DOI: 10.5061/dryad.w6m905qzr
title: Data from: Plastic particles and their additives promote plant invasion through physicochemical mechanisms on seed germination

description: Plant invasions pose a major threat to terrestrial biodiversity, and
 microplastic pollution in soil could exacerbate this problem. Seed
 germination, a crucial stage for plants, can be affected by microplastics
 through both physical interference of plastic particles and chemical
 leaching from plastic additives. We conducted a greenhouse experiment
 using native and invasive plant species of European grasslands, and
 evaluated individual and combined effects of plastic particles and
 additives on germination parameters. We found that plastic particles
 primarily affected seed germination as physical agents, while additives
 from these particles exerted a comparatively lesser impact. Particles
 negatively affected seed germination of all native species. Germination
 velocity, synchrony and total germination decreased by ~30%, ~11% and
 ~11%, respectively, in soils containing plastic particles compared to
 those without. Certain species were negatively affected by plastic
 additives. For Achillea millefolium and Dactylis glomerata, germination
 velocity and total germination decreased by ~26% and ~7%, respectively,
 while germination synchrony of Dactylis glomerata decreased by ~21% in
 soils with additives than without them. Plastic particles may have blocked
 seed pores and inhibited hypocotyl and radicle growth, while toxic
 compounds from additives may have disrupted key germination processes. By
 contrast, particles and additives generally did not affect invasive
 species, suggesting that the negative effects of plastic experienced by
 natives, whether physical or chemical, were counteracted by effects
 resulting from the novel conditions created by microplastics, which may
 include the amelioration of soil physical properties such as increased
 soil porosity and aeration, and potential positive plant-soil feedbacks.
 Invasive species may profit from windows of variable resource
 availability, with positive effects on seed germination. Synthesis:
 Plastic particles and additives may promote plant invasion by negatively
 affecting seed germination of native species while having neutral effects
 on invasive species. The delayed germination of natives due to
 microplastics poses a potential threat, leading to competitive
 disadvantages, reduced reproductive success, and increased vulnerability
 to invasive species. Microplastic pollution appears to favor invasive
 species over natives during the early stages of seed germination,
 highlighting that the negative effect of microplastics on terrestrial
 ecosystems may be more severe than previously thought.
description: We performed an experiment in a glasshouse under controlled
 conditions.  Plastic was cut and sieved through a 1 mm
 mesh to produce microplastic films ~1 mm² in size and then exposed to UV-C
 for degradation. Microplastic films was mixed with water and incubated for
 15 days at 40°C to extract the additives (water-extractable additives). We
 thus have the following treatment: Plastic particles, additives, plastic
 particles+ additives, and a control without microplastics. Then, we
 collected grassland soil and mixed it with the plastic at a 0.4% of
 concentration, according to the treatments. Seeds of 4 natives species and
 3 invasive species were sown and their germination was recorded. At the
 end of the experiment, we calculated different germination
 parameters.
description: # Plastic particles and their additives promote plant invasion through
 physicochemical mechanisms on seed germination
 [https://doi.org/10.5061/dryad.w6m905qzr](https://doi.org/10.5061/dryad.w6m905qzr) ## Description of the data and file structure We collected germination of seeds of native and invasive species of grasslands environment. We did so in soil mixed with pieces (particles), additives, (particles and additives), and in control soil without microplastics added. We registered the germination every two days for until 64 days.  ### Files and variables #### File: germ\_counts\_p\_day\_Lena\_FU.csv **Description:**  ##### Variables * pot: Experimental unit  * treatment: We summarized the 4 treatments used: pieces (particles), additives, particles+ additives, and control. * pieces: It refers to the particles from where the additives were extracted. This is the physical effect of microplastics.  * additives: It refers to the additives extracted from the plastic particles. This is the chemical effect of microplastics. * character: It refers to the provenance of the plant species ( non-invasive (native) or invasive) * species: The plant species from where the seeds were obtained for this experiment.  * start_day:  * day2_nac: Germination on 2nd day (not cumulative) * day4_nac: Germination on 4th day (not cumulative) * day6_nac: Germination on 6th day (not cumulative) * day8_nac: Germination on 8th day (not cumulative) * day10_nac: Germination on 10th day (not cumulative) * day12_nac: Germination on 12th day (not cumulative) * day14_nac: Germination on 14th day (not cumulative) * day16_nac: Germination on 16th day (not cumulative) * day18_nac: Germination on 18th day (not cumulative) * day20_nac:Germination on 20th day (not cumulative) * day22_nac: Germination on 22th day (not cumulative) * day24_nac: Germination on 24th day (not cumulative) * day26_nac: Germination on 26th day (not cumulative) * day28_nac: Germination on 28th day (not cumulative) * day30_nac: Germination on 30th day (not cumulative) * day32_nac: Germination on 32th day (not cumulative) * day34_nac: Germination on 34th day (not cumulative) * day36_nac: Germination on 36th day (not cumulative) * day38_nac: Germination on 38th day (not cumulative) * day40_nac: Germination on 40th day (not cumulative) * day42_nac: Germination on 42th day (not cumulative) * day44_nac: Germination on 44th day (not cumulative) * day46_nac: Germination on 46th day (not cumulative) * day48_nac: Germination on 48th day (not cumulative) * day50_nac: Germination on 50th day (not cumulative) * day52_nac: Germination on 52th day (not cumulative) * day54_nac: Germination on 54th day (not cumulative) * day56_nac: Germination on 56th day (not cumulative) * day58_nac: Germination on 58th day (not cumulative) * day60_nac: Germination on 60th day (not cumulative) * day62_nac: Germination on 62th day (not cumulative) * day64_nac: Germination on 64th day (not cumulative) * total: Total percentage of germination  Data was derived from the Greenhouse experiment.