Invasive Species Exercises: Nested Pixel Plot

This 900-square-meter plot is often used to accomapny a satellite image, but is also good for estimating invasive species.
Within the 900-square-meter plot, there are nine 100-square-meter subplots, that allow for analysis on a fine scale.
Within each of these 100-square-meter subplots, there are four 25-square-meter subplots, for even finer-resolution analysis.

Setting us the Nested Pixel Plot

• Two 50-meter tapes
• Nineteen ground stakes or pin flags
• Compass
• GPS unit
• Palm Pilot PDA with EcoNab
• Reference materials such as floristic keys

1. Choose and flag a starting point for the southwest corner of the plot
2. Use the compass to orient yourself facing north, and walk north for 30 meters. Flag the 10, 20, and 30 meter marks
3. Use the compass to orient yourself east from the 30 meter mark. Walk east for 30 meters, flagging every ten meters. Flag the end of 30 meters
4. Use the compass to orient yourself south from your place, and walk south for 30 meters, flagging every ten meters you walk. Flag the end of the 30 meters
5. Use the compass to orient yourself west from your place, and walk west for 30 meters, flagging every ten meters you walk. This takes you back to the starting point and encloses your 900-square meter plot
6. At every ten-meter flag along the westerly border of the plot, orient yourself facing east, and walk to the easterly border, flagging every ten meters
7. At every ten-meter flag along the northerly border of the plot, orient yourself facing south, and walk to the southerly border, flagging every ten meters again. This process creates your nine 100-square-meter subplots within the 900-square-meter plot
8. In the northwestern, middle, and southwestern 100-square-meter subplots, flag the center of each subplot, and divide it into four 25-square-meter subplots. This finishes the process of nesting subplots within the main plot
9. Use a GPS unit to mark the center of the main plot, and take its coordinates.

• Data from the Nested Pixel Plot is collected in each of the primary subplots (the 100-square-meter and 25-square-meters subplots).
• The plots are oriented north for consistency, and ability to align with satellite imagery if needed.
• At the center of the 100-square-meter plots, soil is sampled for analysis of soil characteristics throughout the plot.
• Percent of vegetation cover is estimated for each subplot within the plot.

NOTE: Estimates of percent cover should be made by the same person for each observation, to maintain consistency in the observations.

The National Institute for Invasive Species Science