Effects of Landform on Site Index for Two Mesophytic Tree Species in the Appalachian Mountains of North Carolina, USA

Table 1

Mean and range of site index, soil, and topographic variables by species for stands sampled in the Southern Appalachian Mountains of North Carolina, USA.

Model	Red oak (𝑛=17)		Yellow-poplar (𝑛=14)
variables	Mean	Range	Mean	Range
Site index (m)	25.5	18–30	32	25–38
A-horizon thickness (cm)	15.8^a	8–36	22.1^a	8–41
Solum thickness (cm)	83.2^a	36–152	89.6^a	43–140
Elevation (m)	966.6^a	442–1329	909.4^a	646–1165
Aspect (deg)	159.3^a	45–330	186.3^a	10–355
Gradient (percent)	28.9^a	10–60	20.7^a	2–38
Landform index	0.133^b	0.01–0.27	0.225^b	0.08–0.38

^a Indicates no significant difference (𝑃<.05) between the two species.
^bIndicates significant difference (𝑃<.05) between the two species.