Pollinator rarity as a threat to a plant with a specialized pollination system. (17th September 2015)

• Record Type: Journal Article
• Authors: Phillips, Ryan D.; Peakall, Rod; Retter, Bryony A.; Montgomery, Kirke; Menz, Myles H. M.; Davis, Belinda J.; Hayes, Christine; Brown, Graham R.; Swarts, Nigel D.; Dixon, Kingsley W.
• Is Part Of: Botanical journal of the Linnean Society. Volume 179:Number 3(2015:Nov.)
• Page Start: 511
• Page End: 525
• Publication Date: 2015-09-17
• Subjects: Botany -- Periodicals; 580
• DOI: 10.1111/boj.12336
• Languages: English
• ISSNs: 0024-4074

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>An increasing diversity of highly specialized pollination systems are being discovered, many of which are likely to be vulnerable to anthropogenic landscape modification. Here, we investigate if a specialized pollination system limits the persistence of C<italic>aladenia huegelii</italic> (Orchidaceae), an endangered species pollinated by sexual deception of thynnine wasps. Once locally common in part of its geographical range, <italic>C. huegelii</italic> is now largely restricted to small habitat remnants in urban areas. Pollinator surveys coupled with DNA barcoding detected a single pollinator taxon, a small form of <italic>Macrothynnus insignis.</italic> Phylogenetic analysis revealed that small <italic>M. insignis</italic> from within the range of <italic>C. huegelii</italic> are strongly divergent from other wasp populations, suggesting that some reproductive isolation may exist. Although common in intact landscapes outside the range of <italic>C. huegelli</italic>, small <italic>M. insignis</italic> individuals were recorded at only 4% of sites in suitable <italic>C. huegelii</italic> habitat. Accordingly, reproductive success in <italic>C. huegelii</italic> was low compared with related <italic>Caladenia</italic> spp., with 33–60% of populations failing to set fruit in any given year. As such, populations are likely to now persist primarily through individual plant longevity rather than reproduction. Due to the low reproductive success of <italic>C. huegelii</italic>, ongoing human intervention will almost certainly be needed to sustain the species. Future research will need to focus on optimizing hand pollination to maintain reproduction and high seed fitness. © 2015 The Linnean Society of London, <italic>B</italic><italic>otanical</italic> <italic>J</italic><italic>ournal of the</italic> <italic>L</italic><italic>innean</italic> <italic>S</italic><italic>ociety</italic>, 2015, <bold>179</bold>, 511–525.</p> </abstract>