Inquiry Into the Vegetation Management (Reinstatement) and Other Legislation Amendment Bill 2016

Submission No. 214

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

Queensland Parliament Agriculture and Environment Committee

Inquiry into the Vegetation Management (Reinstatement) and other Legislation Amendment Bill 2016

Submission By Dr Bill Burrows FTSE Woodland Ecologist

formerly Senior Principal Scientist, Queensland Department of Agriculture & Fisheries (Retired)

21 April 2016

1 Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

Summary This Submission draws upon the writer’s 40 year research career studying grazed woodland systems in Queensland, as an employee of the State Government. It is motivated by a strong belief that most Members of the Queensland Parliament do not understand the scale and nature of the woodland management problem confronting rural landholders. Nor do I believe that these MPs appreciate the implications of the current Bill for the future sustainable management of grazed woodland communities and the viability of the agricultural enterprises dependent on them.

The Submission is founded on factual evidence and a robust science which MPs may not be familiar with, or which has not been fully explained to them. Should any of the information presented herein be questioned by advisers to this Committee or the Government, it is suggested that the Inquiry seeks evidence, rather than opinions, to substantiate any such contrary claims.

Queensland has at least 50 million hectares of grazed woodland communities. This Submission accesses a wide range of sources to inarguably demonstrate that these woodlands are thickening up (increasing in canopy cover, stem number, stem size or basal area) under existing management. The evidence that current woodlands were much more ‘open’ (supported far fewer trees and shrubs) at the commencement of grazing with domestic livestock is compelling. It is contended that this thickening will continue well into the future, if management options are constrained.

Some 29 local government areas are affected by woodland thickening and regrowth from past clearing, with about 2.1 million beef equivalents carried within the wooded portion of the affected Shires. The strong negative exponential relationship between increasing woody plant cover and associated pasture production is emphasised – with the greatest depressant effect exerted at comparatively small woody plant densities/basal areas. Economic data are also presented showing the negative impact of woodland thickening on the financial returns of grazing enterprises.

The Submission challenges the oft repeated statement that ‘clearing bans’ are necessary to minimise greenhouse gas (‘Carbon’) emissions. It cites recently published scientific evidence that show and support the fact that Australia and Queensland withdraw, on average, more carbon dioxide from the atmosphere than they add to it. In other words our land mass is a net ‘carbon sink’. The last assertion is at variance with Government pronouncements simply because government chooses to only undertake a partial accounting of the nation’s carbon budget. That is misleading policy based on misleading ‘science’.

The Submission concludes by pointing out that there are many situations where clearing thickening woodlands and regrowth can benefit threatened fauna and restore habitats lost to thickening. In like vein evidence is presented that sediment loads reaching the GBR lagoon include a large component that has been a natural function of the landscape, well preceding agricultural land use. The sediment that is attributable to human activity is more a result of past grazing practices, than woodland clearing.

It is a disservice to Queensland to imply, as the government is want to do, that all woodland clearing is bad for the State, the environment and the Great Barrier Reef. The challenge for this Inquiry is to provide a better balance and reality check into consideration of the current Bill. Foremost amongst these considerations is the need to recognise that the land targeted by the legislation is land which has been assigned by government for the “purpose of agricultural production” – the raising of food and fibre for human use, both in this country and for our export markets. We would be wise to ensure this agricultural production capacity is maintained.

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

Vegetation Thickening

Vegetation thickening - increases in woody plant stem numbers, foliage cover, stem size/basal area (the area of stems covering the ground) and woody plant biomass - is more or less a universal phenomenon now observed throughout Queensland’s ‘intact’ (uncleared) grazed woodland communities. Further, there is increasing evidence of woody plants invading natural grasslands, which supported few if any woody species before the arrival of Europeans and their domestic livestock. Thickening is also widespread in the top half of the Northern Territory (e.g. Lewis 2002) and in the Kimberley and Pilbara regions of Western Australia (Future Beef eBulletin – Nov 2015). Please note that in all discussion that follows (apart from 2 examples of invading rainforest) the thrust of the argument and evidence presented targets land that has been assigned by government for the prime purpose of agricultural production. This is clearly set out, for example, in documentation associated with most Grazing Homestead Perpetual Leases which states that the Purpose of the Lease is for grazing and agriculture. Vegetation thickening can be quite rapid, but more commonly it is a slow, subtle and invidious process well encapsulated in the abbreviated title of Darrell Lewis’s 2002 book “Slower than the eye can see”, which elegantly documents thickening in the Northern Territory's Victoria River District. For the latter reason people who have not lived or worked in rural landscapes for 10 or more years are usually oblivious to the vegetation changes that are occurring, even though in the absence of management intervention, these ‘flips’ are unidirectional towards more and more woody plant dominance. Importantly, these changes in plant structure and composition will often exert profound effects on the productivity and sustainability of rural enterprises, as well as on the biota and ecosystem processes supported by the affected landscape. Fortunately, we now have a very large, diverse and compelling array of data that documents vegetation thickening in Queensland, along with its ongoing impacts. These will be detailed in the following pages. But one clear message stands out – banning tree and shrub control on rural landholdings will not stop vegetation thickening. [This is because ecological processes which operated under indigenous management cannot be replicated - as the needs of European agricultural practices (for food and fibre production) have now supplanted the former indigenous management]. Consequently, if the landowner’s motivation for clearing woody plants on agricultural land was to restore or improve pasture or crop production, lost to tree thickening, this problem is only going to get worse on all holdings (or part thereof) that are subjected to clearing bans. [A review of literature relevant to this subject area was emailed to all 89 members of the Queensland State Parliament on 13 December 2015. This review is still available at the following link - http://www.beefcentral.com/wp-content/uploads/2015/12/Vegetation-Management-in- Queensland-Background-notes-for-State-MPs-Jan-2016-update.pdf ].

