DOI: 10.5061/dryad.95x69p8r8
title: Artificial night-time lighting and nutrient enrichment synergistically favour the growth of alien ornamental plant species over co-occurring native plant species

description: Insights into ecological drivers of alien plant invasions can be gained
 through comparative studies of growth and fecundity of invasive alien
 plants versus those of co-occurring non-invasive alien plants and native
 plants across environmental conditions in common garden settings. Habitats
 that harbour alien plant species in many ecosystems globally are presently
 experiencing light pollution resulting from artificial light at night
 (ALAN) and increased rates of nutrient enrichment of the soil. However,
 the potential interactive effects of ALAN and nutrient enrichment on
 invasiveness of alien plant species remain unknown. Here, we performed a
 common-garden experiment to test the interactive effects of ALAN and soil
 nutrient enrichment on the growth of a random set of 10 alien (five
 invasive and five naturalized) and seven co-occurring native ornamental
 plant species that are commonly cultivated within urban and peri-urban
 areas of Nairobi city in Kenya. We predicted that a simultaneous increase
 in photoperiod via ALAN and nutrient enrichment will favor growth of
 invasive alien plant species over that of non-invasive alien and native
 plant species. We grew the 17 plant species under natural daylight (ALAN-)
 vs natural daylight followed by ALAN (ALAN+) and fully crossed with two
 levels of nutrient enrichment (low vs high) and competition (competition
 vs no-competition against a native plant Ocimum gratissimum) treatments.
 Under simultaneous high-nutrient and no-competition treatments, ALAN
 enhanced mean total biomass of invasive and naturalized alien species by
 61.1% and 131.4%, respectively but decreased that of native plant species
 by 34%. In contrast, under simultaneous high-nutrient and competition
 treatments, ALAN enhanced mean total biomass of invasive alien plant
 species by 68.6% and that of naturalized alien species by 51.9% and native
 species by 35.4%. High-nutrient treatment enhanced flower formation more
 strongly in invasive and naturalized alien plants than in native plants.
 The invasive and naturalized alien species grew taller than native species
 across the light, nutrient, and competition treatments. Synthesis: The
 present findings suggest that light pollution and nutrient enrichment may
 jointly confer growth advantage to invasive alien plant species over that
 of co-occurring native plant species and enhance invasiveness of alien
 plant species.
description: Here, we performed a common-garden experiment to test the
 interactive effects of ALAN and soil nutrient enrichment on the growth of
 a random set of 10 alien (five invasive and five naturalized) and seven
 co-occurring native ornamental plant species that are commonly cultivated
 within urban and peri-urban areas of Nairobi city in Kenya.
description: GENERAL INFORMATION 1. Title of Dataset: Data from: Artificial night-time
 lighting and nutrient enrichment synergistically favour the growth of
 alien ornamental plant species over co-occurring native plant species. 2.
 Author Information Corresponding Investigator Name: Dr. Ayub M. O. Oduor
 Institution: Technical University of Kenya Email: Ayub.Oduor@tukenya.ac.ke
 <br> Co-investigator 1 Name: Mr. Calvince R. Kawawa Abonyo
 Institution: National Environment Management Authority (NEMA), P.O Box
 67839-00200 Nairobi, Kenya. 3. Date of data collection: December 2019 -
 May 2020 4. Geographic location of data collection: Nairobi, Kenya. 5.
 Funding sources that supported the collection of the data: International
 Foundation of Science (No. D-6495-1); National Geographic Society,
 Washington D.C (grant no. WW-155R-17); Alexander von Humboldt Foundation
 (grant no. 3.4-8151/GA-Nr. 19016); DAAD within the framework of Climate
 Research for Alumni and Postdocs in Africa with funds of the Federal
 Ministry of Education and Research of Germany (fellowship reference no.
 91787649). 6. Recommended citation for this dataset: Oduor, Ayub M.O;
 Abonyo, C. R. K (2023), Artificial night-time lighting and nutrient
 enrichment synergistically favour the growth of alien ornamental plant
 species over co-occurring native plant species, Dryad, Dataset,
 https://doi.org/10.5061/dryad.95x69p8r8 DATA & FILE OVERVIEW 1.
 Description of dataset These data were generated from a common-garden
 experiment to test the interactive effects of artificial light at night
 (ALAN) and soil nutrient enrichment on the growth of a random set of 10
 alien (five invasive and five naturalized) and seven co-occurring native
 ornamental plant species that are commonly cultivated within urban and
 peri-urban areas of Nairobi city in Kenya. We predicted that a
 simultaneous increase in photoperiod via ALAN and nutrient enrichment will
 favor growth of invasive alien plant species over that of non-invasive
 alien and native plant species. We grew the 17 plant species under natural
 daylight only (ALAN-) vs natural daylight followed by ALAN (ALAN+) and
 fully crossed with two levels of nutrient enrichment (low vs high) and
 competition (competition vs no-competition against a native plant Ocimum
 gratissimum) treatments. 2. File List: File 1 Name: Total biomass.xlsx
 File 1 Description: Mean total biomass (g) of 17 test plant species.
