Inter-sexual competition in a dioecious grass

• Published in: Oecologia Vol. 164; no. 3; pp. 657 - 664
• Main Authors: Mercer, Charlene A, Eppley, Sarah M
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Berlin/Heidelberg : Springer-Verlag 01.11.2010; Springer; Springer-Verlag; Springer Nature B.V
• Subjects: Angiosperms; Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Biomedical and Life Sciences; Competition; Conspecifics; Data processing; dioecy; Distichlis spicata; Ecology; Ecosystem; Female animals; females; Fitness; Fundamental and applied biological sciences. Psychology; General aspects; Grasses; Habitat; Hydrology/Water Resources; juveniles; Life history; Life Sciences; Male animals; males; Microenvironments; Microhabitats; Niche differentiation; Niche overlap; Niche partitioning; niches; Plant competition; Plant reproduction; Plant Sciences; Plants; Poaceae - anatomy & histology; Poaceae - growth & development; Poaceae - physiology; Population Dynamics; POPULATION ECOLOGY - ORIGINAL PAPER; Root shoot ratio; Salt marshes; Seedlings; Seedlings - anatomy & histology; Seedlings - growth & development; Seedlings - physiology; Sex; Sex ratio; Sexual system; Sex ratio; Sexual system; Dioecy; Niche partitioning; Monocotyledones; Distichlis spicata; Sexual competition; Gramineae; Angiospermae; Ecological niche; Ecological segregation; Spermatophyta; Herbaceous plant
• ISSN: 0029-8549; 1432-1939; 1432-1939
• DOI: 10.1007/s00442-010-1675-4

Spatial segregation of the sexes (SSS) occurs in many dioecious angiosperms, but little data are available on the fitness advantages, if any, for males and females. We examined whether reciprocally transplanted male and female seedlings of Distichlis spicata, a dioecious grass species that exhibits extreme SSS, differed in their responses to microhabitats and competition treatments. Plants grown without conspecific competitors grew equally well in both male- or female-majority habitats, suggesting that male and female plants do not have differential resource needs at the juvenile life-history stage. However, plants subject to intra-sexual competition were significantly larger than plants subject to inter-sexual competition, suggesting that niche partitioning may occur in D. spicata.