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

Examples of woody plant ‘thickening’:  Great Keppel Island, Yeppoon – Islands are good examples of the transformation of ‘unmanaged’ vegetation following the introduction of domestic livestock, because the land area is unambiguously defined by the sea. Great Keppel Island (off Yeppoon) is said to have carried 3 – 4000 sheep (or 4 – 500 adult cattle equivalents) on its 1140 ha ‘hard’ land area in 1883 (Rowland 2004). This carrying capacity (2-3 ha/beast) would be impossible today given the current dense woody vegetation cover on this island. (Google image below).

Figure 1 – A 2015 image of Great Keppel Island. Note the more or less complete coverage of trees and shrubs which would make it impossible to now support the domestic livestock numbers carried in the 1880’s. Grazing ceased in 1962.

 Curtis Island, (‘Monte Christo’ Station), Gladstone –

Curtis Island, off the coast from Gladstone provides another stark example of vegetation change when there is no concerted effort made to control thickening woody plant populations (or government regulations prohibit it). This island was a large cattle run for about 150 years – centred on Monte Christo Station. Monte Christo carried 5000+ cattle for 90 years, before seeing its carrying capacity decline markedly in the past 60 years or so, as woody plant populations started to rapidly increase on the island.

On the next page is a copy of an advertisement placed in the Sydney Morning Herald on 9 June 1870 (p. 9) advising the Auction of Monte Christo, which at that time had grazing rights to 156 square miles (40,404 ha). Monte Christo was run continuously as a cattle grazing property until 2014, when it effectively surrendered the majority of its holdings to the Crown.

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

Figure 2. Details of Monte Christo as listed in the 1870 Auction advertisement (continued over page).

The stated carrying capacity at the time of the 1870 auction was 12,000 head of cattle in all seasons – with 2000 mixed head included in that current sale. This equates to a beast to c. 3-4ha and indicates the 1870’s vegetation would have had to be very open woodland to support such a carrying capacity. Note: In fact the ad also described the holding then as “richly grassed fattening country”.

The Telegraph (Brisbane 5 Apr 1875 p.2) next reports Monte Christo was sold that year with 2800 cattle included. An article (detailing a pioneer’s personal district recollections) in The Morning Bulletin (Rockhampton, 31 Aug 1925 p. 3) then described Monte Christo as a cattle station which had carried from 5000 to 6000 head for some time. Even as late as 1953 the then owner of Monte Christo (Mr Osborne) said there were still some 5500 cattle on Curtis Island (The Courier-Mail, Brisbane 6 Apr 1953, p. 5).

However such carrying capacities are clearly not feasible to-day (even if grazing was still practised on Monte Christo, which is no longer a grazing holding). The Google Earth image of the island today (p. 8) shows beyond doubt that substantial woody plant thickening has occurred there since the time grazing commenced in the 1860s. It is my experience that most of these vegetation ‘flips’ in Northern Australian cattle country followed from the late 1950’s replacement of British cattle (Bos taurus) breeds with the far better tropically adapted and tick resistant Brahman (B. indicus) infused stock.

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

This change in herd genetics was accompanied by the widespread use of dry season (urea – molasses) feed supplements, with the result that dead grass (fine fuel) was now normally eaten, rather than burnt. Consequently woody plant seedlings were no longer ‘controlled’ by fire before they became well established (see Fensham et al. 2008). Such control (regular burning) occurred when indigenous people managed the country and when graziers burnt dry grass at the end of the dry season to provide ‘green pick’ for British cattle breeds. Paradoxically, returning herd composition to predominantly B. taurus lines is no longer a realistic livestock option (because of the intolerance of British cattle breeds to heat and cattle ticks, compared with available alternatives).

Thus Curtis Island epitomises the transformation in plant structure and composition which regularly occurs on our grazing lands if regenerating woody plant populations are left uncontrolled. Monte Christo’s current dense woody vegetation is a clear bellwether of likely changes in other grazed woodland communities - whenever landholders fail to manage thickening woody vegetation and/or regrowth, or lose their rights to do so. There is no evidence from Monte Christo to suggest that widespread ring barking, chemical injection or bulldozing/chain pulling took place on Curtis Island to reduce woody plant populations after domestic livestock grazing first commenced.

Figure 2 (Cont’d)

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

Figure 3 Contemporary image of Curtis Island showing almost complete woody plant coverage. ‘Monte Christo’ is no longer stocked but it is obvious that carrying capacity today would be very limited (especially in comparison with the 5-6000 head supported for most of the first 90 years of the property’s existence as a cattle run).

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

The approximate location of areas ‘cleared’ (with dominant poplar box trees retained) in 2007-09 is superimposed in pink on the 1952 image (Figure 5). Woody vegetation cover was much more open in 1952 and reflects the original survey description (above) when the block was first taken up by John Moody. The extent of thickening from 1952 to 2011 is very obvious. Compare the woody cover at Points ‘A’ and ‘B’ on the respective images. Vegetation scene (Figure 6 – left photo) is taken from the “cleared” area of the 2011 image, while the thickened vegetation (right photo) is from Point ‘B’ on the same image. [Image scales are only approximately equal].

Figure 6 ‘Cleared’ area on ‘Alpha’ compared with thickened woodland present in 2013

 ‘Wallal’ , Charleville - This is a property 60 km north of ‘Alpha’. The left photo shows the landscape soon after invading green turkey bush (a native weedy shrub, also now common on ‘Alpha’) was killed in 1970. The response of the native pasture in the 1972 photo below is remarkable (note the same tree ‘markers’ right centre of each image) – again starkly illustrating why landholders want to retain the right to manage thickening woody plants on their grazing land. The ‘Wallal’ landscape is similar to that on ‘Alpha’ and the photo of recovered pasture is similar to that shown for ‘Alpha’ (Figure 6 left image).