 <br> File 2 Name: Root-Shoot ratio.xlsx File 2 Description: Mean
 values of root/shoot ratio of 17 test plant species. <br> File 3
 Name: Height.xlsx File 3 Description: Mean values of plant height (cm) of
 17 test plant species. <br> File 4 Name: Flowered plants.xlsx File 4
 Description: Mean values of proportion of individual plants that flowered
 for 17 test plant species. <br> File 5 Name: Flower number.xlsx File
 5 Description: Mean number of flowers per plant for 17 test plant species.
 METHODOLOGICAL INFORMATION We grew the 17 plant species under natural
 daylight only (ALAN-) vs natural daylight followed by ALAN (ALAN+) and
 fully crossed with two levels of nutrient enrichment (low vs high) and
 competition (competition vs no-competition against a native plant Ocimum
 gratissimum) treatments. Data prepration for statistical analysis: We
 computed mean values for each of the 17 plant species under the factorial
 combinations of light, nutrient, competition, and invasive status.
 DATA-SPECIFIC INFORMATION FOR THE FIVE (5) DIFFERENT FILES: (1)
 DATA-SPECIFIC INFORMATION FOR: Total biomass.xlsx 1. Number of variables:
 15 2. Number of cases/rows: 137 3. Variable List: * Species: five invasive
 alien, five naturalized alien, and seven co-occurring native ornamental
 plant species. * Family: taxonomic family identity of each of the 17 plant
 species. * Alien status: whether the plant is alien or native to Kenya. *
 Invasive status: whether the plant is an invasive alien, non-invasive
 naturalized alien, or native. * Life cycle: plant longevity. * Clonality:
 reproduction mode of the plants. * Growth form: whether the plant is
 herbaceous or shrubby. * Photosynthetic pathway: carbon assimilation
 pathway of the plant. * Plot number: plots where the experimental plants
 were grown.\*Light: light treatment in the plots (ALAN- vs ALAN+). *
 Nutrient: nutrient treatment in the pots (low nutrient vs high nutrient).
 * Competition: competition treatment in the pots (each of the 17 species
 was grown in the absence of competition vs under competition). * Mean:
 mean total biomass of each plant under factorial combinations of light,
 nutrient, competition, and invasive status treatments. * SD: standard
 deviation associated with each mean. * n= sample size for each factorial
 combination of light, nutrient, competition, and invasive status
 treatments. 4. Missing data: None 5. Abbreviations used: * ALAN- = Natural
 day time lighting only (without artificial light at night) treatment. *
 ALAN+ = Natural day time lighting + Artificial light at night treatment. *
 High = High nutrient treatment. * Low = Low nutrient treatment. * Comp- =
 No-competition treatment. * Comp+ = Competition treatment.
 #########################################################################
 (2) DATA-SPECIFIC INFORMATION FOR: Root-Shoot ratio.xlsx 1. Number of
 variables: 15 2. Number of cases/rows: 137 3. Variable List: * Species:
 five invasive alien, five naturalized alien, and seven co-occurring native
 ornamental plant species. * Family: taxonomic family identity of each of
 the 17 plant species. * Alien status: whether the plant is alien or native
 to Kenya. * Invasive status: whether the plant is an invasive alien,
 non-invasive naturalized alien, or native. * Life cycle: plant longevity.
 * Clonality: reproduction mode of the plants. * Growth form: whether the
 plant is herbaceous or shrubby. * Photosynthetic pathway: carbon
 assimilation pathway of the plant. * Plot number: plots where the
 experimental plants were grown.\*Light: light treatment in the plots
 (ALAN- vs ALAN+). * Nutrient: nutrient treatment in the pots (low nutrient
 vs high nutrient). * Competition: competition treatment in the pots (each
 of the 17 species was grown in the absence of competition vs under
 competition). * Mean: mean root/shoot ratio for each plant under factorial
 combinations of light, nutrient, competition, and invasive status
 treatments. * SD: standard deviation associated with each mean. * n=
 sample size for each factorial combination of light, nutrient,
 competition, and invasive status treatments. 4. Missing data: None 5.
 Abbreviations used: * ALAN- = Natural day time lighting only (without
 artificial light at night) treatment. * ALAN+ = Natural day time lighting
 + Artificial light at night treatment. * High = High nutrient treatment. *
 Low = Low nutrient treatment. * Comp- = No-competition treatment. * Comp+
 = Competition treatment. * NA = Not available.
