Friends of the Urban Forest

What do they do?

FUF's implementation role includes working with residents and public agencies, selecting planting sites and species, establishing trees, organizing community planting, and caring for young trees. The intervention is therefore not simply handing out a seedling. Site approval, infrastructure, labor, water, and several years of maintenance can all be necessary complements. An inexpensive tree by itself is not the complete health-producing service.

The FY2025 impact report gives the clearest newly checked annual whole-organization planting count: 1,506 new street trees. It calls this the largest annual total in a decade. Its neighborhood table includes 245 in the Mission, 204 in the Sunset, 184 in Bayview, 136 in Visitacion Valley, 86 in the Excelsior, and smaller totals elsewhere. These counts support San Francisco implementation, not measured resident-level exposure or a finding that all beneficiaries live in the city. The model's 100% Bay and 100% San Francisco health shares are nested beneficiary-geography assumptions. Commuters, visitors, migration, and regional ecological effects can make location and residence differ.

The same annual report records 2,598 care visits and about 1,200 trees watered weekly. Care visits are repeated work on a stock of trees, potentially including earlier planting cohorts. Adding them to new plantings would double count exposure and mix flows with stocks. Similarly, the workforce program's 619 trees are part of the organization's planting activity, not an extra health denominator. Eighteen workforce participants (ten Green Crew and eight New Roots), 1,846 volunteers, and 6,806 volunteer hours are useful operational information but not automatically additional healthy life-years.

A city workforce report presented July 10, 2025 records 1,502 street trees as of June 30, 2025, the same care-visit total, and approximately the same weekly watering stock. The four-tree difference is small, but we do not force the sources to agree by inventing a reconciliation. The official annual report's explicit FY2025 total is preferred; the city total is retained as a sensitivity. This replaces the previous 1,412 grant-associated FY2024 count, which was not proven to be a full organization census.

Sidewalk gardens, yard-tree distribution, youth and workforce activity, and community engagement are all inside whole-organization expense. We do not allocate their costs away to make the tree pathway appear cheaper. We also do not add separate health effects for them without evidence. This asymmetry makes the estimate partial in outcome coverage, but not a lower bound: the quantified street-tree scalar could itself overstate benefits.

FUF's current yard-tree page describes 400 distributed cumulatively since February 2023 and funding through August 2027, including an Arbor Day Foundation Community Roots grant for the current season. Those are not another 400 annual street-tree plantings. The funding statement is relevant to baseline substitution in that program but cannot be generalized to the entire street-tree portfolio.

The annual delivery and resource counts above come from the FY2025 official impact report, compared with the July 10, 2025 city presentation. The separate funded program is described on the yard-tree page.

Spending breakdown

We inspected the three latest located original Form 990 returns, not just an aggregator's summary. All use accrual accounting. Fiscal years end in June. Original return identifiers are 202440179349300544 for FY2023, 202541029349300739 for FY2024, and 202611049349302071 for FY2025. The latter was filed April 14, 2026. No later original filing was located in this review.

FUF — functional expense shares

Fiscal years ended June; original whole functional expense, not lower annual-impact-report expense.

Shares are calculated as category expense divided by the stated annual denominator. Rounding may make displayed shares differ slightly from 100%.

The functional expense rows sum exactly to whole expense in each year. Government grants are a component of revenue, not extra resources to add to total revenue. The original event, gaming, and inventory direct-expense lines do not show a separate netted expense requiring an add-back. This differs from organizations where a return's headline expense omits costs netted against fundraising revenue.

FY2025 government grants of $3,761,445 are about 73% of total revenue. This is strong evidence that public funding is a central part of the organization, not a minor outside alternative. It is not evidence that 73% of every donor's gift is displaced, nor that all government revenue is restricted to the street-tree output used here. Grant restrictions, renewal dates, allowable costs, and staff capacity determine how an ordinary gift changes the funded plan.

Reported deficits were $437,089, $666,455, and $268,035 across the three years. Falling net assets can support concern about financial sustainability, but a deficit is not a priced marginal planting opportunity. A gift might preserve staffing, meet restrictions, rebuild liquidity, reduce a planned drawdown, or expand an approved planting tranche. These uses have different counterfactual effects. The model's funding factors are explicit priors over such uncertainty, not conclusions drawn mechanically from the deficit.

