DOI: 10.5061/dryad.n2z34tn2q
title: Data from: Exotic plantations differ in “nursing” an understory invader: A probe into invasional meltdown

description: Forest plantations most likely promote exotic plant invasion. Using an
 in situ monitoring method, this study investigated the traits
 correlated with growth and reproduction of an understory invader,
 Phytolacca americana L., and ecological factors including understory
 irradiance, soil stoichiometry and microbial patterns associated with
 these traits in different exotic plantations of Robinia pseudoacacia L.
 and Pinus thunbergii Parl. at Mount Lao, Qingdao, China. We found that the
 traits of P. americana underneath the R. pseudoacacia stand might be
 situated at the fast side of the trait economic spectrum. The R.
 pseudoacacia stand appeared to “nurse” P. americana. Furthermore, we
 intended to explain the nurse effects of R. pseudoacacia stands by
 examining their ecological factors. First, the R. pseudoacacia stand
 created understory light attenuation, which matched the sciophilous
 feature of P. americana. Second, the soil beneath the R. pseudoacacia
 stand might benefit P. americana more since the soil has greater resource
 availability. Third, a higher microbial diversity was found in the soil
 derived from P. americana underneath the R. pseudoacacia stand. A greater
 abundance of plant pathogens was detected in the soil derived from P.
 americana in the R. pseudoacacia stand, while more abundant mycorrhizal
 fungi were detected in the P. thunbergii stand. We speculate that plant
 pathogens can defend P. americana from aggression from other understory
 competitors. The mycorrhizal fungi in the P. thunbergii stand might
 benefit P. americana while simultaneously benefiting other understory
 plants. Intensive competition from other plants might interfere with P.
 americana. The potential relationships between plant performance and
 ecological factors may explain the invasion mechanism of P. americana. The
 present study provides a novel insight on the facilitative effects of
 exotic tree plantation on an exotic herb through the modification of soil
 biota, with implications for the biocontrol of invasive species and forest
 management and conservation. The trait data including plant biomass, SLA,
 leaf nitrogen concentration, leaf C/N, root nitrogen concentration and
 root C/N of P. americana and ecological factors including understory
 irradiance, soil nitrogen concentration, soil C/N, soil bacterial observed
 species, soil bacterial Shannon's index, soil fungal observed species
 and soil fungal Shannon's index were collected underneath
 respectively three plots of R. pseudoacacia and P. thunbergii. All above
 data were average values derived from different individuals of P.
 americana.
description: The data were collected in three plots in Mount Lao, Qingdao,
 China
description: # Data from: Exotic plantations differ in “nursing” an understory invader:
 A probe into invasional meltdown Dataset DOI:
 [10.5061/dryad.n2z34tn2q](https://doi.org/10.5061/dryad.n2z34tn2q) ##
 Description of the data and file structure ###
 plant_traits_and_ecological_factors.csv Data of plant traits and
 ecological factors derived from P. americana under two exotic plantations
 column A: Plot  column B: Plant biomass (g) column C: specific leaf area
 (SLA) (cm2.g^-1^) column D:Leaf nitrogen concentration (leaf N) (mg.g^-1^)
 column E: Leaf carbon/nitrogen ratio (leaf C/N) (g.g^-1^) column F: Root
 nitrogen concentration (root N) (mg.g^-1^) column G: Root carbon/nitrogen
 ratio (root C/N) (g.g^-1^) column H: Irradiance (understory irradiance)
 (lux) column I: Soil nitrogen concentration (soil N) (mg.g^-1^) column J:
 Soil carbon/nitrogen ratio (soil C/N) (g.g^-1^) column K: Observed
 speciesB (soil bacterial observed species) column L: ShannonB (soil
 bacterial Shannon's index) column M: Observed speciesF (soil fungal
 observed species) column N: ShannonF (soil fungal Shannon's index)