The Tree Blog

Posts Tagged ‘climate’

We’ve had a record heatwave in the last month here in Australia and in the 20th century, heatwaves have caused more deaths than any other natural hazard.   I was in Melbourne recently and shocked by just how hot it got and how long the harsh dry heat was sustained.  Not only were there record temperatures, but record dry as well.

Heatwaves can and do effect our  Australian capital cities.  In February 2004 Brisbane recorded a new record of 41.7 °C during a heatwave.  Records were shattered throughout South East Queensland.  Another similar heatwave last year peaked at 36 °C.  In March 2008, Adelaide experienced maximum temperatures of above 35 °C for fifteen consecutive days, seven days more than the previous longest stretch of 35 °C days. The March 2008 heat wave also included eleven consecutive days above 38 °C. The heat wave was especially notable because it occurred in March, an autumn month, in which Adelaide averages only 2.3 days above 35 °C.  More recently Melbourne this month recorded three successive days over 40 °C and peaking at 45 °C and its driest month in recorded history.

The cost is racking up the millions, with power outages, air conditioning systems on the blink and hyperthermia, dehydration and death in people as well as many unforseen effects.  Environmental effects are significant and long term and include bushfire and drought.

One thing that is also overlooked is the effect it can have on your trees.  Drastic changes to temperature can cause trees to go under extreme water stress which in turn causes them to lose limbs.  But unlike a storm, they can do it without warning.  The first sign of water stress is leaf shedding.  Some scenes in Melbourne looked like an early autumn.  Another lesser known side effect is that many trees can become toxic during heatwaves, emitting chemicals like isoprene which increasing ozone and can cause health problems for children and older athsmatics.

Whether southern Australia’s recent heatwave is a result of climate change manmade or otherwise remains to be seen (you’ll find I’m not 100% on that topic either way), one thing is for sure there will be more heatwaves during our lifetimes.

It is very important to be prepared get your trees checked out, particularly those close to your home, to ensure they aren’t vulnerable and before they do damage.