FY2025 total assets were $3,342,184 and liabilities $1,015,116. Cash plus savings was about $1.055 million, while pledges receivable were $1,439,190. Receivables are not cash on hand and net assets are not synonymous with unrestricted spendable reserves. This is one reason to call the denominator reported accounting expense rather than verified cash spending. Public information here does not identify the unrestricted cash runway or the status of every pledge.

The original return's expense categories also show why whole-cost accounting matters. FY2025 officer compensation was $453,606, other salaries $2,595,830, benefits $478,549, payroll taxes $253,512, and occupancy $207,055. These are subsets of total expense, not additional costs. Skilled and administrative labor cannot be excluded merely because the visible output is a tree. Nor does a workforce program's social value make its staff and support costs disappear.

The official impact report presents a different financial summary: revenue $5,232,031.76 and expense $5,391,171.48, with program expense $3,965,388.77, administration $866,999.17, and development $558,783.54. Compared with the original filing, its expense is $18,923.52 lower and revenue $89,971.76 higher. No reconciliation was located. We use the original filing consistently, disclose the discrepancy, and do not combine whichever components produce a cheaper result. The discrepancy is too small to resolve the main health and additionality uncertainty.

Donated resources require a separate boundary. FY2025 reports 6,806 volunteer hours. At illustrative opportunity costs of $25 or $50 per hour, those are $170,150 or $340,300 annually, not extra cash expenses. Public maintenance, water, resident time and infrastructure are also incomplete external resources. We do not add an inherited gross-resource multiplier to these items as though the inventories were disjoint. The headline retains organizational expense; it is not a complete societal-cost estimate.

Accounting sources: original FY2023 return, FY2024 return, and FY2025 return. The differing public summary is on page 12 of the official impact report linked above.

Monitoring, health and income evidence

The purpose of planting and establishment care is to change the neighborhood environment: shade, greenery and exposure to heat or pollution. That is a plausible health mechanism, but planting counts are not measured health outcomes. The current model uses a primary observational mortality association, with separately identified causal, local and life-years judgments. It does not keep an unexplained constant QALY-per-surviving-tree-year coefficient.

Portland mortality association and the population denominator

Donovan and colleagues' 2022 primary paper studies annual nonaccidental deaths in Portland census tracts. Its age-band associations are 0.154, 0.262 and 0.306 fewer deaths per 100,000 tract residents per tree planted in the preceding 1–5, 6–10 and 11–15 years. The young-tree confidence interval includes zero. The reported mean tract population is 4,318. The conversion is therefore coefficient × 4,318 / 100,000, not coefficient deaths per tree, and not multiplication by the population of the entire city for a single tree.

These are ecological associations. Covariate adjustment does not remove every difference between greener and less green neighborhoods, selection into planting, migration or changes in residents' health. The study does not establish the causal effect of one additional San Francisco tree or remaining quality-adjusted years per averted death. Nonaccidental deaths already include cardiovascular deaths, so the model does not add a cardiovascular channel. Nor do we separately add heat, mental-health or biomarker credits that could overlap the same pathway.

The current bridge retains 10% of the association as a causal judgment and 50% for transfer to San Francisco. It assumes five remaining quality-adjusted years per genuinely prevented death. These three numbers are analyst assumptions, not fitted estimates or measured local outcomes. The cautious and favorable cases vary them together without assigning invented probabilities. Applying historical age-band associations prospectively to a new cohort is itself a transport assumption, not an experimentally validated forecast.

Planting, survival and the finite exposure window

Portland's exposure measure counts trees planted, not trees still alive. Tree-death data were unavailable. Unknown attrition is therefore already inside the observed planting association. We do not multiply a 75% establishment factor and 6% annual mortality onto this bridge again. This does not assume San Francisco trees survive perfectly: matching local and Portland survival could support a relative-cohort adjustment, but current data do not identify one.

