Pollination Ecology of Pedicularis bracteosa in the Montane‐subalpine Ecotone

• Published in: Plant Species Biology
• Main Author: MACIOR, LAZARUS WALTER
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1996
• Subjects: Tundra
• Online Access: http://dx.doi.org/10.1111/j.1442-1984.1996.tb00142.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1442-1984.1996.tb00142.x; http://onlinelibrary.wiley.com/wol1/doi/10.1111/j.1442-1984.1996.tb00142.x/fullpdf

Abstract A study of the pollination ecology of Pedicularis bracteosa var. paysoniana was carried out at four sites distributed over an 840m vertical transect in the montane‐subalpine ecotone of the Wyoming Rocky Mountains. Peak bloom ranged from June 30th at 2105m to August 2 at 2945m. Queens of Bombus flavifrons, B. kirbyellus and B. mixtus were its major pollinators of a total of 363 individuals of nine Bombus species collected foraging on the plants. The alpine tundra‐nesting queens of B. kirbyellus were the commonest pollinators at 2945m and were absent below 2675m. Bombus flavifrons, B. mixtus and B. ternarius spanned the entire transect. Measurement of 229 queen pollinator tongues (glossa‐prementum) indicated that mean tongue length increased with elevation but that each station encompassed a broad range of tongue lengths. With the longest tongue, B. kirbyellus foraged nototribically only; B. flavifrons was nototribic only at 2675m but both nototribic and sternotribically collecting pollen elsewhere. Species with shorter tongues were increasingly sternotribic at 2285–2675m and included more workers at these sites. Corbicular pollen loads from 141 pollinators indicated a distinctly lower pollen‐foraging constancy at 2105m than at higher elevations, but at all elevations pure loads were most frequent. It is suggested that the extension of Pedicularis bracteosa var. paysoniana over the entire montane‐subalpine ecotone has been facilitated both by its adaptability to differences in the physical environment and by its accommodation to related pollinators having distinct foraging patterns.