DOI: 10.6073/pasta/f2f96ec76fbbd4b9db431c79a770c4d5
title: Survival, growth and biomass estimates of two dominant palmetto species of south-central Florida from 1981 - 2017, ongoing at 5-year intervals

description: This data package is comprised of three datasets all pertaining to two
  dominant palmetto species, Serenoa repens and Sabal etonia, at
  Archbold Biological Station in south-central Florida. The first
  dataset, palmetto_data, contains survival and growth data across
  multiple years, habitats and experimental treatments. The second
  dataset, seedlings_data, follows the fate of marked putative palmetto
  seedlings in the field to assess survivorship and growth. The final
  dataset, harvested_palmetto_data, contains size data and estimated dry
  mass (biomass in grams) of 33 destructively harvested palmetto plants
  (17 S. repens and 16 S. etonia) of varying sizes and across habitats.
  Thirty-two of these were used to calculate estimated biomass, using
  regression equations, for palmettos sampled in the palmetto_data.
  Below we summarize experimental setup and data collected for each
  dataset.

      
        Palmetto data
      
      
  Demographic data were collected as three separate components. The
  first component compared growth among habitats. Starting in 1981,
  equal numbers of both palmetto species were marked across scrubby
  flatwoods (oak scrub) and flatwoods habitats (3 sites per habitat) for
  a total of 240 marked plants. These habitats had not burned within the
  last decade, but historically had experienced a natural fire return
  interval of 5 - 20 years prior to this studies initiation. The second
  component added an additional 400 palmettos (200 of each species),
  which were marked in sand pine scrub (n = 200) in 1985 and sandhill
  habitat (n = 200) in 1989 on Archbold's Red Hill. At the time of this
  project's initiation, all Red Hill management units were last burned
  in 1927 and were considered long unburned. Part of Archbold's
  management plan included restoring fire into some management units
  while leaving others long unburned to serve as reference units.
  Therefore, for our second component, we were able to create a 2x2
  factorial design using habitat types on Red Hill and fire management
  as factors, with 100 palmettos in each category (50 of each species).
  The third component involved an experiment to examine the factorial
  effects of clipping and fertilizing on palmetto flowering. We marked
  300 palmettos (150 of each species), all in sand pine scrub habitat on
  Red Hill, and used the 100 palmettos marked in 1985 as controls.

      
  Annual data measures included height, canopy length and width (all in
  cm), number of new and green leaves and flowering scapes. Data were
  collected continuously (not for all variables or sites) from 1981
  through 1997 then again in 2001 and 2017. Data collection is ongoing
  at 5-year intervals. Data on the 100 plants in the experimental
  sandhill on Red Hill were not collected in 2017 due to the removal of
  marked stakes from roller chopping of the site as part of more recent
  sandhill restoration efforts. A subset of the plants in the clipping
  and fertilizing experiment were lost in 2013 when a plow line was
  established to stop the spread of a wildfire. The locations of all
  remaining plants were taken in 2017 using a Trimble GPS unit and are
  included as a separate data file (palmetto_location_data) and
  shapefile (palmetto_shape).

      
        Seedling data
      
      
  In January 1989, we marked 100 putative seedlings in flatwoods
  habitats and 87 in scrubby flatwoods habitats. Putative seedlings
  typically cannot be identified using morphology as either S. repens or
  S. etonia so sample sizes of each are unknown. Annual data recorded
  included survival, standing height (cm) and maximum crown diameter
  (cm). In 1991, we started measuring basal stem diameter (cm) with
  calipers. During annual visits, we noted if the species could be
  identified as S. repens or S. etonia. Data were collected continuously
  starting in 1989 through 1997, then again in 2001 and 2008. Data
  collection is not ongoing for this dataset.

      
        Harvested Palmetto data
      
      
  Thirty-three palmettos, 17 S. repens and 16 S. etonia, were
  destructively harvested at three different sites, from two habitats
  (scrubby flatwoods and sand pine scrub) in 1985. Basic size measures
  as taken for palmetto demography data were recorded including height,
  canopy length and width (all in cm) and the number of green leaves.
  Additional data measures were recorded on the largest leaf blade
  including maximum length and width of the palmetto leaf and petiole
  length and width. Finally, basal diameter at the ground level was
  recorded. Only 32 palmettos were used to develop biomass regressions
  (17 S. repens and 15 S. etonia).

      
  Biomass is the estimated dry mass (g) of each harvested palmetto.
  Fresh palmettos were divided into leaf and stem (both above- and
  below-ground), but roots were not harvested since they grow to depths
  of several meters, making recovery of all root tissues virtually
  impossible for fresh-mass determination. Subsamples of fresh mass were
  oven dried at 80C to constant mass for estimation of dry mass
  equivalent, which in turn was used to estimate the dry mass of the
  harvested palmettos.