Historical Land Research by cdb17169


More Info
									                                                                                                           The Road to Pierce Farm
                                                                            Connecting Land-Use History and Soil Phosphate Concentration
                                                                                                                                                  David Diaz
                                                                                                                                               Harvard University

       Pierce Farm:                                    Mapping Topography:                               Mapping Soil Phosphate:                                  Grid Phosphate                                                                                                                Mapping Soil Phosphate:
                                                                                                                                                                     (0-10cm)                                                                                                                                                                                     Interpolated Phosphate
  Introducing Geography                                Digital Elevation and                                  Coring Grids                                            0    25 50            100                      150                  200
                                                                                                                                                                                                                                                                                            Interpolating Cores to Historical                                            (0-10cm)
Pierce Farm is situated on the Prospect Hill
Tract of Harvard Forest, an area which
                                                          Contour Lines                                  Examination of soil phosphate distribution by
                                                                                                         grid reveals increasing levels of soil

                                                                                                                                                                                                                                                     ¯    Legend
                                                                                                                                                                                                                                                                                                        Land-Use                                                       0       25 50    100    150    200

includes significant topographic variation as                                                            phosphate with increasing intensity of                                                                                                           Soil Cores (0-10cm Data)
                                                                                                                                                                                                                                                                                          When the soil cores were mapped to their respective land-use

                                                                                                                                                                                                                                                          mg P/kg soil

well as distinct land-use histories. The two of                                                          historical land-use which the grids were                                                                                                           (
                                                                                                                                                                                                                                                                     1                    polygons instead of intended land-use type grids, a different
                                                                                                                                                                                                                                                            (        10

these factors cannot easily be separated in the                                                          intended to represent. Within the grid                                                                          (

                                                                                                                                                                                                                                                           (         100                  picture appears. It should first be noted that the potential error
                                                                                                                                                                                                                                                          Historical Land-Use
present or the past because historical land-                                                             framework, both improved pasture and                                                                                                                        Occupied
                                                                                                                                                                                                                                                                                          of GPS data points may confound the joining of these two                                                                    Legend
use was contingent upon geographic qualities                                                             cultivated field have comparable phosphate
                                                                                                                                                                                                                                                                                          features near boundaries of land-use polygons, explicitly at the                                                                  Soil Cores (0-10cm Data)

                                                                                                                                                                                                                                                                                                                                                                                                                      Phosphate (0-10cm)
such as drainage and accessibility.                                                                      levels. While phosphate levels appear to be                                                                                                                 Unimproved Pasture   southern boundary of the Improved Pasture area. This map                                                                    mg P/kg soil

                                                                                                         approximately the same between 0-10cm and                             (
                                                                                                                                                                                       (                                                                  Phosphate (0-10cm)              may be contrasted with that above with the critical point that                                                                    33

There is also a large historical influence in                                                                                                                                                                                                             mg P/kg soil
                                                                                                                                                                                                                                                                                          some of the cores within a particular land-use coring grid are

                                                                                                         15-25cm for both Woodlot and Unimproved                                                                          ( (                                        15

understanding land-use from generation to                                                                                                                                                                                (((                                         33
                                                                                                                                                                                                                                                                                          not always within the same land-use polygon.

                                                                                                         Pasture, phosphate concentration increases                                                              ((

generation as conversion to more intense land                                                                                                                                                                                        (

                                                                                                         greatly with depth in Improved Pasture,                                                                                     (((                             102

use requires progressively more work on the                                                                                                                                                                                                                                               In contrast to the grid phosphate data, at 0-10cm, Improved
                                                                                                                                                                                                                         (( (

                                                                                                         Cultivated, and Occupied Grids, nearly                                                                           (                                          242

land, from clear-cutting woodlot for pasture to                                                                                                                                                                      ((                                                                   Pasture surpasses Cultivated in soil phosphate concentration
                                                                                                         doubling for Cultivated and Improved Pasture                                                                                      (
mowing unimproved pastures to increase the
                                                                                                         from 0-10cm to 15-25cm. These changes by
                                                                                                                                                                                                                         (( ((((
                                                                                                                                                                                                                               ( (                                                        and the two are easily distinguished. At 15-25cm however,
productivity of grasses. In the opposite                                     0   250   500   1,000
                                                                                                                                                                                                                                                                                          this relationship is reversed and the two are still easily
                                                                                                         depth seem to indicate that historical soil                                                                                                                                      distinguished. At a depth of 0-10cm, the phosphate levels of
direction, when plots begin to be abandoned in
the late nineteenth century, land-use recedes        The topography of Prospect Hill has been
                                                                                                         disturbance may initiate some type of                    Grid Phosphate                                                                                                          Unimproved Pasture are relatively close to that of Woodlot.
                                                                                                         feedback cycle which acts upon these two soil              (15-25cm)                                                                                                             This relative similarity disappears at a depth of 15-25cm as
to the most desirable and productive areas,          shown in this map by layering a historic
                                                                                                         depths at different rates.                               0       25 50            100                   150                     200
                                                                                                                                                                                                                                                                                          soil phosphate in Unimproved Pasture increases substantially
predominantly centering on cultivated areas          USGS Contour Map over a modern digital                                                                                                                                                Meters

