RETRACTED ARTICLE: Interspecific competition among ants in the boreal forest: Testing predictions from a linear hierarchical competition model

Abstract

Competitive interactions often play an important role in local community structure, and particularly so in ant communities. We test predictions derived from a competition model proposed for Scandinavian ant communities by comparing ant nest densities inside and outside fifty randomly-selected territories of competitively dominant wood ants within 30 km of Umeå, northern Sweden. As predicted by the model, competitively-intermediate encounter species, as well as other territorial species, showed complementary occurrences with both studied wood ants, Formica aquilonia Yarrow and F. lugubris Zett.. In contrast, complementary abundances, i.e. lower density of competitively-inferior submissive species in the presence of wood ants, as predicted by the model, was not supported for all submissive species. Of the two studied wood ant species, the nest density of submissive species was negatively correlated only with F. aquilonia. Submissives as a group, as well as Myrmica-species, showed complementary abundances with F. aquilonia, but one Leptothorax and two Serviformica species had higher nest densities in the presence of this competitively-dominant species. We propose that, for Leptothorax, these deviations from the model predictions may be because of limited niche overlap with dominant wood ants, a small worker force and a timid behaviour which does not elicit aggression in wood ants. For the two Serviformica species, we propose a combination of protection against social parasites, inter-specific social control performed by F. aquilonia, and dominance relationships between competitively-inferior submissive species as reasons for the higher nest density inside F. aquilonia territories. Monogyny, and thereby smaller nests, lower worker force, smaller territory (as shown by this study) in F. lugubris, as compared to the polygyny in F. aquilonia, may also help explain the differences in their effects on subordinate species. Our analyses indicate that the linear competition hierarchy model proposed for Scandinavian ants accurately predicts the outcome of interaction between and community composition for dominant territorial and encounter species, but that it needs refinement with respect to the relationship between territorial and submissive species and the resulting community composition. Further studies are needed, especially addressing the complex relationships between these latter groups, and the effects of different competitively-dominant wood ants, to determine the mechanisms determining the outcome of these relationships and to more accurately predict community composition.

Nesting Associations without Interdependence: A Preliminary Review on Plesiobiosis in Ants

“…Recent studies have Psyche revealed that F. fusca is one of the most frequent plesiobionts among the studied ants. Similarly to other common plesiobionts, F. fusca is also a submissive species in the three-level classification of the competitive hierarchy in ants [51,52]. The submissive behaviour and the opportunistic character of this species can be considered as one of the main features that contribute to its frequent cooccurrence with other species in plesiobiotic associations.…”

“…Contrary to the afore-mentioned species, several Camponotus species are typically regarded as encounter species that is, they defend not only their nests but the discovered resources as well [51,52]; therefore only submissive species can be expected to be their plesiobiotic partners.…”

Space, Habitat and Isolation are the Key Determinants of Tree Colonization by the Carpenter Ant in Plantation Forests

“…One possible reasons for the carpenter ants' distance from more sunny places is the reduction of competition with other ant species. One of the indications that can explain our results is that carpenter ants encounter species that do not defend their territory [42] and avoid forests with wood ants with large territories [43]. It is possible that carpenter ants can compensate for poorer temperature conditions due to their endosymbiosis with the Blochmannia bacteria, which improves colony growth and immune defense [44,45].…”

The role of environmental vs. biotic filtering in the structure of European ant communities: A matter of trait type and spatial scale

“…Thus, in much colder regions than the Mediterranean (i.e., boreal and alpine), where habitat heterogeneity is low and the abundance of behavioral ant dominant species is high, the biotic filter might play a more relevant role and thus competition might be the predominant force structuring local ant communities. [56][57][58][59]. Still, the role of competitive exclusion in the ant low-diversity systems typical from boreal and alpine forests remains unclear (39).…”