1) The goal was to create a mapped sampling area for research groups to study soils, tree rings, and the age of forests in different areas at Howard Falls Land Trust. 2) Aerial photos from 1939, 1969, 1995, and 2009 were used to define land use patches over time using GIS technology. 3) The map divides the land into patches of similar land use history and will allow researchers to locate and sample patches that were historically agriculture, forested land, or transitional forest areas.

1. Abstract: The goal of this project was to create a mapped sampling area that can be used by other Geoscience research groups to carry out research at Howard Falls Land
Trust in Franklin Township, Erie County, Pennsylvania. The map divides the land within the boundaries of the land trust into patches of similar land use history so that in the
future, others can do field tests on soils and perform dendrochronology (tree rings studies to find the age of forest in different mapped patches). Orthographic
photographs, (aerial photos of the ground taken from an aircraft wing that has been corrected to remove distortions resulting from the curvature of the earth), were used
to define land use patches from 1939, 1969, 1995, and 2009 to create a final study layer using GIS (Geographic Information Systems) technology. This will allow researchers
to go into the field and use a GPS to find each patch, where they can then take samples from patches that today are classified as agriculture, forested land, or patches that
are transitional to forests. The map that I created in the GIS will produce a sampling frame for future studies, and serves as a database to store information that will be
collected by those future studies and can be visualized on the map.
Objective: to estimate the minimum age of forest on the landscape today
using a sequence of historical orthophotos.
Acknowledgements:Funding: Howard Falls Land Trust
®
0
50
100
150
200
250
1939 1969 1995 2009
ACRES
Change in Land Use by Type
Agriculture Forest Transitional Other
Map 3. 1939 Map 4. 1969
Map 5. 1995 Map 6. 2009
Land Use Type
Agriculture
Forest
Other
Transition zone
Map 2. Map of the Howard Falls Land Trust,
located in the Falls Run watershed in Erie County
Map 1. Map of Pennsylvania Counties,
Erie is highlighted in the upper left corner.
Figure 1. Change in Land Use Type over time by area.
Landscape History at Howard Falls Land
Trust in Franklin Township, Erie County,
Pennsylvania
Map 7. Minimum Forest Age
The classifications that were used to define different land use types were
forested, agriculture, transitional, and other. “Forested” is any area that
appeared to have a predominate land cover of trees. “Agriculture” is any area
that appeared to be used for the production of crops. “Transitional” is any area
that appeared to be changing from one land use type to forest. “Other” is any
area that couldn’t be categorized into any of the three previous land use types.
Map 7. (on the right) Minimum age of forested patches at the Howard Falls Land Trust. This layer was
created by using the “intersect” tool in ArcMap to overlay the 4 individual maps to the left representing
four different years. The green patches have always been forest cover and have a minimum age of 76
years, given the oldest photo used is from 1939. The blue patches represent a zone that has transitioned
to forest since 1969 has a minimum age of 46 years. The dark purple patches have transitioned to forest
over the past 20 years. The pink patches have transitioned to forest in the last 6 years. The light purple
patches have always been agriculture since 1939.
Maps 3-6. (to the left) The Howard Falls land parcel from four different years and
how each land use type changes over the represented year. The pie charts show the
percentage of land broken up into four different land use types.
Figure 1. (below) Corresponds to the maps on the left. As you can see from Maps 3-
6 and Figure 1 the forested patches have grown over the years and agriculture
patches have declined
Sources: http://www.pennpilot.psu.edu/ , http://www.pasda.psu.edu
Lisa Rayburg Department of Geoscience
Major: Environmental Studies
Minor: Geographic Information Systems