1970 1972 Figure 7 Benefits of controlling thickened native woody shrubs on ‘Wallal’ for pastoralism and granivorous (grass seed eating) bird populations.

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

 ‘Wongalee’, 40 km East of Wyandra, SW Queensland - Before leaving the south-west it is also instructive to remind ourselves of the capacity of mulga woodlands east of the Warrego River to ‘thicken’ up. While drought feeding with mulga is not impacted by the proposed legislation, mulga thickening (Figure 8 below) is further evidence of the mechanisms operating with woody plants throughout our grazing lands [see mulga photo sequences below from the ‘Wongalee” house paddock 30 km east of ‘Alpha’].

 Kogan, Condamine Highway – White cypress pine is very susceptible to fire and is now invading large areas of sandy soils in south west Queensland (Figure 9) and north-west NSW.

Figure 9 Note central spotted gum (1936) engulfed by cypress pine (1989)

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

 ‘Kaiuroo’, Dingo –

As thickening proceeds (Figure 12) mustering difficulties increase and timbered areas become refuges for feral pigs and goats, along with excess kangaroo populations. Carrying capacity also declines and running costs of the enterprise escalate.

1982

2004

Figure 13 Feral pigs and goats find shelter in thickening woodlands at great cost to landholders

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

 ‘Wandobah’, Dingo –

Poplar box (Eucalyptus populnea and the closely related E. brownii) woodlands are the most widely distributed grazed eucalypt woodland communities in the State. For this reason and because it was known that these communities were thickening under livestock grazing, the Queensland DPI, with financial support from meat research levies, instigated a long term ‘Clearing Strategies’ Trial at Wandobah in 1987. The results of this study have been published (Back et al.2009 a, b). However to the best of my knowledge none of the research staff involved in this comprehensive tree management Trial were ever consulted or invited to comment on its findings, with respect to any aspect of the various VMA legislation changes introduced since 1999.

Figure 14 Sequential photo pairs provide inarguable evidence of vegetation change but trained ecologists can also readily detect thickening signals by examining size class distributions within the woody populations. Such thickening is obvious in the above image from the large number of competing saplings present. The original open woodland trunks had been collar rung in 1935 (Bob Edmistone, personal communication) although the old dead stems show no evidence of ever being burnt in the intervening years. This paddock is on a small grazing block yet clearing of the regrowth could be banned because of its age - if the Vegetation Management (Reinstatement) Amendment Bill is passed.

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

 ‘St Albans’, Clermont -

Dense thickets of silver leaved iron bark (Eucalyptus melanophloia) and box (E. brownii) saplings (left & right respectively) on St Albans are also indicative of vegetation thickening in previously ‘open’ woodland communities that had never been cleared.

Figure 15 Woodland thickening in the Burdekin- Belyando Rivers catchment (see below).

 Reef Catchments – There have been four comprehensive studies of vegetation change (including woody plant thickening) in the three major river catchments (Burdekin, Belyando and Fitzroy systems) which drain into GBR waters. These studies are detailed below: a. Central Highlands region –

A 125,755 km2 area which included large parts of the Belyando - Fitzroy R catchment (Desert Uplands and Brigalow belt bioregions) was selected for an aerial photo interpretation study by Fensham et al. (2003). These authors found the following changes in over-storey cover in uncleared woodlands over the bracketed timeframes:

Eucalypts on clays (1960-1996) 8.44 – 13.37% Eucalypts on sand (1951-1996) 20.12 - 24.61% Eucalypts on hills (1952-1994) 35.63 – 41.4 Eucalypts on texture contrast soils (1952-1993) 24.60 – 29.24%.e. For the mean timeframes compared (41 years) tree cover increased by about one quarter, over its initial baseline levels (mean 22.2% increase, over all communities sampled). [Note: this figure is indicative only, as soil areas proportionally affected are not considered].

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

Figure 16 Area sampled in the Fensham et al. (2003) study.

b. Burdekin Catchment carbon isotope signature study – An elegant technique involving the analyses of stable isotopes of soil carbon has enabled the history of vegetation change to be documented in the Burdekin Catchment. Tropical grasses have a 13C signature with values around -12 to -14, whereas trees have 13C signature values around -26 to -28. When plant organic matter decays the fractionated organic matter still retains the same carbon isotope signature of the vegetation from which it was derived. The older (smaller) fractions generally dominate at depth and the younger material tends to be found closer to the soil surface. So an analysis of the depth and particle size with its 13C signature pattern enables a past vegetation history on the site to be formulated. This was done for 44 “intact” (sensu ‘remnant’) sites in the Burdekin catchment (Krull et al. 2007). It was concluded that 64% of the sites had experienced decadal woody plant thickening, while 29% had remained stable with only 7% having thinned during the past 100-150 years.

Figure 17 Evidence of vegetation thickening in the Burdekin catchment over the past 100-150 years

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

d. Carbon stock change study

Figure 19 Distribution of study sites for biomass and carbon stock change (Burrows et al. 2002). Compare with study area in Figures 17/18. (Average above-ground biomass increment over all sites ≈ 1060 kg per ha per year).

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

 Mt Baldy, Atherton Tableland – A strong indication that changed fire regimes have contributed to vegetation thickening since Europeans displaced indigenous management is provided by evidence that rainforest is invading adjacent wet sclerophyll forest on the Atherton Tablelands (Harrington and Sanderson 1994).

Figure 20 Mt Baldy rainforest invading a grassy flooded gum (Eucalyptus grandis) community.

 Iron Range National Park, Far North Queensland There are serious losses of critical fauna habitat in Cape York because various woody communities are invading grasslands. {These biodiversity losses will be discussed later in this submission}. On a 140 km2 study site in Iron Range an aerial photo study by Peter Stanton has shown the rainforest increased by 37.6 km2 from 1943 to 1991(See: http://www.savanna.org.au/qld/cy/cychange.html )

Figure 21 Overlaid digitised boundaries in Iron Range N.P. showing the expansion of rainforest. The original area in 1943 (dark green) had expanded to the larger area (light green) by 1991.

