Facilitative and competitive interaction components among New England salt marsh plants
- Published
- Accepted
- Subject Areas
- Ecology, Environmental Sciences, Marine Biology, Plant Science
- Keywords
- competition, facilitation, interaction strength, salt marsh
- Copyright
- © 2017 Bruno et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2017. Facilitative and competitive interaction components among New England salt marsh plants. PeerJ Preprints 5:e3129v1 https://doi.org/10.7287/peerj.preprints.3129v1
Abstract
Intra- and interspecific interactions can be broken down into facilitative and competitive components. The net interaction between two organisms is simply the sum of these counteracting elements. Disentangling the positive and negative components of species interactions is a critical step in advancing our understanding of how the interaction between organisms shift along physical and biotic gradients, and whether component interactions are unique or redundant across species in natural communities. We performed a manipulative field experiment to quantify the positive and negative components of the interactions between a perennial forb, Aster tenuifolius, and three dominant, matrix-forming grasses and rushes in a New England salt marsh. Specifically, we asked whether positive and negative interaction components: (1) are unique or redundant across three matrix-forming grass and rush species (Juncus gerardi, Distichlis spicata, and Spartina patens), and (2) change across Aster life stages (seedling, juvenile, and adult). For adult forbs, the strength of the facilitative component of the matrix-forb interaction was stronger than the competitive component for two of the three matrix species, leading to net positive interactions. There was no statistically significant variation among matrix species in their net or component effects, however, the competitive effect of J. gerardi was negligible, especially compared to that of D. spicata. We found little difference in the effects of J. gerardi on Aster at later life-history stages; interaction component strengths did not differ between juveniles and adults. However, mortality of seedlings in neighbor removal plots was 100%, indicating a particularly strong and critical facilitative effect of matrix species on this forb during the earliest life stages. Overall, our results indicate that matrix forming grasses and rushes have important, yet largely redundant, positive net effects on Aster performance across its life cycle. Studies that untangle various components of interactions and their contingencies are critical to both expanding our basic understanding of community organization, and predicting how natural communities and their component parts will respond to environmental change.
Author Comment
This is a submission to PeerJ for review.
Supplemental Information
Species interaction components based on relative growth
Net, negative, and positive effects of three salt marsh matrix species on adult and juvenile Aster based on relative growth. Apparent differences in the strength of interaction components among the matrix species were not statistically significant (P>0.05, ANOVA).