19.6 Land Survey Records
mile) within townships for states west of Pennsylvania (Galatowitsch, 1990). The U.S. Congress authorized public land surveys using the rectangular
system in 1785, but only a small fraction of public
land was surveyed prior to 1815 (Bourdo, 1956).
Each township, section, and quarter-section comer
was marked by up to four trees, whose common
name, diameter, compass bearing, and distance to
the comer were recorded in surveyors' field notes
(Grimm, 1984). Such trees are also known as bearing trees (Bourdo, 1956). Characteristics of trees
intersecting section lines were also recorded. Public land survey records represent a systematically
collected estimate of tree abundance, distribution,
and association (Schwartz, 1994) and can provide
a relatively reliable method for reconstructing presettlement vegetation (Leitner et aI., 1991), given
the limitations described in the following. Most
studies utilizing public land survey data have been
conducted in upland forests, but survey notes have
been used to establish baseline conditions of riparian habitat in Colorado and Oregon and grassland
in Colorado and New Mexico (Galatowitsch,
1990). Galatowitsch (1990) lists dates of survey
and location of survey notes (state government or
Bureau of Land Management office) for states covered by General Land Office surveys.
Limitations in the use of survey data include the
fact that public land surveys were not fully standardized prior to 1855 and instructions to surveyors changed from time to time (Bourdo, 1956). In
addition, the time period over which survey data
were recorded was only a few years in any given
area. Surveyors may have selected witness trees that
were not the closest trees to comers because they
were intended to perpetuate the comer. Criteria for
selection included size, age, species longevity, distance from the comer, and conspicuousness in the
stand (Grimm, 1984). Consequently, witness tree
records underestimate tree density and do not permit reconstruction of absolute tree density or size,
but can provide relative density or size information
for comparisons within the data (Grimm, 1984).
Surveyors were shown to select a disproportionate number of medium-sized trees (l0 to 14 inches
diameter at breast height) to provide sufficient
room for the inscription of the township, range, and
section on the tree, leading to bias against species
that do not attain this size (Bourdo, 1956). Bias may
also have existed in favor of selection of species
that were easy to inscribe, such as beech, or that
attained a large size, such as red pine (Whitney,
1986). However, tests of differences in post-to-tree
distances between beech and sugar maple in lower
Michigan did not reveal any significant preference
281
for beech, indicating a lack of bias in species selection, at least in that location (Whitney, 1986). A
check on possible biases in the selection of witness
trees is provided by the descriptions written by surveyors for each I-mile section line; such descriptions include a ranking of tree species by abundance
(Leitner et aI., 1991).
Public land survey information has been employed to reconstruct disturbance regimes using
section line descriptions that record disturbance
events, such as fire or windthrow, encountered
along the survey line. Whitney (1986) reconstructed pre settlement disturbance regimes in
Lower Michigan using section line descriptions to
estimate return times for windfall and fire. Limitations to such an approach include the small time
interval over which the survey was conducted, lack
of consideration of the effects of multiple events,
and documentation of only the more severe events
(e.g., destructive crown fires) (Whitney, 1986).
EXAMPLES
Witness tree data from public land surveys have
been used to reconstruct presettlement vegetation
in a number of locations in the United States, especially in the upper Midwest.
1. Grimm (1984) reconstructed vegetation of the
Bigwoods and adjacent areas along the prairiewoodland border in Minnesota and related vegetation distributions to environmental factors.
2. Delcourt and Delcourt (1996) mapped presettlement vegetation cover types and conducted
spatial landscape analyses in West Mackinac
County, Michigan. The results included determination of the most appropriate cell size for characterizing landscape heterogeneity using survey data.
3. In Michigan's Upper Peninsula, comparison
of presettlement with present-day forest composition revealed that in deer-yarding areas plant
species palatable to deer or intolerant of browsing
have decreased in abundance and browsing-tolerant species have increased (Van Deelen et aI.,
1996).
4. The relative structure and composition of presettlement vegetation were estimated from survey
data along the 5th Principal Meridian in Mississippi
and Arkansas (Nelson, 1997). The evidence suggested that an open woodland was present in 1815
in areas where mesophytic tree species abundance
is currently increasing.
