| Popis: |
A mixed pine-oak stand in the Turkey Creek Unit of the Big Thicket National Preserve was logged in 1929-1930 and has experienced no fires since at least 1974. Stand basal area, density, and species richness increased from 1980-1993. A stage projection of the longleaf pine population at the site indicates the population will slowly decline ($\lambda$ = 0.9957) after an initial increase in population size as the population approaches stable size class distribution. Survivorship in the largest size class, 50+ cm dbh, had the largest effect on the outcome. Variations on the base model with potential stronger negative effects from fire suppression reduced $\lambda$ only slightly. Alternatively, small changes in demographic characteristics reflecting positive effects of fire raised $\lambda$ above 1.00. The modeling results suggest that the population is resilient to long-term unfavorable conditions because of the longevity of individual trees. |
