Physiographic analysis of witness-tree distribution (1765–1798) and present forest cover through north central Pennsylvania

1995 ◽  
Vol 25 (4) ◽  
pp. 659-668 ◽  
Author(s):  
Marc D. Abrams ◽  
Charles M. Ruffner
Keyword(s):  
Forest Cover ◽  
Forest Composition ◽  
North Central ◽  
Tree Distribution ◽  
High Plateau ◽  
European Settlement ◽  
Central Pennsylvania ◽  
Witness Trees ◽  
Allegheny Mountains ◽  
Allegheny Plateau

This study analyzed witness-tree data recorded from 1765 to 1798 with respect to landform in four major physiographic provinces represented through north central Pennsylvania. These data were also compared with present-day forest composition to evaluate broad changes that occurred 200 years after European settlement. In the Allegheny High Plateau, Tsugacanadensis (L.) Carr. represented 40–47% of witness trees in mountain coves and stream valleys, but only 9% on plateau tops, which comprised 45% Fagusgrandifolia Ehrh. Pinusstrobus L. represented ≤4% frequency across all landforms. The original forests of the Allegheny Mountains were dominated by mixed Quercus, Acer, Castaneadentata (Marsh.) Borkh., and Pinus and had significant T. canadensis only in stream valleys. The presettlement forests of the Allegheny Front and the Ridge and Valley provinces had a similar mix of Quercus, Pinus, Castanea, and Carya, with increased P. strobus on the more mesic sites and Pinusrigida Mill, on the xeric ridges. Comparisons of presettlement with present-day forest composition indicate a dramatic reduction of T. canadensis (32% to 4%) and F. grandifolia (33% to 12%) in the High Plateau and increases in Acer (11% to 37%), Quercusrubra L. (0% to 10%), Prunusserotina Ehrh. (1% to 6%), and Betula (5% to 10%). Other units exhibited reductions in P. strobus, P. rigida, Quercusalba L., and Carya spp. and increases in Quercusprinus L., Q. rubra, Acerrubrum L., and P. serotina. Castaneadentata had its greatest abundance on higher elevation sites in each physiographic unit, and the elimination of this species this century apparently facilitated the increase in Q. prinus and Q. rubra on ridge sites. South of the Allegheny Plateau, increases in A. rubrum, P. serotina, and other mixed-mesophytic species may be in response to fire exclusion this century. The results of this study indicate the importance of landform and physiography on presettlement forest composition as well as the dramatic changes that have occurred as a result of altered disturbance regimes following European settlement.

Vegetation–site relationships of witness trees (1780–1856) in the presettlement forests of eastern West Virginia

1996 ◽  
Vol 26 (2) ◽  
pp. 217-224 ◽  
Author(s):  
Marc D. Abrams ◽  
Deanna M. McCay
Keyword(s):  
West Virginia ◽  
Forest Composition ◽  
Contingency Table Analysis ◽  
European Settlement ◽  
Table Analysis ◽  
Fire Exclusion ◽  
Witness Trees ◽  
Allegheny Mountains ◽  
Pinus Spp ◽  
Ridge And Valley

Witness tree data from 1780–1856 for the Monongahela National Forest in eastern West Virginia were analyzed with respect to physiographic unit (Ridge and Valley versus Allegheny Mountains) and landform, and compared with present-day forest composition. Contingency table analysis and standardized residuals were used to quantify the preference or avoidance of common tree species with various landforms. Pre-European settlement forests in the Ridge and Valley were dominated by mixed oak (Quercusalba L., Quercusprinus L., Quercusvelutina Lam. and Quercusrubra L.), Pinus spp., Castaneadentata (Marsh.) Borkh., and Carya on ridge sites and Q. alba, Acersaccharum Marsh., Pinus, Tiliaamericana L., and Tsugacanadensis (L.) Carr. on valley floors. The original forests in the Allegheny Mountains were dominated by Fagusgrandifolia Ehrh., T. canadensis, A. saccharum, Acerrubrum L., Betula spp., and Pinus, with predominantly Fagus–Tsuga–Pinus forests on mountain tops and Tsuga–Acer–Betula forests on valley floors. Compared with the presettlement era, present-day forests on both physiographic units lack overstory C. dentata and have decreased Pinus and (or) Q. alba. Species that have increased substantially following Euro-American settlement include Q. prinus, Q. rubra, Quercuscoccinea Muenchh., and A. rubrum in the Ridge and Valley and Prunusserotina Ehrh., A. rubrum, and Betula spp. in the Allegheny Mountains. These dramatic changes in forest composition were attributed to the chestnut blight (caused by Endothiaparasitica (Murrill) P.J. Anderson & H.W. Anderson), widespread logging, intensive wildfires, and more recently, fire exclusion.

