This document discusses methods for inventorying and monitoring tree resources outside of forests using high-resolution aerial imagery. It summarizes research mapping trees in agricultural landscapes to quantify their ecosystem functions. The research uses object-based image analysis of National Agriculture Imagery Program imagery to map trees at county-scales. Functions like windbreaks and riparian areas are identified. Historical windbreak plantings are also digitized from archives to assess changes over time. The research aims to fill gaps in quantifying trees outside forests to better account for their benefits.

1. Inventory and Monitoring of Tree
Resources in Agroecosystems
Using High-Resolution Imagery
Todd Kellerman
USDA Forest Service
National Agroforestry Center

2. USDA National Agroforestry Center
Mission
Accelerate the adoption of agroforestry
US Forest Service
Research & Development
State & Private Forestry
Natural Resources
Conservation Service
Agroforestry: The intentional integration of
agriculture and forestry to create productive and
sustainable farms, ranches, and woodlands.

3. What is Agroforestry?
…..the intentional combining of agriculture and
working trees to create sustainable farming and
ranching systems. 3

4. USDA Agroforestry Strategic
Framework
Objective 2.2—DISCOVER: Conduct
interagency, multidisciplinary research to
advance agroforestry science and technologies.
4. Develop the knowledge and technologies to improve the
accounting of agroforestry benefits by: a) Establishing
measurement, inventorying, and monitoring protocols that more
accurately reflect agroforestry plantings and their impacts.

5. Trees in the Great Plains?

6. The Dust Bowl
Black Sunday – April 14, 1935
‘The storm carried twice as much dirt as was dug out of
the earth to create the Panama Canal. The canal took
seven years to dig; the storm lasted a single afternoon.
More than 300,000 tons of Great Plains topsoil was
airborne that day.”
from “The Worst
Hard Time” by Tim Egan

7. The legacy…
Shelterbelt Program of 1935-1942
• 30,233 shelterbelts
• 220+ million trees
• 18,600 linear miles
“Baby picture” of
the 1st tree planted.

8. Shelterbelts
Year Planted
35
36
37
38
39
40
41
42
Prairie States Forestry Project – Nebraska
Nebraska PSFP
Year Sites Counties
1935 66 5
1936 408 11
1937 701 14
1938 2,166 25
1939 2,257 39
1940 1,742 46
1941 1,605 45
1942 1,077 49

11. ?

12. Background – FIA Forest Land and “Trees Outside Forests” (TOF)
• US Forest Service Inventory
• Forest Inventory & Analysis (FIA)
• National sample-based inventory
• How do we define TOF?
• Trees on lands that do not meet FIA’s
definition of forest land.
• Must have/had 10% or more canopy cover
• 1-acre in area
• 120-feet wide
These critical ecological
resources not being counted

13. How wide is the gap between FIA forest land and TOF?
• There is MUCH interest in the TOF
resources in the U.S. but very little data
• USDA Agroforestry Strategic Framework
• Calls for inventory & monitoring of agroforestry
• State Forestry Agencies
• Rural ecosystem services
• Invasive species
• Carbon sequestration
Emerald Ash Borer

14. How do we fill these inventory gaps?
• MISSION
• Our mission is to develop methods for efficient
mapping of trees outside forests (TOF)
resources as well as for identifying and
quantifying their ecosystem functions in rural
landscapes.
• Sole source of imagery is NAIP
• Fill the gap and extend the FIA inventory to all
lands
• Create a baseline TOF inventory that can be
monitored over time
• In doing this, we can meet the needs of USDA
Strategic Framework and other natural resource
agencies and personnel
National Agriculture Imagery Program (NAIP)
• 1-meter resolution; 4-band
• Publically available
• Frequently flown (typically every other year)
• Wall-to-wall coverage

15. Image-based approach to mapping trees
• Object-based image analysis (OBIA)
• Simulates human interpretation of
identifying objects in an image
• Groups pixels into “image objects” that are
representative of your landscape features
of interest
• Examples: buildings, roads, groups of trees
• Classification occurs on image objects rather
than individual pixels
• “better looking” output maps
• High-resolution (1-meter) GIS datasets
• Identify and quantify tree and other land cover
• Produced at the county-level for easier data
management and distribution

16. Process
• Image segmentation
• Use eCognition software to segment the aerial
photos into “image objects”
• Supervised classification using sampling of
training data
• Use custom made ArcTools in ArcMap running
computer learning algorithms using R

