Friday, August 9, 2019

"White Oak(Quercus alba) dominated the pre-European settlement(prior to 1780's) forests of southwestern Pennsylvania, eastern Ohio and central West Virginia"..........."20th century reduction in fire frequency resulted in reduced oak abundance and accelerated recruitment of fire intolerant species such as Red Maple(Acer rubrum"..................."Based on witness tree data, the presettlement forests were primarily oak forests"........... "White oak was dominant by a large margin; on average, black oak was the second most abundant species and, notably, much more important than northern red oak".......... "Shade tolerant species, particularly red maple, were much less abundant than in current inventories"................"For the one area where size distribution data are available, the structure of this forest suggests a variable disturbance regime that allowed trees of all shade tolerances and growth strategies to occupy the overstory"................"For the counties of this study, forest clearing was at least initially more closely tied to early settlement patterns and local economies"................"Although some intensive logging occurred in the study area in connection with the charcoal industry and the extension of the railroads, the processes of forest clearing for agriculture, fire, and grazing were well underway by the time the most intensive logging operations of the late 1800s occurred elsewhere in the region"..............."Thus human disturbances began earlier, lasted longer, and varied in intensity; but their impact on forest composition was no less significant, and continued into the early 20th century when clearing of second growth forests, as well as invasive insects and disease, further altered forest composition and structure"............... "By the time of the most current forest inventories, significant shifts in species composition and dominance became evident"............."This change was marked by a significant increase in early successional species such as yellow-poplar, red maple, and black cherry that thrived in a high light environment where a combination of fire suppression, deer herbivory, and high levels of understory shade had reduced the potential for oak success"

http://community.wvu.edu/~jrentch2/pub4.pdf

Changes in Presettlement Forest Composition for Five Areas in the Central Hardwood Forest, 1784-1990 

James S. Rentch1 Ray R. Hicks, Jr.2 Division of Forestry West Virginia University P. O. Box 6125 Morgantown, WV 26506; 2005

Study Area: Eastern Ohio, south western Pennsylvania and 
north-central West Virginia










































ABSTRACT: Witness tree tallies from early land surveys show that presettlement forests in eastern Ohio, southwestern Pennsylvania, and north central West Virginia were oak-dominated forests. Quercus alba(White Oak) was dominant by a large margin – at minimum, twice as abundant as Q. velutina(Black Oak), the second ranked species. Acer saccharum(sugar Maple) and Fagus grandifolia(American Beech) were among the top ten ranked species at each site; however, their importance value was consistently less than one-third the value for Q. alba.

White Oak leaves are round-lobed(not cut like red oak)



















Quercus rubra(red oak), Q. prinus(chestnut oak), Castanea dentata(American Chestnut), and A. rubrum(red maple) were relatively minor components of presettlement forests, rarely ranked among the 10 most abundant tree species. Where diameter-distribution data were available, results show that oaks were well distributed among all but the smallest size classes, suggesting that oak replacement was a stable feature of these forests.

The majestic White Oak















 Multiple response permutation procedure analysis of pre-settlement and modern U.S. Forest Service Forest Inventory analysis (FIA) data shows a clear separation by historical period. Modern inventories consistently show a significant decline in Q. alba abundance and a large increase for A. rubrum. Other early successional species such as Prunus serotina(black cherry), Liriodendron tulipifera(tulip tree), and Fraxinus americana(American Ash) showed large increases, although this trend varied somewhat among the sites studied.

The red maple leaf(and forest below)







































The species composition of presettlement forests suggests a highly variable disturbance regime in which a variety of species with different life history strategies, disturbance tolerances, and growth requirements shared overstory position. Changes in species dominance over the time period reviewed suggest that 20th century reduction in fire frequency resulted in reduced oak abundance and accelerated recruitment of fire intolerant species.

No comments:

Post a Comment