Native American influences on the forest composition of the Allegheny Plateau, northwest Pennsylvania

2006 ◽  
Vol 36 (5) ◽  
pp. 1266-1275 ◽  
Author(s):  
Bryan A Black ◽  
Charles M Ruffner ◽  
Marc D Abrams
Keyword(s):  
Native American ◽  
Forest Type ◽  
Detrended Correspondence Analysis ◽  
Forest Composition ◽  
Tree Distribution ◽  
Archaeological Data ◽  
European Settlement ◽  
Tree Data ◽  
Allegheny Plateau ◽  
American Agriculture

We integrate witness tree distribution, Native American archaeological sites, and geological and topographic variables to investigate the relationships between Native American populations and pre-European settlement forest types on the Allegheny Plateau, northwest Pennsylvania. Detrended correspondence analysis of witness tree data separated the presettlement forests into oak–hickory–chestnut and beech–hemlock–maple communities. Oak, hickory, and chestnut forests were centered on Native American village sites. Using archaeological data, an index of Native American influence (NAI) was derived to reflect the intensity of Native American land use across the landscape. In a comparison among species, mean NAI value of oak, hickory, and chestnut trees was significantly higher than that of beech, maple, and hemlock. Logistic regression demonstrated that among geology type, landform, elevation, aspect, slope, and NAI, NAI was by far the most significant predictor of oak, hickory, and chestnut distribution. Although cause and effect of this relationship cannot be tested, we suggest that long-term Native American activity selected for the disturbance-adapted oak, hickory, and chestnut. We contend that Native American agriculture, burning, and resource extraction could have converted maple–beech–hemlock to oak–hickory–chestnut, or at least reinforced the dominance of this forest type.

scholarly journals Measuring changes in stress and vitality indicators in limed sugar maple on the Allegheny Plateau in north-central Pennsylvania

2002 ◽  
Vol 32 (4) ◽  
pp. 629-641 ◽  
Author(s):  
Philip M Wargo ◽  
Rakesh Minocha ◽  
Betty L Wong ◽  
Robert P Long ◽  
Stephen B Horsley ◽  
...  
Keyword(s):  
Soil Ph ◽  
Acer Saccharum ◽  
Sugar Maple ◽  
Soluble Sugars ◽  
North Central ◽  
Tree Vitality ◽  
Molar Ratios ◽  
Central Pennsylvania ◽  
Allegheny Plateau ◽  
Highly Correlated

A study established in 1985 in north-central Pennsylvania to determine effects of lime fertilization on declining sugar maple (Acer saccharum Marsh.) was evaluated in 1993 and showed that liming positively affected growth and crown vitality in sugar maple. This effect of lime on sugar maple offered an opportunity to assess other indicators of tree vitality and their response to lime additions. Foliar polyamines, starch and soluble sugars in root tissues, and cambial electrical resistance (CER) at breast height were evaluated. Foliar putrescine, soluble sugars, and CER decreased, while starch increased in lime-treated trees. Changes in these indicators were correlated with tree growth and crown vitality, which improved in limed plots. However, they were more highly correlated with lime-induced changes in foliar and soil elements and soil pH. Putrescine, soluble sugars, and CER decreased and starch increased, as Ca and Mg and molar ratios of Ca/Al and Mg/Mn increased and as Al and Mn decreased in both soil and foliage, and as soil pH increased. Results showed the beneficial effect of lime on tree vitality that was not reflected in visual assessments of crown vitality and demonstrated the potential utility of these physiological and biochemical measures as indicators of vitality in sugar maple.

