Comparison of Changes in OakSaw Palmetto Scrub Openings

1
Comparison of Changes in Oak-Saw Palmetto Scrub
Openings

• Antonnine R. Cooper
• Oakwood College
• Principal Investigator Paul Schmalzer
• Dynamac Corporation

2
Initial Description

• By comparing data, including area and species
  composition, before and after a prescribed burn,
  management of the scrub is possible. Results
  showed that Galactia elliottia was one of the
  first species to respond in terms of growth. The
  area of recently burned openings was much greater
  than that of the previously burned openings.
  This knowledge can help with the management of
  scrub.
• Right Measuring vegetation cover along the
  major axis of the elliptical opening.

3
Main Story

• Background
• Management of the oak saw palmetto scrub is
  critical for the survival of several endangered
  species, like the Florida Scrub Jay (Aphelocoma
  coerulescens), and the gopher tortoise (Gopherus
  polyphemus). Scrub vegetation varies depending
  on the region, yet it also varies locally within
  regions (Myers 1990, Schmalzer 1999). Evergreen
  oaks, palmettos, and vines dominate the
  vegetation of scrub in Florida (Myers 1990,
  Schmalzer 2003). This environment is naturally
  controlled by fires caused by frequent lightning
  strikes. At Kennedy Space Center (KSC), these
  fires are simulated by conducting prescribed
  burns. Piles of oak stems help to burn the scrub
  during this restoration process. These piles
  cause openings to appear within the scrub.
  Prescribed burning of scrub vegetation at the
  study site on Kennedy Space Center (KSC)/ Merritt
  Island National Wildlife Refuge (MINWR) began in
  1993.
• Methods
• The location of this study was two areas between
  State Route 3 and WSEG Rd. There was a total of
  eleven openings, seven of which burned this past
  May. The lengths of the major and minor axes of
  these openings were measured to determine the
  area. The current area was measured by
  subtracting the encroachment length of
  surrounding vegetation. The species occurring on
  the major axis were also measured. Cover data
  were summarized as the percent cover of each
  species. The linear association between area and
  time since burning was analyzed by performing a
  Pearson Correlation. A paired sample t test
  was calculated to test for a significant
  difference (p 0.05) in areas remaining open
  before and after the last burn.

4
Results and Figures

• Results
• In 2003, after ten years of growth, Quercus
  geminata was the most abundant vegetation cover
  in openings (Figure 1).
• Galactia elliottii was the most abundant
  vegetation cover in openings after the 2004 burn
  (Figure 1).
• Opening area declined significantly from
  1993-2003 (Figure 2) Pearson Correlation
  coefficient r -0.626 with p value of 0.01.
• Openings that burned in 1993 but not 2004 (Figure
  3) did not differ significantly in open area
  between 2003 and 2004 (paired t- test, t 2.28,
  p gt 0.05, df 3).
• Openings that burned in 2004 (Figure 4) differed
  significantly in area remaining open between 2003
  and 2004 (paired t- test, t 3.77, p 0.05, df
  6).

Figure 1 Most Abundant Vegetation Cover
Figure 2 Trend of Opening Areas
Figure 3 Mean Area of Previously Burned Openings
Figure 4 Mean Area of Recently Burned Openings