What is an Urban Forest?

Our urban forest includes all trees - from a single maple in a planter, to a row of elms lining a downtown street, to carefully tended pines in residential backyards, to islands of native forest amidst urban development. Their natural diversity and their interconnectedness with human activities and the built environment make urban forests both complex and dynamic.

What is Urban Forestry?

Urban Forestry is the care and management of trees located in urban and suburban areas.

Where is HRM’s urban forest and how big is it?

HRM’s urban forests encompass communities in HRM that receive municipal water and wastewater services. These urban and suburban areas generally feature higher population densities as well as accompanying intensifications of commercial, institutional and industrial land uses. These communities comprise the UFMP Study Area, a 17,539-hectare management unit where the UFMP will be implemented.

What is the estimated canopy cover for the UFMP Study Area?

Canopy cover is defined as the proportion of land area occupied by tree crowns when visualized from above. Surveys conducted in 2006-07 indicated an estimated canopy cover of 43%. Over half of the Study Area’s canopy cover is on private property.

How much canopy cover has been lost in the UFMP Study Area since 2006-07?

Development activities that have occurred since this time are conservatively estimated to have reduced canopy cover by 5 %.

What canopy cover goal is recommended for the UFMP Study Area?

An overall canopy cover goal of 53% is recommended to achieve a sustainable urban forest in HRM.

Why do we need an urban forest master plan?

Trees are just as important to a city's economic health as roads, bridges, water, sewer, electricity, transit, and other services that a city needs to prosper. Trees are also important to a city's social health because they affect the look and feel of the places where we live, work, and play. An urban forest master plan will help safeguard the municipality's trees by providing comprehensive direction for the growth and maintenance of our urban forest.

Who owns and maintains HRM’s street trees and park trees?

HRM owns and is responsible for maintaining street trees along its road rights of way and in its parks. The work of planting, pruning and removing trees is generally done by HRM arborists under the direction of John Simmons, the City’s Urban Forester. Additional work is provided by private sector arborists. Nova Scotia Power Inc. is responsible for maintaining its utility corridor easements throughout HRM and works in cooperation with HRM to ensure that its pruning activities achieve a balance between protecting the structural integrity of street trees and reducing tree/power line conflicts.

What percentage of HRM’s annual operating budget goes to urban forest management?

Current allocations for urban forest management amount to about 0.2% of HRM’s annual operating budget. Regional Council recently approved an operating budget for 2012/13 of almost $789M with roughly $1.5M allocated for urban forest management. 

What are the current estimates for street tree conditions in the UFMP Study Area?

In 2007, an inventory of HRM’s street trees was conducted using the Street Tree Analysis Tool for Urban Forest Management (STRATUM). STRATUM has been used by cities throughout North America for many years and has been proven to be a reliable tool for urban forest management. The following chart shows an estimate of the number of street trees in the HRM UFMP Study Area. It also estimates the number of sites where new street trees could be planted in the future. The STRATUM chart provides information concerning the number of trees in conflict with utility lines and includes facts about the overall environmental benefits provided by street trees. While the estimated numbers of street trees is impressive it is also important to note the substantial number of spots available for new trees. The number of trees estimated to be in conflict with utility lines is a concern that should also be addressed.

How much does it cost HRM to plant a tree?

Depending on annual market prices, the cost of a standard street tree with a trunk diameter of 60 mm can range from $160 to $210. Planting costs increase the price to a range of $375 to $500 per tree. The lower cost applies if HRM staff does the work; the higher cost applies if the work is done by contractors. Smaller trees would cost less to buy and plant but they are less resilient and generally die within a few years if they are planted along streets but they can flourish in parks where they are more protected.

How much does it cost HRM to remove a dead or diseased tree?

In general, the larger the tree, the more expensive it will be to remove it. On average, for a 50-year-old street tree, it costs about $500 to cut it down and another $300 to remove the stump.

Is HRM increasing the number of its trees in parks and along its streets?

No, but the current number of city-owned trees is being maintained. Depending on annual market prices, HRM plants approximately 1500 trees/year at a cost of about $325,000. Unfortunately, a similar number of dead or diseased trees are removed resulting in a current replacement ratio of 1:1.

How often do street trees need to be pruned?

Many cities in North America with urban forest management plans have adopted a 7-year pruning cycle. This is an adaptive approach which aims to resolve structural issues encountered during normal tree growth. It is a general guideline for each street tree as not all seasonal, species-based growth rates, or incidental damage can be foreseen. Overall, pruning can significantly increase the lifespan of a street tree and its environmental benefits while reducing costs associated with its eventual removal and replacement.  HRM currently only prunes some of its trees on an “as needed” basis although the draft UFMP recommends a 7 year pruning cycle

How long can we expect a street tree to live in HRM? What about a tree in a park?

This is highly dependent on the tree species and the condition of area the tree is planted in. In good conditions, a fast-growing, short-lived species could be expected to live 40-50 years while a Red oak might live 100 years or more. The lifespan of a street tree is reduced dramatically if the soil quality is poor, there is little room to grow, and if the tree is surrounded by impervious surfaces. Without special growing containers such as “Silva Cells” or berms, trees planted along highly urbanized streets usually have lifespans of less than 10 year and never provide canopy cover. Conditions in parks are more favourable to tree growth and generally result in healthier and longer-lived trees.

Why do so many new street trees die after a few years?

Street trees need good soil, water and room to grow. Research conducted for the HRM UFMP has shown that other cities in Canada have adopted design standards that specify the conditions required for a street tree to thrive in an urban environment.

