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Trees Outside Forests Image-based Inventory (TOFii)

Research Issue

Severe dust storms of the 1930s in the Great Plains region of the United States spurred the creation of federal programs designed to combat soil erosion. Under the Prairie States Forestry Project (1935-1942), more than 220 million trees were planted in 33,000 windbreaks totaling more than 18,000 miles in a swath stretching from North Dakota into Texas. The purpose of planting trees in these formations was to slow desiccating winds and to protect soil. This sparked widespread adoption of agroforestry practices across the central United States, particularly windbreaks and riparian buffers. However, the current state of these resources is largely unknown because there hasn’t been a coordinated monitoring effort for several decades. While there are national efforts to inventory and monitor forests, these programs employ a definition of "forest" that have area and width requirements that often exclude agroforestry practices; hence, we refer to such trees as “Trees Outside Forests” (TOF). This lack of information has left decision makers unable to answer commonly asked questions, such as:

1. What is the extent of the TOF resource?
2. Where are TOF located?
3. What role do TOF serve on the landscape?
4. How is the TOF resource changing?

Our research seeks to fill this information gap and provide the answers to these questions.

Our Research

We have several inter-related activities underway with two main objectives:

1. Develop cost-effective, repeatable methods for extracting information from aerial imagery regarding Trees Outside Forests in the agricultural central U.S.
2. Produce usable GIS-ready data products and information for land managers and decision makers.

To that end, we are mapping tree cover over large areas using 1-m resolution imagery from the USDA’s National Agriculture Imagery Program in two phases:

• Phase 1: We have developed a method that we are using in conjunction with partner agencies to map all tree cover in North Dakota, South Dakota, Nebraska, Kansas, and the panhandle of Texas. Funding for these statewide mapping efforts comes from USFS Forest Inventory & Analysis Program, USFS State & Private Forestry, and state agencies.
• Phase 2: We have developed shape-based classifiers to infer the function of these trees on the landscape.

Additionally, we recently received a Microsoft A.I. for Earth and ESRI award under which we will be exploring cloud-based computing technology to speed up our mapping process.

In collaboration with the USDA Forest Service’s Geospatial Technology & Applications Center, a line intersect sampling tool was developed for use in estimating total length of windbreaks. In collaboration with partners, we have applied this tool for two different points in time for both Nebraska and Kansas. This process is a rapid assessment tool intended to provide some information as a bridge to a time when statewide mapping will become a more rapid process.

Expected Outcomes

A number of geospatial datasets will result from our mapping process. These datasets will be available as both file downloads and web mapping services. See the results section below for examples.

We will aggregate the results from these statewide datasets to produce summaries of the tree resources at the state and sub-state level (watersheds, ecoregions, natural resource districts, etc.). These summaries will be made available as fact sheets and other published materials.

State agencies are already using the geospatial datasets as a starting point for engaging land owners to consider windbreak renovation or adoption, specific to each farm’s situation dependent on factors such as condition of existing windbreaks, proximity to water, susceptibility of soils to wind erosion, etc.

Research Results

Kellerman, Todd; Benagas, Jospeh; Meneguzzo, Dacia; Liknes, Greg. 2019. Making Trees Outside Forests Count. U.S. Dept. of Agriculture Forest Service National Agroforestry Center Story Map.

Paull, Darci A.; Whitson, Jakob W.; Marcotte, Abbey L.; Liknes, Greg C.; Meneguzzo, Dacia M.; Kellerman, Todd A. 2017. High-resolution land cover of Kansas (2015). Fort Collins, CO: Forest Service Research Data Archive. Updated 27 November 2017. https://doi.org/10.2737/RDS-2017-0025.

Liknes, Greg C.; Meneguzzo, Dacia M.; Kellerman, Todd A. 2017. Shape indexes for semi-automated detection of windbreaks in thematic tree cover maps from the central United States. International Journal of Applied Earth Observation and Geoinformation. 59: 167-174. https://doi.org/10.1016/j.jag.2017.03.005.

Meneguzzo, Dacia M.; Liknes, Greg C.; Nelson, Mark D. 2013. Mapping trees outside forests using high-resolution aerial imagery: a comparison of pixel- and object based classification approaches. Environmental Monitoring and Assessment. 185: 6261-6275.

Research Participants

Principal Investigators

• Dacia Meneguzzo, USDA Forest Service Northern Research Station, Research Forester

Research Partners

• Todd Kellerman, USDA Forest Service National Agroforestry Center, GIS Specialist
• Darci Paull, Kansas State University – Kansas Forest Service
• Milda Vaitkus, University of Nebraska-Lincoln – Center for Advanced Land Management Information Technologies
• Lezlee Johnson, North Dakota State University – North Dakota Forest Service
• Doug Haugan, South Dakota Dept. of Agriculture, Division of Resource Conservation and Forestry
• Shruthi Srinivasan, Texas A&M University – Texas Forest Service