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

 Ti-tree invaded Grasslands, Cape York Leaving country unburnt, or burning regularly in the early dry season, along with overgrazing, can lead to vegetation thickening on Cape York Peninsula. In the space of 10 to 15 years, it is possible for open country to become completely impassable. Country types most at risk are open flats and ti- tree flats. Thickened country is hard to muster. Open grassy flats can support four times as many cattle as flats covered by ti-tree. On Cape York Peninsula, thickened flats are also poor habitat for wildlife. (See:http://www.firemanager.org.au/sites/default/files/resources/attachments/cyp-fireplan- complete.pdf )

Figure 22 Ti-tree actively invading grassland habitat of the golden shouldered parrot on Cape York.

 ‘South Terrick’, Blackall – By way of stark contrast to the preceding examples grasslands are also being invaded by native woody plants in Queensland’s arid zone.

Figure 23 Brigalow invading heavily stocked Mitchell grassland. Heavy stocking favours the thickening of trees just as much as reduced fire incidence.

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

 ‘Strathdarr’, Longreach - Gidgee (Acacia aneura) and other Acacias are invading Mitchell grasslands in the Central West.

Figure 24 Gidgee is an active invader of Mitchell grasslands in the Longreach district. This was confirmed by the late Frank Dean, a long-time resident in the area who claimed that the expansion of gidgee in the grasslands was a relatively recent (1950s+) phenomenon. This was later quantified by application of the  13C soil signature technique (Krull et al. 2005).

 ‘Timber Creek’, Northern Territory –

Woody plant thickening is not unique to Queensland. It is also common in the NT (Lewis 2002) and in the Pilbara and Kimberley areas of WA ø

Figure 25 Timber Creek in the NT in 1950 (left) and again in 1996 (below). The Victoria R. is in the top right of the photos (Lewis 2002)

ø .https://futurebeef.com.au/resources/newsletters/futurebeef-ebulletin/woody-thickening-can- reduce-carrying-capacity/

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

Wooded areas within Queensland’s Grazed Woodlands So far this Submission has established that woody plant thickening is ubiquitous throughout this State’s grazed woodland communities. The message is clear and unequivocal – when trends are followed over a period which involves both above- and below- average seasonal conditions (say 10- 15 years or more) woody plants will have noticeably thickened up in almost all our grazed woodland communities, if preventative measures are absent. Thus this fate awaits all woody plant communities which are subject to clearing bans. No ifs, no buts. The structure of affected grazed woodland communities does not stay still. They will continue to thicken after bans are placed on them. The consequences for the productivity, sustainability and viability of affected grazing enterprises are obvious, and are not ones that experienced land administrators can sensibly ignore. To get a ‘feel’ for the impact alluded to above I now provide extracts from a Report entitled “The Impact of Tree Thickening in Grazed Remnant Woodlands” prepared under Departmental instructions as a basis for a proposed Submission to a Productivity Commission Inquiry into the “impacts of Native Vegetation and Biodiversity Regulations” in 2003. My copy of this Report was forwarded to me after I retired from my research position in DAF in 2004. It was obtained by another person under FOI. The Report was never submitted to the Productivity Commission by the Government of the day. Nevertheless it was prepared by a very well qualified team of cross- department staff and, to the best of my knowledge, there have been no substantive claims challenging the results or methodology employed. [NB: In the following discussion it is important to note that the facts and figures used are those available in 2003. Still I believe the most significant disparity (if any) with to-day’s information would mostly relate to the potential monetary impact of “thickening”, given current cattle prices and interest rates.] The basis of the analysis of potential thickening impacts was to partition the State into units arranged on Shire boundaries (as existed in 2003). Data was obtained1for each local government area in Queensland. This area was constrained by identifying those Shires most affected by woodland thickening from a grazing perspective (Figure 26). Many Shires in south-east Queensland were deemed to be largely urbanized or cleared and some areas of western Queensland are naturally open (e.g. most Mitchell grasslands) and were regarded as not being affected by tree thickening. However, even in the excluded Shires, native tree thickening may be locally significant (e.g gidgee, Acacia cambagei) ingress into Mitchell grasslands in the Longreach district).

1 NR&M (2003)

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

Figure 26 Shires, as defined by 2003 boundaries, where tree/shrub thickening could have an impact on future livestock carrying capacity if/when/after clearing control bans are imposed on selected areas – whether at the paddock, property or district scale. See text for exemptions.

The area of wooded vegetation cover in each Shire was calculated from the percentage identified as wooded in 19992. The total area wooded in the selected Shires was calculated to be 68.3 m ha (Table 1). A conservative approach to determining the area subjected to thickening was adopted by allowing for the exclusions identified above. For the purpose of this analysis, 50 m ha was chosen as the minimum area of grazed remnant woodlands that is affected by tree/shrub thickening in Queensland's grazing lands. [This minimum would still apply in 2016].

