Biological facilitation of the giant tree fern Angiopteris evecta in the germination of the invasive velvet tree Miconia calvescens
- Published
- Accepted
- Subject Areas
- Biodiversity, Ecology, Environmental Sciences, Plant Science
- Keywords
- Biological facilitation, Nurse plants, Biological invasions, Miconia calvescens, Angiopteris evecta, Velvet Tree, invasive species
- Copyright
- © 2017 Lee
- 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. Biological facilitation of the giant tree fern Angiopteris evecta in the germination of the invasive velvet tree Miconia calvescens. PeerJ Preprints 5:e2643v2 https://doi.org/10.7287/peerj.preprints.2643v2
Abstract
Background. Biological facilitation is a type of relationship between two taxa that benefits at least one of the participants and harms neither. Although invasive species are widely known to compete with native taxa, recent studies suggest that invasive and native species can have positive relationships. This study aims to examine the biological facilitation of the germination of invasive Miconia calvescens by giant tree fern Angiopteris evecta, native to French Polynesia.
Methods. Field surveys were conducted to measure A. evecta and M. calvescens by applying the 10×10 m2 quadrat survey method. The density of seedlings, saplings, and matures of M. calvescens growing on the rhizomes of A. evecta and on bare soil was compared, and the correlation between the size of the rhizomes and the number of M. calvescens growing on them was verified. Two separate sets of nutrient measurements of substrates were performed to compare the nutrient of A. evecta rhizome and other environments (abiotic and potential biotic environments). Leaf decomposition rate of five dominant tree species was compared to verify whether A. evecta has quickly decomposing leaves, and therefore induce the germination of M. calvescens indirectly.
Results. Field surveys show that there is a greater number of seedlings and saplings of M. calvescens growing on the rhizomes of A. evecta as compared to bare soil. Furthermore, there is a positive correlation between the size of rhizomes and the number of M. calvescens growing on them. Substrates of A. evecta had higher phosphorus and potassium contents compared to other soils and substrates, but did not differ from bark of other tree species that could potentially offer favorable microenvironments. A. evecta has quickly decomposing leaves.
Discussion. A. evecta facilitates the germination of M. calvescens, supported by the much higher number of seedlings and saplings growing on the rhizomes and the positive correlation between the size of the rhizome and the number of M. calvescens growing on it. Microslopes on the rhizomes of A. evecta prevent leaf litter from accumulating on the rhizomes, and enable more sunlight to reach and facilitate the germination of M. calvescens seeds. Also, quickly decomposing leaves of A. evecta prevent the accumulation of leaf litter on the ground and enable more light to reach seed bank. Although the chemical components is not different from other tree species, physical structure of the rhizome and consequent higher light availability, and higher amount of potassium than bare soil would be the possible reason for the facilitation. Biological facilitation of the germination of invasive M. calvescens by native A. evecta can give better understanding on the invasion success and the relationship between the native and invasive species. Invasion of A. evecta can induce and promote further invasion of M. calvescens. Therefore, thorough management of ongoing invasion of A. evecta is particularly required.
Author Comment
Some data are added to methods, results, and discussion because further study was conducted. Also there are some minor revise in general description.
Supplemental Information
A. evecta - M. calvescens Quadrat Survey Raw Data
Figure 1
Map of study sites. The study was conducted at sites along two well-known hiking trails: Three Coconuts Trail and Three Pines Trail, in Moorea, French Polynesia
Figure 2
Seedlings and saplings of M. calvescens. (1st row: seedlings, 2nd row: saplings. Scale: 1cm)
Figure 3
Density of seedlings, saplings, and mature plants of M. calvescens on A. evecta rhizome and bare soil. Data represents sites on the Three Coconuts Trail.
Figure 4
Density of seedlings, saplings, and mature plants of M. calvescens on A. evecta rhizome and bare soil. Data represents sites on the Three Pines Trail.
Figure 5
Correlation between the height of A. evecta rhizomes and the number of M. calvescens on them. Data represents sites on Three Coconuts Trail (a) and sites on Three Pines Trail (b). Density values were log transformed prior to analyses.
Figure 6
Soil nutrient comparison between three different microenvironments; substrates of the rhizomes of Angiopteris evecta, soil under the rhizomes, and bare soil.
Figure 7
Nutrient contents comparison between the substrates and the barks of six species; Angiopteris evecta, Inocarpus fagifer, Neonauclea forsteri, Falcataria moluccana, Barringtonia asiatica, and Hibiscus tiliaceus.
Figure 8
Leaf decomposition rate of five dominant tree species in Opunohu Valley, Mo'orea.
Figure 10
Rooting ability of M. calvescens. The figure depicts an individual plant that is re-rooting from the middle of the mature trunk (>3 m) after the trunk has fallen across a creek.
