International Society of Arboriculture
Through research, technology, and education, the International Society of Arboriculture will promote the professional practice of arboriculture and foster a greater worldwide awareness of the benefits of trees.
International Society of Arboriculture at a glance
In short: International Society of Arboriculture gave $61K across 1 grant in 2024 (avg $61K), mostly in Illinois. Source: 2024 IRS Form 990.
- Annual giving (2024)
- $61,268
- +0.8% vs 2023
- Grants made (2024)
- 1
- +0.0% vs 2023
- Average grant
- $61,268
- +0.8% vs 2023
- Median grant
- $61,268
- Total assets
- $15,617,040
- +8.6% vs 2023
- Primary geography
- Illinois (100% of itemized 2024 grant dollars)
- Latest 990 filing
- Form 990, 2024 View filing
Data from IRS Form 990, 2024; updated September 2026.
Who International Society of Arboriculture funds
How this funder distributes its grants
Top Recipients
Top recipient in 2024
The largest 2024 recipient was Tree Research and Education Endowment Fund ($61K).
Grant Size Distribution
5 grants across all recorded years
The most common grant size was in the $50–100K range: 3 grants of 5 (60%).
Geographic Focus
Where this funder awards grants
Grant Distribution by State
Share of the 2024 grant dollars on its one itemized grant.
States
Cities
How International Society of Arboriculture gives
- Giving grew 76% from 2021 to 2024. Method
From the foundation's IRS Form 990 filings. Methodology.
Giving History
Giving Over Time
Total grant dollars and number of grants per year
From 2019 to 2024, annual grant giving ranged from $30K (2020) to $91K (2022). In 2024 it made 1 grant totaling $61K.
Grants by year
Grant recipients and amounts by year
| Recipient | Purpose | Amount |
|---|---|---|
| Tree Research and Education Endowment Fund Naperville, IL | Support arboriculture research to benefit the professional arborists and unban foresters | $61,268 |
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Financial History
Multi-year comparison from IRS filings
| Filing year | Total Assets | Revenue | Expenses | Grants paid | Grants | Net Investment Income |
|---|---|---|---|---|---|---|
| 2024 | $15,617,040 | $11,573,930 | $10,674,901 | $61,268 | 1 | $736,257 |
| 2023 | $14,385,560 | $10,747,280 | $9,882,585 | $60,781 | 1 | $128,418 |
| 2022 | $12,667,373 | $10,071,372 | $8,880,457 | $90,978 | 1 | — |
| 2021 | $12,941,286 | $10,308,280 | $7,222,912 | $34,759 | 1 | $3,132 |
| 2020 | $10,397,561 | $7,156,880 | $8,066,767 | $30,300 | 1 | $-892,789 |
| 2019 | $11,767,254 | $8,987,074 | $10,248,586 | $60,036 | 1 | $184,393 |
About International Society of Arboriculture
Based on IRS filings
International Society of Arboriculture is a public charity, based in Atlanta, GA. IRS filing data is available from 2019 through 2024. As of 2024, the organization holds $15.6M in total assets. In 2024, it awarded 1 grant totaling $61K. Net investment income was $736K.
Leadership & Key People
Officers and directors from IRS filings
International Society of Arboriculture is led by Caitlyn Pollihan, CEO & Executive Director since 2024 (on filings since 2019); 6 of 26 officers listed in 2024 are compensated.