The current calculation applies the age-band coefficients for fifteen years, discounted at 3% at each year's midpoint. It adds neither an extra maturation ramp nor a separate lag to those age bands, and claims no benefit beyond that window. Nursery trees were several years old at planting; years since planting are not biological age. A historical San Francisco study's selected species had substantial long-term survival, but that abstract is not a current FUF cohort census. Species, microclimate, care, canopy growth and replacement remain important for the local transport judgment.

Experimental greening evidence and its limits

The Philadelphia cluster-randomized vacant-lot trial supports the possibility that changing a neighborhood environment improves some self-reported mental-health outcomes. Its intervention combined rubbish removal, grading, grass, trees, fencing and maintenance. It neither isolates scattered street trees nor provides a FUF QALY coefficient. We do not turn relative symptom reductions into absolute reductions in clinical depression among all nearby residents.

The Green Heart project reports inflammatory-marker differences after intensive neighborhood greening. Those intermediate outcomes do not identify prevented clinical events without a validated causal bridge. This evidence informs plausibility, not an additional quantified benefit.

Temporary income: ten Green Crew participants, not all payroll

FY2025 reporting distinguishes ten Green Crew participants and eight New Roots participants. Their combined 619 trees are already inside the 1,506 annual plantings. The April 2026 Green Crew posting offers $23.68/hour, 24–30 hours weekly and a temporary six-month position. It is not evidence that all eighteen participants earned that wage, or that the earlier ten worked exactly the current schedule.

The model combines the ten-person annual scale with the current midpoint of 27 hours over 26 weeks as a cross-vintage projection. Six-month gross pay is $16,623.36. We assume half replaces counterfactual earnings and 75% of the remaining increment survives taxes, benefit withdrawal and work expenses: $6,233.76 in incremental household resources. These incidence assumptions and the $50,000 annual household-resource baseline are judgments, not participant measurements.

Using the Coefficient Giving reference crosswalk, the six-month resources are annualized inside the logarithm and credited for six monthly periods, discounted at 3%. We do not repeat them as annual gains after the program. Postprogram earnings receive no positive central credit because reported employment transitions have no comparison group, wage amounts or durable follow-up. Existing staff salaries are ordinary labor payments, not automatically added income benefits. Job-related harms or recipient burdens can be negative; they do not disappear merely because a placement fails.

Tree health and temporary participant resources concern different mechanisms. No separate financial-distress or employee mental-health benefit is added, avoiding an unsupported overlapping welfare channel. Rent, energy and property-price effects remain unquantified rather than being assigned a generic multiplier.

Monitoring priorities

The highest-value next evidence is a dated, approved but unfunded planting and care plan: sites, staff, water, maintenance handoff, expected grant receipts, private funding and the alternative without the gift. General appeals, accounting deficits and citywide grant announcements do not identify this tranche. A philanthropic contribution may complement public money by solving a bottleneck, or may substitute for another payer; neither is established by the government-revenue percentage alone.

Planting cohorts should distinguish first plantings, replacements, deaths, species, survival, canopy growth and maintained sites. Repeated care visits and watered stock are not additional unique beneficiaries. Comparing these cohorts with the Portland exposure definition would be more useful than adding another arbitrary survival haircut. A credible local comparison would also examine migration, pre-existing health trends and neighboring exposure.

Workforce monitoring should separate Green Crew from New Roots and record actual paid hours, completion, taxes, benefits, work expenses, preprogram earnings and a defensible comparison group. Six reported employment transitions do not identify a durable wage gain. Longer-term earnings, household incidence and displacement are important open questions, not automatic additions to the central estimate.

Current financial records should continue to distinguish organization expense, government revenue, dated cash balances and receivables. The three-year mean original-return expense is $5,246,177. No prevention-only or planting-only denominator is invented to lower the price. Current giving-room verification would improve additionality but would not alone validate the mortality-to-health conversion.

Revision and reproducibility

The October 1 calibration rechecked the FY2025, FY2024 and FY2023 original returns, official annual report, current Green Crew posting, current care and workforce pages, city workforce report and primary Portland paper. Source receipts and closed researcher intervals are preserved separately. Older experimental greening and local-survival evidence is retained with its actual limitations rather than relabeled as a new local trial.

