the vascular flora of the natchez trace parkway - NPS Inventory and ...

Table 5: Summary of Field Dates and Sampling Effort
Trip Field
Number of Days Number of Sites Sampled in Each Trip
% of Total
Dates
Spent in the Field
State
Total
TN AL MS
1 August 19 - 26, 2004 8 21 6 35 62 12.4
2 March 11 - 14, 2005 4 12 7 43 62 12.4
3 May 5 - 19, 2005 15 34 7 134 175 35.0
4 July 13 - 17, 2005 5 28 4 76 108 21.6
5 October 16 - 21, 2005 5 7 3 83 93 18.6
Total sites sampled in each state 102 27 371 500
Percentage of total sites sampled in each state 20.4 5.4 74.2
Percentage of NATR in each state1 1 Figures from Table 1
23.0 7.4 69.6
Although the actual number of specimens collected on each trip was not analyzed, and regardless
of individual trip length, the March and July field dates produced lower numbers of collections while the
May, August, and October trips produced a larger number of collections. Several factors may have
impacted individual collection success on any given trip, i.e., local temperatures and rainfall. However, with
the exception of the August field dates, one consistent factor is believed to have contributed significantly to
differences in collecting success.
While it is understood that the nature of the NATR is largely a “scenic roadway”, maintenance of
the roadsides and adjacent prairies often prevented the flora of these sites from developing to the point
where representative plant specimens were collectable. The regular maintenance (mowing) of the
roadsides and many open prairie sites for aesthetic or agricultural reasons most likely resulted in lower
collection success during each trip, and of the inventory overall. Figures 8 and 9 illustrate this point. The
photograph in figure 8 was taken on the August 2004 trip and shows a diverse mix of vegetation that is well
developed. The photograph in Figure 9, taken on the July 2005 trip, shows the local vegetation removed to
the point where no collectable material was present. During the course of the inventory this scene was
repeated throughout the length of the NATR on both the roadsides, and the prairie sites. In many such
instances, the only collections made at any given site were done on one trip only. Subsequent trips,
scheduled to account for different flowering periods, yielded no collection from the same site.
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