Witness Tree Data Research Articles

Native American landscape modification in pre-settlement south-west Georgia

ABSTRACT Our objective was to interpret the presence and magnitude of landscape modification by Native Americans on Georgia’s southern coastal plain. Specifically, we aimed to understand how the Native American presence influenced the distribution of fire-tolerant, mast-bearing and fruit-bearing tree species in the fire-dominated landscape of south-west Georgia. Our study area was comprised of sixteen contiguous counties in the south-west region of Georgia, in southeast USA bordering the Atlantic, investigating the taxon Angiosperms and Gymnosperms native to the early landscape of this region. We used witness tree data collected during the early 1820s across sixteen modern-day counties to reconstruct pre-settlement forest composition, particularly pyrophillic trees that are well-adapted to tolerate fire, and mast- and fruit-bearing species. We then used geographic distribution models (Boosted Regression Tree) to interpret the presence and magnitude of landscape modification by Native Americans on Georgia’s forested south-west plain. The pre-settlement distribution of pyrophillic and mast-bearing trees within our study area were best explained by a combination of environmental (topographic relief, proximity to riparian zones, and soil depth) and Native American factors (AUC = 0.64 and 0.66, respectively). However, the addition of Native American presence as predictors greatly increased the explanatory power of soft mast (fruit)-bearing models (AUC = +0.17). Our results demonstrate that Native American activities had a measurable influence on pre-settlement plant communities in south-western Georgia. However, the effects of these activities on vegetative composition were most notable in the distributions of fruit-bearing trees. In contrast, distributions of fire-tolerant and mast-bearing taxa were found to be largely explained by a combination of environmental and anthropogenic factors.

Habitat heterogeneity and life-history traits influence presettlement distributions of early-successional tree species in a late-successional, hemlock-hardwood landscape

In landscapes dominated by late-succes- sional plant communities, early-successional species may lead a tenuous existence, persisting only as fugitives or relying on refuges in marginal habitats to provide a persistent seed source. The objective of this study was to relate fine-scale distributions of early- successional tree species in hemlock-hardwood forests of northern Wisconsin, USA to potential landscape persistence strategies. A special emphasis was placed on eastern white pine (Pinus strobus), a restoration priority in the region. Witness tree data from nine- teenth century US Public Land Survey records (encompassing 40,610 km 2 and 106,790 trees) were used with modern environmental data to relate species distributions to habitat characteristics. Early-succes- sional tree species had strong positive associations with marginal habitats such as inclusions of sandy soil and margins of lakes, wetlands, and rivers. Marginal habitats occupied*44 % of the landscape, which may help account for the abundance of early-successional species in our study area relative to other hemlock- hardwood forests. Populations of early-successional species in marginal habitats could also have provided important seed sources for the upland mesic landscape matrix, as(70 % of the landscape was within 200 m of these habitats. The degree to which early-succes- sional species were limited to marginal habitats largely followed predictions based on species life- history characteristics, except that white pine was more common than expected in upland mesic habitats. These findings illustrate the potential importance of landscape heterogeneity for persistence of early- successional species in late-successional forest land- scapes and provide baseline information on habitat associations and landscape dynamics that will be useful in restoration efforts.

Visualizing Plant Community Change Using Historical Records

Ecological data from land surveys from 1811 for the 100,000-acre Connecticut Tract in western New York were transcribed and then analyzed using ArcGIS and IDRISI GIS software. The surveys contained both witness tree data and line descriptions, which were analyzed for species composition and community type. Results illustrate that many changes have occurred in species composition. Possible causes of these changes to the mature forests may include introduced pests and diseases or anthropogenic land-use change. Comparisons to the National Wetlands Inventory Database reveal that while some of the wetlands that were present in 1811 still exist today, particularly in the Byron-Bergen Swamp and in the wetlands along the Lake Ontario shoreline, other original wetlands have been lost while new wetlands have replaced some upland forests. This study helps elucidate past causes of temporal and spatial variability, and it provides a reference point for land managers who need to understand the effects of land-use history for ongoing restoration efforts.

