Trees and Lamp posts:- Asset management versus resource management
-Why aren’t street trees like lamp posts?
Lamp posts stay in one place.
Street trees grow, spread and develop above and below ground over decades.
Lamp posts don’t change shape or size.
Lamp posts are effective as soon as they are wired up.
Street trees start off having no effect on their surroundings and gradually increase in impact over decades. Their value at planting is negligible but can be almost priceless after a century.
The cost and value of lamp posts is relatively easy to calculate and keep track of.
The costs of tree planting are easily calculated (at a superficial level) but the needs of new trees are routinely ignored.
The value of a lamp post depreciates predictably following installation.
The value of a tree rises for decades after planting.
Lamp posts are subject to a limited range of deterioration factors.
Street trees are subject to a wide range of damage factors.
The design life of lamp posts is similar regardless of size.
Some trees have an expected lifespan of 50 years as street trees while others may go on for centuries.
Lamp posts either work or they don’t; there are very few ‘grey’ areas (except where trees grow over the light).
Trees are very rarely without defect but their capacity to continue to provide benefits despite defects is large.
Once damaged a lamp post becomes a severe liability.
Trees limit damage to and reinforce parts of their body that are damaged.
Installation of lamp posts is straightforward and doesn’t affect many other underground services.
Planting of street trees requires a suitable volume of surrounding soil into which the tree can grow to the ‘planned’ size.
Lamp posts are designed to do one job; illuminating their surroundings. They are not often described as aesthetically pleasing or benefiting the amenities of an area. However, lamp posts can, in certain situations, help to maintain a ‘sense of place’ and add to the architectural features of an area.
Trees provide multiple benefits to an area; from pollution control to soil stability and water control to temperature amelioration to framing views to forming a link with nature to screening eyesores. They help to attract tourism and can improve property prices. Trees even have a positive effect on public health and stress levels.
People don’t get emotionally involved with lamp posts.
(The lady recently married to a fairground ride and the one who, last year married the Eiffel Tower are not typical.)
People regularly get very emotive about trees.
There are very few lamp posts in private ownership
Street trees within falling distance of a highway can become a problem for street tree managers.
Article written by Steve Cox on February 12, 2010