Journal of Student Research 2023

Tamarack Restoration in a Wetland Reserve Property: Comparison with a Natural Reference Site 13 Data Analysis The density of tamaracks and other woody species was calculated in stems per square meter for each plot. A scatter plot was made to show the relationship between water depth and tamarack size. Spearman’s rank correlation was used to assess the relationship between tamarack size and water depth at Muddy Creek. A two-sample t-test was used to compare mean non-tamarack stem densities at Downsville Wetland and Muddy Creek. Results A greater number of tamaracks was measured at the planted site in Downsville, but these trees were, on average, smaller in diameter than the trees at Muddy Creek. The DBH of 217 tamaracks was measured in the planted stand in Downsville and 58 tamaracks at Muddy Creek. The mean DBH was 6.41 cm (+/- 2.39 SD) at the planted stand, 19.49 cm (+/- 9.57 SD) at the natural stand, and the median DBH was 6.3 cm and 18.7 cm, respectively. Table 1: Summary statistics of data collected at the planted Downsville site and the natural Muddy Creek site.

Downsville

Muddy Creek

6.41 (2.39)

19.49 (9.57)

Mean DBH (S.D.) (cm) Median DBH (cm) Minimum DBH (cm) Maximum DBH (cm) DBH range (cm) Stem count (<1 cm) Stem count (1-2 cm) Stem count (>2 cm)

6.3 1.3

18.7

4.9

11.6 10.3

51.9

47

0 7

0 1

210 217 196

57 58 58

Total stem count

Stem count with cones

0

2

Dead stem count

Mean count of non-tamarack woody species (S.D.) Mean standing water depth (S.D.) (cm)

4.05 (5.77)

23.85 (9.88)

10.37 (2.14)

The range of size for individuals varied greatly between the two stands. The natural tamarack stand had a much wider range of DBH measurements (47cm) compared to the planted stand (10.3 cm, Table 1, Figure 3). Muddy Creek contained a small number of large trees while the Downsville Wetland showed a normal distribution centered around a much larger mean size (Figure 3).