Growth and demography of Quercus coccinea and Q. prinus ramets and genets after clearfelling

Growth and mortality of ramets (stump sprouts) and genets (sprout clumps) of scarlet and chestnut oak were examined on three sites at ages 1-2 (YRI-2), 4-5 (YR4-5) and 7-8 (YR 7-8). Based on a test of the older site with the younger using 2-year-old data, it was concluded that the two populations do not represent a chronosequence and stands of scarlet and chestnut oak sprouts cannot be matched up on the basis of site characteristics. Both species exhibited variation in ramet growth rate and efficiency among the sites: diameter growth was higher in the 4-5 and 7-8 year-old stands than in the 1-2 year-old stand, whereas relative growth rate and efficiency was highest for both species in the youngest stand. Ramet growth increased with site quality at ages seven and eight, but more in chestnut oak than in scarlet oak. Percent mortality of ramets declined steadily with age of the stand, dropping from 21 % at YRI-2 to 11 % at YR 7-8. In contrast, none of the genets died over the two-year observation period. Diameter growth and survival models were developed for YRI-2, YR4-5 and YR 7-8. The most common predictors were initial size of the stem or genet. Competition-related variables were important in every ramet growth equation and clump attributes were consistently important for predicting ramet survival. The number of surviving stems per genet was strongly linked to the number present at the beginning of the period. Despite numerous similarities, significant differences between species were noted at the ramet (population) level. These differences included size, response to site quality, efficiency and the importance of stem-to-stem competition. Examination of the two genet populations, as represented by an aggregate of all genets, indicated only slight differences between the species. There were virtually no differences for the four- or seven- year-old genets in size or efficiency attributes. In addition, clump size and clump density prediction equations did not differ between the species. In contrast, some of the structural attributes of the genets varied between species. The most important differences were more widely spaced stems in scarlet oak clumps and larger crowns for chestnut oak. The differences between species and between clumps within a species appear to compensate for one another and thus these clumps converge to a common structure by year four-to-eight. Three measures of the shape of diameter and length distributions indicated little difference between species. The diameter distribution was positively skewed at all three sites and the length distribution was positively skewed at YRl-2 but was near normal for the oldest site. Self-thinning within genets was slightly faster for scarlet oak and increased with site quality. The thinning lines had an average slope of approximately -0.9, which is similar to other clonal species, but deviates substantially from the -3/2 Thinning Line (Yoda et al. 1963).

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Forestry

Department dc:contributor.department

Forestry

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1988

Author dc:creator

• Cook, James E.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10919/109235

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/109235