Weed Ecology

by

Lauren Lazaro, Karla L. Gage

• LAST REVIEWED: 11 January 2017
• LAST MODIFIED: 11 January 2017
• DOI: 10.1093/obo/9780199830060-0168

Introduction

In this article, “weed ecology” is defined as the study of the interaction or relationship between a weed and another plant and its environment. In the past, the understanding of weed ecology has been a weak link in weed management, when in fact the ecology of a weed species could be the most important tool to determining the correct course of action. Some basic aspects of weed ecology include weed characteristics and weed classification. Some characteristics of plants that support weediness include rapid seed germination, rapid growth, the ability to take up and utilize large amounts of nutrients, prolific seed production, seed characteristics that promote dispersal, seed dormancy mechanisms, continual flushes of germination, the ability to adapt to various environmental conditions, and high tolerance to stresses. Furthermore, the classification of weeds can be comprised of population dynamic factors (i.e., habitat, growth form, life cycle, reproduction) and seed type. Once the basic ecology of a weed is known, proper management strategies can be implemented to prevent the plant from producing seed. However, weed ecology also encompasses seed production, the amount of seed produced and in what form, and seed dispersal through abiotic and biotic factors. Weed ecology is directly correlated with the plant community composition, the evolution of weeds (potentially through factors such as herbicide resistance), allelopathy, and competition. The importance of weed ecology to both natural and agricultural systems cannot be stressed enough. However, this article will focus on agricultural systems—to ensure that the targeted system is kept intact. Thanks to Micheal D. K. Owen for an insightful review of this article.

General Overviews

The foundations of weed ecology span back to the early 1900s (see Historical Accounts), but a wealth of research and information has been discovered since the mid-20th century in this field. This section highlights some of the newer texts that focus heavily on weed ecology. These textbooks range from very general weed ecology and weed science principles (Booth, et al. 2003) to very detailed, concise works (Randall 2012). Weed ecology is the foundation of weed science principles. Monaco, et al. 2002 begins its weed science with a discussion of weed biology and ecology, and proceeds to build upon this foundation with chapters on integrated weed management and herbicide-environment interactions. Heap 2014 builds upon ecological contexts in an examination of the evolution of herbicide-resistant weeds in response to crop management practices. Cousens and Mortimer 1995 uses foundational plant ecology tools by examining the study of weed population changes in response to management. While weed ecology, along with weed and crop species distributions and tolerances, varies based on geography, common principles may be identified through an examination of texts from diverse geographies (Hakansson 2003, Inderjit 2004). Effective weed management programs in agricultural systems must be based in knowledge of the target species’ biology and ecology; works such as Radosevich, et al. 1997 and Zimdahl 2004 outline the need for ecologically based management and offer principles that are relevant for new technologies in weed control.

• Booth, B. D., S. D. Murphy, and C. J. Swanton. 2003. Weed ecology in natural and agricultural systems. Wallingford, UK: CABI.

  DOI: 10.1079/9780851995281.0000

  Beginning-level textbook that focuses on the basic principles of weed science and ecology. It introduces ecological principles from a weed science and weed management point of view and includes examples from the literature.

• Cousens, R., and M. Mortimer. 1995. Dynamics of weed populations. New York: Cambridge Univ. Press.

  DOI: 10.1017/CBO9780511608629

  This book offers an excellent introduction into the recent agricultural literature relating to plant population biology by taking a different approach to weed management by focusing on ecological contexts. It considers the dynamics of abundance and spatial distribution at both geographic and local scales, as well as examines the factors that influence the basic ecological processes of dispersal, reproduction, and mortality.

• Hakansson, S. 2003. Weeds and weed management on arable land: An ecological approach. Wallingford, UK: CABI.

  DOI: 10.1079/9780851996516.0000

  This unique weed science book details weed research in Scandinavia and elsewhere. The book discusses the effects of weed-crop interactions, what influences weed occurrence in different crops and cropping systems, and how different management tactics affect the weeds in this geographic area.

• Heap, I. M. 2014. Herbicide resistant weeds. In Pesticide problems. Vol. 3 of Integrated pest management. Edited by David Pimentel and Rajinder Peshin, 281–301. Dordrecht, The Netherlands: Springer.

  Heap’s chapter within this book focuses on the evolution of herbicide resistance as well as the mechanisms of resistance. He further describes herbicide-resistant weeds and categorizes them by cropping systems.

• Inderjit. 2004. Weed biology and management. Dordrecht, The Netherlands: Kluwer Academic.

  DOI: 10.1007/978-94-017-0552-3

  A great review of general weed biology and ecology principles as well as how these apply to various management strategies.

• Monaco, T. J., S. C. Weller, and F. M. Ashton. 2002. Weed science: Principles and practices. New York: Wiley.

  A detailed account of weed science that focuses on three large topics: principles, herbicides, and practices. Weed ecology and the principles associated with them from a weed science point of view are detailed individually and are included in each chapter.

• Radosevich, S. R., J. S. Holt, and C. Ghersa. 1997. Weed ecology: Implications for management. New York: Wiley.

  This book looks at weeds from an ecological perspective by integrating basic principles and theories from plant ecology, physiology, and genetics. It considers the role of weeds in human systems and touches on herbicides generally.

• Randall, R. P. 2012. A global compendium of weeds. 2d ed. Melbourne, Australia: Department of Agriculture and Food.

  A very detailed and concise record of weeds worldwide and where information about each weed has been found.

• Zimdahl, R. L. 2004. Weed-crop competition. 2d ed. Oxford: Blackwell.

  DOI: 10.1002/9780470290224

  Highly cited textbook that highlights weed science research from 1980 to 2004. This book focuses on important works and new methodologies, but also critiques them. Does a wonderful job synthesizing weed-crop competition with the field of weed ecology.