Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

Explaining the Effects of Floral Density on Flower Visitor Species Composition

Carla J. Essenberg
The American Naturalist
Vol. 181, No. 3 (March 2013), pp. 344-356
DOI: 10.1086/669157
Stable URL: http://www.jstor.org/stable/10.1086/669157
Page Count: 13
  • More info
  • Cite this Item
Explaining the Effects of Floral Density on Flower Visitor Species
                    Composition
Preview not available

Abstract

Abstract Floral density often influences the species composition of flower visitors. This variation in visitor species composition could have significant effects on pollination success and plant fitness but is poorly understood, especially in the many pollination guilds dominated by nonterritorial species. This article presents a foraging model that explores how flower visitors with diverse traits should distribute themselves across resource patches differing in floral density. The model predicts that species with low flower search speeds and low flower handling costs compared to those of competitors will usually dominate dense flower patches. In addition, among flower visitors that have lower energy expenditure rates while handling flowers than while traveling, species maximizing energetic efficiency are typically associated with dense flower patches, whereas those maximizing net rate of energy intake are associated with sparse patches. The model is able to predict some key aspects of a previously observed effect of floral density on species composition of flower visitors to the yellowflower tarweed (Holocarpha virgata). By providing insights into how flower visitors’ traits shape the effects of floral density on the species composition of flower visitors, this study makes an important step towards understanding how pollinator diversity influences relationships between plant density and plant fitness.

Page Thumbnails

  • Thumbnail: Page 
1
    1
  • Thumbnail: Page 
2
    2
  • Thumbnail: Page 
3
    3
  • Thumbnail: Page 
4
    4
  • Thumbnail: Page 
5
    5
  • Thumbnail: Page 
6
    6
  • Thumbnail: Page 
7
    7
  • Thumbnail: Page 
8
    8
  • Thumbnail: Page 
9
    9
  • Thumbnail: Page 
10
    10
  • Thumbnail: Page 
11
    11
  • Thumbnail: Page 
12
    12
  • Thumbnail: Page 
13
    13