Loss of foundation species: consequences for the structure and dynamics of forested ecosystems

• Published in: Frontiers in ecology and the environment 2005-11, Vol.3 (9), p.479-486
• Main Authors: Ellison, Aaron M., Bank, Michael S., Clinton, Barton D., Colburn, Elizabeth A., Elliott, Katherine, Ford, Chelcy R., Foster, David R., Kloeppel, Brian D., Knoepp, Jennifer D., Lovett, Gary M., Mohan, Jacqueline, Orwig, David A., Rodenhouse, Nicholas L., Sobczak, William V., Stinson, Kristina A., Stone, Jeffrey K., Swan, Christopher M., Thompson, Jill, Von Holle, Betsy, Webster, Jackson R.
• Format: Article
• Language: English
• Subjects: anthropogenic activities; Aquatic ecosystems; case studies; Castanea dentata; community structure; core species; degradation; dominant species; ecosystem processes; forest communities; Forest ecology; Forest ecosystems; forest health; Forest hydrology; forest pests; Forest stands; forest succession; forest trees; Human ecology; microclimate; Old growth forests; Pine trees; Pinus albicaulis; population dynamics; Reviews; riparian forests; riverine habitat; soil; Species; species loss; streams; tree diseases; Trees; Tsuga canadensis; vegetation structure
• ISSN: 1540-9309; 1540-9295; 1540-9309
• DOI: 10.1890/1540-9295(2005)003[0479:lofscf]2.0.co;2

In many forested ecosystems, the architecture and functional ecology of certain tree species define forest structure and their species-specific traits control ecosystem dynamics. Such foundation tree species are declining throughout the world due to introductions and outbreaks of pests and pathogens, selective removal of individual taxa, and over-harvesting. Through a series of case studies, we show that the loss of foundation tree species changes the local environment on which a variety of other species depend; how this disrupts fundamental ecosystem processes, including rates of decomposition, nutrient fluxes, carbon sequestration, and energy flow; and dramatically alters the dynamics of associated aquatic ecosystems. Forests in which dynamics are controlled by one or a few foundation species appear to be dominated by a small number of strong interactions and may be highly susceptible to alternating between stable states following even small perturbations. The ongoing decline of many foundation species provides a set of important, albeit unfortunate, opportunities to develop the research tools, models, and metrics needed to identify foundation species, anticipate the cascade of immediate, short- and long-term changes in ecosystem structure and function that will follow from their loss, and provide options for remedial conservation and management.