Cradle-knoll microtopography has been shown to influence soil and vegetation. However, the scale of commonly used topographic maps is too coarse for representation of microtopography. The objectives of this study were to investigate the influence of cradle-knoll microtopography on the distribution of trees, to develop a method to quantify the spatial patterns and characteristics of cradle-knolls, and to test for pattern similarity of cradle-knolls within and among drumlins in the Nicolet National Forest, Wisconsin. Six drumlins were selected for study. Tree species, tree diameter, and microsite location (e.g., cradle, knoll, or neither) within which each tree was found were inventoried in three, 10-m-radius plots across each drumlin. The spatial location, length, width, relief, and orientation of 220 cradle-knolls were inventoried along 200-m transects using a T-square sampling technique on summit and backslope positions of each drumlin. Sixty percent of the trees inventoried were growing on knolls and only 2% were growing in cradles. The same number of knolls and cradles occurred among drumlins and among backslopes and summits within drumlins. Cradle-knoll relief differed among drumlins, and knoll relief is greater on backslopes than on summits within drumlins. Cradle-knoll orientation differed among slops positions. These findings suggest that treethrow rates and the size of the uprooted trees are roughly the same among and within drumlins. Differences in relief among drumlins are probably an indication of how recently treethrow has occurred. Greater relief of knolls among backslopes and summits is probably because of slope-mediated differences in cradle-knoll formation. Slope position also affects cradle-knoll orientation in these landscapes.
|Original language||English (US)|
|Number of pages||9|
|Journal||Soil Science Society of America Journal|
|State||Published - Jan 1 1997|
ASJC Scopus subject areas
- Soil Science