2 NR&M (2003) – the total grazed wooded area would not have changed very much today, given the clearing restrictions variously put in place after the passing of the VMA (1999) 23

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

Table 1: Selected Shires, their areas and the calculated areas wooded within each Shire3

Shire Area (000ha) Area Wooded

1999 ('000ha)

Aramac 2331 946 Balonne 3109 1039 Banana 1572 466 Bauhinia 2360 1213 Belyando 3020 1488 Booringa 2776 1674 Bowen 2959 2041

Broadsound 4240 2100 Bungil 1332 431 Calliope 1906 1106 Carpentaria 6420 3294 Chinchilla 869 476 Cook 18330 17349 Croydon 2948 2703 Dalrymple 6812 5739

Duaringa 1771 867 Emerald 1040 487 Etheridge 3921 3381 Flinders 4139 2094 Herberton 969 925 Jericho 2183 1191 Livingstone 4697 2994 Mareeba 5345 4607 Murweh 4069 2428 Nebo 1001 633 Paroo 4766 2984

Peak Downs 811 350 Quilpie 6753 2452 Taroom 1860 843

Total 85979 68303

3 Calculated using data from NR&M (2003) 24

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

Cattle numbers in the targeted woodland Shires There were around 5.3 m beef equivalents (BE) running in the selected Shires affected by tree/shrub thickening in 2003. The following steps were taken to calculate the number of cattle running in the wooded portions of each Shire:

 BE were obtained for each Shire in Queensland4 excluding all animals in feedlots.  A ratio of stocking rates was assigned to each shire designed to reflect the differences in carrying capacity between wooded and unwooded areas within each of those shires. Tree clearing commonly leads to a sustainable doubling of livestock carrying capacity,5 although this figure varies according to the initial tree basal area, mean annual rainfall and the soil fertility of the treated country. Estimates of carrying capacity ratios between cleared/natural grassland areas and wooded zones in the targeted Shires were made. These ratios varied from 1.1 (Cook and Croydon Shires) to 3 (e.g. Bauhinia Downs and Taroom Shires). The areas of urban lands, roads etc. in the Shires were ignored for the purposes of livestock allocation.  This allowed the calculation of the proportion of cattle running on wooded areas (as opposed to unwooded) and hence the actual number of cattle (expressed as beef equivalents) run in wooded areas. Approximately 2.1 m BE run exclusively in ‘remnant’ (‘intact’/uncleared) wooded areas of the selected Shires. (Table 2).

------

[Note: If this exercise was repeated with information available in 2016 it might produce different numbers based on woodland management, seasons and livestock markets between 2003 -16. However I would be surprised if they differed markedly. It is possible that government staff have already updated the calculations as part of advice given to the government when considering the impact of the proposed Vegetation Management Amendment Bill on the operation/viability of affected agricultural enterprises - and for the information of this Parliamentary Committee?].

4 ABS 2001 statistics — J. Carter (NR&M) personal communication 5 Burrows (2002) 25

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

Table 2: The number of Beef Equivalents running in wooded areas in Shires affected by woodland thickening (based on latest data in 2003).

Shire Beef Number of Equivalents Beef Equivalents in the Shire in Woodlands

Aramac 71599 22400 Balonne 153455 30776 Banana 371476 45759 Bauhinia 365507 95241 Belyando 299058 83674 Booringa 146757 63346 Bowen 282798 168817 Broadsound 211559 52147 Bungil 194189 31228 Calliope 72034 29444 Carpentaria 289744 75321 Chinchilla 64712 24386 Cook 74814 70435 Croydon 52830 48046 Dalyrmple 544961 396656 Duaringa 03539 84220 Emerald 157985 48316 Etheridge 193044 155765 247206 62902 Herberton 7664 6701 Jericho 245989 100146 Livingstone 147503 69015 Mareeba 104725 84432 Murweh 167273 71143 Nebo 160898 74316 Paroo 62323 32868 Peak Downs 90244 30371 Quilpie 86570 23841 Taroom 220016 47657

Total 5390472 2129369

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

Tree thickening impacts on Pasture Production

The effect increasing woody plant cover exerts on potential pasture production has been widely studied in Queensland (see Burrows 2002 and references therein). The relationship between pasture yield and any expression of woody plant competition follows a negative exponential pattern. This means that even small numbers of woody plants (excluding fodder trees with palatable leaves) present in a pasture can have a significant depressing effect on potential pasture production

Figure 27 Woody plant competition effects on potential pasture yield – Burrows (2002) (continued on following page).

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

Figure 27 (Cont’d) Woody plant competition effects on potential pasture yield.

Figure 28. Seasonal conditions also have an impact as shown in this generalised diagram.

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

Economic impacts of woody plant thickening (and regrowth control bans) in the grazed woodlands The foregoing data should enable Parliamentary Committee members to appreciate the scale of the potential problem if tree/shrub thickening is allowed to proceed unchecked in Queensland’s grazed woodland communities. Hopefully Committee members will also understand that there is now convincing, multi sourced evidence, that woodland thickening is a unidirectional process on grazing lands. In other words, while we will always experience “drought and flooding rains” it is inevitable that the livestock carrying capacity of grazed woodlands will continue to decline – wherever control bans are voluntarily imposed or enforced as a result of government regulation. A Net Present Value (NPV) analysis of lost grazing production as a result of uncontrolled vegetation thickening (based on a 50 year timeframe) was carried out for the draft Productivity Commission Report mentioned earlier. It is beyond my ability to update these economic impact figures which are founded on gross margins, livestock capital and interest rates significantly different to those applying in 2016. Yet even in 2004 published results showed that reducing tree cover by half increased cash flow by $90,000 per year for a self-replacing cattle property of 20,000 ha near Charters Towers. Clearing box woodlands near Dingo, with 20 percent retention in retained blocks and strips gave NPVs of $40-64 per ha greater than for uncleared controls. In north-west NSW sheep country, the gross margin for land cleared of unwanted woody plants is double that for land with high tree-shrub densities (see Burrows 2004). Again I presume the Government considered the economic impacts of tree thickening (given it affects 50 M + ha) prior to introducing the current Bill to Parliament? Staff charged with this responsibility would be well served to consult the draft Productivity Commission Report for essential tree – grass, carrying capacity and woody plant growth rate relationships which are necessary precursors to undertaking such an economic study. They could also revisit Living Area Standards as a non-regulatory form of advice to landholders who will be affected by both tree thickening and/or clearing bans. Likewise banning the control of regrowth (an inevitable consequence of almost all clearing of native vegetation on agricultural land) will negate the benefits of increased livestock carrying capacity resulting from the initial clearing. Furthermore, bans on managing regrowth have the potential to seriously impact on the viability of agricultural enterprises (proportional to the area affected and its potential productivity compared with the rest of the holding). Regulatory and economic constraints on land clearing over many years, along with common sense, dictate that most regrowth will be found on more productive parts of a property; when compared with the potential of remaining uncleared areas. Such regrowth paddocks should be seen as “pockets of viability” within the grazing enterprise, because they will increase livestock production 2-4 fold on a treated area basis when they reach their pasture potential. In other words they will often represent the difference between financial success and failure of the enterprise. The history of land settlement in Queensland is replete with examples of owner/managers who had a non-viable land holding. Unfortunately this often led to such operators “flogging” the land, their livestock and figuratively themselves, before they were forced to eventually leave the property. [Has the government had its agricultural economists evaluate any of the above scenarios before tabling the current Bill?]

