Intra-specific variability and sex influence the allelopathic capacity of Empetrum nigrum

Allelopathic plant species play significant roles in shaping natural ecosystems. While a high degree of inter-species variation in allelopathic capacities is commonly reported, variation across intra-specific groups and between dioecious sexes is limited. Here we use the ecologically important, allelopathic dwarf shrub Empetrum nigrum L. to assess how allelopathic capacity varies between intra-specific groups (i.e., the diploid and dioecious “nigrum” group and the tetraploid and synoecious “hermaphroditum” group of Empetrum) and sex (i.e., male and female plants of the nigrum group). Specifically, we tested Icelandic Empetrum, as its allelopathic nature may influence long-term land degradation across Icelandic highlands. The allelopathic capacity of Empetrum leaves was measured in a series of bioassays as the inhibition of seed germination and seedling root elongation of the grass Festuca richardsonii. A very strong allelopathic response of Empetrum leaves was observed. Intra-speci..., , # Intra-specific variability and sex influence the allelopathic capacity of *Empetrum nigrum*

Dataset DOI: [10.5061/dryad.73n5tb38z](10.5061/dryad.73n5tb38z)

## Description of the data and file structure

The data files contain recordings of germination and root elongation of the grass species *Festuca richardsonii* seeds and seedlings, incubated in bioassays with different amounts of leaves from three different intra-specific groups and sexes of the dwarf shrub *Empetrum nigrum*: the \"*hermaphroditum*\" group, and male and female sexes of the \"*nigrum*\" group. There is also a data file of foliar concentrations of the previously designated key allelochemical Batatasin-III (BIII), assessed in the leaf material used for the bioassays.

### Files and variables

Inside the folder Ryde_et_al._2025.zip, there are eight data files (.csv) accompanied by eight code files (.R) used for statistical analyses. Code files are named similarly to the data files they were analyzing. 

**Meaning of col...,