Abstract
Phylogenetic ecology uses evolutionary history to improve understanding of plant interactions. Phylogenetic distance can mediate plant interactions such as competition (e.g., via limiting similarity) and facilitation (e.g., via niche complementarity), influencing community assembly patterns. Previous research has found evidence both for and against a relationship between phylogenetic distance and the strength of plant interactions, and has found that other factors, such as trait differences, may be more influential. In addition to phylogenetic distance and species’ traits, environmental conditions can also influence competition, with facilitative interactions—particularly among distantly related species—potentially becoming more pronounced under stressful, resource-limited conditions. We tested the prediction that greater phylogenetic distance is associated with decreased competition in a greenhouse experiment using plant species of the North American tallgrass prairie. We calculated the Relative Interaction Index for 81 species pairs using plant height, leaf length, and biomass as indicators of performance. We found that phylogenetic distance alone did not significantly affect competition. However, the interaction between phylogenetic distance and stressful conditions (sandier soils with low nutrient availability and water retention vs. resource-rich potting soil) altered plant traits and competition. Under stressful conditions, more distantly related species competed more strongly, leading to smaller plants. Conversely, under benign conditions more distantly related species pairs competed less and were larger. These results were contrary to our expectations that distant relatives would compete less under stressful conditions. Our experiment provides evidence that, while relatedness alone may not drive competition, phylogenetic distance can nonetheless be influential through interactions with environmental conditions.
Original language | English (US) |
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Pages (from-to) | 459-469 |
Number of pages | 11 |
Journal | Oecologia |
Volume | 197 |
Issue number | 2 |
DOIs | |
State | Published - Oct 2021 |
Bibliographical note
Funding Information:The authors thank the staff of the Chicago Botanic Garden greenhouses, particularly Brian Clark and Barb Raue, for their invaluable cooperation and assistance, and Jared Garcia for assistance collecting data. This work was supported by the National Science Foundation [grant numbers DEB-1354426, DEB-1354551, and DBI-1461007].
Publisher Copyright:
© 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
Keywords
- Facilitation
- Prairie
- Relatedness
- Resource availability
- Stress gradient
PubMed: MeSH publication types
- Journal Article