Studying the Past for the Future: Managing Modern Biodiversity from Historic and Prehistoric Data

Management of biodiversity and anthropogenic effects on the environment are some of the most difficult challenges facing humans today. In this paper, we describe how archaeological, historical, and ecological data can be combined to identify metrics of ecological change. Archaeological surveys, historic witness tree data, analysis of ancient pollen, and recent satellite imagery are combined to create indicators of change that are useable by modem environmental managers at Fort Benning Military Reservation in Georgia and Alabama in the United States. Archaeological data were collected at 30 meter intervals, historic vegetation data were collected from early nineteenth century survey maps, and ancient pollen and charcoal were collected from soil cores in lakes. We show how data sets collected with disparate goals from anthropology and ecology can be applied to make policy decisions about environmental management.

Patterns from the past: modeling Public Land Survey witness tree distributions with weights-of-evidence

The Public Land Survey (PLS) witness tree data provide one of the few quantitative data sets of pre-and early-European settlement composition and structure of the forests and woodlands in the western United States. However, quantifying the areal extent of individual woody species from PLS records has proven difficult due to the coarse sampling structure of the data. Several attempts have been made to convert the discrete PLS witness tree data into continuous distributions through the use of various interpolation techniques. While these methods may adequately represent the spatial patterns of individual species over large areas, they fail to consider the numerous environmental covariates that can influence the distribution of individual tree species at finer scales. A more statistically rigorous method calls for combining species–environment relationships to estimate the areal extent of individual species from point data. In this study, we utilize weights-of-evidence (WofE), a discrete multivariate method, to estimate the probable historical distribution of six important woody plant taxa of the cross timbers of south-central Oklahoma. We successfully created posterior probability distribution maps for Quercus stellata, Q. marilandica, Q. velutina, Carya texana, C. illinoinensis, and Juniperus spp. Each posterior probability map was classified into four predictive categories, thereby enabling better estimations of the historical distribution of individual taxon from coarse-resolution PLS data. Model validation indicated that the WofE method effectively estimated the posterior probabilities of all taxa under consideration.

Forest Dynamics Across Three Century-Length Disturbance Regimes in the Illinois Ozark Hills

