21272001
not annotated - annotated - LINNAEUS only
Field tests of interspecific competition in ant assemblages: revisiting the dominant red wood ants.
1. There has been considerable debate on the importance of competition in ecological communities, but its importance in structuring ant assemblages has often been uncritically accepted. Here, we briefly review field experiments examining competition in ant assemblages and use a removal experiment to test the effect of the classical territorial dominant ant, Formica aquilonia. Ants of this species group are thought to structure communities through a dominance hierarchy. 2. First, we used pitfall traps to compare the abundance of other ants in replicated sites with low and high densities of F. aquilonia. We found differences in community composition, in particular, Camponotus herculeanus was more common in low-density sites, in accordance with predictions. Differences in ant assemblages were not owing to differences in measured habitat variables. 3. We removed F. aquilonia from a set of high-density sites, using physical and chemical methods, and repeated these procedures at procedural control sites. One year after removal, abundances of F. aquilonia at removal sites were similar to those at low-density sites. However, the composition of other species did not change in response to F. aquilonia removal. Replication rates were identical in the mensurative and experimental components of this study, so this is unlikely to be owing to the analysis being insufficiently powerful. 4. We suggest three possibilities for the lack of difference. First, the study may have been too short term or small scale to detect differences. However, previous studies have shown effects on smaller spatial- and temporal-scales. Second, priority effects may be important in the successful colonisation by F. aquilonia. Thirdly, boreal ant assemblages may be too depauperate for redundancy in ecological roles and for competition to play an important structuring role. 5. We thus recommend that long-term large-scale experiments be considered essential if we are to distinguish between competing hypotheses in community ecology.
Ann file
T1 Species 462 479 Formica aquilonia
N1 Reference T1 Taxonomy:258703
T2 Species 698 710 F. aquilonia
N2 Reference T2 Taxonomy:258703
T3 Species 774 796 Camponotus herculeanus
N3 Reference T3 Taxonomy:36169
T4 Species 973 985 F. aquilonia
N4 Reference T4 Taxonomy:258703
T5 Species 1154 1166 F. aquilonia
N5 Reference T5 Taxonomy:258703
T6 Species 1300 1312 F. aquilonia
N6 Reference T6 Taxonomy:258703
T7 Species 1804 1816 F. aquilonia
N7 Reference T7 Taxonomy:258703