and homesteads. An important shortcoming in
using soil disturbance profiles to reconstruct
                                                     elevation model which has been hillshaded
                                                     to create the optical illusion of three-
                                                                                                         Within each grid the phosphate levels of each
                                                                                                         core can be seen to vary widely. The


                                                                                                                                                                                                                                                     ¯   Legend
                                                                                                                                                                                                                                                         Soil Cores (15-25cm Data)
                                                                                                                                                                                                                                                                                          with depth.
                                                                                                                                                                                                                                                                                          These maps were created with a spatial join between soil
                                                                                                                                                                                                                                                                                                                                                                  Interpolated Phosphate
                                                                                                                                                                                                                                                                                                                                                                           0    25 50    100    150    200

                                                                                                                                                                                                                                                         mg P/kg soil                                                                                                                                    Meters

historical land-use is that it can only detect the   dimensional space. The Pierce Farm                  westernmost grid has suspiciously low                                                                                                                  (
                                                                                                                                                                                                                                                                                          cores and historical land-use polygons. The hue of the
most intense land-use, preventing us from            (highlighted with the red outline above) is         phosphate levels considering it is assumed to                                                                                                          (         10

                                                                                                                                                                                                                                                                                          polygons indicating phosphorus levels is representative,
witnessing this retreat.                             situated on a plot incorporating the lowland
                                                     swamp area at the base of Prospect Hill
                                                                                                         be the same land-use as the grid 150m to the
                                                                                                         northeast. This may be due to the low                                               (

                                                                                                                                                                                                                                                          (               1,000
                                                                                                                                                                                                                                                                                          meaning it closely portrays the contrast of phosphate levels
Reconstruction of this retreat and                                                                                                                                                                                                                       Historical Land-Use              between polygons with a synchronous contrast in hue.
                                                     moving southwest away from the summit               sample size of the westernmost grid, but                                                                                                                   Occupied

abandonment may be accomplished through                                                                                                                                                                                                                             Cultivated
                                                                                                                                                                                                                                                                                          The extraction of more soil cores would facilitate a more
                                                     upwards in elevation back towards the               merits further investigation.                                                                                                                              Mowing/Improved                                                                                                                                   Legend
the historical record and be explained in                                                                                                                                                                                                                           Unimproved Pasture
                                                                                                                                                                                                                                                                                          accurate interpolation of soil phosphate, particularly along                                                                     Soil Cores (15-25cm Data)
                                                     town road and later administration                                                                                    (
                                                                                                                                                                                   (                                                                                Woodlot                                                                                                                                           Phosphate (15-25cm)
relation to present-day forest cover and                                                                 These maps were created with a spatial join                                                                                                     Phosphate (15-25cm)              boundary zones, or with the intent of discovering boundary
                                                     buildings of the Harvard Forest.                                                                                                                               ( (
                                                                                                                                                                                                                                                                                                                                                                                                                      mg P/kg soil

undergrowth (Foster 1992, Motzkin et al.                                                                 between soil cores and the soil coring grid                                                              (
                                                                                                                                                                                                                                                         mg P/kg soil
                                                                                                                                                                                                                                                                                          zones through soil phosphate alone.

                                                                                                                                                                                                         (( (((
                                                                                                                                                                                                                                                                    33                                                                                                                                                     108

1999).                                               Swamp areas can be seen on from the                 polygons. The hue of the grid indicating                                                                                                                   38                                                                                                                                                     163

                                                                                                                                                                                                                                 (                                  89                                                                                                                                                     195

In the present, the wayward visitor to the
                                                     historic USGS map to occupy most of the             phosphorus levels is representative, meaning

