|Photo: J Edwards
“The ecological roles of logs in Australian forests and the potential impacts of harvesting intensification on log-using biota”, is the rather complex title of a 2002 report by scientists based at the Australian National University which, to put it simply, is a review of the ecological values of logs in Australian eucalypt forests. While more than 10 years old the report still has relevance with on-going timber industry lobbying to allow the burning of wood to generate electricity.
The ecological value of hollow logs, and standing dead trees is recognised in law, with the destruction of both deemed Key Threatening Processes under the Threatened Species Conservation (TSC) Act , and their destruction is identified as a threat to many high profile species such as Quoll, Glossy-black Cockatoo, Regent Parrot, Brush-tailed Phascogale, Large Forest Owls, and Squirrel and Yellow-bellied Gliders.
While this knowledge is generally well-known, it is just the tip of the ecological role provided by logs. The study identifies that they provide crucial functions throughout their life which could last many decades, even centuries, with those functions changing with mind-boggling complexity as they decompose over time.
Logs have critical functions for forest biodiversity, providing places for key social behaviour for an astonishing range of living creatures from reptiles to rodents, birds to bacteria; snails, beetles, borers, millipedes, worms, weevils and roaches. The list is endless. In fact the report lists 57 reptile species alone in south eastern Australia that utilise logs for shelter, safe passage, foraging, hibernation, and even basking.
As they decompose, logs provide plant germination sites, providing substrates to promote growth of fungi, and refuge for living organisms during drought and fire, while also contributing to heterogeneity in the litter layer, and playing a significant role in nutrient cycling.
However, many see logs, particularly residue from logging operations, as unsightly waste needing to be removed or burned. While often claiming otherwise, usual forestry practice is to burn residues seeing them as obstacles to future operations, giving little thought to the crucial role they play in maintaining the amazing biodiversity which provides us humans with everything we need to survive.
This post was originally published (without the photos) in the VOICES FOR THE EARTH column in The Daily Examiner on 4 May 2015.
|Photo: J Edwards