But don't we need trees too?
Yes, we most certainly do. There are a number of reasons for keeping trees or allowing regrowth of some trees. These include
Habitat for maintaining biodiversity - A 10% to 15% retention rate is the world wide standard. (We believe a well grassed timbered area gives better biodiversity results than trees with bare ground under them. Many native insects, birds, reptiles and mammals need the seed and leaves of grass for food. Trees regrow on pulled areas quickly. (How thick the trees become when they regrow depends on management).
Providing stock (and native animal) shelter.
To keep a selection of trees for things such as forestry or fencing timber.
In most Australian states, landholders have to submit a plan of how they want to manage their vegetation. Provided the plan ensures the minimum retention area and no endangered ecosystems or endangered animals habitats are destroyed, a permit is supposed to be given. Some states have a list of other requirements as well (and unfortunately some states have government departments overstepping the law and putting restrictions on landholders that are illegal.)
We believe more research should be done with regards to maintaining biodiversity because very little has been done to date. (E.G. how does grass cover, size of retention areas, climate, vegetation type & density, and grazing management systems affect biodiversity?)
On the rangelands of Northern Australia the problem is not so much keeping enough trees after pulling, as preventing them from growing back too thickly. Tree regrowth after pulling is usually thicker and more likely to crowd out grasses than the original stand of timber was unless it is well managed with fire and appropriate grazing. Some environmental groups acknowledge this regrowth problem (see Queensland Conservation Council web site) but fail to understand that natural timber thickening is creating the same environmental problems as regrowth does. (See second photo on this page).
The "tree clearing" debate should be raising the question, "What is the best way to manage trees for a sustainable productive landscape?" rather than, "How many trees should landholders be allowed to pull down?"
One approach to forest management that could be helpful is called "Variable retention in forestry"
One of the founders of Greenpeace (Patrick Moore) advocates this method of management. Please follow the link to learn more about it.
Answering critics of treepulling
Senator Robert Hill has said tree clearing in Queensland is unsustainable - However the facts are
approximately 400,000 hectares were pulled in Queensland in 2000.
85% (340,000 ha) was not for a land use change ( it was grazing land before and remains grazing land still and the tree pulling was for regeneration of grasses and tree control purposes
Only 15% (60,000 ha) was for a land use change (housing, mining, cropping etc)
Dr Bill Burrows (Tree researcher at the Beef institute) has research showing 60,000,000 ha of Queenslands grazing land has trees increasing at an average of 911kg/ ha of biomass (see his article on carbon sequestration
) That`s over 54,000,000 tonnes / year. His research also shows timber biomass on grazing land range from 30 - 100 tonnes / ha across Queensland. If we use an average of 80 tonnes / ha as the biomass of all the pulled timber, then 400,000 ha x 80 t/ha = 32,000,000 tonnes of timber is pulled each year. If you assume all the timber is burnt or rots (which is not the case) then Queensland still has a surplus of approx 22,000,000 tonnes biomass growing each year on grazing lands
(The actual figure would be greater than this, as not all the pulled timber is burnt and the average biomass could be less than 80 tonne/ ha.) Therefore tree pulling is a sustainable land management tool
in the grazing lands of Queensland.
Dr Barry Traill (Wilderness society of Queensland) said on ABC radio that if tree clearing continues as it is, then in 20 years time, there will be no bush left as we know it .
The above figures demonstrate his lack of understanding about Queensland ecosystems which have trees that germinate constantly (treethickening), regrow after pulling, and encroach on to new areas.(see tree increase) His maths is inaccurate too (60 million ha / 400,000 ha = 150 not 20)
Senator Hill has stated Queensland needs to cap the treeclearing rate to reduce Australia`s greenhouse gas emissions.
Queensland has a biomass increase of approx 22,000,000 tonnes each year
Thats approx 10,000,000 tonnes of extra carbon stored in vegetation each year.
Sure by reducing tree pulling rates, even more carbon would be stored, but Queensland is already a vegetation sink, so any extra should be paid for via carbon credits as those areas not able to pull timber will eventually become non grazing lands once the tree density reaches it`s maximum.
Senator Hill has also said Queensland`s treeclearing should be brought into line with other states.
What does he mean?
All other states still allow land clearing provided endangered ecosystems, protected species habitat and retention rates are retained, which Queensland does as well.
Tasmania has more treepulling as a percentage of total land mass than Queensland. (according to ABC radio`s Earthbeat program )
Western Australia has 6 government departments making "memorandums of understanding" which are defacto (illegal) vegetation laws, which have never been debated in parliament.
And South Australia has very little vegetation left. (2.7 million ha on grazing land)
Which states does he want Queensland to follow?
In Queensland all endangered ecosystems and endangered animals habitats are protected, and retention rates adhered to. All tree pulling requires a property plan and a permit.
Mr Hill should be prepared to help the Queensland Government sort out a method of compensation for landholders badly affected via loss of freehold rights they have paid for, and imposed "public good" conservation, which have ocurred as a result of the above restrictions.