CBD to South East Light Rail (CESLR) Project: Why our threatened urban trees are valuable to us – 30th November 2015

Greens Councillor Murray Matson stresses the advantage of keeping established urban trees by reporting that American trees that have lived for fifty years has been calculated to be worth $41,769 USD over that period. Poorly planted trees actually lost money by failing to recoup the cost of their plantings.

“Urban trees shelter our buildings and reducing the demand for heating and air conditioning, which mean less CO2 in the production of energy.  Properly planted and long lived trees will all so reduce intercept storm water while removing contamination and sediments from it, increase property values, and directly sequester carbon. These factors all contribute to the financial, environmental and social benefits for both individual residents and governments.”

Greens Councillor Matson once helped plant urban trees at an environment conference in China. But did he plant this one deep enough?

Greens Councillor Matson once helped plant urban trees at an environment conference in China. But did he plant this one too deep?

The State Government has promised to plant eight replacement trees for everyone removed for the CSELR rail line. But Councillor Matson states that there are advantages to retaining established trees rather than attempting to replace them with younger plantings.

He said,

“The Alison Road trees in particular are not typical Council street trees constrained by pavement and road requirements. An American study has found that most urban trees have less than 1/10th of the rooting volume they need to thrive. Our Alison Road trees on the other hand are essentially forest trees with ample root space growing on the edge of Centennial Park.”

Councillor Matson points out that there is always a risk that any replacement trees may not take. He says

“Newly planted seedlings or saplings do not have a hundred percent survival rate. Furthermore the ones that do take root may have dramatically shorter life spans if they are planted too deep above their root balls or in too constricted a growing area. “ (Source “1 Million Trees: Vision or Nightmare”.

Councillor Matson sees a key overseeing role for his newly reestablished ‘Greening Randwick Committee’ of Councillors and resident representatives. He said;

“As well as fighting to retain trees using clauses in our signed development agreement, I would like to see the Greening Randwick Committee taking a keen interest in how the CLELR contractors do the promised re plantings. If they employ assembly line planting methods then we may not get as much of a bargain as promised. Expediency may in fifty year’s time cost our residents many millions in today’s dollars.”

BACKGROUND

“Most urban trees have less than 1/10th the rooting volume they need to thrive.” (source “Investment vs. Returns for Healthy Urban Trees: Lifecycle Cost Analysis”)

One study in Minneapolis, MN has shown that the benefits over the stunted 13 year life span of an “improperly” planted trees is only $2,717 (USD). This means that the tree fails to recoup its initial $4,000 planting cost plus $600 eventual removal cost. This is verse $41,769 for a professionally done job which allows the tree to last 50 years. (source “Investment vs. Returns for Healthy Urban Trees: Lifecycle Cost Analysis”)

The same Minneapolis study listed the financial benefits to Americans provided by properly planted and long lived urban trees as being:

  • savings from reduced building energy costs;
  • stormwater interception;
  • Reduced fees imposed by government authorities for stormwater control;
  • increased property values;
  • the net value of carbon sequestration in the tree;  and
  • “bioretention”in which contaminants and sedimentation are removed from stormwater;
  • Shoppers in well-landscaped business districts are willing to pay more for parking and up to 12% more for goods and services;Increased property values increase tax base resulting from higher property value;
  • Tree shade has been correlated with better pavement performance, which translates into reduced pavement maintenance costs, and increased pavement durability (McPherson and Muchnick 2005).
error20

Leave a Reply

Your e-mail address will not be published.