Regardless of their number, it remains to be every tree owner’s responsibility to get their trees checked. The more trees they have, especially those in high-risk areas, the higher the responsibility. A Tree survey is of huge importance in not only maintaining safety but also the proper growth and development of new trees, whether they be in small wooded areas or vast forests.
A professional arborist can conduct a tree survey on either public or private property. The result gives property owners useful information, so they can decide what to do with the trees and, consequently, their land. The information captured includes:
● The species and measurements of the tree
● Age and overall health of the tree
● Life expectancy
● Severity of damage or presence of pests (if any)
● Management recommendations
The data produced from a tree survey can highlight any number of issues with individual trees, groups of trees or the entire site.
Issues Identified by Tree Surveys
It’s important then that you identify relevant tree issues and provide practical advice for the following:
1. Pests, disease, and decay detection
Depending on the insect, pests can cause anywhere from leaf decay to growth disruption to weakening the tree until it eventually dies.
Tree surveys should detail which pests are causing the decay via the use of reliable evaluative tools like sonic tomograph, tree motion sensors, and chlorophyll fluorimeter, among others.
2. Diversity in tree population
A tree survey should also identify if there’s an imbalance in terms of tree species. You can then recommend other trees to diversify. A diverse population can protect a landowner from losing all their trees in the event of a disease.
On top of that, you can also recommend trees that are appropriate for a site and how they should manage them (e.g. planting, adopting, removal, maintenance, etc.).
3. Safety risks
Trees located near people and property can pose a risk. If a client lets a tree go into an advanced stage of decay, it starts becoming hazardous to anyone within the property. Your report should then assess if there are any health and safety risks to employees, the public, or anyone living within the property—and recommend felling them, if needed.
The same goes for those buying or developing a land with unkempt trees. Your report should provide accurate information, so landscape designers and site managers can come up with realistic designs.
4. Compliance with government laws
Depending on their location, certain regions require tree surveys. For instance, the Wildlife and Countryside Act prevents a protected tree from being cut down, as these are homes to certain animals.
There are numerous laws to watch out for in terms of caring for trees. This includes Section 3 of the Health and Safety at Work Act, which protects employees in high-risk work areas, as well as a duty of care which outlines a landowner’s responsibility to make sure no one is injured on their property.
How to Conduct A Tree Survey
A tree survey can come in the form of a tree health survey (to check for the health of trees), a targeted survey (to establish the extent/severity of tree disease), or a pre-property development inspection to ensure compliance with British Standard BS5837:2012 (“Trees in relation to construction”).
Phase 1: Pre-planning, Setting Parameters
First, plan out how you’ll conduct the survey. Here are a few methods to use:
Source: Forestry Commission
● Line transects – The most common method, walk a series of parallels of evenly-spaced transect lines. Conduct a visual exam of trees left and right to see any damage/disease.
Source: Forestry Commission
● Quarter point transects – To use this method, walk a line north, south, east, and west with the diseased tree as starting point. This can help you estimate how many trees are affected.
Source: Forestry Commission
● Radius survey – This method is advisable for trees that were planted with huge distances in between them, like oak. Survey all susceptible trees within the vicinity (e.g. 50-mile radius) and extend the distance until there are no more trees that are affected.
Source: Forestry Commission
● Complete survey – Look at all the trees of the same species for signs of pests or disease. This method is best for park trees or smaller woodlands.
Although almost all tree surveys are done from the ground, sometimes, it’s better to climb them. This will help you examine the top of branches, tall crowns, cavities, and other areas that are not visible from below.
Lastly, pick the right time for your survey, as seasons tend to affect the diseases and pests that riddle trees.
Once you’ve mapped everything out, prepare your equipment and head out to the field.
Phase 2: Site Survey
To be methodical with surveying your site, do the following:
● Note tree species, position (coordinates or location on the map), physiological conditions, age, and life expectancy
● Assess tree dimensions and crown spread
● Inspect the crown and look for gaps in the canopy
● Note the colour of leaves
● Look for deadwood
● Look for damaged branches or those that have cracked or split (these can be easily blown by the wind or rot away)
● Check any abnormal features like ivy growth, bark damage, swellings, fungus
● Look for signs of decay within the main trunk or its base
● Note if the roots are exposed or have any damage
● Check the soil for cracks or uplifting of concrete structure
During the course of surveying, use tree tags to mark them by species and accurately map them.
Once you’ve completed this this step, assess tree conditions and their landscape value: Good usually means healthy and no signs of damage, fair has some defects of low significance, poor means major defects, and dangerous/dead means you’re requiring removal.
Phase 3: Impact Assessment
Next, assess the impact of the tree damage to the property.
The Arboricultural Impact Assessment (AIA) is often used as part of a property’s survey report, as it details the following:
● Which trees need to be removed and which can be kept
● How to protect trees during construction
● Visual illustration of how to protect trees and special construction measures
● A list of tree recommendations that fit the property
Depending on your client’s needs, you can also produce a planning and development survey, as well as the Arboricultural surveys and Tree Constraints Plan—both in compliance with BS5837:2012.
Phase 4: Method Statement
Following the approval of your recommendations, a final method statement will be sent to the Local Planning Authority and the Site Manager.
The method statement includes how many trees will be protected with minimal disturbance (e.g. no-dig paving, storing chemicals away from roots, fencing, etc.). You can also recommend to oversee operations, especially in sensitive areas.
Show Your Expertise
A tree survey gives your clients vital information on the proper way to care for their trees and those that need preventative maintenance procedures. This will, in the end, give them an accurate picture of their land and how they can act accordingly.
Given the importance of this task, make sure that you are meticulous with your planning and execution, as damaged trees risk injury to landowners, their families, and the general public.
About the Author: Paul George is the managing director of Landmark Trading Ltd, and has worked in the arborist industry for 14 years. Landmark Trading are one the UK’s leading suppliers of arborist equipment. You can connect with Paul on Twitter, Facebook or call Landmark Trading on 01780 482231.
