Abstract
The Interior Highlands physiographic province of Arkansas is considered the ecological center of the geographic distribution of shortleaf pine (
Pinus echinata Mill.). I used data from the U.S. Forest Service, Forest Inventory and Analysis (FIA) program to identify the major tree species associates of
P. echinata across this 66,700-km
2 landscape. Across the region, 41,207 km
2 were covered by timberland. The study population was represented by 434 relatively undisturbed upland sample plots from the 1995 forest survey of Arkansas.
P. echinata ≥12.7 cm in diameter at breast height (DBH) occurred on 211 of these sample plots. Additionally, it ranked first in basal area on 119 plots, second on 39 plots, and third on 19 plots. Where
P. echinata was dominant, stand basal area averaged 23.1 m
2 ha
-1 (±0.57 SEM). I used chi-square to test for degree of association between the stand dominants and to test for positive and negative associations. There was a positive association between
P. echinata and
Quercus alba L. (X
2 = 0.490; 1df). In contrast, there was a negative association between
P. echinata and
Q. velutina Lam. (X
2 = 15.571; 1df). These results demonstrate that the chisquare test of association is effective even on the larger scales of sampling where lack of sample homogeneity may sometimes complicate analysis. Such quantitative tests for species associations offer meaningful insights into
P. echinata communities at the landscape scale of sampling.
Parent Publication
Citation
Rosson, James F., Jr. 2007. Tree species associations of
Pinus echinata mill. over a large-scale sampling regime on the interior highlands of Arkansas. In: Kabrick, John M.; Dey, Daniel C.; Gwaze, David, eds. Shortleaf pine restoration and ecology in the Ozarks: proceedings of a symposium; 2006 November 7-9; Springfield, MO. Gen. Tech. Rep. NRS-P-15. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station: 76-87.
