Facilitation promotes changes in leaf economics traits of a perennial forb

• Published in: Oecologia Vol. 179; no. 1; pp. 103 - 116
• Main Authors: García-Cervigón, Ana I, Linares, Juan Carlos, Aibar, Pablo, Olano, José M
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.09.2015; Springer; Springer Nature B.V
• Subjects: Analysis; Biomedical and Life Sciences; carbon; Carbon - metabolism; Drought; Droughts; Ecology; Economic aspects; Economics; Environment; Environmental changes; Environmental conditions; environmental factors; forbs; Helleborus - anatomy & histology; Helleborus - growth & development; Helleborus - metabolism; Helleborus foetidus; Hydrology/Water Resources; intraspecific variation; Juniperus; Juniperus - anatomy & histology; Juniperus - growth & development; Juniperus - metabolism; Juniperus sabina; leaf area; Leaves; Life Sciences; mechanistic models; Models, Theoretical; nurse plants; Nurses; Nutrient content; nutrients; petioles; Phenotype; Plant communities; Plant Leaves - anatomy & histology; Plant Leaves - growth & development; Plant Leaves - metabolism; Plant Sciences; POPULATION ECOLOGY; Population ecology - Original research; Resource allocation; Seasons; Spain; Species Specificity; Stress, Physiological; water stress; Water use; Water use efficiency; Spain; Mediterranean high mountains; Functional traits; Leaf economics spectrum; Plant-plant interactions; Intraspecific trait variation
• ISSN: 0029-8549; 1432-1939
• DOI: 10.1007/s00442-015-3312-8

Optimal allocation of resources is crucial to maximize plant success. Plants modify their economic strategies by adjusting functional traits in response to shifts in environmental conditions. Facilitation has been recognized as a major biotic filter of trait distribution in communities, although the effect of facilitation on intraspecific variability has been scarcely explored. We evaluated intraspecific shifts in leaf functional traits of a perennial forb (Helleborus foetidus) in relation to the presence of a nurse plant (Juniperus sabina) in two sites with contrasting abiotic stress levels. The effects of abiotic (site) and biotic (juniper presence, microsite) environments on specific leaf area (SLA), leaf area (LA), lamina/petiole length ratio (LPR), intrinsic water use efficiency (iWUE) and leaf nutrient content (N, P and N:P) per mass were evaluated. Alleviation of drought stress associated with nurse plant presence was reflected in SLA, LA, LPR and iWUE at the high-stress site. Individuals growing in open areas showed more resource-conservative traits, supporting the argument that this strategy is advantageous in environments that limit opportunities for rapid carbon gain. Leaf nutrients were unrelated to other traits. The large amount of intraspecific variation in leaf functional traits related to facilitative processes highlights the importance of facilitation as a major source of plant trait variation. Both positive and negative biotic interactions, as well as intraspecific trait variability, should be considered in mechanistic models of plant communities’ functional responses to environmental changes.