Demonstration of pollinator‐mediated competition between two native Impatiens species, Impatiens noli‐tangere and I. textori (Balsaminaceae). Issue 6 (25th February 2015)

• Record Type: Journal Article
• Authors: Tokuda, Nanako; Hattori, Mitsuru; Abe, Kota; Shinohara, Yoshinori; Nagano, Yusuke; Itino, Takao
• Is Part Of: Ecology and evolution. Volume 5:Issue 6(2015:Jun.)
• Page Start: 1271
• Page End: 1277
• Publication Date: 2015-02-25
• Subjects: Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.1431
• Languages: English
• ISSNs: 2045-7758

Abstract

<abstract abstract-type="main" id="ece31431-abs-0001"> <title>Abstract</title> <p>Plant–plant interspecific competition via pollinators occurs when the flowering seasons of two or more plant species overlap and the pollinator fauna is shared. Negative sexual interactions between species (reproductive interference) through improper heterospecific pollen transfer have recently been reported between native and invasive species demonstrating pollination‐driven competition. We focused on two native <italic>Impatiens</italic> species (<italic>I. noli‐tangere</italic> and <italic>I. textori</italic>) found in Japan and examined whether pollinator‐mediated plant competition occurs between them. We demonstrate that <italic>I. noli‐tangere</italic> and <italic>I. textori</italic> share the same pollination niche (i.e., flowering season, pollinator fauna, and position of pollen on the pollinator's body). In addition, heterospecific pollen grains were deposited on most stigmas of both <italic>I. noli‐tangere</italic> and <italic>I. textori</italic> flowers that were situated within 2 m of flowers of the other species resulting in depressed fruit set. Further, by hand‐pollination experiments, we show that when as few as 10% of the pollen grains are heterospecific, fruit set is decreased to less than half in both species. These results show that intensive pollinator‐mediated competition occurs between <italic>I. noli‐tangere</italic> and <italic>I. textori</italic>. This study suggests that intensive pollinator‐mediated competition occurs in the wild even when interacting species are both native and not invasive.</p> </abstract>