COF 2026-95 · Agenda item attachment · Jun 22 2026

COF 2026-95 FIRST IN COUNCIL June 22, 2026 City of Cambridge A true copy; ATTEST:- Paula M. Crane, Interim City Clerk

City of Cambridge A communication was received from Andrew Putnam, Superintendent of Urban Forestry and Landscapes, transmitting a presentation related to the Urban Forest Master Plan.

Cambridge Urban Forest Master Plan Health and Environment Committee 1 5 Year Update June 22, 2026

Cambridge Urban Forest Master Plan Health and Environment Committee 2 Agenda: • Background • Progress towards Goals and New Targets • Plan for the Next 5 Years • Questions / Comments

Cambridge Urban Forest Master Plan Health and Environment Committee 3 Agenda: • Background

4 Cambridge Urban Forest Master Plan A health forest is a vital part of a healthy city We all share responsibility to care for our urban forest

5 Background and Process Builds on the findings of the Cambridge Climate Change Vulnerability Assessment (CCVA) and supports the goals of the Climate Change Preparedness and Resilience (CCPR) study Supports the Core Values of Envision Cambridge Livability & Diversity Equity Economic Opportunity Sustainability & Resilience Community Health and Wellbeing Learning

6 Grow canopy to maintain and improve the livability, resiliency, and well-being of Cambridge and its residents. Goals

7 Goals of the 5- Year Update

8 Timeline

9 Public Meetings

10 Committee on Public Planting Input

Cambridge Urban Forest Master Plan Health and Environment Committee 11 Agenda: • Progress Towards Goals and New Targets

12 Measuring Progress — 5 Year Plan

13 Citywide Canopy Cover - 2020 Goals

14 Citywide Canopy Cover - Good News We have more canopy cover today than we did in 2009. The rate of loss has slowed. The rate of gain has increased.

17 Citywide Canopy Cover – 2026 Target

18 Equity - 2020 Goals EQUITY Increase canopy cover where it is currently lacking, particularly in areas with high concentrations of minorities, the elderly, non-English speakers and those with low incomes

19 Equity - Canopy Cover While canopy cover is still not equitably distributed …

20 Equity - Canopy Growth Canopy cover is growing, especially in the neighborhoods that need it the most.

21 Equity - Planting Rates Because new planting has been focused in the neighborhoods with the lowest canopy cover.

22 Equity - Canopy Change The rate of growth is highest in under-canopied neighborhoods.

23 Equity – 2020 Target Most neighborhoods are on track to meet the 25% canopy cover target.

24 Equity – 2026 Target Most neighborhoods are on track to meet the 25% canopy cover target. Retain 25% minimum canopy cover for each neighborhood

25 Equity - East Cambridge Case Study East Cambridge has limited area available for new plantings. It will take a concerted effort to make space for new trees. Sidewalks, parking lots, and DCR land are key opportunity areas.

26 Equity - East Cambridge Case Study DCR Land Along Memorial Drive Parking Lots Street ROW Street Intersections DCR Land Along Edwin H. Land Blvd

27 Resiliency - 2020 Targets RESILIENCY Enhance canopy cover in the public realm to create “cool corridors” that reduce heat island where people are impacted the most

28 Resiliency - Canopy Diversity The City has increased the diversity of its planting, adding 109 unique species in the last 5 years.

29 Resiliency – Species Diversity 2026 Target No more than 10% of a single species, 20% of a genus, and 30% of a family across the city and Apply for the same goal within each neighborhood

30 Resiliency – Genetic Diversity 2026 Target 50% of newly planted trees in parks should be native trees sourced locally (within the ecoregion)

31 Resiliency – Cool Corridors Canopy over sidewalks has grown in the last 5 years.

32 Resiliency - Cool Corridors 2026 Target 50% canopy cover over sidewalks for Type 1 corridors 55% canopy cover over sidewalks for Type 2 corridors

33v Resiliency – Priority Areas Populations vulnerable to heat Commonly travelled corridors Heat islands Prioritize action based on need. Areas of high need are a product of:

34 Resiliency – Priority Areas 2026 Target 17% canopy cover within priority areas (currently 11%)

35 2020 Goals SHARED RESPONSIBILITY Incentivize each landowner to increase canopy cover — a thriving forest requires mutual care by many parties Image Credit: Billy Hickey

36 Shared Responsibility - Canopy Growth Canopy is growing on all types of property.

37 Shared Responsibility - Canopy Ownership The majority of canopy grows on private property.

38 Shared Responsibility - Canopy Ownership The most loss and least growth is occurring on residential property.

39 Set specific, achievable targets for public and private entities Shared Responsibility – 2026 Target

Cambridge Urban Forest Master Plan Health and Environment Committee 40 Agenda: • 5 Year Plan: Key Recommendations

41 Key Recommendations

42 Focus on Quality over Quantity Implement enhanced planting details and care regimes, especially in the most challenging conditions, to create the best conditions for long-term growth and well-being.

43 Focus on Quality over Quantity Plant trees to meet priority area, neighborhood, and land use targets, which may mean planting in more challenging places. Reduce the 2-year mortality rate from an already- low 10% — planting 750/year instead of 1,200.

44 Manage More Strategically Organize and optimize management strategies based on site type, planting condition, and risk level as opposed to neighborhood.

