Figure 4 – Elevation Histogram

Histogram of Positive and Susceptible location’s Elevation

Geospatial Analysis of USDA/PDA Plum Pox Eradication Project Data By Laura F. Starkey

Department of Biological Sciences, York College of Pennsylvania

USDA/PDA Survey Methods ResultsThe Cost Map below indicates by color the most likely areas where a positive plant may be found. The USDA’s current homeowner survey method involves surveying every susceptible tree on every property located within the blue survey line (see below).

With my results I suggest that properties be prioritized based on my Cost Map. That way every year when the survey ends, more susceptible locations won’t be missed because time was spent surveying the less susceptible locations.

This Cost Map could be enhanced by including another cost layer that would account for distance from the nearest positive location.

Background on Plum Pox Virus (PPV)

• PPV is a debilitating tree virus• Infects stone (pitted) fruit trees such as; Peaches, Plums, Almonds, Cherries, Apricots, etc. as well as non-fruit bearing ornamental relatives• Infected trees have reduced quality and quantity of fruit production• 4 strains located worldwide, USA only has PPV-D located only in 4 counties in PA • United States Dept. of Agriculture (USDA) and the Pennsylvania Dept. of Agriculture (PDA) have implemented The Plum Pox Eradication Project

My Project • Make use of GIS in order to refine the USDA and PDA’s eradication project

• Look at Land Usage and Elevation of positive and susceptible locations in order to create a Cost map of most susceptible locations

ArcGIS Methods Obtain data (various sources; PASDA, USDA, Chesapeake Bay project) Sort, organize, and group data into a Personal Geodatabase (every data source has its own projection and method of labeling) Create new attribute tables by extrapolating data from multiple layers Create cost layer by overlapping two layers and assigning color costs.

Acknowledgements• Dr. Bruce Smith, Mentor

• Donald Albright, Director of USDA, APHIS, PPV Project

• Stewart Bruce, GIS Instructor

• Arthur Freda, IT Support for USDA, APHIS, PPV and cartoonist

What is Geographic Information Systems?

• Geographic Information Systems (GIS) contains 3 parts; the Geography (maps, GPS, etc), Information (elevation, precipitation, land use, etc), and the computer System (software and hardware) to combine and make use of the previous 2 parts.• GIS simply is applying location-dependent information such as elevation to a map• Allows for analysis of geographic-dependent data

Figure 2 – Elevation Map

This map displays the arrangement of Positive and Susceptible locations as they occur over Elevation (meters above sea level)

Figure 3 – Land Use Histogram

Histogram of Positive and Susceptible location’s Land Use types

Figure 5 - Cost Map

This map was created by giving each land use and elevation feature a percentage of the color red based on the number of positives found there, then overlaying the maps

Figure 1 – Land Use Map

This map displays the arrangement of Positive and Susceptible locations as they occur over Land Use types

Orchard Survey Pre-2003 orchards were sampled using a random zig-zag pattern for long narrow blocks and a crossing pattern for relatively square blocks Post-2003, 100% of all host trees were sampled within 5 miles of a previous positive site

Home Owner Survey 100% of the host plants are sampled Pre-2003 4 leaves were collected from each host plant, unless there was only 1 susceptible plant and then 8 leaves were taken Post-2003, 8 leaves are collected from each host plant.