Forest community dynamics in the Illinois Ozark Hills was studied over a 300 y period that included three sequential disturbance regimes. Presettlement forest community patterns were reconstructed using witness tree data taken from the 1806–7 General Land Office survey records. Species, stem diameter and distance from the corner were obtained for a total sample of 958 witness trees on 479 section and quarter-section corners. Data were separated by site type based on 13 aspect and slope positions, but later were combined into six Ecological Land Type Phases (ELTPs) using cluster analysis and percent similarity. At the end of the presettlement and Disturbance Phase 1 (ca. 1810), Quercus and Carya species dominated forest communities (combined Importance Value, IV100 = 68–76) on the Southwest Slope, South Slope, Ridgetop and North Slope ELTPs. The combined IVs for all early successional species ranged from 74–81 while IVs of late successional fire-intolerant mesophytic species ranged from 19–26. Using mortality/damage data on mesophytic stems after prescribed fire and growth data on healthy stems, we estimated that the presettlement forest of mid to upper slopes and ridgetops developed under a fire return cycle of 30–45 y, a range that permitted a modest proportion of mesophytes to attain tree size. Forest communities on the cool moist Low Slope and Terrace ELTPs were dominated by mesophytic species, mostly Fagus grandifolia and Acer saccharum (combined IV100 = 50 and 63, respectively). We believe forest composition at the time of the land survey in 1806–7 primarily reflected the long-term effect of Early American burning during the 1600s and 1700s. The start of the Disturbance Regime 2, distinguished by the severe 1810–11 earthquakes that damaged thousands of hectares of forest, was followed by a period of settlement (ca. 1820–1930) characterized by a high level of fire, grazing and timber cutting. Based on early records, this level of disturbance was judged to be greater than that of presettlement time. The present forest was established in the mid to late 1800s and early 1900s of Regime 2. To provide continuity and reliability, tree, sapling and seedling data on the present forest were collected in all ELTPs from nested quadrats located at randomly selected, but continuously forested section and quarter-section corners from which witness tree data were previously recorded. In the presently mature forest overstory, Quercus and Carya had higher combined importance values on the Southwest Slope, South Slope and Ridgetop ELTPs (combined IV100 = 73–88) than presettlement communities on these ELTPs. On the North Slope ELTP, a sharp decrease in Quercus importance was partially offset by increases in Carya and Liriodendron tulipifera importance. On the Low Slope ELTP, there was an increase in the Quercus, Carya and L. tulipifera component from the presettlement forest to the present forest. The Terrace ELTP community was composed primarily of early successional lowland species in contrast to the forest of presettlement time. Disturbance Regime 3 of the last 75 y (ca. 1930–2005) was marked by near complete protection with the cessation of fire that accompanied the development of national and state forests, wilderness areas and wildlife refuges. This third period served as a reference to demonstrate the effect of absence of disturbance on the Quercus–Carya community. The absence of fire permitted major increases in mesophyte importance in the present understory (combined IV100 = 50–77) and stem growth into small tree stratum of nearly all Quercus–Carya dominated community types of all ELTPs. Based on a structure-for-time projection, related research analyses and an absence of disturbance that will permit continued growth of mesophytic species, the Illinois Ozark Hills may be the first contiguous forest region in central North America to completely convert from a Quercus–Carya to an Acer–Fagus dominated ecosystem.

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

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.

A Method to Use Ranked Timber Observations to Perform Forest Composition Reconstructions from Land Survey Data

The goal of this research was to develop a novel method to make use of ranked timber observation descriptions, which have been underutilized in survey reconstruction research. The new method involves assuming that ranking position reflects relative importance and thereby produces four separate measures that can be used to describe the geographic distribution, relative abundance and dominance of taxa recorded in historical surveys. We believe the method allows researchers to describe the composition of the forest from the line description data in a manner that would be impossible working only with witness tree data. The method is demonstrated using the Twenty Townships survey (central New York) as a case study, an area not previously discussed in the literature. We found that beech (Fagus grandifolia), maple (Acer spp.), basswood (Tilia americana) and hemlock (Tsuga canadensis) were the most widely distributed taxa and that these four taxa were more or less abundant in this same order. Where they were present, beech and hemlock were dominant, while maple and basswood were less so. Ash (Fraxinus spp.), birch (Betula spp.), elm (Ulmus spp.), cherry (Prunus spp.), pine (Pinus spp.) and cedar (Thuja spp.) were minor elements of the forest composition, but ash and cedar were both the primary constituents of swamps in the region, making them dominant taxa when they were present. Chestnut (Castanea dentata), oak (Quercus spp.), alder (Alnus spp.), ironwood (Ostrya virginiana), butternut (Juglans spp.) and walnut (modern day Carya spp.) were also present, but they were extremely rare.

Modeling and spatial prediction of pre-settlement patterns of forest distribution using witness tree data

At the time of European settlement, land surveys were conducted progressively westward throughout the United States. Outside of the original 13 colonies, surveys generally followed the Public Land Survey system in which trees, called witness trees, were regularly recorded at 1 mi by 1 mi grid intersections. This unintentional sampling provides insight into the composition and structure of pre-European settlement forests, which is used as baseline data to assess forest change following settlement. In this paper, a model for the Public Land Surveys of east central Alabama is developed. Assuming that the locations of trees of each species are realized from independent Poisson processes whose respective log intensities are linear functions of environmental covariates (i.e., elevation, landform, and physiographic province), the species observed at the survey grid intersections are independently sampled from a generalized logistic regression model. If all 68 species found in the survey were included, the model would be highly over-parameterized, so only the distribution of the most common taxon, pines, will be considered at this time. To assess the impact of environmental factors not included in the model, a hidden Gaussian random field shall be added as a random effect. A Markov Chain Monte Carlo algorithm is developed for Bayesian inference on model parameters, and for Bayes posterior prediction of the spatial distribution of pines in east central Alabama.

