August 12th 2004
After the fire
There is little doubt that the fuel and weed reduction fire lit by rangers three weeks ago at the Horseshoe Bay Lagoon Environmental Park brought about a strong reaction from neighbours. But after inspecting the effects of the fire yesterday and discussing the reasons for the burn with, Ranger in Charge, Patrick Centurino the fact that fires can be both destructive and beneficial in the Australian landscape was only reinforced.
It's a blackened and stark environment after any fire but perhaps more so at the popular lagoon area where locals especially are used to the shade of the magnificent towering paperbarks and the lush green undergrowth. Many of the smaller trees have been burnt to their crowns and the larger ones show only patches of unsinged leaf well up in their canopies. At ground level blackness is like a canvas upon which the new leaf litter is settling in abstract patterns. Old bottles and cans are revealed and, as if a blanket has been drawn away, one can look across and see the shape of the ground and, closer still, the emergence of tiny green shoots.
"The major thing that we had to stop was the para grass. Otherwise it would have advanced right through to the other side of the lagoon" said Patrick. He showed me wet season photos of this major weed clearly smothering the ground and mounting well up onto the base of trees - blocking any chance of other plants ever getting a start.
The para grass near the lagoon in February
(Photo: coutesy QPWS)
Loss of habitat for native species through weed invasion and the risk of allowing enough fuel to build for a far more dangerous wildfire are at the core of the Queensland Parks and Wildlife Service (QPWS) strategy. "I didn't want a cool burn, nor a hot one either but a medium burn," said Patrick adding, "We needed enough heat to burn up the weed's seed banks dumped over the years on the surrounding soil."
The burn was stage two of a scheduled attack on the para grass and Guinea grass which were dense throughout the area. Stage one was a poisoning program back in February: timed to kill the weeds at their most vigorous stage of growth and when they are most vulnerable to the short-lived herbicides. This was while the ground was moist but not submerged from the lagoon's wet season waters. These are important factors to consider as peat lies beneath. Had it caught fire the large melaleucas would have been in trouble and if water still submerged the ground the bio-active glyphosphate herbicide may have spread on its surface.
Patrick inspects a remaining clump of
para grass for later removal
Stage three will be a follow-up weeding of any surviving clumps. It was clear that the Guinea grass was already beginning to reshoot but Patrick was confident that teams working under Queensland Parks and Wildlife Service (QPWS) would be able to remove the Guinea grass and create an environment for the local native species to re-establish themselves.
Patrick was keen to demonstrate that appearances are not everything - scraping a couple of millimetres of paperbark away from the sooty trunk of a large Melaleuca to reveal layers of very healthy bark just below the surface (see photo at top).
According to the Society for Growing Australian Native Plants, "melaleuca" means "black and white" and presumably refers to the blackened lower bark and white upper bark of some species, resulting from fire. Following flowering, three-celled woody seed capsules develop with each capsule containing many small seeds. The seed pods usually remain tightly closed unless stimulated to open by fire or by the death of the plant.
A seedling emerges
Most of the native plants here have fire resistant capabilities and further on into the heart of the burnt area Patrick found a knee high melaleuca - one of many the QPWS had raked leaves away from in preparation so as to stop surrounding mulch from burning it. The frail looking sapling was still partially burnt but, on closer inspection, glossy young shoots were already evident. "The ash will provide good nutrient for these" said Patrick.
A melaleuca begins its recovery
Some locals reported to Magnetic Times that ash and smoke blew right through their homes and soiled washing on lines. Others were annoyed at the damage inflicted on trees by the service vehicles while concerns for wildlife were also raised.
According to Patrick, two possums were disturbed by the flames and sadly one was lost to the fire. It is these sorts of results which heavily underline how a burn can create a no-win situation for professionals even with the best of intentions. Forty seven dead trees were also felled and burned up in the blaze but Patrick was relieved that as far as he could ascertain they were mainly inhabited by termites. At the same time the removal of the strangling weeds and their seeds was intended to promote the recruitment of a new generation of melaleucas.
Patrick is clearly sensitive to the issues he faces in the management of the park and speaks with an air of resignation as if to suggest that no matter what he were to do there was always going to be upset, especially so close to residential areas.
"We began the fire nearest to the homes so it would burn away from them. Had we started at the other end it could have really swept towards the houses and would have been harder to control," he explained, adding, "I understand that unfortunately it burned a bit longer than we wanted and we could have given the residents more notice." A notice was left in neighbour's letterboxes the day before but if the number of times this reporter's visit to the site with the busy Ranger had to be rescheduled, it isn't hard to believe that simple under resourcing was a more likely reason.
According to Patrick, there are clear expected outcomes from burns such as this and that these outcomes are measurable. QPWS do not operate in isolation on a park to park basis and accordingly, evaluating, monitoring and reporting procedures are in place at the State level.
"As Rangers we are expected to submit to a panel of rangers, botanists and scientists from different departments our planned burns for the year ahead, stating clearly our intent and expected outcomes and follow-up.
"The next year we then present our findings to this panel to be discussed, reviewed and commented on.
"Botanists also visit burn areas before and after fire and it is a process of continuous improvement, we get to see and hear what other parks are doing in similar situations and the successes and failures they are having. This way we get to learn of the current research findings and ways of incorporating that into our vegetation management," said Patrick.
Patrick accepted that some trees in the recently weeded and revegetated strip between the lagoon and the residences in Henry Lawson Drive had been damaged but was obliged to ensure vehicles were there to ensure the safety of the homes nearby.
Charlie McColl with bamboo
Local, Charlie McColl, who supervised the revegetation of the area last year was however sanguine about the damage whilst being impressed that the fire had now made it possible to attack some more recent weeds such as the very dense, over 5 metre high, bamboo species Arundo donax, which had established itself making more and more of the park area impenetrable.
Story & Photos: George Hirst