Photo Point Monitoring Protocols: Invasive Species Monitoring

Sample Project: Forest Habitat Survey

Description:
  • Can determine change in number/density/percent cover of invasive species (or special status/endangered species) in a specific area
  • Can obtain a quantitative value for monitoring (i.e. Determine how percent cover of invasive and/or dominant species in quadrat changes with the season)

 Part 1: Determining quadrats for random sampling

Equipment Needed:

  • Aerial photograph of site on computer, including coordinates (from GoogleEarth, etc)
  • Numbered grid overlaid on photograph
  • Random number generator (available online)
  • Hard copy of aerial photograph or map of the area

Selecting random quadrats

1.     Create a numbered grid and lay it over the aerial photograph of your site. If this is difficult to do on the computer, laying a transparent numbered grid on the computer screen works well.

2.  Use the random number generator to determine where on grid you will be sampling.

3.     Move the mouse arrow to that box on the screen so that you can record the coordinates associated with the four corners of the quadrat.

4.     Mark the quadrat locations and numbers on a hardcopy of the map to take into the field.

                 Note: Just a general idea of the location, in combination with your GPS unit, will make it much easier to locate the predetermined quadrat locations. A problem  encountered with this method was randomly selected areas being inaccessible due to overgrown vegetation. Attempt to reach as close to your predetermined site as possible, and be sure to record the exact coordinates of where you surveyed.

 

Part 2: Collecting the data

Equipment needed:

  • Map of site with predetermined quadrat locations and GPS coordinates noted
  • GPS unit
  • Digital camera that as been calibrated with GPS (see Calibrating your Digital Camera with your Trimble GPS Unit)
  • Large tripod
  • Tape measure
  • Brightly colored stakes to visually identify the corners of the quadrat – for photos and onsite determination of percent cover
  • Field book
  • Appropriate field guide to flora or fauna of area, if needed

What to photograph:

·        Pre-determined quadrats

·        Use meter X meter quadrats if you want to accurately measure species abundance or percent cover

  • If larger quadrats are desired, to cover a larger area, you could take multiple photographs within the quadrat, which could later be put together for the large view.

When to photograph:
  • Most useful to photograph with the desired species is in full bloom
  • Midday: “photos taken near midday have less shadowing and may be easier to interpret”[1]

Procedure:

1.     Using your GPS unit, find pre-determined quadrats at your site and mark their four corners using the tape measure and brightly colored stakes

2.     Calibrate your digital camera with your GPS unit

3.     Set up tripod such that is centers the camera above and at the middle of the quadrat for an aerial view

4.     Be sure GPS unit is located by tripod to get coordinates of quadrat location

5.     Include scale bar appropriate to the species you are monitoring and photo ID tag with site name, photograph number, quadrat number, and species name

6.     If multiple photographs are taken to document a large quadrat, be sure to include some reference point (i.e. a stake) in each consecutive photograph for overlap and ease in putting pictures together to view larger scene

Determining abundance or percent cover of desired species:
  • Can be done on computer or by hand
  • On computer, once the photographs are downloaded, programs can calculate the exact area covered by the invasive species
  • By hand, a transparent grid can be overlaid and the percent cover calculated

Webpage and project content by:

Dr. Joel Elliott, University of Puget Sound, Department of Biology
Liz Fly, University of Puget Sound, Department of Biology
Erin Spear,  University of Puget Sound, Department of Biology

This project is funded by the Northwest Academic Computing Consortium and the University of Puget Sound

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jkelliott@ups.edu | lfly@ups.edu | Send Feedback!