Sessions and Kelly (2002): Predator-mediated apparent competition between an introduced grass and a native fern.

Sessions, L.A. & Kelly, D. 2002. Predator-mediated apparent competition between an introduced grass (Agrostis capillaris) and a native fern Botrychium australe (Ophioglossaceae) in New Zealand. Oikos 96: 102-109.

A 1995 wildfire burnt a population of Botrychium which had been studied since 1986. The fern survived the fire well, but from 1997 on suffered very high levels of herbivory which prevented reproduction, reduced plant size and increased mortality. Exclusion experiments identified the introduced slug Deroceras reticulatum as the culprit; the slug increased due to greater shelter from Agrostis which increased after the fire. Therefore this is an example of apparent competition: the introduced grass negatively affected the native fern by harbouring an introduced invertebrate herbivore. The future for this population of Botrychium looks bleak.