Asymmetric and frequency-dependent pollinator-mediated interactions may influence competitive displacement in two vernal pool plants

作者：Runquist Ryan Briscoe^*; Stanton Maureen L

来源：Ecology Letters, 2013, 16(2): 183-190.

DOI：10.1111/ele.12026

• Asymmetrical competition
• frequency dependence
• heterospecific pollen transfer
• Limnanthes
• pollination
• vernal pools

A plant species immigrating into a community may experience a rarity disadvantage due to competition for the services of pollinators. These negative reproductive interactions have the potential to lead to competitive displacement or exclusion of a species from a site. In this study, we used one- and two-species arrays of potted plants to test for density and frequency dependence in pollinator-mediated and above-ground intraspecific and interspecific competition between two species of Limnanthes that have overlapping ranges, but rarely occur in close sympatry. There were asymmetric competitive effects; the species responded differently to their frequency within 16-plant replacement series arrays. Limnanthes douglasii rosea experienced stronger reductions in lifetime and per-flower fertility, likely due to pollinator-mediated competition with Limnanthes alba. This effect may be linked to asymmetrical competition through heterospecific pollen transfer. This study demonstrates that pollinator-mediated competition may discourage establishment of L. d. rosea in sites already occupied by its congener.

• 出版日期2013-2