 #########################################################################
 (3) DATA-SPECIFIC INFORMATION FOR: Height.xlsx 1. Number of variables: 15
 2. Number of cases/rows: 137 3. Variable List: * Species: five invasive
 alien, five naturalized alien, and seven co-occurring native ornamental
 plant species. * Family: taxonomic family identity of each of the 17 plant
 species. * Alien status: whether the plant is alien or native to Kenya. *
 Invasive status: whether the plant is an invasive alien, non-invasive
 naturalized alien, or native. * Life cycle: plant longevity. * Clonality:
 reproduction mode of the plants. * Growth form: whether the plant is
 herbaceous or shrubby. * Photosynthetic pathway: carbon assimilation
 pathway of the plant. * Plot number: plots where the experimental plants
 were grown.\*Light: light treatment in the plots (ALAN- vs ALAN+). *
 Nutrient: nutrient treatment in the pots (low nutrient vs high nutrient).
 * Competition: competition treatment in the pots (each of the 17 species
 was grown in the absence of competition vs under competition). * Mean:
 mean height (cm) of each plant under factorial combinations of light,
 nutrient, competition, and invasive status treatments. * SD: standard
 deviation associated with each mean. * n= sample size for each factorial
 combination of light, nutrient, competition, and invasive status
 treatments. 4. Missing data: None 5. Abbreviations used: * ALAN- = Natural
 day time lighting only (without artificial light at night) treatment. *
 ALAN+ = Natural day time lighting + Artificial light at night treatment. *
 High = High nutrient treatment. * Low = Low nutrient treatment. * Comp- =
 No-competition treatment. * Comp+ = Competition treatment. * NA = Not
 available.
 #########################################################################
 (4) DATA-SPECIFIC INFORMATION FOR: Flowered plants.xlsx 1. Number of
 variables: 15 2. Number of cases/rows: 137 3. Variable List: * Species:
 five invasive alien, five naturalized alien, and seven co-occurring native
 ornamental plant species. * Family: taxonomic family identity of each of
 the 17 plant species. * Alien status: whether the plant is alien or native
 to Kenya. * Invasive status: whether the plant is an invasive alien,
 non-invasive naturalized alien, or native. * Life cycle: plant longevity.
 * Clonality: reproduction mode of the plants. * Growth form: whether the
 plant is herbaceous or shrubby. * Photosynthetic pathway: carbon
 assimilation pathway of the plant. * Plot number: plots where the
 experimental plants were grown. * Light: light treatment in the plots
 (ALAN- vs ALAN+). * Nutrient: nutrient treatment in the pots (low nutrient
 vs high nutrient). * Competition: competition treatment in the pots (each
 of the 17 species was grown in the absence of competition vs under
 competition). * Mean: mean proportion of individual plants that flowered
 under factorial combinations of light, nutrient, competition, and invasive
 status treatments. * SD: standard deviation associated with each mean. *
 n= sample size for each factorial combination of light, nutrient,
 competition, and invasive status treatments. 4. Missing data: None 5.
 Abbreviations used: * ALAN- = Natural day time lighting only (without
 artificial light at night) treatment. * ALAN+ = Natural day time lighting
 + Artificial light at night treatment. * High = High nutrient treatment. *
 Low = Low nutrient treatment. * Comp- = No-competition treatment. * Comp+
 = Competition treatment. * NA = Not available
 #########################################################################
 (5) DATA-SPECIFIC INFORMATION FOR: Flower number.xlsx 1. Number of
 variables: 15 2. Number of cases/rows: 137 3. Variable List: * Species:
 five invasive alien, five naturalized alien, and seven co-occurring native
 ornamental plant species. * Family: taxonomic family identity of each of
 the 17 plant species. * Alien status: whether the plant is alien or native
 to Kenya. * Invasive status: whether the plant is an invasive alien,
 non-invasive naturalized alien, or native. * Life cycle: plant longevity.
 * Clonality: reproduction mode of the plants. * Growth form: whether the
 plant is herbaceous or shrubby. * Photosynthetic pathway: carbon
 assimilation pathway of the plant. * Plot number: plots where the
 experimental plants were grown. * Light: light treatment in the plots
 (ALAN- vs ALAN+). * Nutrient: nutrient treatment in the pots (low nutrient
 vs high nutrient). * Competition: competition treatment in the pots (each
 of the 17 species was grown in the absence of competition vs under
 competition). * Mean: mean number of flowers per plant under factorial
 combinations of light, nutrient, competition, and invasive status
 treatments. * SD: standard deviation associated with each mean. * n=
 sample size for each factorial combination of light, nutrient,
 competition, and invasive status treatments. 4. Missing data: None 5.
 Abbreviations used: * ALAN- = Natural day time lighting only (without
 artificial light at night) treatment. * ALAN+ = Natural day time lighting
 + Artificial light at night treatment. * High = High nutrient treatment. *
 Low = Low nutrient treatment. * Comp- = No-competition treatment. * Comp+
 = Competition treatment.