Characteristics and spatial pattern of old-growth forests in the midwest
Abstract
This research examined old-growth forests in the midwest to determine long-term dynamics, spatial relationships, differences from second-growth forests and to determine characteristics of old-growth in Indiana, Illinois, Missouri and lowa. The first phase examined woody biomass in a midwestern old-growth forest over 270 years. Results indicate two disturbances occurred, one around 1730 and one around 1824. In 1926 the biomass of 10-to-25 cm dbh trees was greater for early seral Quercus species than for Acer soccharum. This relationship reversed by 1992. Equilibrium patch size was estimated to be 0.64 ha. Dry weights of living biomass reached a maximum in 1981 of 220,220 kg/ha and decreased since due to mortality of dominant early seral trees. Based on these mortality rates, this forest could reach a steady-state phase by the year 2070. The second phase examined spatial and temporal relationships of old-growth and secondary forests in Indiana. Reforestation of riparian areas between secondary forests would reduce the number of forest fragments by 62%. All existing old-growth sites were isolated from each other. If current public forest management plans are followed, the area and number of old-growth forests will increase as relative isolation decreases. The third phase dealt with differences in characteristics between old-growth and second-growth forests in Indiana. Significant differences were found for forest structure, depth of soil A-horizon, standing deadwood volume, down deadwood volume and species. The fourth phase dealt with characterization of old-growth forests within Indiana, Illinois, Missouri and Iowa. For sites without recent wind disturbance in Indiana, Illinois and Iowa, basal area values were $>$25 m$\sp2$/ha. Most Missouri sites had basal areas $<$25 m$\sp2$/ha. Volume of deadwood, soil phosphorus levels, percent organic matter, soil A-horizon depth and dry weight of forest litter were variable among sites. Percent of cavities in living trees divided by cavities in all trees was 82%, SD = 9.4% among all sites. Age of dominant trees ranged from 75 years for a Missouri site to 336 years at an Indiana site.
Degree
Ph.D.
Advisors
Parker, Purdue University.
Subject Area
Forestry|Ecology
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