SPATIAL TECHNOLOGY FOR THE SURVEY AND MONITORING OF INVASIVE PLANTS. Dale A. Loberger, ESRI, Charlotte, NC. (dloberger@esri.com)

ABSTRACT

There is a great deal of technology available to scientists and researchers in the field of natural resources, so the selection of appropriate tools can become quite cumbersome. In order to choose wisely, researchers must know not only what is available, but how it assists in fulfilling their mission. When it comes to exotic pest control, the job is to survey, inventory, and monitor invasive plants, their invasion characteristics, document control treatments, and evaluate the results of control efforts. In short, these tasks involve the measurement, documentation, and analysis of the pest and efforts to control it. Two primary spatial technologies designed to do exactly this are the Global Positioning System (GPS) and Geographic Information Systems (GIS).

GPS

The Global Positioning System is a constellation of satellites that facilitate a handheld tool for measuring geographic coordinates at any location on the earth by triangulating the distances from an observer in the field to a collection of these man-made "stars". The GPS receivers come in a variety of different quality and price levels in order to balance the need for accuracy and speed of data collection with the cost of hardware. Typically available devices can range in error anywhere from 30 meters to a few centimeters in horizontal (latitude, longitude) measurement with a somewhat higher error in the vertical (elevation) readings. The application of this technology is well known for the measurement of the location and extent of pests or treatments.

Just knowing the coordinates of geographic features, however, is not enough. These geospatial observation measurements can be documented in a geographic database and then analyzed with a collection of tools designed for spatial analysis. These software systems are known collectively as Geographic Information Systems.

GIS

The term GIS addresses a class of software available from a number of competing software vendors, but in general these applications provide a tool for maintaining and analyzing spatial features and the relationships between these features as they are defined through geographic coordinates or measurements. The geodatabase format that contains the data becomes a repository for documenting field measurements, but its functionality goes even further since it can model the behavioral characteristics of features being described. Just as plants relate to their environment, modeled features in a GIS can also respond to the proximity and influences of other modeled environmental factors. By building digital models of natural systems, we can explore the interactions of various phenomena and evaluate potential treatments in a digital laboratory.

Conclusion

These technologies are not out-of-the-box solutions and although they have generally become much easier to use, they do require some basic understanding of the technological capabilities they wield and how it can be harnessed. With thoughtful planning and an understanding of their application, they can contribute greatly to research objectives and even reduce the costs of experimentation.