The API exposes the current explicit health/income ledger, scenario diagnostics and the frozen prior calculations. The source-versus-judgment distinction, net-resource assumptions, geographic assignment and signed null/harm boundaries are part of the estimate. No verified marginal funding offer or transaction is claimed.

Qualitative assessment

FUF combines a concrete local implementation role with environmental and workforce goals. Low-canopy targeting, establishment care, community participation and training are reasons to investigate it. Gardens, biodiversity and aesthetics may also matter without being forced into invented QALYs. The organization has current program and job information and three recent original financial returns; these establish activity and accounting, not a verified marginal donation opportunity.

The main quantitative uncertainty is not whether trees exist. It is the causal health effect of additional exposure relative to existing city and private plans. A fifteen-year association in Portland is not a local intervention trial. Species, climate, resident selection, canopy, baseline mortality and maintenance can all change the result. Counterfactual wages and taxes can make the temporary-income increment much smaller than payroll; postprogram gains could matter but are currently unmeasured.

The central model includes all organizational expense but only two quantified outcome channels. That makes it incomplete, not automatically conservative: the included health bridge can overstate effects. External public maintenance, resident time, water and infrastructure costs are not comprehensively priced. Allergens, sidewalk damage, failure risk and displacement need species- and site-specific monitoring. Signed stresses keep possible harms visible rather than suppressing them whenever benefits fail.

We retain FUF as a systems-oriented research candidate. Its general giving link is not an accepted offer for a priced additional planting or workforce tranche. A donor considering a large commitment should obtain the additional plan, obligations and counterfactual funding before relying on the modeled ratio. This judgment concerns the evidence available, not a finding that the organization lacks value or legitimacy.

What do you get for your dollar?

What do you get for your dollar?

Our conditional central estimate is about $660K per DALY, defined here as one modeled equivalent year. It covers neighborhood tree exposure and a small temporary-workforce resource contribution, not measured clinical QALYs alone. FUF's expense divided by its annual plantings is about $3,592 per planting equivalent. That is a retrospective allocation of all organizational costs, including gardens, workforce activity and overhead—not a quote for purchasing an extra tree.

For reproducibility, an illustrative $100,000 donor budget divided by FY2025 expense of $5,410,095 gives an organization-budget share of 0.018484. Multiplying by 1,506 annual trees and a 40% gift-response assumption gives 11.134740 incremental planting proxies. Half of their beneficial exposure is assumed net new relative to replacement or earlier planting by another payer. Gift response and net-new exposure describe different counterfactuals; the 50% exposure factor does not also reduce workforce jobs or implementation harms.

For each year t=1 through 15, gross health per planted-tree proxy is age-band mortality coefficient × 4,318 / 100,000 × 0.10 causal retention × 0.50 local transfer × 5 remaining quality-adjusted years / 1.03^(t−0.5). Summing gives 0.03 gross health years per incremental planted-tree proxy. Applying net-new exposure and subtracting 0.002 health-equivalent harm per implemented tree gives 0.15 health years per illustrative donor budget. The harm allowance is a judgment, not an observed FUF injury rate.

Workforce scale is ten Green Crew participant equivalents. The same budget share and a separately adjustable 40% job-additionality judgment give 0.0739358551 additional six-month participant equivalents. With $6,233.76 in net incremental resources and a $50,000 annual household baseline, each monthly term is (0.5 / 12) × ln(1 + $12,467.52 / $50,000), discounted to that month's midpoint. Six months yield 0.06 income-equivalent years per participant, or 0.0040847089 per donor budget.

The combined denominator is 0.1515675013 years. Ten times donor cost divided by it gives $660K. Income-equivalent years are a normative comparison unit, not extra measured healthy life years. Both components are assigned once to the same modeled geographic portfolio; SF is nested inside the Bay total, never added to it. Reducing local attribution leaves donor cost unchanged.

