Origin of White Pine in Virgin Forest Stands of Northwestern Pennsylvania as Indicated by Stem and Basal Branch Features

Abstract

It is common knowledge that white pine, Pinus strobus L., was an important component of the primeval forests in northwestern Pennsylvania. It appears that the species generally occurred as scattered individuals in mixture with hemlock and hardwoods but occasionally formed pure or nearly pure stands. In view of the inability of white pine to satisfactorily reproduce and develop under dense canopies of species such as hemlock, beech and sugar maple, the question naturally arises as to how it originated in the virgin stands. Did the virgin white pine originate on relatively open forest sites, as pure pine stands commonly do today, or did it develop under relatively open forest canopies? Heretofore, so far as is known to the writers, there has been no direct attempt to answer this question.The methods employed in the investigation here reported consisted essentially in comparing stem and basal branch features of pines which developed in virgin forest stands with the features of pines now developing ( 1) on open sites such as clear cut or old field areas and ( 2) on sites which support a somewhat open forest stand (density usually 0.3 to 0.6, which appears to be about the maximum density under which white pine is capable of development). All trees employed in the study developed on similar welldrained soils in the same general climatic region.Data representing virgin forest conditions were obtained from two localities in northwestern Pennsylvania, namely, Heart's Content and Ludlow. At Heart's Content the pine occurred as scattered individuals in a virgin hemlockbeech stand. Based on the number of individuals in the dominant tree class white pine had an abundance of approximately 11 per cent ; there were about 7 pine trees per acre. At Ludlow the virgin stand contained a considerably larger proportion of pine; in fact it must have approached a pure pine forest over portions of the area. The average number of pine trees per acre was about 20. From the standpoint of size the pines in these two virgin stands were similar.

Disturbance History and Historical Stand Dynamics of a Seasonal Tropical Forest in Western Thailand

“…Architectural analysis.-Individual tree form can provide important information on historical growing conditions and can be particularly informative when comparing species with similar growth patterns (Lutz andMcComb 1935, Kohyama 1980). Two approaches were used to characterize individual tree architecture.…”

Surveyor and analyst biases in forest density estimation from United States Public Land Surveys

“…Echoing anecdotal testimony of old‐time and modern surveyors (Bourdo, 1956; Gordon, 1969; Lutz, 1930), there is a persistent belief that surveyors favored certain species as witness trees (Grimm, 1984; Liu et al, 2011; Manies et al, 2001; Whitney, 1994). Yet, if all chosen trees were the nearest to the corner in their sectors, the sample is by definition unbiased for species composition.…”

“…Proposed reasons for surveyor bias are varied: subjective choice of trees (Sears, 1921, 1925); tree size (Kenoyer, 1930); species (Lutz, 1930; Shanks, 1938); economic value (Lutz, 1930); longevity (Cottam & Curtis, 1949); quadrant position (Bourdo, 1956); ease of marking (Bourdo, 1956); spatial pattern of the trees (Bourdo, 1956; Siccama, 1971); age (Grimm, 1981); conspicuousness (Grimm, 1981); tree health (Almendinger, 1996); bearing (Manies, 1997); or ease of locating (Schulte & Mladenoff, 2001). Eric Bourdo, uniquely qualified as both a surveyor and an ecologist, presented the definitive exploration of PLS surveying techniques in Michigan and the potential for bias in surveyor selection of witness trees (Bourdo, 1954, 1956).…”

Using witness trees as pyro-indicators to depict past fire environments across the eastern United States

“…Given the enormity of work needed to transcribe and interpret hardcopy data, early studies of witness trees understandably focused on reconstructing tree composition (Sears 1921;Lutz 1930). By connecting quantitative witness-tree data to qualitative field notes taken along transects, investigators were able to derive forest stand maps (Sears 1925;Kenoyer 1929Kenoyer , 1933Kenoyer , 1939Kenoyer , 1942 or prairie locations (Sears 1926;Wackerman 1929).…”