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

The government’s response to the reality of thickening trees and shrubs in grazed ‘intact’ woodlands is to say that “thinning” will be allowed in certain circumstances. However to the best of my knowledge there has only been one well designed experimental study that has evaluated thinning impacts on beef production in Queensland (See Burrows 2002, Back et al. 2009 a). The thinning treatments were imposed on a poplar box woodland near Dingo in 1987. When thinning is carried out in forests and woodlands the remaining live trees respond vigorously to the reduced competition (Back et al. 2009 b), such that the benefits to pasture production are only short-lived. In other words, the woodland generally recovers its pre-thinning competitive ability with the underlying pasture before the cost of the thinning can be recouped. Figure 29 Example of a growth response in a poplar box woodland subjected to tree thinning in 1987.

Figure 30 Economics of ‘thinning’ compared with some ‘standard’ clearing treatments (Burrows 2002)

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

Carbon storage and abatement

Governments concerned over rising carbon dioxide (C02) levels in the atmosphere would have more credence if they were not selective in their approach to abatement. Fossil fuels have a far greater carbon intensity (percentage content) in their mass than has woody biomass. Yet Ms Trad (Queensland Hansard 24.2.16 p.517) chooses to focus on limiting the capacity of rural landholders to manage thickening woody plants on their agricultural land, rather than on reducing fossil fuel usage. Why has government disproportionately elected to target the livelihood of individual farmers and livestock producers to achieve abatement, rather than the community at large? The simple fact is that the government is promoting its carbon abatement argument with little apparent understanding of the latest scientific studies and published results addressing Australia’s and Queensland’s true net emissions of CO2. Few people are aware that our published emissions are based on only a partial carbon accounting budget. [Hugh Grossman of market analysts Reputex refers to our “tricks of (carbon) accounting”]. Thus, while the National Greenhouse Gas Inventory includes emissions from the Land Use, Land Use Change and Forestry sector of our economy, we report changes in carbon stocks from only c.10% of the 157 M ha national forest estate (areas with woody plants >2m tall, >20% canopy cover, >1 ha in extent). In like vein only about 6% of c. 76 M ha of forested land in Queensland is currently reported in our inventory. This partial carbon budgeting is astonishing, given the inarguable evidence for woody plant thickening in our ‘intact’ grazed woodland communities along with acceptance of a 15% response in plants due to the CO2 fertilisation effect (Prof Graham Farquhar, pers. comm.) But this is even more so when one considers that, in terms of any effect that CO2 exerts on the world’s climate, no distinction is made as to the origin of each molecule that contributes to the concentration of this gas in the atmosphere.

So CO2 is CO2, and 400 ppm concentration = 400 ppm, whatever its source. Therefore if we are going to manage the atmospheric content we need to account for all sources and sinks that contribute to it. [No financial accountant would sign off on a set of books if pages of credits or debits were omitted from the accounts he/she was tasked to audit. Yet the Queensland government is asking its’ citizens to accept its’ self-proclaimed pronouncements on this State’s CO2 emissions as if they truly represented the State’s net contribution to the atmosphere above our land mass. The government and its’ advisers need to be reminded that they can legislate laws, but they can’t legislate scientific facts, which they are not the prime authority on in any event]. A recent paper in Geophysical Research Letters (Detmers et al. 2015) describes an enhanced carbon sink detected over Australia in GOSAT records from the end of 2010 to early 2012 which amounted to some 2800 Mt CO2-e (equivalent) per year. This contrasts with Australia’s reported National Greenhouse Gas Inventory emissions for 2011 of some 552 Mt CO2-e. The latter figure is less than one-fifth of the land sink that was mostly excluded from that inventory year’s calculations. These findings are discussed in more detail and for a range of conditions in the April 2016 edition of Focus (a publication of The Australian Academy of Technological Science and Engineering – see http://atse.uberflip.com/i/665800-focus-195-innovate-or-perish-thats-the-mantra-we-must-turn-our- ideas-into-world-products-and-services/29 ). Queensland, through its huge woodland area makes a very significant contribution to this enhanced carbon sink, because of the widespread tree/shrub thickening in the grazed woodlands documented earlier in this submission. A rising trend in woody biomass carbon has also been reported (Liu et al.2015) in our northern savannas for the 20 year period 1993-2012; including years of well above and well below average rainfall (Se Figure 18 above). Observations were obtained from satellite borne passive microwave 31

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

Biodiversity Conservation Any change in vegetation structure and composition will have an effect on the biodiversity values of the impacted ecosystem. Unfortunately government has chosen to focus solely on land clearing impacts on biodiversity, while assiduously ignoring the impacts of the far greater extent of vegetation thickening. Much of the research on impacts of woody thickening has focussed on livestock production and ecosystem processes such as soil erosion and nutrient cycling. Although few studies have addressed the impact of woody thickening on biodiversity, it is suggested that native species adapted to open grassy ecosystems may be disadvantaged or even face local extinction as woody cover increases. In Cape York Peninsula, dramatic declines in granivorous birds such as the golden-shouldered parrot, star finch, Gouldian finch, buff-breasted button-quail and black-faced woodswallow (see photos below) have been attributed to woody thickening associated with changed fire regimes (Crowley 2001). The latter has also led to invading rainforest displacing the habitat of the mahogany glider (Jackson et al.2011) [Figure 29]. The thickening processes involved in loss of habitat include changes in vegetation structure. This has led to more successful predation by birds such as pied butcherbirds and loss of perennial grasses such as cockatoo grass ( Alloteropsis semialata ), which seed-eating birds rely upon for food at critical periods of the year (especially the early wet season). Vegetation thickening also results in loss of termite mounds in which the golden-shouldered parrots nest. (http://www.savanna.org.au/all/ ).

