caa a22 4500 469098937 CHVBK 20180323133039.0 cr unu---uuuuu 170328e19920501xx s 000 0 eng 10.1007/BF00317187 doi (NATIONALLICENCE)springer-10.1007/BF00317187 Fox John Department of Biology and Wildlife, University of Alaska Fairbanks, 99775-0180, Fairbanks, Alaska, USA aut Pollen limitation of reproductive effort in willows [Elektronische Daten] [John Fox] Summary: Pollen limitation of seed set differs from resource limitation in its implications for the evolution of floral traits. Willow flowers attract insects, but also abundantly produce wind-dispersed pollen. I demonstrated pollen limitation in single branches bearing 2-4 inflorescences (catkins) in a field experiment with five species by artificially increasing or decreasing the pollen load. Because the responses by single branches might be explained by diversion of resources to better-pollinated branches within a plant, a second experiment with one species tested both pollen limitation of whole plants and the autonomy of catkins. Seed set of single willow catkins is unaffected by experimental alterations of seed set in other catkins on the same plant. Hand-pollination of single catkins and of whole plants increased seed set to the same degree, suggesting there is little or no competition for resources between catkins only 5-10 cm apart. Thus, seed set in willows appears to be pollen limited, favoring insect pollination and the evolution of entomophilous traits. The data support previous views that willows have a dual pollination system utilizing wind and insects. Springer-Verlag, 1992 Entomophily nationallicence Pollination nationallicence Reproduction nationallicence Salix nationallicence Seed set nationallicence Oecologia Springer-Verlag 90/2(1992-05-01), 283-287 0029-8549 90:2<283 1992 90 442 https://doi.org/10.1007/BF00317187 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00317187 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Fox John Department of Biology and Wildlife, University of Alaska Fairbanks, 99775-0180, Fairbanks, Alaska, USA aut NATIONALLICENCE 773 0- Oecologia Springer-Verlag 90/2(1992-05-01), 283-287 0029-8549 90:2<283 1992 90 442 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer