EKOLOGIJA. 2009. Vol. 55. No. 3–4. P. 165–174 DOI: 10.2478/v10055-009-0020-x © Lietuvos mokslų akademija, 2009 © Lietuvos mokslų akademijos leidykla, 2009 Vacant niches in nature, ecology, and evolutionary theory: a mini-review Edmundas Lekevičius Th e use of the term “vacant niches” (unused but potentially usable resources) has recently increased in ecological literature. According to some studies, vacant niches are quite nu- Centre for Ecology and merous in nature, especially, but not exclusively, in disturbed ecosystems. However, the Environmental Sciences, concept of “vacant niche” is still controversial in ecology because of the failure to reach Vilnius University, an agreement on how to defi ne a situation when an ecosystem is devoid of such niches. M. K. Čiurlionio 21/27, In evolutionary biology, as distinct from ecology, this concept arouses fewer controversies LT-07119 Vilnius, and has contributed to the creation of the ecological theory of adaptive radiation. Still Lithuania other evolutionists have used this concept to describe the course and mechanisms of the evolutionary assembly of ecosystems (nutrient cycles and ecological pyramids). Th ese evo- E-mail:
[email protected]; lutionists attempt to prove that in the course of diversifi cation, vacant niches are not only
[email protected] occupied but are also created by newly evolved organisms. Key words: saturated communities, ecosystem evolution, succession, assembly INTRODUCTION rection favoring greater integration with the surrounding ecology”. Some ecologists (e. g. Cornell, 1999; Tilman, Lehman, 2001; According to this author, vacant niches may be defi ned see a survey of Rohde, 2005) tend to think that a niche can as negative species or species waiting to happen.