Officers on the 2024 filing
Caitlyn Pollihan
CEO & Executive Director
Executive Director → Ex-Officio Member, 2020
Ex-Officio Member → CEO & Executive Director, 2024
On filings since 2019
40 hrs/week
$192K (2019) → $360K (2024)
Nicolaas Verloop
President
Board Member → Member, 2021
Member → President, 2023
On filings since 2019
15 hrs/week
No compensation reported
Thomas Smiley
President
Vice President → President -Elect, 2023
President -Elect → President, 2024
On filings since 2021
10 hrs/week
No compensation reported
Alice Bagley
Director of Marketing
Director & Marketing → Director of Marketing, 2024
On filings since 2023
40 hrs/week
$113K (2023) → $118K (2024)
Chastity Austin
Director of Human Resources
Director & Human Resources → Director of Human Resources, 2024
On filings since 2023
40 hrs/week
$110K (2023) → $132K (2024)
Luana Vargas
Director of Credentialing
Director & Credentialing → Director of Credentialing, 2024
On filings since 2023
40 hrs/week
$125K (2023) → $127K (2024)
Freddie Harroway
Director of Finance
New on the 2024 filing
40 hrs/week
$133K (2024)
Jamie Vidich
Director of Educational Products
New on the 2024 filing
40 hrs/week
$117K (2024)
Gail Nozal
Vice President
Member → Secretary, 2021
Secretary → Vice President, 2023
On filings since 2019
5 hrs/week
No compensation reported
John Gathright
Member
Board Member → Member, 2020
On filings since 2019
5 hrs/week
No compensation reported
Christopher Boza
Treasurer
Member → Treasurer, 2024
On filings since 2020
5 hrs/week
No compensation reported
Carlos Llanos Rojas
Member
On filings since 2021
5 hrs/week
No compensation reported
John Coles
Member
On filings since 2021
5 hrs/week
No compensation reported
Randall Miller
Secretary
Member → Secretary, 2023
On filings since 2021
5 hrs/week
No compensation reported
Samuel Ma
Member
On filings since 2021
5 hrs/week
No compensation reported
Sharon Jean-Philippe
President- Elect
Treasurer → President- Elect, 2024
On filings since 2021
5 hrs/week
No compensation reported
Susan Day
Member
On filings since 2022
5 hrs/week
No compensation reported
Tadashi Touchi
Member
On filings since 2022
5 hrs/week
No compensation reported
Jason Grabosky
Member
On filings since 2023
5 hrs/week
No compensation reported
Jessica Sanders
Vice President
Member → Vice President, 2024
On filings since 2023
5 hrs/week
No compensation reported
Michael Watson
Member
On filings since 2023
5 hrs/week
No compensation reported
Lauren Marshall
Member
New on the 2024 filing
5 hrs/week
No compensation reported
Lori Brockelbank
Member
New on the 2024 filing
5 hrs/week
No compensation reported
Rebecca Johnson
Member
New on the 2024 filing
5 hrs/week
No compensation reported
Stephen Lane
Member
New on the 2024 filing
5 hrs/week
No compensation reported
Tim Walsh
Member
New on the 2024 filing
5 hrs/week
No compensation reported
Former officers (18)
- Former: Ashley Robinson (2023) — Director & Events
- Former: Chris Walsh (2019–2022) — President -Elect
- Former: Dana Karcher (2019–2022) — President
- Former: Russ Carlson (2019–2022) — Member
- Former: Janine Lester (2020–2022) — Member
- Former: Shirley Vaughn (2021–2022) — Member
- Former: Anne Beard (2019–2020) — President -Elect
- Former: Cecil Konijnendijk (2019–2020) — Member
- Former: Gordon Mann (2019–2020) — Member
- Former: Jim Flott (2019–2020) — Treasurer
- Former: Paul Johnson (2019–2020) — President
- Former: Pedro Castro (2019–2020) — Member
- Former: Scott Prophett (2019–2020) — Member
- Former: Skip Kinkaid (2019–2020) — Member
- Former: Tom Wolf (2019–2020) — Member
- Former: Herb White (2020) — Member
- Former: Nicloaas Verloop (2020) — Member
- Former: Tom Smiley (2020) — Member
Data from IRS Form 990 filings, 2019–2024. "On filings since" is the earliest filing we hold that lists the person; hours are average hours per week as reported.
Compensation Overview
From 2024 IRS filing
The highest reported compensation on the 2024 filing was $360K, to Caitlyn Pollihan (CEO & Executive Director). 6 officers or directors reported compensation on that filing.
Frequently asked questions about International Society of Arboriculture
How much does International Society of Arboriculture give each year?
International Society of Arboriculture gave $61K across 1 grant in 2024, according to its 2024 IRS Form 990. In 2023 it gave $61K across 1 grant.
How large is International Society of Arboriculture?
International Society of Arboriculture reported $15.6M in total assets on its 2024 IRS Form 990. Its revenue that year was $11.6M.
Where does International Society of Arboriculture operate?
International Society of Arboriculture has awarded grants in Illinois.
What is International Society of Arboriculture's EIN?
International Society of Arboriculture's EIN (Employer Identification Number) is 37-1004119. IRS Form 990 filing data is available on this page for 2019–2024.
Data last updated September 2026. Sourced from IRS Form 990 filings.
Data update history
(7)
When this profile's IRS filing data changed on Grantable
- Updated Form 990 for fiscal year 2019 (received by the IRS March 11, 2021)
- Updated Form 990 for fiscal year 2020 (received by the IRS May 14, 2021)
- Updated Form 990 for fiscal year 2021 (received by the IRS November 9, 2022)
- Updated Form 990 for fiscal year 2022 (received by the IRS November 15, 2023)
- Updated Form 990 for fiscal year 2023 (received by the IRS October 3, 2024)
- Updated Form 990 for fiscal year 2024 (received by the IRS October 23, 2025)
- IRS filings on file for fiscal years 2019–2024
Explore Open Grants
Browse active grant opportunities in International Society of Arboriculture's focus areas in our free grants database
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