17. Legend
Tree
Other
Water
City/Town

18. Legend
Tree
Other
Water
City/Town

19. Antelope County, NE
(858 sq. mi.)
Source Attribute Measured Estimate (acres)
Forest Inventory
and Analysis (FIA)
Forest land
(1-acre minimum)
8,309
1-m OBIA map tree canopy 27,038
NLCD
‘forest’ classes
+woody wetlands
class
12,571
22,768

20. Monitoring Change/Trends
2009 2012
33
acres
lost

21. Beyond forest land: additional 1.3 million acres of TOF
2015

22. Additional 600,000 acres of tree cover beyond forest land
2014

23. Output Products
• Science Delivery
• FS R&D data archive
• file download
• ESRI story maps
• Web-mapping services
• Application
Targeted windbreak renovation
• Target Marketing and Tools for Engaging
Landowners Effectively (TELE) will be used
to engage landowners in windbreak
establishment and/or renovation

25. Phase II: Determining TOF function
Hypothesis: shape can be used to determine function – windbreak vs. riparian

26. New shape
indexes separate
narrow, planted
windbreaks from
narrow riparian
corridors and
help determine
different
functional types
of windbreaks.
Liknes, G.C.; Meneguzzo, D.M., Kellerman, T.A. 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.
Beyond tree cover – inferring tree function

27. TOF Category Area (acres) Average size (acres) Number of features
N-S windbreak 338 1.1 318
E-W windbreak 3,252 3.6 900
L-windbreak 698 1.5 474
Complex windbreak 2,716 22.4 121
Riparian 5,096 4.9 1,048
Blocks/isolated patches (0.25 ac+) 5,172 2.2 2,309
Forest 40 acres+ 1,404 66.9 21
Patches less than 0.25 acres 149 0.1 1,104
Total 18,825 3.0 6,295
additional 1,014 acres of tree cover compared to FIA estimate of forest land
N-S windbreak
2%
E-W windbreak
17%
L-windbreak
4%
Complex
windbreak
14%
Riparian
27%
Blocks/isolated patches
(0.25 ac+)
28%
Forest 40 acres+
7%
Patches (< 0.25
acres)
1%

28. Land Cover Class Potential TOF Functions Percent of Buffer Area
Grass/pasture Field windbreak, silvopasture 60%
Corn Field windbreak 19%
Soybeans Field windbreak 9%
Developed/open space
Farmstead winbreak, living snowfence, visual
screen, field windbreak 6%
Woody wetlands Riparian buffer 3%
Deciduous forest Part of forest 2%
Developed/low intensity
Farmstead winbreak, living snowfence, visual
screen, odor mitigation 1%
Alfalfa Field windbreak 1%
Ecosystem functions for
Antelope County, NE

29. • Obtain linear
estimates (miles)
of windbreaks
• Assess change
over time
• 2006 and 2016
(NE)
Digital Line intersect sampling
• Sample based
inventory
• Windbreaks only
Cate, N.; Schaaf, A.; Clark, J; Liknes, G; Schoenberger, M.; Meneguzzo, D.; Kellerman, T. 2016. Line Intersect Sampling Tool. GTAC-
10113-RPT1. Salt Lake City, UT: U.S. Department of Agriculture, Forest Service, Geospatial Technology and Applications Center

30. Windbreak change: Nebraska results (2006 – 2016)

31. Historical Windbreaks Mapping
• Complete set of Prairie States
Forestry Project archives at
National Agroforestry Center
• Township/Section maps with hand
drawn windbreaks
• Owner, tree species, spacing, photos,
etc.
• Original plantings from 1935-1942
• Locating and digitizing using current
aerial imagery

32. Nebraska PSFP Status 2003 - 2016
Year Intact % Intact Partial %
Partial
Removed % Removed Total_Sites
Status 2003 5,002 50 3,107 31 1,913 19 10,022
Status 2010 4,544 45 3,333 33 2,145 21 10,022
Status 2014 4,272 43 3,408 34 2,342 23 10,022
Status 2016 4,040 40 3,573 36 2,409 24 10,022

33. ‘Phase III’: Value-added analyses
• Soil erosion, water quality, etc.
Make mapping go faster!
• Cloud computing
• Microsoft’s AI for Earth award
Project title: Accounting for trees in agricultural landscapes
What’s next?

34. North Dakota – in progress
South Dakota – in progress
Nebraska – 2009 in progress; 2014 (review
complete)
Kansas – 2015 published
Texas – in progress
Research Participants
Principal Investigator
•Dacia Meneguzzo, USDA Forest Service Northern Research Station, Research Forester
•Greg Liknes, USDA Forest Service Station, Northern Research Station, Research Physical Scientist
Research Partners
•Todd Kellerman, USDA Forest Service National Agroforestry Center
•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