Southern Rockies Reforestation Tool (SRRT)

Abstract

The Southern Rockies Reforestation Tool (SRRT) identifies climatically and topographically suitable sites to plant ponderosa pine and Douglas-fir seedlings after wildfire in the Southern Rocky Mountains, USA.

Purpose

High-severity wildfire activity in ponderosa pine and Douglas-fir forests of the Southern Rocky Mountains has increased since the 1980s, and future projections suggest additional increases over upcoming decades. Natural tree regeneration in the interior of high-severity patches is often insufficient to re-establish forests, leading to conversion to grassland or shrubland communities for decades following fire.

Tree planting is a common post-fire management activity that may help to offset forest loss due to high-severity wildfire. Because tree planting requires a considerable investment of time and money – seeds must be collected and grown into 1- or 2-year old seedlings, planting sites must be identified and prepared, and finally, seedlings must be planted – efficiently tackling forest loss will require a detailed understanding of how to best allocate resources.

A simple tool that uses best-available science to identify climatically and topographically suitable sites could help managers optimize planting efforts by focusing on sites with the greatest chance for success. To that end, we have developed the Southern Rockies Reforestation Tool.

Overview and Applicability

This tool was developed using Google Earth Engine, a cloud-based computing platform that is designed to efficiently perform calculations using spatial datasets across large areas. The tool only requires a small number of simple user-specified inputs, such as the area of interest, the species to be planted, and the year the area was burned. In the background, the tool obtains and processes pre- and post-fire satellite images for the area of interest and uses these images to identify severely burned areas. Based on statistical models developed in Rodman et al. (2020), a synthesis of natural post-fire regeneration in over 1,300 plots throughout the Southern Rocky Mountains, climate data and topography are used to predict the locations that are most suitable for planted ponderosa pine or Douglas-fir seedlings following fire. 

Optionally, the user can restrict the layers to places adjacent to roads and flatter slopes, where post-fire planting might be most cost-effective and feasible. After fire severity and seedling suitability layers have been developed, the user can explore them using the Map Window by zooming and panning. There are also options to download the layers for use in GIS software such as ArcGIS and QGIS. Currently, all suitability maps are restricted to historical species ranges, but maps that include upslope areas (to help in planning assisted migration activities) will be developed in the future.

Inputs

Area of interest, species to be planted, year of fire occurrence, maximum slope angle for planting, maximum distance to road for planting, climate scenario (i.e., current climate, future climate – moderate emissions, future climate – high emissions).

Outputs

Raster format spatial datasets of fire severity (RdNBR) and climatic/topographic suitability for Douglas-fir or ponderosa pine seedlings in the area of interest.

Requirements

SRRT is accessible from internet-accessible mobile, laptop, and desktop devices.