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Cofrin Center for Biodiversity

An Ecological Index of Forest Health Based on Breeding Birds

By: Erin E. Gnass Giese, Dr. Robert Howe, Dr. Amy Wolf, Nicholas Miller, and Nicholas Walton

Click to go to introduction. Link to introduction. Click to learn more about Indicies of forest health. Link to IEC Explained. Click to download the calculator. Link to the IEC calculator. Click to go to IEC instructions. Link to calculator instructions.

IEC Calculator Download

Before using the IEC calculator, please read all instructions carefully.

 

Computer Requirements:

MS Excel Version:

  • Windows:  MS Excel versions 5.0 (1993) or higher
  • Macintosh:  MS Excel versions 11.6.6 (2004) or higher
Download IEC Calculator

MS Excel Solver Add-in Installation:

Windows users:

  • MS Excel versions 2000-2003:  Go to the Tools tab and select Add-Ins….  Enter a checkmark next to the Solver Add-in box in the Add-ins window and select OK.  The Solver function can now be found in the Tools tab.

  • MS Excel versions 2007 & 2010:  Go to Excel Options (in 2007, found by clicking on the Microsoft logo action button; in 2010, found in the File tab).  Then select the tab Add-Ins on the left-side of the window.  Select the Solver Add-in under the heading Inactive Application Add-ins.  Then make sure that Excel Add-ins (found next to the word Manage at the bottom of the window) is selected and click Go… A small Add-Ins window will open.  Enter a checkmark next to the Solver Add-in box and select OK.  The Solver add-in can now be found under the tab Data and header Analysis.

Macintosh users:

  • MS Excel version 2004:  No download needed - Solver comes with MS Excel v 11.6.6.  Go to the Tools tab and select Add-ins.  Within the Add-ins box, enter a checkmark next to the Solver.xlam and then click OK.  The Solver add-in can now be found under the tab Data.
  • MS Excel version 2008:  You need MS Excel v 12.1.2 or later.  Go to this link (http://www.solver.com/solver-2008-mac), download SolverSolver must be re-opened each time you use it. 
  • MS Excel version 2011:  No download needed - Solver comes with MS Excel v 14.1.0.  Go to the Tools tab and select Add-ins.  Within the Add-ins box, enter a checkmark next to the Solver.xlam and then click OK.  The Solver add-in can now be found under the tab Data.

Bird Data Requirements:

In order to use the IEC calculator, bird monitoring points must be from a northern mesic forest landscape (Curtis 1959) in parts of Bird Conservation Region (BCR) 12. In order to avoid bias, points should be positioned at least 250 m apart from each other (Howe et al. 1997).  Bird data must consist of standard 10-minute unlimited-radius point counts (Howe et al. 1997; Knutson et al. 2007) collected during the breeding season (approximately late May through early July).   These methods require expert bird observers* to record all birds seen or heard (including flyovers), regardless of distance to the observer, from a stationary point count location.  Point counts should be conducted during the early morning hours and in good weather with minimal wind (<12 mph) and rain. Ideally, points should be located at least 100 m within a forest area. 

*To ensure that high quality bird data are collected, visit the Birder Certification Online website and have your observers validate their bird identification skills.

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