Pollination Ecology

by

Nicole E. Rafferty

• LAST REVIEWED: 16 August 2022
• LAST MODIFIED: 24 July 2013
• DOI: 10.1093/obo/9780199830060-0121

Introduction

Pollination is the transfer of pollen from anthers to a stigma, a process that can be effected by abiotic vectors such as wind and water and by a diversity of animals, including insects, birds, and mammals. It is worth noting, however, that the definition of pollination is somewhat variable, in that some authors (e.g., Faegri and van der Pijl 1979, cited under General Overviews) include the transfer of pollen in gymnosperms, which do not possess flowers, whereas others (e.g., Kearns and Inouye 1993, cited under Reference Books) restrict the term to angiosperms. The study of the natural history of pollination stretches back to the 18th century and has long been approached from both evolutionary and ecological perspectives. In the 19th century, Charles Darwin contributed a great deal to the early study of pollination, particularly in the areas of cross-pollination and floral adaptations in orchids. In the early 1900s Paul Knuth’s multi-volume compendium on pollination was published in English as Handbook of Flower Pollination. Within the broader field of pollination biology, pollination ecology is concerned primarily with the study of the reciprocal interactions between flowering plants and pollinators, along with abiotic modes of pollination. Pollination ecology encompasses lines of inquiry at many different scales, from studies focused on the effectiveness of a particular pollinator of a single plant species, to those addressing the properties of interactions within entire communities of floral visitors and plants, to those dealing with regional and even global, biogeographic patterns. As a discipline, pollination ecology has been shaped both by detailed empirical studies and by theoretical models. Although plant-pollinator interactions are generally mutualistic in that plants gain the transfer of pollen among flowers and pollinators gain resources (often in the form of nectar) a spectrum of interaction types can exist, with some visitors even acting as thieves and some plants luring visitors while offering no reward. Furthermore, the costs and benefits of any given interaction need not be fixed but can be context-dependent, varying over the course of an individual’s life history and as a function of interactions within the community as a whole. Although obligate, co-evolved plant-pollinator mutualisms have received much study, they are rare, and the degree of specialization within a study system can depend not only on the perspective of interest (plant vs. pollinator) but also on the community context. In addition to basic research, pollination ecology has an applied side. One reason for the long-standing interest in plant-pollinator interactions is their importance in our understanding of the reproduction of food crops. With almost 90 percent of all flowering plants relying on some mode of biotic pollination, the consequences of pollination disruption for both agricultural and natural communities could be severe. Thus, much of the 21st-century work in pollination ecology has addressed the conservation of plant-pollinator interactions under global change, including the effects of habitat loss and fragmentation, invasive species, and climate change.

General Overviews

General texts on pollination ecology range from largely descriptive natural history treatments to edited volumes of empirical and theoretical work that have played a significant role in shaping the discipline in the last several decades. Faegri and van der Pijl 1979 is one of the earliest and most detailed summaries of pollination syndromes (suites of floral traits thought to reflect adaptation to a specific pollen vector), which were first proposed by Federico Delpino in the mid-1800s, and they also discussed floral rewards and attractants in depth. Jones and Little 1983 helped usher in the modern experimental and theoretically driven approach to pollination ecology, and Real 1983 is a compendium covering a broad variety of topics in pollination biology for an advanced audience. Mitchell, et al. 2009 emphasizes the synthesis of ecology and evolution in studies of pollination, and this special issue of Annals of Botany on plant-pollinator interactions is a good representation of 21st-century thought in the field. Waser and Ollerton 2006 also addresses many of the contemporary topics in pollination ecology, especially those dealing with specialization and generalization in plant-pollinator interactions. Proctor, et al. 1996 is an accessible book that includes many illustrative figures and photographs, including color plates. Willmer 2011 provides the most up-to-date and comprehensive text on pollination ecology as a whole and would serve as a good textbook for undergraduates.

• Faegri, Knut, and Leendert van der Pijl. 1979. Principles of pollination ecology. 3d ed. revised. Oxford: Pergamon.

  Among the first tomes on pollination ecology as a discipline, still frequently cited for its description of pollination syndromes. A collection of illustrated case histories is used to exemplify the syndromes in various plant families.

• Jones, C. Eugene, and R. John Little, eds. 1983. Handbook of experimental pollination biology. New York: Van Nostrand Reinhold.

  This compilation of empirical studies and methodological considerations and techniques for pollination research helped shape the modern field of pollination ecology. Not widely available in libraries, however, and no longer in print.

• Mitchell, Randall J., Rebecca E. Irwin, Rebecca J. Flanagan, and Jeffrey D. Karron. 2009. Ecology and evolution of plant-pollinator interactions. Annals of Botany 103:1355–1363.

  DOI: 10.1093/aob/mcp122

  Introductory article to special issue on plant-pollinator interactions. Provides a concise history of pollination biology, as well as analysis of its current trajectories and future directions combining ecological and evolutionary approaches. The special issue covers many of the most active areas of research, including multispecies interactions and the specialization-generalization spectrum.

• Proctor, Michael, Peter Yeo, and Andrew Lack. 1996. The natural history of pollination. Portland, OR: Timber.

  A great resource on a variety of topics in pollination biology that covers different groups of flower visitors. Also includes chapters devoted to pollination oddities, such as orchid pollination and brood-site pollination of yuccas and yucca moths and figs and fig wasps.

• Real, Leslie, ed. 1983. Pollination biology. Orlando, FL: Academic Press.

  A classic with a chapter on the history of pollination biology by Herbert G. Baker, as well as chapters on wind pollination, the evolution of plant breeding systems, pollinator foraging behavior, and other topics. Written for an advanced audience.

• Waser, Nickolas M., and Jeff Ollerton, eds. 2006. Plant-pollinator interactions: From specialization to generalization. Chicago: Univ. of Chicago Press.

  Addresses many of the driving questions in pollination ecology. Divided into three main sections: the ecology and evolution of specialized and generalized pollination, community and biogeographic perspectives, and applications in agriculture and conservation. Has insightful opening and closing chapters by the editors.

• Willmer, Pat. 2011. Pollination and floral ecology. Princeton, NJ: Princeton Univ. Press.

  The most recent and comprehensive text on pollination biology. Covers the mechanisms of pollination, pollination modes, floral signals and rewards, as well as current thought regarding pollination syndromes, pollination in a community context, and conservation issues. Richly illustrated. Suitable for undergraduates.