Modifying Distance Methods to Improve Estimates of Historical Tree Density from General Land Office Survey Records1

Abstract Distance sampling methods are widely applied to witness tree data from General Land Office (GLO) survey records to determine historic vegetation. Most researchers apply modifications of the point-centered quarter or random pairs distance methods to witness tree distances as if these data were collected according to the procedures required for the methods. Application of five methods (three modifications of the point-centered quarter method (Q1, Q2, and Q1+Q2) and random pairs with 180° or 203° exclusion angles) to GLO records from the 345,000 ha Shawnee National Forest Purchase Area in southern Illinois, resulted in tree density ranging from 117.8–177.5 trees ha−1. We present a new procedure, the adjustable exclusion angle method, which empirically estimates the exclusion angle of the random pairs method based on the proportion of trees in quadrants opposite versus adjacent to the quadrant of the first witness tree. For our data, the distributions of witness trees in quadrants was best described ...

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

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.

Landscape patterns as indicators of ecological change at Fort Benning, Georgia, USA

This research examined landscape indicators that signal ecological change in both intensely used and lightly used lands at Fort Benning, Georgia. Changes in patterns of land cover through time affect the ecological system by altering the proportion and distribution of habitats for species that these cover types support. Landscape patterns, therefore, are important indicators of land-use impacts, past and present, upon the landscape. This analysis of landscape pattern began with a landscape characterization based on witness tree data from 1827 and the 1830s and remotely sensed data from 1974, 1983, 1991, and 1999. The data from the early 1800s, although coarse, were useful in characterizing the historical range of variability in ecological conditions for the area. The steps for the analysis involved the creation of a land-cover database and a time series of land-cover maps, computation of landscape metrics, and evaluation of changes in those metrics over time as evidenced in the land-cover maps. We focused on five cover types (bare/developed land, deciduous forest, mixed forest, pine forest, and non-forest vegetated land), for they reveal information important to resources management at Fort Benning. An examination of land-cover class and landscape metrics, computed from the maps, indicated that a suite of metrics adequately describes the changing landscape at Fort Benning, Georgia. The most appropriate metrics were percent cover, total edge (km), number of patches, descriptors of patch area, nearest neighbor distance, the mean perimeter-to-area ratio, shape range, and clumpiness. Identification of such ecological indicators is an important component of building an effective environmental monitoring system.

A Witness Tree Analysis of the Effects of Native American Indians on the Pre-European Settlement Forests in East-Central Alabama

Witness tree data from the southeastern United States (lat 33°30' N, long 86°30' W) were analyzed using catchment and distance analysis to quantify the effects of Native American settlement on the composition of forest trees. Thirty Creek Indian villages comprising 18 settlement catchments were included in the sample, which is the largest Native American–forest interaction study using witness trees to date. Lower frequencies of Pinus spp. were observed within village catchments of the Coastal Plain and Ridge and Valley. Elevated frequencies of early succession species were observed surrounding 2 km village catchments. Distance analysis at two relatively isolated towns showed that Pinus increases in frequency beyond 2000 m from villages while Carya had the opposite result. Field and fruit species were more frequent within 6000 m of villages and then dropped off in frequency. Fire-sensitive tree species appear to be in a spatially cyclical pattern.

Where Has All the White Oak Gone?

