Organisms as Ecosystem Engineers

Clive G. Jones
Institute of Ecosystem Studies

Many organisms build, modify or destroy physical structures in the environment. For example, both beavers and the Army Corps of Engineers build dams. Beaver dams and many other physical structures have important ecological effects on other species because these physical structures control the amount of resources that other species can use. Rock-eating snails in the Negev Desert control the amount of soil for plants. Desert isopods control soil erosion and remove salts that decrease soil fertility for plants. Desert porcupines dig pits that trap water and seeds, making an ideal place for annual plants to grow. There are hundreds of other examples of physical modification of the environment by species in all sorts of ecosystems. And yet, in general we know far less about these engineers and their ecological effects than we know about the effects of predation or competition for resources among organisms. How and why do engineers have effects? How important are these effects? Dr. Jones' research combines empirical studies on the effects of engineers with the development of concepts and models of ecosystem engineering.

Work in the Negev Desert, Israel, with Dr. Moshe Shachak is investigating how species of hydrological engineers (soil crust communities of microorganisms, porcupines, shrubs and humans) determine the diversity and productivity of annual plants. Work by Mr. Justin Wright in the Adirondack Mountains, N.Y. is measuring the impact of beaver-engineered meadows on the diversity of riparian plant species. Research in this area is helping us understand how species, including human engineers, affect species diversity and ecosystem functioning.

Collaborators
Prof. John Lawton, IES Adjunct Scientist, Centre for Population Biology, Imperial College, Silwood Park, UK
Dr. Moshe Shachak, IES Adjunct Scientist, Ben Gurion University of the Negev, Israel
Mr. Justin Wright, Graduate Student, Cornell University

Selected Publications

• Jones, C. G., Lawton, J. H., and Shachak, M. 1997. Positive and negative effects of organisms as physical ecosystem engineers. Ecology 78: 1946-1957.
  
• Jones, C. G. 1996. Ecosystem engineering by vertebrates: a review of Butler, D.R. 1995. Zoogeomorphology: Animals as Geomorphic Agents. Cambridge University Press. 231pp. Ecology 77: 653-654.
  
• Jones, C. G. and Lawton, J. H. (eds.). 1995. Linking Species and Ecosystems. Chapman and Hall, New York.
  
• Lawton, J. H. and Jones, C. G. 1995. Linking species and ecosystems: organisms as ecosystem engineers. pp. 141-150. In: Jones, C. G. and Lawton, J. H. (eds.). Linking Species and Ecosystems. Chapman and Hall, New York.
  
• Shachak, M. and Jones, C. G. 1995. Ecological flow chains and ecological systems: concepts for linking species and ecosystem perspectives. pp. 280-294. In: Jones, C. G. and Lawton, J. H. (eds.). Linking Species and Ecosystems. Chapman and Hall, New York.
  
• Shachak, M., Jones, C. G. and Brand, S. 1995. The role of animals in an arid ecosystem: snails and isopods as controllers of soil formation, erosion and desalinization. Adv. in GeoEcol. 28: 37-50.
  
• Jones, C. G., Lawton, J. H. and Shachak, M. 1994. Organisms as ecosystem engineers. Oikos 69: 373-386.
  
• Jones C. G., and Shachak, M. 1994. Desert Snails' Daily Grind. Natural History 103(8): 56-61.
  
• Lawton, J. H. and Jones, C. G. 1993. Linking species and ecosystems. Trends Ecol. Evoln. 8: 311-313.
  
• Jones, C. G. and Shachak, M. 1990. Fertilization of the desert soil by rock-eating snails. Nature 346: 839-841.
  
• Shachak, M., Jones, C. G. and Granot, Y. 1987. Herbivory in rocks and the weathering of a desert. Science 236: 1098-1099.

An Overview of Organisms as Ecosystem Engineers

• Alper, J. 1998. Ecosystem 'engineers' shape habitats for other species. Science 280: 1195-1196.

Scientific Correspondence on Organisms as Ecosystem Engineers

• Jones, C. G., Lawton, J. H. and Shachak, M. 1997. Ecosystem engineering by organisms: why semantics matters. Trends Ecol. Evoln. 12: 275.
  
• Power, M.E. 1997. Estimating impacts of a dominant detritivore in a neotropical stream. Trends Ecol. Evoln. 12, 47-49.