The pre-European settlement forest composition of the Miramichi River watershed, New Brunswick, as reconstructed using witness trees from original land surveys

2008 ◽  
Vol 38 (5) ◽  
pp. 1159-1183 ◽  
Author(s):  
Mélanie Aubé
Keyword(s):  
New Brunswick ◽  
Riparian Forest ◽  
Abies Balsamea ◽  
Forest Composition ◽  
River Watershed ◽  
European Settlement ◽  
Tree Data ◽  
The Difference ◽  
Witness Trees ◽  
Definition Of

The goal of this investigation was to characterize the pre-European settlement forest composition of the Miramichi River watershed using witness trees to contribute to the definition of a baseline for assessing changes over time in the Acadian forest. The witness tree data were stratified by ecoregion and by ecosite, for the portions of the watershed that are in the Northern Uplands, Continental Lowlands, and Eastern Lowlands ecoregions of New Brunswick, as well as by riparian and inland forest; and pre-settlement forest composition (1787–1847) was compared with current forest composition (1998–2000). The witness tree data constitute evidence that a distinctive riparian forest existed before European settlement and that the difference between riparian and inland forest has lessened. They show that the proportions of Betula spp., Tsuga canadensis (L.) Carrière, Ulmus americana L., and Thuja occidentalis L. have decreased; that the proportion of Acer spp. has increased and that Picea spp. and Abies balsamea (L.) Mill. var. balsamea have maintained their overall dominance of the forest in number of individuals, and have increased it on at least 50% of the watershed area.

scholarly journals First Report of Fenhexamid-Resistant Botrytis cinerea Causing Gray Mold on Heurchera in a North American Greenhouse

Plant Disease ◽  
2012 ◽  
Vol 96 (1) ◽  
pp. 147-147 ◽  
Author(s):  
G. W. Moorman ◽  
A.-S. Walker ◽  
S. May
Keyword(s):  
Botrytis Cinerea ◽  
Mode Of Action ◽  
Gray Mold ◽  
North Central ◽  
First Report ◽  
Group I ◽  
Central Pennsylvania ◽  
Commercial Operation ◽  
Penn State ◽  
Botryotinia Fuckeliana

Greenhouse-grown Heuchera plants, treated with fenhexamid (Decree, SePRO, Carmel, IN; FRAC group 17 hydroxyanilide), with active gray mold were submitted to the Penn State Plant Disease Clinic in December 2010 from a commercial operation in north-central Pennsylvania. Genetic and phenotypic analyses identified the isolate as Botrytis cinerea Pers. (teleomorph Botryotinia fuckeliana (de Bary) Whetzel), HydR3 phenotype (2) and not B. pseudocinerea (previously Botrytis group I) (4), naturally resistant to fenhexamid (phenotype HydR1) (1). While 0.2 μg of fenhexamid per ml or less is required to slow mycelial growth and germ tube elongation of sensitive isolates by 50% (EC50), the radial growth EC50 of the Heuchera isolate was approximately 2,000 μg of fenhexamid per ml in culture. Five cucumber seedlings receiving 25 μl of 0.1 M dextrose containing the label rate of Decree (1,800 μg/ml) on the growing tip were inoculated with colonized agar in the drop. Five check plants received 25 μl of 0.1 M dextrose. B. cinerea from silica gel storage since 1988 was also tested. This experiment was repeated three times. The 1988 isolate killed all fungicide-free but no fenhexamid-treated plants. The Heuchera isolate killed all fungicide-free and fenhexamid-treated plants within 4 days. To our knowledge, this is the first report of B. cinerea from a greenhouse in North America with fenhexamid resistance. Resistance occurs in U.S. fields (3). The Heuchera isolate's HydR3 resistance phenotype (2) has been detected in Germany, Japan, and France and has mutations affecting the 3-keto reductase protein, encoded by the erg27 gene, the specific target of fenhexamid and involved in Botrytis sterol biosynthesis. The Decree label states that it is to be used only twice on a crop before switching to a different mode of action. Greenhouses have resident Botrytis populations that are likely to be exposed to any fungicide applied in the structure. Growers should consider using fenhexamid only twice in a particular greenhouse, rather than on a particular crop, before switching to a different mode of action. References: (1) P. Leroux et al. Crop Prot. 18:687, 1999.(2) P. Leroux et al. Pest Manag. Sci. 58:876, 2002. (3) Z. Ma and T. J. Michailides. Plant Dis. 89:1083, 2005. (4) A.-S. Walker et al. Phytopathology 101:1433, 2011.

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