How to do a Tree Survey

Tree surveys give property owners vital information about their trees, so they can maintain and keep their land safe. It is the responsibility of every landowner to make sure all the trees on their land are structurally safe, especially if that land is open to the public.

Tree Consultancy is focused on the health of individual trees, including the cataloguing of species and regular measurements of the tree, overall health, and severity of damage either by the elements or pests. This allows the growth and development of forests and woods to be managed and controlled to maximise results, whether that’s regeneration or protecting established trees.

In this guide we’re going to be taking a deep dive into tree surveys and why they are important to arboriculture and silviculture.

How to Conduct a Tree Survey

There are several types of tree survey. To make sure that your client’s land stays safe, you would perform a tree health survey, which is a targeted survey to establish the extent of tree disease. A pre-property development inspection is another type of tree survey that fulfils the requirements of British Standard BS5837:2012, which refers to trees in relation to construction.

In this article, we’re going to focus on a tree health survey for identifying tree disease and establishing how far it has spread. Let’s break down each stage of the tree survey process.

1. Pre-planning

If the land that you need to survey involves a wide area (e.g. a golf course), you need to create a system that would help you cover each corner without missing a tree. There are four methods that you can follow:

  • Line transects

Line Transects

Source: Forestry Commission

For this method, you need to follow a series of parallels of evenly-spaced transect lines. This is the most common method used for tree surveys. While walking down each line, check all the trees on your left and right.

  • Quarter point transects

Quarter point transects

Source: Forestry Commission

To do this, start from the diseased tree. Then, walk a line on its north, south, east, and west to determine how many more trees are affected.

  • Radius Survey

Radius Survey

Source: Forestry Commission

If your project involves trees that were planted in huge distances (e.g. oak trees), radius survey would be the best method to apply. Establish a radius within the vicinity—say, a 50-mile radius—and keep extending the distance until you stop seeing any diseased/damaged trees.

  • Complete Survey

Complete Survey

Source: Forestry Commission

A complete survey method is best applied for park trees or small woodlands. All you need to do is examine all the trees that fall under the same species that exhibits signs of pests or disease.

Most tree surveys are conducted on ground level. However, if need be, you can also climb trees to see the top of branches, crowns, cavities, and other areas which would be invisible from the ground.

Also, note that seasons tend to affect the occurrence of some diseases and pests, so time your survey right.

2. Conduct The Site Survey

When examining the trees, note the following:

  • Tree species, location/coordinates, physical conditions, age, life expectancy
  • Tree dimensions, crown spread, colour of leaves
  • Any gaps in the canopy
  • Deadwood or damaged branches/barks
  • Ivy growth, swellings, fungus
  • Exposed or damaged roots
  • Any cracks in the soil or uplifting of the concrete structure

Arbotag Tree Tag

When logging the status of any tree it’s important to use tree tags to mark each tree by species and their respective locations. This will help you or the landowner to quickly identify trees upon returning to the site.

Afterwards, provide an assessment of tree conditions. If the trees are healthy, mark these on your report as good. Any tree with defects of low significance can be marked fair, while those with major damage or are dead should be marked as poor and would require removal.

3. Impact Assessment

When assessing the effects of your findings, you can use the Arboricultural Impact Assessment (AIA). The AIA details the trees that need to be removed or kept, how to manage trees during construction, and a list of any tree species that would better fit the property.

You can also provide a planning and development survey or an Arboricultural survey and Tree Constraints Plan, both of which follow the regulations of BS5837:2012.

Whichever type of report your client needs, you need to include the following details:

  • Presence of damage, pests, diseases, and decay – Pests can cause decay, trunk/branch damage, or growth disruption. If left untreated, this can weaken the tree until it falls and dies (which would then endanger the public). Use the right equipment (e.g. tomographs, sensors, etc.) to determine the amount of damage or decay. For trees that are damaged, or in danger of damage - for example, due to uneven growth or the presence of cracks, it may be appropriate to recommend tree bracing to help minimise or forestall any worse damage and prolong the life of the tree.
  • Need for tree diversity – If a property has a lot of poor-quality trees, you need to note this imbalance and recommend better trees. A diverse tree population would prevent the fast spreading of any tree-specific diseases.
  • Safety risks – Assess the health and safety of each tree relative to the people living or working within the property. This goes for any client who intends to buy or develop a land.
  • Compliance with laws – There are a number of UK laws that cover trees within a given property. This includes the Wildlife and Countryside Act (protects trees that are home to animals), the Health and Safety at Work Act (protects employees in high-risk work areas), and the Duty of Care (landowner’s responsibility to keep their property safe).

Presence of damage, pests, diseases, and decay

4. Method Statement

With your recommendations approved, you then need to submit a final method statement to the Local Planning Authority and the Site Manager. Make sure that you report is accurate, as landscape designers and site managers would depend on it for the designs. Include trees needing to be protected or planted and how to manage them, as well as your recommendation to oversee the construction process (if needed).

Don’t Skimp On The Details

As a professional arborist, it’s your job to present accurate information to clients, as this could mean the difference between a regulation-compliant land and a high-risk property. Make sure that you look over every detail, as exposure to damaged trees can injure the people who occupy and use the property.

And of course, if you’re having to climb trees to inspect them, then make sure the work is carried out by a trained climber using the correct safety equipment.