                                                     low-lying elevations on the Prospect Hill           it closely portrays of the contrast of phosphate                                                                (
woods may find stone walls and a cellar hole                                                                                                                                                                                                                        303

of the Pierce Farm, but would likely miss a
                                                     Tract. In contrast to neighboring Prospect          levels between grids with a synchronous                                                                                         ((
                                                     Hill, Pierce Farm encloses relatively               contrast in hue. Coring grids were established
large part of the history of the region without
                                                     smaller slopes, likely providing for different      in the field in 80m x 20m rectangles, intended
knowing what has happened beneath the
                                                     drainage patterns and perhaps more                  to cover local variations in slope and
surface of the land for the past two and a half
                                                     productive soil than the land parcels to the        vegetation. They have been reconstructed
                                                     north across the town border with                   here as 90m x 30m rectangles to incorporate
The objective of this project is to introduce        Phillipston. Despite the smoother slopes            the potential error within GPS coordinates.
what happened historically above and below           of Pierce Farm in the higher end of the             Note: the Occupied Land-Use polygon is not
the surface of Pierce Farm and relate that           plot, the presence of the swamp at the              visible because it is the exact same shape as
history to present soil conditions.                  base of Prospect Hill in the northeastern           the Occupied Coring Grid.
                                                     region of the Farm surely had an effect on
                                                     historical land-use. This swamp region is
                                                     documented by the Harvard Forest not as
         Methods:                                    Woodlot, but instead as Unimproved
                                                     Pasture, suggesting that despite its soggy
   Displaying Geography                              ground and seemingly undesirable
                                                     qualities, it may in fact have been utilized                                                                                                                                                                                                                 Foster, David R. “Land-use history (1730-1990) and vegetation dynamics in central New
Through the utilization of Geographic                by the occupants of Pierce Farm.                                                                                                                                                                                                                                   England, USA.” Journal of Ecology 80 (1992): 753-772.
Information Systems, the geography of the
land may be displayed and analyzed in                                                                                                                                                                                                                                                                             Motzkin, Glenn et al. “Vegetation patterns in heterogeneous landscapes: The
relation to several different elements. The                                                                                                                                                                                                                                                                            importance of history and environment.” Journal of Vegetation Science 10 (1999):
spatial framework of GIS facilitates visual                                                                                                                                                                                                                                                                            903-920.
comprehension of multiple variables and
relationships and allows for a more holistic
appreciation of spatial relationships.
                                                                                                                                                                                                 Conclusion:                                                                                                      GIS Data:

                                                                                                                                        While GIS analysis may provide incredible potential for manipulating and displaying                                                                                       Historical Land-Use polygons modified from existing Harvard Forest data.
The materials used to construct these maps
vary in source, context and date of initial                                                                                             spatial information, it is contingent upon the accuracy and precision of the underlying
                                                                                                                                        spatial data. The source of the most confounding errors is the GPS unit used to                                                                                           The 1946 USGS Map was taken from University of New Hampshire Government
construction, but may be fused together to                                                                                                                                                                                                                                                                        Documents Department Historic USGS Maps of New England and New York website.
offer a specifically tailored spatial portrayal of                                                                                      determine the UTM coordinates of each soil core. At such a small scale, errors of up to
                                                                                                                                        10m can become increasingly difficult to reconcile with the grid on the ground as well as                                                                                 (Available at http://docs.unh.edu/nhtopos/nhtopos.htm)
the Pierce Farm area and provide fertile
ground for interpreting changes in the land.                                                                                            complicate any spatial joins and interpolation between soil cores and land-use layers.
                                                                                                                                                                                                                                                                                                                  USGS aerial photos of the Prospect Hill tract in Harvard Forest collected from
The data for this mapping project are                                                                                                   The use of GIS technology has enabled the interpolation of soil phosphate values and                                                                                      TerraServer. (Available at http://terraserver.microsoft.com)
displayed primarily through the use of Vector-                                                                                          allowed the visualization of contrast between historical land-use regions based on soil
Relational methods as opposed to Raster                                                                                                 phosphate concentrations. This spatial analysis highlights a pattern of increasing soil
based GIS applications. All of these maps                                                                                               phosphate with corresponding increases in historical land-use intensity.
displayed in UTM 18N projection                                                                                                         The most valuable aspect for GIS in interpretation these experimental data is in the
                                                                                                                                        recognition of spatial error and shortcomings of both GIS datalayers as well as on-the-                                                                                                               Acknowledgements:
                                                                                                                                        ground experimental design. The boundaries created in GIS layers are not necessarily
                                                                                                                                        the same boundaries that can be seen in the forest composition and soils, nor should                                                                                      Special thanks to Noreen Tuross, Joshua Wright and Cheryl Makarewicz for leading the
                                                                                                                                        they be misconstrued to be error-proof. In this circumstance, GIS analysis has                                                                                            research project, creating positive and encouraging feedback, and providing
                                                                                                                                        highlighted the problem with data collection at boundaries where precise measurements                                                                                     transportation to the site and to the apple orchard, among other things.
                                                                                                                                        of geographic location were not available.
                                                                                                                                        The integration of GIS into experimental design may facilitate more productive                                                                                            Thanks to Dave Orwig and Paul Cote for their help in creating and “wrangling” this data
                                                                                                                                        distinctions between boundary zones and enable more definitive results.                                                                                                   and to Bronwen Everill for her help conducting research.

To top