Allelopathy

by

Diego A. Sotomayor, Christopher J. Lortie

• LAST REVIEWED: 31 August 2021
• LAST MODIFIED: 23 May 2012
• DOI: 10.1093/obo/9780199830060-0038

Introduction

Allelopathy—the production by an organism of substances inhibitory or harmful to other organisms—as a concept has been utilized for more than 2,000 years, although the term was coined in 1937 (see Historical Background). Initial empirical studies of allelopathic interactions began to appear around the 1960s, and since then the field has grown rapidly. The importance of these interactions has been shown for many ecosystems, both terrestrial and aquatic. Allelopathy is currently considered an important factor for the structure and dynamics of communities and is viewed as a competitive advantage that exotic plants have in their introduced ranges. Inhibitory chemicals against native plant species in introduced systems are thought to be one of the key traits associated with plant species invasiveness. The field has changed from methodological concerns on how to support the occurrence of allelopathy (i.e., providing empirical evidence of its effects) to how it can be used to explain community dynamics and the success of invasive species. The readings presented in this bibliography include the history of allelopathy (Historical Background), methodological aspects (Methodological Aspects, Allelopathy vs. Competition), Biochemistry and Physiology, Ecological Aspects, its relation with invasional success (Invasion), its occurrence in different ecosystems (Allelopathy in Different Ecosystems), and its applications (Applied Allelopathy in Agriculture and Forestry).

General Overviews

Although the concept of allelopathy was described at the beginning of the 20th century, it was not until the publication of Muller 1966 that empirical evidence of these interactions was provided. In this classic paper, bioassays for volatile compounds were used along with the extraction of the terpenoids responsible for the allelopathic inhibitory interactions. Later, a broad review, Rice 1979, summarized the knowledge of allelopathic interactions, including applied aspects. This review paper is comprehensive, although currently is not up to date, and raised many questions. Langenheim 1994 provides an ecological perspective on the role of terpenoids in which allelopathy is discussed. This specific aspect of allelopathy is augmented by Wardle, et al. 1998, in which it is argued that allelopathy should be best studied at the ecosystem level rather than at the population/community level of analysis. After this paper, the link between allelopathy and the success of plant invasions became a central theme in allelopathic studies. Hierro and Callaway 2003 presents the idea that allelopathic interactions are the basis for the success of exotic plants. Bais, et al. 2006 provides an up-to-date wide-scope review on the role of root exudates for plant-plant and plant-microbe interactions. An interesting perspective on the role of allelopathy in community dynamics and structure for microbes is presented by Czaran, et al. 2002, wherein it is argued that allelochemical warfare is responsible for coexistence in microbial communities, which can also be argued for aquatic systems (see Allelopathy in Different Ecosystems). On the applied side, Weston 1996 provides a comprehensive review of the applications of allelopathy in cropping systems for weed management.

• Bais, Harsh P., Tiffany L. Weir, Laura G. Perry, Simon Gilroy, and Jorge M. Vivanco. 2006. The role of root exudates in rhizosphere interactions with plants and other organisms. Annual Review of Plant Biology 57:233–266.

  DOI: 10.1146/annurev.arplant.57.032905.105159

  Wide-scope review article dealing with interactions that are mediated by root exudates in the rhizosphere, dividing them into plant-plant interactions and plant-microbe interactions. A definition and methodological aspects of root exudates are also provided.

• Czaran, Tamas L., Rolf F. Hoekstra, and Ludo Pagie. 2002. Chemical warfare between microbes promotes biodiversity. Proceedings of the National Academy of Sciences of the United States of America 99:786–790.

  DOI: 10.1073/pnas.012399899

  This paper addresses the “paradox of the plankton,” in which the diversity of bacterial communities is considerably higher than the diversity of macrobial systems. The authors used a model to test the hypothesis that antibiotic interactions within microbial communities are the key to the maintenance of diversity.

• Hierro, José L., and Ragan M. Callaway. 2003. Allelopathy and exotic plant invasion. Plant and Soil 256:29–39.

  DOI: 10.1023/A:1026208327014

  This pioneer paper proposed allelopathic interactions as the basis for the success of exotic plants. The main argument is based on the prominent monocultures that exotics establish and the hypothesis that resident plants will be naive toward chemicals released by newly arrived species.

• Langenheim, Jean H. 1994. Higher-plant terpenoids: A phytocentric overview of their ecological roles. Journal of Chemical Ecology 20:1223–1280.

  DOI: 10.1007/BF02059809

  A classic review paper on the interactions involving terpenoids. Among these interactions, allelopathy is included, and a discussion of how these compounds are involved in ecological interactions is presented.

• Muller, Cornelius H. 1966. Role of chemical inhibition (allelopathy) in vegetational composition. Bulletin of the Torrey Botanical Club 93:332–351.

  DOI: 10.2307/2483447

  A classic paper, one of the first papers that provided empirical evidence of allelopathic interactions. Muller used bioassays on shrubs of southern California and extracted their terpenes. A link between allelopathy, community dynamics, and succession is also provided.

• Rice, Elroy L. 1979. Allelopathy: Update. Botanical Review 45:15–109.

  DOI: 10.1007/BF02869951

  A classic review paper by one of most influential authors on this topic. The author presents the many disciplines where allelopathy has a role, emphasizes its applied aspect, covers its ecological function, and discusses the mechanisms of some allelopathic compounds.

• Wardle, David A., Marie-Charlotte Nilsson, Christiane Gallet, and Olle Zackrisson. 1998. An ecosystem-level perspective of allelopathy. Biological Reviews 73:305–319.

  DOI: 10.1017/S0006323198005192

  Excellent review in which the authors argue that the concept of allelopathy should be understood at the ecosystem level, rather than at the population/community level of analysis. They present the wide-ranging effects of allelochemicals and illustrate these concepts using two exotic species as examples.

• Weston, Leslie A. 1996. Utilization of allelopathy for weed management in agroecosystems. Agronomy Journal 88:860–866.

  DOI: 10.2134/agronj1996.00021962003600060004x

  This paper presents the applied aspect of allelopathy in crop systems for weed suppression. The author presents two main approaches for this use: rotational crops that interfere with the growth of surrounding weeds, and crop residues that suppress weed growth for variable lengths of time.