Linda and Roger's Bunhybee Grasslands - Grazing

This is a page within Roger and Linda's Bunhybee Grasslands Web-Site.

Bunhybee Grasslands is a 49 hectare / 120 acre conservation property 35km south of Braidwood, in southern N.S.W.

You can follow through the internal links, or you may find it easier to use the Site-Map.

Background

This page contains information about the grazing strategy for the property.

The strategy reflects our current understanding of the property's history.

It seems incongruous that a native grassland that is subject to a Conservation Agreement should be grazed at all. The reasons for conducting grazing appear to be that:

• The Risk of Grass Growth Reducing the Diversity of Native Plants. The property is currently a balance between grasses and about 100 species of forbs (i.e. small native plants that fit in the spaces between the predominantly tussocky grasses). If the property is left entirely to its own devices, the grass will take over (particularly the kangaroo grass), and the forbs will be squeezed out. ("... Too much grass biomass can effectively “choke“ out the diversity of forbs, herbs, lichens, mosses, orchids, etc. that rely on the inter-tussock spaces as habitat to grow and germinate from" – Plan of Management, p. 16)
• The Possible/Probable Beneficial Effects of (Light) Grazing. The property may be in its present, highly desirable state due to light grazing having been conducted reasonably consistently (at least up until about 2000 and by sheep), or crash grazing conducted from time to time (cattle, in two short periods since 2000). It simply isn't known. Some amount of experimentation may be necessary in order to find out. ("Stock grazing has performed the service of grass biomass removal for the last few decades" – p. 16)
• The Risk of Excessive Fuel-Load Inviting Devastating Fire. The fuel load of dense native grasses is sufficient to create a fire hazard (as advised by David O'Connell, 1km away, and an ex-RFS Fire Chief). There are only a couple of ways to reduce fuel-load. One is grazing. The other is a fire, whether a natural grass-fire or controlled burning

On the other hand, reasons to not graze, or minimise grazing, include:

• The Introduction of Weeds. Animals carry seeds on their hooves, on their hides, and in their intestines. They come from properties that have improved pasture (i.e. non-native grasses) and weeds. Even in the case of local animals, some of the grasses and weeds aren't currently on Bunhybee. And the further afield the animals come from, the more likely they carry seeds that are not a current problem on the property
• Damage to the Ground. Animals do damage. Cattle's hooves do more damage than sheep's. Sheep's nibbling does more damage than cattle's. Both invite weeds
• Possible Advantages to Weeds. To the extent that native grasses are harmed by grazing, exotic plants may gain a foothold, or increase in intensity
• Damage to Grazing-Sensitive Native Plants. The Plan of Management gives the examples of "lilies, daisies and orchids that [are palatable and] have been lost from much of the surrounding landscape [which has been more intensively grazed]" (p. 11)
• Damage to the Moister Eco-Systems. The animals are naturally attracted to the waterlines (for the better grazing there) and the dams and pools (for the water). The waterlines, dams and pools, being moist, are softer, and hence more amenable to damage from the animals' hooves. Some flora and fauna (e.g. frogs, which are present) are utterly dependent on these areas

The following sections present the following information:

• the state of knowledge at the date of purchase
• local knowledge acquired since the date of purchase
• implications
• elements of a strategy for 2009-10
• our current intentions

The State of Knowledge at the Date of Purchase

This is summarised in the Plan of Management, from which the following quotations are taken. Most of the emphases have been added. Those in the original are noted accordingly.

"'The Parlour Paddock' has a long history of grazing by sheep and more recently cattle. The two large paddocks were historically set stocked by sheep at low rates, predominately due to the paucity of water in the paddocks. There is no history of cultivation and fertilizer was only applied once to the Jerrabatgulla valley paddock (Pers. Comm. David O’Connell Dec 2007). There is evidence of clearing across “The Parlour Paddock” particularly of the Snow Gum Woodland community occurring on the lower slopes. The area has been burnt at some time in recent decades, with fire scars present on trees in the forested slopes of Bunhybee Hill" (Plan of Management p. 5).

NCT's Nigel Jones advised on 18 Feb 09 that "Previous to the famous 9 (10?) whilst the property was for sale [i.e. during 2007?], there was black cattle grazing for around 7 months ... not sure of numbers but safe to say 30-40 across - both properties [presumably 2005-06?] ... Unfortunately a bit of pugging occurred during Spring ...". We think 'pugging' means (highly undesirable) soil compaction arising from grazing on wet soil and grass.

Grazing Management is discussed on pp. 11-18 of the Plan of Management, incl. photographs.