45 Share Responsibility And Also Share Cost Deploy funding tools or cost sharing to incentivize new planting and retention of mature trees on private property. Revise policies to optimize tree protection and in-kind replacement.

46 Broaden What Resiliency Means Go beyond species diversity by diversifying tree genetics. Distribute species strategically to minimize risk from climate pressures.

47 Key Recommendations Focus on Quality over Quantity Manage More Strategically Share Responsibility and Share Cost Broaden what Resiliency Means

48 Key Recommendations What the City can do. What the City can do, with residents’ support. What residents can do

49 5 Year Action Plan

50 5 Year Action Plan

51 Tree Protection Ordinance - Takeaways Not all trees being removed under the Tree Protection Ordinance are being replanted. Half of the canopy trees which are removed are being replaced with subcanopy trees.

52 TPO Recommendations: Replace more trees 75% of privately owned trees that are permitted for removal are considered "hazardous" and therefore do not require mitigation under the current ordinance. For “hazardous” trees: • Require 1:1 replacement so the forest continues to regenerate without being punitive by requiring caliper-inch mitigation. • Recommend that Green Cambridge plant replacement trees where cost is an issue for the owner.

53 TPO Recommendations: Replace canopy with canopy In the analysis of the replacement trees from the last five years of TPO data, 50% of canopy trees are replaced with understory trees, which provide less cooling when mature. • Require at least one replacement tree for each removal be from the same size category and from a city-approved list of species, unless there is a significant lack of space as determined by the City Arborist. • Add language that tree species must be climate suitable and add recommendation on genetic diversification and nursery sourcing

54 TPO Recommendations: Include ROW Trees Covered by Chapter 87 Protect critical root zones • Define a tree-protection zone buffer around existing street trees, including extending onto public sidewalks. Identify ROW trees in City applications • Show abutting trees within 30’ of the property boundary on Building Permits and Tree Protection Plan Protect all trees from over-pruning • Define a threshold for maximum allowable pruning of the tree’s canopy within a specified timeframe

55 TPO Recommendations: Allow management of invasive trees In naturally regenerating areas such as Fresh Pond and Alewife Reservation, trees are grown tightly together. It is onerous for the City to comply with the TPO requirements when removing large invasive trees in these areas, especially since there is limited room to replant in those areas • For naturally regenerating areas, set a mitigation requirement of 1:1 replacement to facilitate restoration areas and removing of invasive species.

56 Green Factor 70 projects went through Green Factor between 2023 and 2025. Of those projects, 858 existing trees were retained, and 1,080 new trees were planted. At maturity, these projects will average 30% canopy cover. 18% Existing canopy cover 30% Canopy cover at maturity

57 Green Factor Recommendations • Broaden the applicability of the Green Factor requirements. • Review the weighting structure of different strategies (preserving existing canopy, planting new trees) to ensure that the structure is incentivizing tree preservation and planting. • Require / Verify compliance with minimum soil volumes for new trees. • Track and analyze the impact of the recent zoning change that converted all residential to C-1 zoning classification. • Require during the certificate of occupancy approvals that the design is reviewed for compliance in terms of the number and types of trees planted.

58 Responding to Multi-Family Residential Zoning What can be done to protect trees? • Strengthen the protection of trees (and critical root zones) on abutting properties • Calibrate Green Factor to better protect existing trees • Re-evaluate set-backs and open space definitions (green roofs and balconies)

59 Outreach and Engagement Be a Leader in Stewardship • Join Forest Friends and care for the City’s trees • Create and Lead Neighborhood Teams Be a Tree Advocate • Speak up for trees at public meetings • Voice support for policy changes recommended in this plan (TPO, GF, Tree Trust, parking lots) • Share messages with your neighbors about the importance of sourcing locally and planting diverse species

60 5 Year Action Plan

Cambridge Urban Forest Master Plan Health and Environment Committee 61 5 Year Update June 22, 2026 Questions & Comments

62 Respond to Multi-Family Residential Zoning Change • If those parcels were built out (not assuming they use green roofs as open space) up to 135 acres of canopy cover could be removed, resulting in 26% canopy cover for residential areas. • Citywide, current canopy cover is 30%. This would reduce to 28%. Residential A 50% open space requirement Residential B 40% open space requirement Residential C1 30% open space requirement

63 Resiliency – Priority Areas Areas of high need Low canopy cover (projected) + Priority Areas are determined by:

64 Measuring Progress — Long-term Plan Of the recommended actions: 29% are completed 27% are in progress 44% are not yet started

65 Policy and Partnerships: Parking facilities • 6.48.1 On grade, open parking facilities which contain five or more parking spaces must have at least five percent of the interior area of the parking facility landscaped • Each planting area to be at least 25’ long and contain at least one tree. • At least one tree for every ten parking spaces. • Green Factor only comes into play with new surface lots. • Parking lot ordinance applies to newly striped parking lots and new parking lots.

66 Policy and Partnerships: Parking facilities • Modify the parking lot ordinance to include more specific canopy tree planting requirements (percentage of canopy cover at maturity and minimum soil requirements). • Provide funding (tax rebates, grants, proceeds from the Tree Fund) for planting in existing parking lots. • Create a database of parking lot owners amenable to accepting more planting on their parking lots that can provide off-site in-kind mitigation for TPO removals instead of mitigation payments to the Tree Fund.