Star Finches are under threat from habitat changes due to grassland thickening. Photo M. Todd

Golden shouldered parrot

Figure 32 Some iconic Queensland fauna threatened by increased tree/shrub thickening in woodlands and forests.

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

Gouldian finch Buff-breasted button-quail

Crimson finch (white bellied)

Black faced wood swallow Australian bustard

Figure 32 (Cont’d) Some iconic Queensland fauna threatened by increased tree/shrub thickening in woodlands and forests.

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

Mahogany glider Northern bettong

Figure 32 (Cont’d) Some iconic Queensland fauna threatened by increased tree/shrub thickening in woodlands and forests.

Franklin (1999) utilized reliable RAOU records, going back to the 1800s, to show that the marked decline of grass seed eating birds in northern Australian savannas preceded any land clearing activity. Franklin attributed this change to the replacement of Aboriginal land management with European pastoralism and alternative fire regimes. The latter are the same causes thought to have led to tree and shrub thickening elsewhere in the State and over similar landscapes and time frames to Franklin’s study (See earlier discussion of Vegetation Thickening). So more trees = less grass = fewer grass seed eating birds Subsequently an IBRA study of the Brigalow Belt North bioregion (13.5 M ha) – see https://web.archive.org/web/20080615000000*/http://www.anra.gov.au/topics/vegetation/pubs/table s/birds bbn.xls [Accessed via The Wayback Machine 17.4.16] - documents an increased reporting rate for grassland birds – which the Study notes [possibly reflects the increase in cleared land!]. [Also see Franklin et al. 2000]. In mixed eucalypt communities ‘thickened’ narrow leaved ironbark and gums are relatively simple to control, leading to regrowth that may be dominated by harder to kill bloodwoods. Likewise root suckering species are favoured post-clearing, compared with species that only regenerate from seed. This in turn can lead to significant changes in the fauna supported as well. Consider a community originally composed of brigalow, belah and wilga. Following clearing the regrowth will be predominantly a monospecific stand of dense brigalow suckers. Allowing the brigalow suckers to grow out will not restore the previous food source of glossy black and Major Mitchell cockatoos (belah seed cones) or eastern spinebills (nectar from the flowers of mistletoe parasitising wilga). The point being made here is that while Government finds it convenient to associate tree clearing and regrowth control with “loss of biodiversity” – this is not a one way street as far as biodiversity outcomes are concerned. Likewise restricting the clearing of regrowth on agricultural land will not restore the original structure and composition of the vegetation, nor its original fauna population or species mix.

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

Woodland Management and the Great Barrier Reef It is fashionable, more than factual, to associate GBR health with sediment loads which supposedly increased as a result of tree clearing activities. Because of their large size the catchments of the Fitzroy and Burdekin-Belyando river basins are the ones most associated with this ‘problem’. Lewis et al. (2007) employed a novel technique to examine the multi-trace element record in long lived Porites coral, as a means of detecting past land-use changes in the Burdekin catchment. Before the arrival of Europeans and the introduction of sheep into the Burdekin River basin in 1854, coral manganese (Mn) levels at their study site were uniformly low (<1 ppm). However after 1854 coral Mn levels rose dramatically, fluctuating in parallel with livestock numbers (leading to surface soil erosion) before returning to more ‘normal’ values by 1900. Another pulse between1945-1960 is attributed to the expansion of the cattle industry after World War II. These signals of surface soil erosion showed up before widespread tree clearing took place. The Fitzroy estuary makes a good case study because it has been subject to extensive research. This estuary empties into Keppel Bay, whose waters have always been turbid. Consider the following extract from the journal of Matthew Flinders: Tuesday 17 August 1802 “Keppel Bay was discovered and named by Captain Cook, who sailed past in 1770. A ship going in will be much deceived by the colour of the water, for the shores of the bay being soft and muddy, the water running out by the deep channels with the latter part of the ebb is thick------Not only are the shores for the most part muddy, but a large portion of the bay itself is occupied by shoals of mud and sand” [Emphases added]. (Flinders 1814). A Geoscience Australia study concluded (Bostock et al. 2006) that the Fitzroy River has deposited an average of 136, 000 tonnes of mud and fine sediment into Keppel Bay per year, for the past 6000 - 7000 years! This contributes to constant levels of turbidity, promoted by the shallowness of the Bay and the regular sediment inputs, which are mobilised by advective transport whenever winds exceed 15-20 knots. Two points are relevant from the above discussion – i. There is a pronounced level of background (natural) sediment load being deposited into the GBR ‘lagoon’ each year that is independent of any human related land management activity. ii. It is more likely that it is heavy stocking with domestic livestock, rather than tree clearing per se, that is most responsible for any pulse in sediment loads into the GBR lagoon. So, if it is considered desirable for GBR health to reduce run-off sediment, the focus of attention should be on grazing management, rather than reducing tree clearing. There are two features in the following satellite overview (Figure 33) of the southern GBR waters deserving comment. First, while there is obviously a large on-going sediment input from the Fitzroy River into Keppel Bay the deeper waters of the Curtis and Capricorn channels (15 m deep) are a barrier to this sediment reaching the ‘reef proper’ (the Bunker Group to the east and the Swain Reefs further north) by advective transport. Second, Broad Sound is a large coastal bay south-east of St Lawrence. It has only a small River (the Styx) flowing into it, yet Broad Sound always shows up as being turbid on satellite imagery. So the turbidity here is a natural feature (resulting from the shallowness of the Bay) and has no relationship with nearby land use.