The favorable case uses 75% tree/job response, 75% net-new exposure, 25% causal retention, 75% local transport, ten remaining health years, 30 weekly hours, 25% counterfactual earnings and 90% net resource retention. The cautious case uses 20% response, 25% net-new exposure, 2% causal retention, 25% transport, three remaining health years, 24 hours, 75% counterfactual earnings and 50% net retention. These are joint judgment stresses, not a confidence interval, posterior distribution or weighted expected value. Different combinations can give other prices.

Explicit signed cases preserve implementation harms when health benefit is null and incurred recipient costs when jobs are not additional. Funding replacement with no physical or applicant exposure gives zero, not a cheap positive price. No separate public-payer saving, landlord benefit, durable earnings gain or workforce-tree multiplier is added.

What changed from the earlier calculation?

The frozen earlier engines remain available as historical diagnostics. Their source-updated weighted illustration was $94K and their central case $165K per DALY-labeled units. They used unsupported constant health scalars per surviving tree-year; their favorable world supplied 84.9% of net expected benefit. Those are not the current ranking estimate. The current bridge exposes the mortality denominator, causal and transport assumptions, finite age bands and temporary net resources; it removes independent survival stacking and invented probability-weighted averaging. The resulting deterioration is a change in the model, not evidence that FUF's real-world effectiveness declined on this date.

The new model is still weakly identified. Better accounts cannot establish causal health effects or a donor-additional tranche. A more defensible local health study, counterfactual planting plan or participant-income follow-up could substantially change it in either direction.

Funding and previous grants

The earlier report relied on a city contract that ended in August 2025. That is no longer an adequate description of the publicly visible baseline. A more recent San Francisco County Transportation Authority article describes $1.1 million in transportation sales-tax support alongside $2 million in capital improvement funding and $3 million in federal Inflation Reduction Act funding, within a program of up to 2,500 trees through June 2026. A specific project involves approximately 407 trees in Districts 9, 10, and 11. These are nested program figures, not additive counts, and not all funds are FUF revenue.

A November 2025 Public Works account separately describes a $12 million federal grant for 3,500 trees and more than $7 million in workforce planting and watering grants to local nonprofits, with 1,800 trees and maintenance of up to 3,000 young trees over the following two years. We do not assume these announcements are disjoint from other city programs or that their full balances remain available today. They nevertheless show a funded pipeline extending beyond the old contract. Saying that there is no known later public activity would be wrong.

The same account describes FUF and a neighborhood partner investigating planting sites where earlier trees failed because of vandalism or inadequate care. This makes the replacement and stewardship issue concrete. Replanting can still produce health benefits compared with leaving a site empty, but a new planting count does not by itself identify net canopy gain. If the city or another partner would have replaced the tree shortly anyway, the incremental exposure is only the delay avoided.

Public funding can complement donations as well as displace them. Private money might pay for an unfunded enabling task, maintain staff between reimbursements, or secure sites needed to use an existing grant. In such a case, the gift could be highly consequential. Alternatively, it could finance activity already planned, shift another donor's contribution, or replenish reserves. The public evidence does not choose among these cases. A statement that public funding exists is not a proof of zero additionality; a fundraising appeal is not a proof of positive marginal capacity.

The central funding response of 40% and favorable response of 75% remain inherited analyst priors. They are deliberately not replaced by the share of government revenue or by a contract's dollar total. The model asks what fraction of the historical whole-budget output equivalent becomes additional exposure because of the gift. This factor includes displacement and organizational response, but cannot capture every non-linear bottleneck. A site-specific gift plan could have a different allocation and cost structure.

The direct giving pathway is a general donation route. It is not a verified offer to produce a number of additional trees at a fixed price. Historical cost illustrations, including a roughly $2,500 tree package in an older impact report, are not current marginal quotes. Likewise, corporate sponsorship levels identify recognition categories, not necessarily incremental health-producing capacity.

The $100,000 modeled gift is a bounded illustration, not assurance of linear scaling or spendability. A smaller gift may support fungible operating costs; a larger gift may encounter site, labor, permitting, water, or grant restrictions. We do not authorize an unrestricted $100,000 recommendation on the basis of the expense ratio.

The later funding evidence is in the SFCTA project account and November 2025 Public Works newsletter. The general giving page confirms a donation route, not a marginal quote.