It is concluded that " the high floral diversity indicates a conservative stocking rate between one and two Dry Sheep Equivalent (DSE)/ ha (with one DSE representing a 55 kg wether). A low stocking rate/ha needs to be kept in place if domestic stock are to be kept for longer periods (e.g. a few months per year) on the property. However if stock are to be used only occasionally throughout the year, i.e. as part of a crash grazing regime where higher densities are used over a short time period, then stocking rates will need to be adjusted accordingly. Stocking rates may also need to be adjusted to take into account additional grazing pressure from kangaroos.

"Getting the right balance in integrating grazing and conservation management will require experience and evolve over time in response to varying factors, and so the best management will need to be dynamic and adaptive. Success in meeting the goals will rely on good on-going monitoring and communication between the landholder and the Trust, and a developed understanding of practical management conditions for grazing of the Conservation Area" (p.11).

The 'Grazing Management Goals' were defined (p.12) as:

• Allow native ground cover species to be able to flower, set seed and increase their abundance
• Allow for natural regeneration of woody shrubs and trees in woodland areas
• Avoid creating areas of bare ground through overgrazing
• Avoid creating areas of dense grass swards through a lack of disturbance
  [Note that some of the wet grassland (Zone 4) had dense grass swards at the outset]
• Maintain native ground cover in good condition

"Whilst the Trust and local extension staff will be available to offer recommendations on a suitable grazing regime, the restoration and maintenance of Bunhybee Grasslands will ultimately rely on the experience of the Landholder to judge the timing of moving and excluding stock at the right time to keep the native ground cover in good condition.

"Factors which indicate native ground cover vegetation in a good condition are:

• retained high level of vegetative ground cover (> 80% which includes any mosses and lichens)
• tussocks of grass tall and spreading in shape during spring/summer (may include standing dry matter) ["grass height ranges from 5 to 15cm for wallaby grass", but about 20cm in mid-summer 2008-09; and "> 15cm for kangaroo grass", but about 50cm in mid-summer 2008-09]
• retained/increased diversity of herbs (especially palatable species such as orchids)
• small open spaces maintained between grass tussocks (which may be covered by mosses and lichens)
• presence of new low/prostrate shrub regeneration and/or actively growing tips in mid-spring
• evidence that native grasses have set and dispersed seed
• retained cover of litter (dry plant matter)" (p. 12, emphasis in original).

"[Conversely, ]Native ground cover is generally regarded as deteriorated due to over grazing if any of the following factors are observed across the majority of the Conservation Area:

• significant increase in cover of bare ground,
• the average grass height is below 2cm high,
• tussocks of taller species such as kangaroo grass (Themeda australis) are narrowed (not spreading) and less than 15cm high,
• woody shrub/tree regeneration present has a majority of growing stems chewed off
• stock are markedly browsing less palatable plants such as Purple wiregrass (Aristida ramosa) and Poa Tussock (Poa labillardieri)" (p. 15).

"Native ground cover is generally regarded as deteriorated due to under grazing if monitoring by the Landholder and/or the Trust indicates a marked decrease in the area of inter-tussock spaces combined with a significant increase in cover of tussock grasses (including standing dry matter) across the majority of the paddock" (p. 16). [We interpret this to mean that the height of native grasses (e.g. wallaby grass 20cm, kangaroo grass 50cm) is not an indicator of deterioration, whereas density is.]

"A rest (spell) over spring/summer allows many/most native species to produce seeds and favours seedling recruitment. Grazing during spring/summer may also favour weed species ... These species quickly colonise bare ground and suppress/displace some native species, particularly the small herbs" (p. 14).

Grazing Management Conditions [5.3(e)] are defined as follows (p. 17):

• Native ground cover will be maintained in “good” condition, as defined in this plan
• Grazing must not occur from the start of September to the end of January to allow plants to flower and set seed (this period will be dependant on monitoring and may be subject to change)
• If the condition of the native ground cover has deteriorated due to over grazing, then the Landholder will decrease/remove stock immediately or when practical in the short term, until the paddock has been restored to at least good condition
• If the condition of the native ground cover has deteriorated due to under grazing, then the Landholder will reintroduce/increase stock immediately or when practical in the short term, until the paddock has been restored to at least good condition
• To reduce the risk of introducing weed species, supplementary feeding of fodder or grain [if at all!!] is to occur outside of the Conservation Area (or within a designated feed-out area)
• Following a fire, stock must be excluded (where practicable) from the burnt area until the regeneration is sufficient to sustain the pressure of stock grazing

Grazing Management Recommendations were defined as follows (p. 18):