Abstract Before European settlement, vast areas of deciduous forest in what is now the eastern United States were dominated by oak species. Among these species, white oak (Quercus alba) reigned supreme. White oak tended to grow at lower elevations but was distributed across a broad range of sites, from wet mesic to subxeric, and grew on all but the wettest and most xeric, rocky, or nutrient-poor soils. A comparison of witness tree data from early land surveys and data on modern-day forest composition revealed a drastic decline in white oak throughout the eastern forest. By contrast, other dominant oaks, such as red oak (Quercus rubra) and chestnut oak (Quercus prinus), often exhibited higher frequency in recent studies than in surveys of the original forest. The frequency of red oak witness trees before European settlement was quite low, generally under 5% in most forests. Red oak's distribution was apparently limited by a lower tolerance to fire and drought and a greater dependence on catastrophic disturbances than that of white oak. During the late 19th and early 20th centuries, much of the eastern forest was decimated by land clearing, extensive clear-cutting, catastrophic fires, chestnut blight, and then fire suppression and intensive deer browsing. These activities had the greatest negative impact on the highly valued white oak, while promoting the expansion of red oak and chestnut oak. More recently, however, recruitment of all the dominant upland oaks has been limited on all but the most xeric sites. Thus, the dynamic equilibrium in the ecology of upland oaks that existed for thousands of years has been destroyed in the few centuries following European settlement.

Combining environmentally dependent and independent analyses of witness tree data in east-central Alabama

We reconstructed pre-European settlement forest composition across 13 000 km2 of east-central Alabama using 43 610 witness trees recorded in the original Public Land Surveys. First, we interpolated the witness tree data to estimate broad-scale vegetation patterns. Next, we conducted species–site analysis on landforms, an approach that was dependent on underlying environmental variables yet better resolved fine-scale vegetation patterns. East-central Alabama was dominated by three community types: oak–hickory across the Piedmont physiographic province and valleys of the Ridge and Valley province, pine – blackjack oak on the Coastal Plain province and ridges of the Ridge and Valley province, and white oak – mixed mesophytic in stream valleys and floodplains. Witness tree concentration (trees/km2) was highly uniform across much of the study area. However, there was an unusually low concentration of witness trees in the southwestern corner of the study area, and an unusually high concentration in stream valleys. Another irregularity was the inability of surveyors to distinguish black oak and red oak. Overall, the interpolations provided an unbiased, yet broad-scale estimate of forest composition, while the species–landform analysis greatly increased resolution of forest cover despite the subjectivity of defining environmental variables a priori.

Analysis of temporal variation and species-site relationships of witness tree data in southeastern Pennsylvania

Witness tree species – site relationships are described with respect to parent material, soil drainage, and soil surface texture in Lancaster County, southeastern Pennsylvania. Quercus velutina Lam. and Carya were positively associated with "limestone" parent materials and well-drained, loamy sites. Quercus velutina was strongly associated with "acid shale and sandstone" parent materials and well-drained, upland soils. Quercus alba L. was most abundant on parent material classes associated with stream valleys and coves while Qurecus prinus L. and Castanea dentata (Marsh.) Borkh. were positively associated with well-drained, rocky sites on "quartzite" parent materials. Procedures were then developed to test for significant changes in witness tree species frequencies over the 100-year period of metes and bounds surveys in Lancaster County. These tests revealed that Quercus coccinea L., Nyssa sylvatica Marsh., and early successional species were surveyed much later than Quercus rubra L., Q. alba, and Carya spp. Agricultural land clearing, cutting for firewood, selective logging, and the charcoal-iron industry all probably contributed these species changes. Overall, abundances of minor species appear to be much more sensitive to these early settlement land uses. Given the extent of metes and bounds surveys, these tests for temporal variations may be applied to witness tree data throughout the eastern United States.