What design standards could be adopted to restore canopy cover in the urban core?

Urban trees face several challenges, but the worst is the problem of soil compaction. Most street trees planted in HRM’s urban core live less than 10 years but with proper planting conditions they could live well over 50 years and provide canopy cover to urban residents. Trees thrive when they are planted in uncompacted soil because this allows water, air and nutrients to reach their roots. However, an urban environment requires hard surfaces to support people and vehicles, and hard surfaces naturally compact soil. Silva Cells are rigid frames that support hard surfaces such as asphalt parking lots or sidewalks, but they keep soil loose and provide space for irrigation systems and utilities.  Although expensive, trees planted with this system can grow as much as 25 cm in one season.  A study conducted in Minneapolis showed that the cost of planting a tree using Silva Cells averaged around $14,000. Although a tree planted without a Silva Cell had a lower installation cost, an analysis of total estimated costs and benefits showed that each of its tree plantings in a Silva Cell would save the city $28,521.51 over 50 years compared to a tree planted without a Silva Cell.

Why aren’t more street trees planted in new subdivisions?

In fact, more street trees than ever before are being planted in new subdivisions. In the past, in some areas of HRM, street trees weren’t required when subdivisions were developed. Now they are seen as an important element of any new subdivision.

Does HRM have a by-law to protect its trees?

HRM’s Tree By-Law (Respecting Trees on Public Lands: By-Law Number T-600) came into effect in 1999. It provides protection to HRM-owned streets trees and in trees in HRM parks.

Can you provide an example of how other cities are conserving their trees?

Some cities such as Ann Arbor, in the State of Michigan charge canopy cover loss fees if a tree is removed from city property for development purposes. This fee is an estimate of the canopy value the city-owned tree has to thecommunity. It is determined by measuring the diameter of the tree and calculating replacement compensation based on current costs per caliper inch for a new tree of an equivalent size.

Ann Arbor also has land use regulations for the conservation of “landmark trees” in the city’s urban forest. Landmark trees according to Ann Arbor regulations are “large, old, picturesque, rare, well-located, or otherwise special and interesting trees that play an important role in the character of individual properties and in the fabric of the City as a whole”. Developers are required to consider landmark trees in their site plans.

Does HRM require a permit before trees can be cleared and isn’t tree removal prohibited along watercourse buffers?

In most cases private land owners may remove trees from their property without the requirement for a permit or approval from HRM. However, as a result of the adoption of the Regional Municipal Planning Strategy in 2006, provisions were included in the various HRM land use by-laws requiring the retention of watercourse buffers (riparian buffers) in relation to development within certain designations within the Municipality.

Does a developer have to submit a development plan prior to undertaking work/ clear-cutting?

A development plan is not required prior to removing trees from properties in areas of HRM where development is permitted as-of-right. An as-of-right development is one that complies with all applicable zoning regulations and does not require any discretionary action by HRM Council. As-of-right developments may be developed according to the requirements of the Zone and the Regional Subdivision By-law.  Once an application for subdivision is submitted, the developer must comply with the requirements of the Regional Subdivision By-law. No construction may take place until a Servicing Agreement is signed between HRM and the Developer allowing them to go forward with street and services construction.

Is as-of-right development permitted everywhere in HRM?

No. In some areas of HRM there are other approaches to the HRM development permitting process such as development agreements and site plan approvals.  In some cases, development agreements can be negotiated to include landscaping requirements for the property to be developed.  Site plan approval processes can also include landscaping requirements.  Both approaches may also include plans for tree retention and replacement.

Does HRM have a Private Tree By-Law?

Not at this time, but in central Canada, municipalities such as Toronto and Mississauga, Ontario have adopted by-laws for the conservation of trees on private property in order to preserve canopy cover.  Property owners can still remove trees but a permit fee is charged and replacement trees can be required. Trees less that 30 cm (12”) in diameter, and diseased and dead trees can usually be removed without a permit or requirements for replacement trees. It should be noted that it has taken these municipalities several years to develop their own urban forest toolbox of plans, public education programs and by-laws based on their unique needs.  An HRM by-law concerning trees on private property could be an effective public policy tool for the retention of canopy cover but it would require a “made in HRM” approach that considered local urban forest conditions as well as the cultural values of its citizens.

Does HRM have the legislative authority to adopt a Private Tree By-Law?

Yes. Amendments to the Halifax Regional Municipality Charter, passed into law by the provincial legislature on May 10, 2010, gave Council authority to create by-laws within serviced areas to regulate tree cutting on private property as well as to create by-laws to establish watercourse buffer zones where tree cutting would also be regulated.

How much does it cost to buy and plant a tree on private property?

This is dependent on the species and size of the tree to be planted. Costs can range from $0.15 to $300. Softwood seedlings and hardwood whips can be purchased for less than a dollar and planted on private property at no cost. Mid-size nursery trees can be purchased for prices ranging from $50 to $100. Trees on private property can be protected and smaller trees tend to grow faster than larger transplants. The high end of this cost range would be for a large nursery tree planted by a contractor.

Does HRM have a public education program for citizen-led urban forest stewardship?

Not at this time but the draft UFMP points to the opportunities and benefits that local stewardship efforts could have. Many cities across Canada have developed outreach programs and grants for local volunteer groups. Some cities have partnered with national organizations such as Tree Canada and corporate sponsors. Others have established local non-profit foundations or partnered with local environmental groups.