RESULTS


 HUMMOCK-TO-HUMMOCK COMPARISON


 Change in Cross-Sectional Area

 The change in cross-sectional area of each hummock measured along the major
 and minor transects was intended to show the amount of erosion or settling in each soil
 type used in hummock construction. Figure 5.6 shows the percent change in cross-
 sectional area for the hummocks in the Agrifos wetland. The changes shown are averages
 for each hummock type. A decrease in percent change from the first sampling period to
 the last sampling period indicates a continued soil shifting throughout the first growing
 season after construction. The hummocks constructed from organic matter show the
 largest decrease in cross-sectional area along both the major and minor transects. By the
 last sampling period (1999), the organic hummocks showed a change around -6.00%
 from the original height. Overburden hummocks were next, with a change of around -
 4.00%. Sand hummocks showed the least amount of change with a shift of -2.50%.
 Sampling during the summer of 2000 revealed continued decreases in cross-sectional
 area. Organic hummocks still showed the greatest decrease at -16.0%. Sand hummocks
 showed an average decrease of slightly greater than 6.0%. Although still decreasing in
 cross-sectional area, the magnitude of the change decreased in overburden hummocks
 (less than -2.0%).

 Figure 5.7 shows the percent change in cross-sectional area for the Cargill
 wetland. After the first season, there was little difference between organic and
 overburden hummocks. After the second season, there appears to be larger decreases in
 overburden hummocks than organic hummocks. This is particularly apparent along the
 minor transect.

 Figure 5.8 shows percent change in cross-sectional area for the Iluka Resources
 wetland. This mature site has hummocks constructed only from overburden. These
 appear to show a slight increase in area by the end of the growing season. Along the
 major transect, the increase is about 1.00%. Along the minor transect, the increase is
 around 4.00%. The purpose of this figure is to that show after the initial negative shifting
 of the hummock soil seen in above figures, a growth or stability of the hummock occurs.


 Species Diversity

 Species diversity indices were intended to show the differences in the ability of
hummocks to support understory vegetation. Table 5.1 shows the species diversity as a
simple species count and as a Shannon index for each hummock type and each sampling
period. Included is a percent cover of vegetation on the hummocks. In the Agrifos
wetland, the overburden hummocks have the highest number of species during the first


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