Data from: Biotic resistance to tropical ornamental invasion

Bufford, Jennifer L., University of Hawaii at Manoa

Lurie, Matthew H., University of Hawaii at Manoa

Daehler, Curtis C., University of Hawaii at Manoa

Published Dec 11, 2016 on Dryad. https://doi.org/10.5061/dryad.b1v2c

Cite this dataset

Bufford, Jennifer L.; Lurie, Matthew H.; Daehler, Curtis C. (2016). Data from: Biotic resistance to tropical ornamental invasion [Dataset]. Dryad. https://doi.org/10.5061/dryad.b1v2c

Abstract

We examined invasive, casual (found occasionally outside cultivation) and non-invasive (found only in cultivation) species to investigate the role of species traits and two forms of biotic resistance (plant neighbours and herbivores) in limiting invasion in Hawaiian lowlands. Seeds of 21 species of common woody ornamentals from three plant families (Acanthaceae, Apocynaceae, Bignoniaceae) that are non-invasive, casual or invasive in Hawai'i were outplanted at two field sites. We measured germination of seeds and growth and survival of seedlings for one year in plots with and without neighbours from the naturally-assembled community. The presence of neighbours reduced survival in some species, mostly non-invasive or casual species and completely excluded two non-invasive species from community plots. Damage from the existing community of herbivores was correlated with lower survival in the Acanthaceae and Bignoniaceae, but not the Apocynaceae. Non-invasive and casual species had lower survival and growth rates than invasive species and lower photosynthetic rates in the presence of neighbours than invasive species. Non-invasives without neighbours also had lower specific leaf area than invasives and casuals. We found evidence for barriers to invasion in some non-invasive and casual species, including low growth rate, low survival, or low survival in the presence of neighbours. By contrast, five of the six invasives flowered and three began setting fruit within the duration of the experiment, as did one of the casual species. Synthesis: Our research demonstrates biotic resistance, presumably as a result of competition. Neighbouring plants reduced survival and growth for most species. For non-invasive species with low survival and growth even without competition from neighbouring plants, this resulted in complete exclusion from community plots or such low growth rates that exclusion over longer time frames was likely. We also provide evidence for traits-based barriers to invasion in non-invasive and casual species. However, no single barrier to invasion was shared across all non-invasive and casual species.

Usage notes

Germination, survival and traits of tropical ornamentals in the field

These data show the germination, survival, and traits from 21 species of introduced tropical ornamental plants in Hawai'i. Plant species were drawn from three taxonomic families and classed as invasive, casual or non-invasive. Seeds were planted at two sites (wet or seasonally dry) in 10 blocks per site in plots with or without neighbours. Seedlings were monitored for one year to track germination and survival. After one year, leaf traits were measured on any remaining plants and plants were harvested to measure biomass. Canopy cover and richness and biomass of the plant community in plots with neighbours are also included.

Field_Seedling_Data.csv

Germination of tropical ornamentals in germination chambers

These data show the results of controlled germination trials of 21 species of introduced tropical ornamental plants in Hawai'i. Plant species were drawn from three taxonomic families and classed as invasive, casual or non-invasive. Germination trials were conducted in two germination chambers in petri dishes of damp sand, with two dishes (specified by location on upper or lower rack) per species per chamber. Germination trials were conducted simultaneously with experimental plantings at two field sites and germination chamber settings mimicked light and temperature regimes of the two sites.

Lab_Germination_Data.csv

Plant community composition in field plots with neighbours

These data show the plant community composition of plots at two sites (wet or seasonally dry) in 10 blocks per site in plots with neighbours. All plots were cleared of vegetation and planted with seeds of 21 species of introduced tropical ornamental plants in Hawai'i. Subsequently, the plant community was allowed to regenerate in plots with neighbours. In these plots, plant community was measured by visually estimating the percent cover of all species within two 1 m x 1 m quadrats (excluding experimentally planted species). Data were collected at the end of the experiment when experimentally planted species were harvested. Sites and blocks are the same as those recorded in Field_Seedling_Data.csv (Data 1).

Plant_Community_Data.csv

Location

Hawaii