5. Survey records for 127,653 trees used to map
species and community type distributions across
northern Florida supported the overwhelming dominance of pine in presettlement vegetation
(Schwartz, 1994).
mile) within townships for states west of Pennsylvania (Galatowitsch, 1990). The U.S. Congress authorized public land surveys using the rectangular
system in 1785, but only a small fraction of public
land was surveyed prior to 1815 (Bourdo, 1956).
Each township, section, and quarter-section comer
was marked by up to four trees, whose common
name, diameter, compass bearing, and distance to
the comer were recorded in surveyors' field notes
(Grimm, 1984). Such trees are also known as bearing trees (Bourdo, 1956). Characteristics of trees
intersecting section lines were also recorded. Public land survey records represent a systematically
collected estimate of tree abundance, distribution,
and association (Schwartz, 1994) and can provide
a relatively reliable method for reconstructing presettlement vegetation (Leitner et aI., 1991), given
the limitations described in the following. Most
studies utilizing public land survey data have been
conducted in upland forests, but survey notes have
been used to establish baseline conditions of riparian habitat in Colorado and Oregon and grassland
in Colorado and New Mexico (Galatowitsch,
1990). Galatowitsch (1990) lists dates of survey
and location of survey notes (state government or
Bureau of Land Management office) for states covered by General Land Office surveys.
Limitations in the use of survey data include the
fact that public land surveys were not fully standardized prior to 1855 and instructions to surveyors changed from time to time (Bourdo, 1956). In
addition, the time period over which survey data
were recorded was only a few years in any given
area. Surveyors may have selected witness trees that
were not the closest trees to comers because they
were intended to perpetuate the comer. Criteria for
selection included size, age, species longevity, distance from the comer, and conspicuousness in the
stand (Grimm, 1984). Consequently, witness tree
records underestimate tree density and do not permit reconstruction of absolute tree density or size,
but can provide relative density or size information
for comparisons within the data (Grimm, 1984).
Surveyors were shown to select a disproportionate number of medium-sized trees (l0 to 14 inches
diameter at breast height) to provide sufficient
room for the inscription of the township, range, and
section on the tree, leading to bias against species
that do not attain this size (Bourdo, 1956). Bias may
also have existed in favor of selection of species
that were easy to inscribe, such as beech, or that
attained a large size, such as red pine (Whitney,
1986). However, tests of differences in post-to-tree
distances between beech and sugar maple in lower
Michigan did not reveal any significant preference
281
for beech, indicating a lack of bias in species selection, at least in that location (Whitney, 1986). A
check on possible biases in the selection of witness
trees is provided by the descriptions written by surveyors for each I-mile section line; such descriptions include a ranking of tree species by abundance
(Leitner et aI., 1991).
Public land survey information has been employed to reconstruct disturbance regimes using
section line descriptions that record disturbance
events, such as fire or windthrow, encountered
along the survey line. Whitney (1986) reconstructed pre settlement disturbance regimes in
Lower Michigan using section line descriptions to
estimate return times for windfall and fire. Limitations to such an approach include the small time
interval over which the survey was conducted, lack
of consideration of the effects of multiple events,
and documentation of only the more severe events
(e.g., destructive crown fires) (Whitney, 1986).
EXAMPLES
Witness tree data from public land surveys have
been used to reconstruct presettlement vegetation
in a number of locations in the United States, especially in the upper Midwest.
1. Grimm (1984) reconstructed vegetation of the
Bigwoods and adjacent areas along the prairiewoodland border in Minnesota and related vegetation distributions to environmental factors.
2. Delcourt and Delcourt (1996) mapped presettlement vegetation cover types and conducted
spatial landscape analyses in West Mackinac
County, Michigan. The results included determination of the most appropriate cell size for characterizing landscape heterogeneity using survey data.
3. In Michigan's Upper Peninsula, comparison
of presettlement with present-day forest composition revealed that in deer-yarding areas plant
species palatable to deer or intolerant of browsing
have decreased in abundance and browsing-tolerant species have increased (Van Deelen et aI.,
1996).
4. The relative structure and composition of presettlement vegetation were estimated from survey
data along the 5th Principal Meridian in Mississippi
and Arkansas (Nelson, 1997). The evidence suggested that an open woodland was present in 1815
in areas where mesophytic tree species abundance
is currently increasing.
5. Survey records for 127,653 trees used to map
species and community type distributions across
northern Florida supported the overwhelming dominance of pine in presettlement vegetation
(Schwartz, 1994).