Species assemblage turnover is greater horizontally than vertically in a
complex habitat
- Shuang Xing,
- Amelia Hood,
- Roman Dial,
- Tom Fayle
Amelia Hood
University of Cambridge University Museum of Zoology
Author ProfileTom Fayle
University of South Bohemia and Institute of Entomology
Author ProfileAbstract
Abiotic and biotic factors structure species assembly in ecosystems both
horizontally and vertically. However, the way community composition
changes along comparable horizontal and vertical distances in complex
three-dimensional habitats, and the factors driving these patterns,
remain poorly understood. By sampling ant assemblages at comparable
vertical and horizontal spatial scales in a tropical rain forest, we
compared observed patterns with those predicted according to decreased
resource availability in the upper canopy, environmental filtering by
microclimate and microhabitat structure, presence of competition in the
form of ant mosaics, and structural connectivity. We found although
dissimilarity between ant assemblages increased with vertical distance,
the dissimilarity was higher horizontally but was independent of
distance in this dimension. Moreover, there was not a more rapid
increase in horizontal distance-dissimilarity at greater heights in the
canopy, as would be predicted if large competitive ant colonies drove
these patterns. The pronounced horizontal and vertical structuring of
ant assemblages across short distances is likely explained by a
combination of microclimate and microhabitat connectivity. Our results
demonstrate the importance of considering three-dimensional spatial
variation in local assemblages and reveal how highly diverse communities
can be supported by complex habitats.