Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-48349
Sieber, Y; Holderegger, R; Waser, N M; Thomas, V; Braun, S; Erhardt, A; Reyer, H U; Wirth, L R (2011). Do alpine plants facilitate each other’s pollination? Experiments at a small spatial scale. Acta Oecologica, 37(4):369-374.
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Short growing seasons, low temperatures, and frequent strong wind classify high mountains as adverse environments, in which pollinator abundance and activity are reduced. In such environments, plants growing in dense stands comprising several species and thus exhibiting larger and more diverse flower displays may profit by attracting more visits from scarce alpine pollinators than do plants that grow alone or in patches only composed of conspecifics. To study whether aggregation of plants increases (facilitation) or decreases (competition) the attraction of pollinators, we measured the rate and numbers with which insects entered experimental plots in the Swiss Alps, and their behaviour at flowers in plots that they entered. The plots contained individuals of the blue-flowering cushion plant Eritrichium nanum, either alone or mixed with white- to yellowish-flowering Saxifraga species. Pollinators were generally rare: in 55% of 236 observation periods, no pollinators were observed. Over 95% of the pollinators were Diptera. The average probability of observing any insect at all was higher in plots that contained some Saxifraga flowers, including mixed plots, than in those containing only E. nanum flowers. However, although insects tended to choose Saxifraga as the first flower visited in mixed plots, in all other regards their visitation of Saxifraga and E. nanum flowers in such plots was statistically indistinguishable.We also detected no effect of floral neighbourhood on the frequencies of potentially geitonogamous visits or of transitions among individual plants of the same or different species. Thus, our study suggests that the presence of Saxifraga may facilitate visitation to E. nanum at larger spatial scales, but gives no evidence for either competition or facilitation at small scales within floral neighbourhoods.
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|Item Type:||Journal Article, refereed, original work|
|Communities & Collections:||07 Faculty of Science > Institute of Evolutionary Biology and Environmental Studies|
|Dewey Decimal Classification:||570 Life sciences; biology
590 Animals (Zoology)
|Uncontrolled Keywords:||Attractiveness Competition Facilitation Floral display Eritrichium nanum Pollinator behaviour Saxifraga|
|Deposited On:||16 Jun 2011 07:39|
|Last Modified:||17 Jul 2014 11:29|
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