Limiting similarity between invaders and dominant species in herbaceous plant communities?

Abstract

Summary 1.Limiting similarity theory predicts that successful invaders should differ functionally from species already present in the community. This theory has been tested by manipulating the functional richness of communities, but not other aspects of functional diversity such as the identity of dominant species. Because dominant species are known to have strong effects on ecosystem functioning, I hypothesized that successful invaders should be functionally dissimilar from community dominants. 2. To test this hypothesis, I added seeds of 17 different species to two different experiments: one in a natural oldfield community that had patches dominated by different plant species, and one in grassland mesocosms that varied in the identity of the dominant species but not in species richness or evenness. I used indicator species analyses to test whether invaders had higher establishment success in plots with functionally different dominant species. 3. A large percentage of invader species (47-71%) in both experiments showed no difference in affinity across the different dominant treatments, although one-third of species did show some evidence for limiting similarity. Exotic invaders had much higher invasion success than native invaders, and seemed to be inhibited by dominant species that were functionally similar. However, even these invasion patterns were not consistent across the two experiments. 4. The results from this study show that there is some evidence that dominant species suppress invasion by functionally similar species, beyond the effect of simple presence or absence of species in communities, although it is not the sole factor affecting invasion success. Patterns of invasion success were inconsistent across species and experiments, indicating that other studies using only a single species of invader to make conclusions about community invasibility should be interpreted with caution.

Disturbance governs dominance of an invasive forb in a temporary wetland

“…the principle of limiting similarity (Macarthur and Levins 1967;Vilà and Weiner 2004). However, experimental studies testing this have found conflicting results (Emery 2007;Fargione et al 2003;Von Holle and Simberloff 2004). We found strong inter-specific competition between different lifeforms, i.e.…”

Competing drivers lead to non-linear native–exotic relationships in endangered temperate grassy woodlands

“…2a, c and Prober et al (2013)], and when time since fire was added to the native-exotic richness model the residual relationship with exotics was no longer significant. This common response to fire suggests similarities between natives and exotics in their environmental response, despite the strongly differing life form of most natives (perennial) from most exotics (annual), conflicting with the limiting similarity or empty niche hypotheses (MacArthur and Levins 1967;Emery 2007). Rather these trends provide further support for our second hypothesis that natives and exotics covary due to common drivers.…”

Early emergence and resource availability can competitively favour natives over a functionally similar invader

“…Several field and mesocosm studies have shown that native plant communities can resist invasion by a functionally similar species (Dukes 2001;Emery 2007;Fargione et al 2003;Turnbull et al 2005). If an invader and a native are functionally similar, the invader may lack the competitive advantage needed to increase its abundance from rarity, unless other mechanisms, such as disturbance, facilitate an opportunity for establishment (Davis et al 2000).…”