Farmers argue the legislation as it stands is working and has let an additional 430,000 hectares of "woody growth" emerge between 2012 and 2014, according to the state government's own data.

The AgForce-organised rally, in Elizabeth Street's Queens Park and the march on Queensland's Parliament House is timed with the start of the Ekka, the week "the bush comes to the city".

AgForce has since March 2016 argued the increase in "woody vegetation" has been captured by Landsat satellite imagery in the Statewide Landcover and Trees Study (SLATS).

However senior conservationists argue AgForce is ignoring the science which says the satellite imagery is measuring soil moisture, weeds and extra branches on existing trees, not extra trees.

AgForce's chief executive Grant Maudsley rejected the conservationists claims, saying the measure was exactly the same as it had been since Peter Beattie introduced the legislation.

"That is the figures that the government presented to us; foliage protection cover has been used ever since Peter Beattie introduced tree clearing laws in the early 2000s," Mr Maudsley said.

"That is thickening timber – over and above – any clearing that we have done," he said.

Mr Maudsley said everyone who worked in the bush recognised the bush was seeing "tree thickening".

He said conservationists were confusing clearing of mulga land in south-west Queensland for fodder harvest with permanent clearing of tree species.

"A lot of the clearing that the conservationists are talking about is in the mulga lands," he said.

"That is between 62 and 65 per cent of the land. The reality is that timber will come back twice as hard and twice as thick after we clear it."

Dr Catterall, from Griffith University's School of Australian Environmental Studies, told Queensland's Agricultural and Environment Committee on June 3, 2016, it was "spurious" to say woody vegetation had increased by almost 500,000 hectares.

"The bottom line is that when you have some wet years you get an increase in the growth of grass and herbs and weeds as well as an increase in the foliage density of existing trees, so a little spindly tree can become a tree with lots of leaves," Dr Catterall said.

"That gives what is essentially a false reading of increased vegetation cover," she said.

"Without actually delving technically in much more detail than ever has been done into these data, it is really impossible to use the SLATS data to argue for an increase in vegetation extent."

The Queensland Government's own senior bureaucrat in this area, Graham Nicholas, from the Department of Natural Resources and Mines told a public hearing on March 22, 2016, the "woody vegetation" measures could not be used from year to year.

"It is important to note that clearing figures cannot be derived by comparing wooded extent from year to year," Mr Nicholas told the hearing.

"It is simply the way the information is presented and how they undertake their scientific analysis. "But it is very clear in the report that you cannot compare from year to year the extent of woody vegetation."

In March 2016, Environment Minister Dr Steven Miles explained the additional woody vegetation in this way in state parliament.

"The estimation of early vegetation regrowth and very low cover woody vegetation is approaching the limit of what can be detected from annual Landsat satellite imagery," Dr Miles said.

"Therefore, the wooded extent is not used for comparisons from year to year or to derive loss or gains in vegetation extent," he said.

" It is, however, useful information about tree and shrub  foliage  cover for a range  of other  government  applications—regional  ecosystem  mapping updates, assessments of bushfire hazard and risk, riparian vegetation mapping for reef reporting, and biodiversity planning and mapping," he said.

"What it is not used for is assessing vegetation change from year to year."

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