plants; Europe; Trait-environment; Intraspecific variation; Herbaceous layer; Soil properties; Functional trait; Resource availability; Light availability; Forest understorey; Community-weighted mean; Microclimate
• ISSN: 1466-822X; 1466-8238; 1466-8238; 1466-822X
• DOI: 10.1111/geb.13789

Aim The microclimate and light conditions on the forest floor are strongly modified by tree canopies. Therefore, we need to better consider the micro‐environment when quantifying trait–environment relationships for forest understorey plants. Here, we quantify relationships between micro‐environmental conditions and plant functional traits at the community level, including intraspecific trait variation, and their relationship with microclimate air temperature, light and soil properties. Location Deciduous temperate forests across Europe. Time period 2018. Major taxa studied Herbaceous vegetation. Methods We sampled 225 plots across 15 regions along four complementary gradients capturing both macro‐ and microclimatic conditions including latitude, elevation, forest management and distance to forest edges. We related the community‐weighted mean of five plant functional traits (plant height, specific leaf area [SLA], plant carbon [C], plant nitrogen [N] and plant C:N ratio) across 150 vascular plant species to variation in local microclimate air temperature, light and soil properties. We tested the effect of accounting for intraspecific variation in trait–environment relationships and performed variation partitioning to identify major drivers of trait variation. Results Microclimate temperature, light availability and soil properties were all important predictors of community‐weighted mean functional traits. When light availability and variation in temperature were higher, the herb community often consisted of taller plants with a higher C:N ratio. In more productive environments (e.g. with high soil nitrogen availability), the community was dominated by individuals with resource‐acquisitive traits: high SLA and N but low C:N. Including intraspecific trait variation increased the strength of the trait–micro‐environment relationship, and increased the importance of light availability. Main conclusions The trait–environment relationships were much stronger when the micro‐environment and intraspecific trait variation were considered. By locally steering light availability and temperature, forest managers can potentially impact the functional signature of the forest herb‐layer community.