Analysis of temporal variation and species-site relationships of witness tree data in southeastern Pennsylvania

Witness tree species – site relationships are described with respect to parent material, soil drainage, and soil surface texture in Lancaster County, southeastern Pennsylvania. Quercus velutina Lam. and Carya were positively associated with "limestone" parent materials and well-drained, loamy sites. Quercus velutina was strongly associated with "acid shale and sandstone" parent materials and well-drained, upland soils. Quercus alba L. was most abundant on parent material classes associated with stream valleys and coves while Qurecus prinus L. and Castanea dentata (Marsh.) Borkh. were positively associated with well-drained, rocky sites on "quartzite" parent materials. Procedures were then developed to test for significant changes in witness tree species frequencies over the 100-year period of metes and bounds surveys in Lancaster County. These tests revealed that Quercus coccinea L., Nyssa sylvatica Marsh., and early successional species were surveyed much later than Quercus rubra L., Q. alba, and Carya spp. Agricultural land clearing, cutting for firewood, selective logging, and the charcoal-iron industry all probably contributed these species changes. Overall, abundances of minor species appear to be much more sensitive to these early settlement land uses. Given the extent of metes and bounds surveys, these tests for temporal variations may be applied to witness tree data throughout the eastern United States.

Temporal Patterns of Woody Species Diversity in a Central Appalachian Forest from 1856 to 1997

This study examined the composition of woody species in a mixed mesophytic forest in the central Appalachian region with respect to both time and different disturbance regimes. Species composition and diversity were assessed from 1856 to 1997 on a tract of land that currently is part of the Fernow Experimental Forest in north-central West Virginia. Additionally, the effect of different silvicultural disturbances are described using inventory data from four silvicultural demonstration areas initiated in 1948. These areas included a commercial clearcut, diameter- limit harvesting, single-tree selection, and an area that has not been artificially manipulated since initial logging around the turn of the century (ca 1907). Witness tree data from early land surveys (1856 and 1915) conducted in the same watershed were used to gain some insight into species frequency prior to and after initial logging. A forest inventory conducted in 1922 provided a more detailed description of the vegetation in the vicinity of the post-1948 stand data. The Shannon-Weiner Diversity Index was calculated based on species importance values for all time periods and management activities. Detrended correspondence analysis was used to assess differences in composition related to time and management activity. Data from old-growth (1856), early second-growth (1915 and 1922), and more mature second-growth stands were well separated in ordination space. A decline in species diversity from a high in 1922 to a low in 1997 appears to be driving this separation. Diversity declined primarily due to a reduction in evenness, which was significantly correlated with increasing importance of Acer saccharum. Relative A. saccharum importance is increasing in both the overstory and understory for all disturbance regimes. The increasing dominance of this species with time, regardless of stand age or disturbance regime evaluated, may be unprecedented and suggests new silvicultural techniques are needed to maintain the diversity of central Appalachian forests.

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

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.

Old-growth forest landscape transitions from pre-European settlement to present

We conducted a multi-temporal spatial analysis of forest cover for a 9600 ha landscape in northern Wisconsin, U.S.A., using data from pre-European settlement (1860s), post-settlement (1931), and current (1989) periods. Using GIS we have shown forest landscape changes and trajectories that have been generally described in aggregate for the norther Great Lake States region. We created the pre-European settlement map from the witness tree data of the original federal General Land Office survey notes. The 1931 cover was produced from the Wisconsin Land Economic Inventory, and the 1989 cover map was based on color infrared photography. We used GIS to analyze 1) land area occupied by different forest types at different dates, 2) temporal transitions between dates and their driving proceses, and 3) successional trajectories with landforms and spatial associations of forest types. Over the 120 year period, forest cover has changed from a landscape dominated by old-growth hemlock (Tsuga canadensis) and hardwood forests (Acer saccharum, Betula alleghaniensis) to largely second-growth hardwoods and conifers. The former dominant hemlock is largely eliminated from the landscape. From 1860 to 1931, large-scale disturbances associated with logging were the dominant processes on the landscape. Early successional forest types covered much of the landscape by the 1930s. From 1931 to 1989, succession was the dominant process driving forest transitions as forest types succeeded to a diverse group of upland hardwood and conifer forest types. If successional trajectories continue, a more homogeneous landscape may develop comprised of both a northern hardwood type dominated by sugar maple, and a boreal conifer/hardwood forest.