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

Figure 33 Terra satellite image of the Fitzroy River estuary (Keppel Bay) and the southern GBR [22 June 2015].

------

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

References

Back, P.V., Anderson, E.R., Burrows, W.H. and Playford, C. (2009 a) Woody plant responses to various clearing strategies imposed on a poplar box (Eucalyptus populnea) community at Dingo in central Queensland Tropical Grasslands 43: 37–52.

Back, P.V., Anderson, E.R., Burrows, W.H. and Playford, C. (2009 b) Research note: Poplar box (Eucalyptus populnea) growth rates in thinned and intact woodlands in central Queensland, Tropical Grasslands 43: 188-190.

Bostock, H., Ryan, D., Brooke, B., Skene, D., Hancock, G. and Pietsch, T. (2006) Holocene evolution and modern sediment accumulation on a tropical micro-tidal coast – KeppelBay, central Queensland, Australia. (Coastal CRC: Indooroopilly).

Bray, S.G., Liedloff, A.C., Sim, A.K., Back, P.V., Cook, G.D. and Hoffmann, M.B. (2007) Comparison of woody vegetation change datasets from the grazed woodlands of central Quensland. Proceedings Northern Beef Research Update Conference pp. 70-77.

Burrows, W.H. (2002) Seeing the wood(land) for the trees – An individual perspective of Queensland woodland studies (1965-2005). Tropical Grasslands 37: 202-217.

Burrows, W. H. (2004) Tropical Grasslands News and Views 20 (3): 8-10.

Burrows, W.H., Henry, B.K., Back, P.V., Hoffmann, M.B., Tait, L.J., Anderson, E.R., Menke, N. N., Danaher, T., Carter, J.O. and McKeon, G.M. (2002) Growth and carbon stock change in eucalypt woodlands in northeast Australia: ecological and greenhouse sink implications. Global Change Biology 8: 769-784. Crowley, G. (2001) Grasslands of Cape York Peninsula - a fire dependent habitat. Savanna Burning - Understanding and Using Fire in Northern Australia (eds R. Dyer, P. Jacklyn, I. Partridge, J. Russell- Smith & R. Williams), p.34. Tropical Savannas Cooperative Research Centre, Darwin.

Detmers, R. G., O. Hasekamp, I. Aben, S. Houweling, T. T. van Leeuwen,A. Butz, J. Landgraf, P. Köhler, L. Guanter,and B. Poulter (2015), Anomalous carbon uptake in Australia as seen by GOSAT, Geophysical Research Letters 42: 8177–8184.

Fensham, R.J., Choy, S.L, Fairfax, R.J, and Cavallaro, P.C. (2003) Modelling trends in woody vegetation structure in semi-arid Australia as determined from aerial photography. Journal of Environmental Management 68, 421-436.

Fensham.R.J., Fairfax, R.J. and Buckley, Y.M. (2008) An experimental study of fire and moisture stress on the survivorship of savanna eucalypt seedlings. Australian Journal of Botany 56: 693-697.

Flinders, M. (1814) A Voyage to Terra Australis Vol. II.

Franklin, D.C. (1999) Evidence of disarray amongst granivorous bird assemblages in the savannas of northern Australia, a region of sparse human settlement. Biological Conservation 90: 53-68.

Franklin, D.C., Woinarski, J.C.Z., and Noske, R.A. (2000) Geographical patterning of species richness among granivorous birds in Australia. Journal of Biogeography 27: 829-842.

Vegetation Management (Reinstatement) Amendment Bill 2016 Dr Bill Burrows

Harrington,G.N. and Sanderson,K.D. (1994) Recent contraction of wet sclerophyll forest in the wet tropics of Queensland due to invasion by rainforest. Pacific Conservation Biology 1: 319-327.

Jackson, S.M., Morgan, G., Kemp, J.E., Maughan, M. and Stafford, C.M. (2011) An accurate assessment of habitat loss and current threats to the mahogany glider (Petaurus gracilis). 33: 82-92.

Krull, E., Bray, S., Harms, B., Baxter, N., Bol, R. and Farquhar, G. (2007) Development of a stable isotope index to assess decadal-scale vegetation change and application to woodlands of the Burdekin Catchment, Australia. Global Change Biology 13: 1455-1468.

Krull, E.S., Skjemstad, J.O., Burrows, W.H., Bray, S.G., Wynn, J.G., Bol, R., Spouncer, L. and Harms, B. (2005) Recent vegetation changes in central Queensland, Australia: evidence from 13C and 14C analyses of soil organic matter. Geoderma 126: 241-259.

Lewis, D. (2002) Slower than the eye can see: environmental change in the Victoria River District since European settlement. (Tropical Savannas Cooperative Research Centre, Darwin).

Lewis, S. E., Shields, G. A., Kamber, B. S. and Lough, J.M. (2007) A multi-trace element coral record of land-use changes in the Burdekin River catchment, NE Australia. Palaeo 246: 471-487.

Liu, Y.Y., van Dijk, A.I.J.M., de Jeu, R.A.M., Canadell, J.G., McCabe, M.F., Evans, J.P. and Wang, G. (2015) Recent reversal in loss of global terrestrial biomass. Nature Climate Change 5: 470-474.

Rowland, M. (2004) Myths and non-myths: Frontier ‘massacres’ in Australian history – the Woppaburra of the Keppel Islands. Journal of Australian Studies 28: 1-16.

------

WHB 21.4.16