Characteristics of transplants, recruits and mother plants of Minuartia smejkalii
Data files
Dec 26, 2025 version files 422.57 KB
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Minuartia_data_characteristics.csv
419.99 KB
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README.md
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Abstract
Many habitat-specialist plant species have been endangered by the fragmentation or destruction of their habitats. We evaluated two conservation methods to reinforce M. smejkalii populations: sowing seeds collected from natural populations and transplanting pre-grown individuals in three consecutive years to sites currently or recently occupied by the species. We checked for seed emergence (recruitment) and followed the survival and performance of the transplants and recruits to identify factors responsible for the establishment success for up to three years after transplantation. Recruitment from sown seeds was unsuccessful, but overall, 83% of transplants survived the first year and 49% until the third year. Survival depended on the year of transplantation, the size of the transplanted individual, and the mother plant's characteristics. Mother plant characteristics were important for growth and flowering in the first year, but not for survival. Across years, initial size and age were more important for the size and number of flowers than mother plant identity. Population differences had a larger effect on the size and number of flowers in the first year than across years. Seedlings established from seeds of the transplants in four of the five populations. This led, despite the mortality of transplants, to a four to six times larger population size after three years in two populations, compared to the number of transplanted individuals.
Dataset DOI: 10.5061/dryad.6wwpzgnct
Description of the data and file structure
We planted M. smejkalii individuals pre-grown ex situ at five sites (populations Z1, Z2, Z3, Z6, and Z7) from seeds collected in natural populations. We also recorded and recruited offspring in the following years.
The dataset includes measurements of mother plants that were used as seed source, of transplants before and after transplantation (their survival, size, number of flowers, relative growth rate,) and of recruits in their second vegetation season. Seeds were collected from mother plants in populations Z1 to Z6 in 2016, 2017 and 2018 to be used in the transplant experiment. The extant populations Z1, Z2, Z3 and Z6 received transplants from local seeds. The extinct Z7 received transplants from Z2, Z3, Z4 and Z5 to maximize genetic variability.
Files and variables
Minuartia_data_characteristics.csv
Variables:
- Year_transplantation: year in which transplantation was conducted (2017/2018/2019), recruits have NA here
- Year_after_transplantation: number of years after the transplantation was conducted (2018/2019/2020)
- Transplanted: was the individual transplanted? (Y/N)
- Plant_ID: unique identifier of each transplant or recruit
- Population: population, in which the transplant or recruit was recorded (D1/D2/D3/D6/D7)
- Mother_ID: unique identifier of plant, from which the seeds for the transplants were obtained
- Mother_size: size (ellipse area of length and width) of mother plant [cm ²]
- Mother_flower_stems: number of flower-bearing stems of mother plant
- InitialSize: size (ellipse area of length and width) before transplantation or at first recording of recruits [cm ²]
- Size: size (ellipse area of length and width) at measurements after transplantation or in the second vegetation season of recruits [cm ²]
- RGR: relative growth rate [cm ² yr ⁻¹], can be negative due to die back and regrowth the following year
- Flowers: total number of flowers per individual (per population mean of flowers per stem determined by counting their number on ten stems with terminated growth per year then multiplied by number of stems per individual)
- Survival: was the plant alive (= present, no matter if dry or green) or not in the year of recorded data (1/0)
- NA indicates missing values
Code/software
Any text reader or any program that will open a spreadsheet, such as Excel is recommended.
Measurements
The length, width, and the number of flowering and non-flowering stems of each mother plant (which served as seed source) were measured in June in natural sites, and mother plant size was calculated as the area of an ellipse (because M. smejkalii grows predominantly vertically in separate stems, area is a better fitness estimate than plant height). We also counted the number of flowers on ten randomly chosen stems with terminated growth (dichotomous stem division) and multiplied this by the number of flowering stems to calculate the total number of flowers for each flowering plant. The number of flowers per individual stem was averaged per population and year. Prior to transplantation, we measured the maximum length and width of each plant to calculate plant size as above and determined if the plant was flowering or not. Plant characteristics in the years after transplantation were evaluated likewise at the time of flowering during June and July. The data collection was done at two levels: whole site and transects (permanent plots).
At the level of the whole site, we evaluated the status of each transplanted individual in the following years as flowering, non-flowering, dry, absent (but potentially still able to regenerate in the following years), and lost (when both plant and label could not be found). Survival was encoded as 0 or 1. Individuals were counted as alive (=1) if they could be found, even though they were dry at the time of observation. Individuals that were absent in one or two years but re-emerged in the next year were also counted as alive in the years they had been missing previously (0.26 % of total individuals). Absent individuals (no aboveground parts visible or disappeared for unknown reasons, including the tag) and did not re-grow later were considered dead (=0). Additionally, we counted the total number of newly recruited plants at the whole part of the site, where the transplantation had been done.
Transects with a width of two meters passed through the area of newly transplanted individuals and covered the heterogeneity of the environment, and at least 50% of the transplanted individuals, to reduce sampling effort in the years following transplantations. The transect length and number of transects per population were dependent on population size and plant distribution in the terrain. In these transects, we measured and calculated the same parameters as above (size, flowering, and non-flowering stems and flowers).
Recruits within the transects in the years after transplantation were numbered and tagged, and similarly recorded and measured in consecutive years as the transplanted individuals.
The relative growth rate (RGR) of individual plants was computed for each measurement time (tx, with x being 1, 2, or 3 years since transplantation) compared to the initial measurement before transplantation (t0)
RGR = [ln(Size_tx) - ln(Size_t0)] / [tx-t0]
