Karst Formation: Second Growth (Clearcut, CT, PCT) Forest Suitable for Timber Harvest, SE Alaska

This map was created to review data and facilitate conversations about the progress of transitioning to a second growth timber strategy in Southeast Alaska.

This map displays second growth (clearcut, CT, PCT) forest suitable for timber harvest on karst formations in Craig, Petersburg, Thorne Bay, Wrangell, and Ketchikan-Misty Ranger District of Tongass National Forest. Layers showing site index (the number of meters trees would be expected to grow in 50 years) and stand age class for karst areas are shown on this map. 

Karst formations were delineated using the "Transboundary Karst" dataset created by Audubon Alaska, which is availible on Data Basin at: https://databasin.org/datasets/dc84ca088f1f46e98c5913e97e52fdcf

Site index (the number of meters trees would be expected to grow in 50 years) is based on the "Transboundary Site Index Mapping" dataset, by Audubon Alaska (published 5/22/2012). 

The Conservation Biology Institute performed GIS analysis identifying the following areas based on criteria specified by Mater Engineering:

Areas on karst where: 1. Either clearcuts or commercial and precommercial thinning have taken place,  3. on acreage suitable for timber harvest with less than 72% slope (based on prior Forest Service analysis), 4. with null suitability values removed, 5. potential habitat conservation areas removed using Land Use Designations (“DESCRIPTION” = ‘Old Growth Habitat’), and 6. roadless areas removed (“CATEGORY” = '1B' or '1C').