• Due to the grazing history of the Land, sheep are preferred over cattle as they will have a lighter impact on fragile plants and ground cover, particularly in the wet grassland communities
• If stock are to be brought in from outside the local Braidwood region – they should be quarantined for a period of 6 days in a holding paddock, preferably located outside of the Conservation Area, or in a temporarily fenced area (of lower plant diversity) close to the road to reduce the potential of new weed species introductions
• Consider new internal or temporary fencing if required to suit grazing regime – consult the Trust or the Southern Rivers CMA as incentives may be available
• Monitoring of condition will need to be more regular if using rotational grazing with large stocking rates (crash grazing). Crash grazing can be a useful management tool to minimize selectivity of stock and maximize their ability to control weeds and/or manipulate the diversity of the grass sward
• Avoid using vehicles to muster stock due to risk of soil compaction damage – mustering by foot or on horseback is preferable
• The Landholder/s should keep a record of the stock numbers and grazing duration so that grazing intensity (DSE/ha/time) can be calculated and used to guide future management decisions

Local Knowledge Acquired Since the Date of Purchase

We've met and/or had phone conversations with Di Izzard (neighbour to the north incl. the incursion on the NW, who's been there over 10 years and whose deceased husband was from the district), Kitty and Harry Tischler (neighbour to the west, at 'Warragandra', who moved there about 2002) and David and Jeanette O'Connell (immediately to the west of 'Warragandra', 5 generations in the district, and at some stage captain of the local Rural Fire Service).

According to David O'Connell, the 'Parlour Paddock', from about 1960 to 2000, carried sheep (merinos, of course), prettymuch constantly, of the order of 650-700 head. The Parlour Paddock was 403 or 424 ha; so assuming on average 50kg wethers, that's 1.5-1.7 DSE/ha/p.a.

That's consistent with what appears to be the appropriate page at DPI, which rates "good quality native pasture, e.g. wallaby grass", at 1.5–3.0 DSE/ha/pa. For 403 or 424 ha, that's 600-1272 DSE. There is limited access to water throughout the old Parlour Paddock (and even less on the northern segment that is now Bunhybee Grasslands), so the bottom end of the range would appear to have been about right.

Allowance needs to be made for kangaroo-grazing. Although a mob is resident on Bunhybee Peak, and one or two have been on the upper edge of the property most times we've been there, they do not seem to have ventured down to the wetter areas much during 2008.

Allowance may need to ne made for grazing by ferals, in particular pigs. The primary impact appears to have been bare patches arising from them grubbing for roots. This peaked in mid-2008, but seems to have eased off in late 2008.

According to both David O'Connell and Kitty and Harry Tischler, little grazing was conducted at all during the period 2002-07. That is consistent with the state of the fencing in late 2008 prior to the sale, along the road and up against Bunhybee Peak – fencing that cattle would have strolled through – and did.

Cattle appear to have only ever on the property in two periods, briefly in the mid-2000s, followed by the famous 8-12 head early in NCT's time, which strolled through the inadequate fencing and had to be 'rescued' by Lauren van Dyke and moved to Scotsdale [in late 2007? – to be confirmed].

Availability of sheep for agistment is limited, because there are few in the region now (because the returns are so low). The main use of pasture in the district is for cattle these days. However, the dam surrounds are weak, and, with very limited water available, the damage that cattle would do to the dam area would probably be substantial. Di Izzard warns that the UK breeds are more likely to find the gaps in the fences (e.g. on the several wombat tracks), so merinos are preferable.

David O'Connell remarked that the paddocks were a fire-risk. Based on the RFS map, we're at the southern end of Palerang zone; but that's not much use, because it merely tells us that RFS zones are based on Local Government Areas. Looks like 'local knowledge' still beats the Web ...

Implications for Bunhybee

Summarising NCT's thinking as at 2007-08, they had a preference for:

• grazing as the control mechanism
• sheep (because of hoof- and weight damage from cattle)
• local mobs (because of the higher risk of importing weeds with non-local stock)
• crash-grazing, i.e. "a big mob for a short period rather than a small mob for a long time" ("as a small mob are more selective to herbs and forbs instead of eating the grasses") – quotes from Nigel Jones' email of 18 Feb 2009
• late summer / early autumn grazing, after seeding and before winter

Based on:

• the area of 48 hectares
• the DPI figure of 1.5-3 DSE/ha/p.a.
• the historical carrying capacity on the Parlour Grasslands as a whole 1.5-1.7 DSE/ha.p.a.
• the limited water available (less than on the other three parts of the old Parlour)

what seems appropriate for Bunhybee is a DSE/ha/p.a. of at most 1.

That suggests a carrying capacity of 50 x 50kg wethers, year-round.

For very light crash-grazing for 3-4 weeks, the equivalent might be a mob of 150?

The target time-period is February-April.

Elements of a Strategy for 2009-2010

1. Differentiate Areas

The need for grazing to control grass-growth varies between areas, and grazing in the poorer-quality grasslands could be harmful. So areas need to be distinguished. The Plan of Management identifies "four Grazing Zones, which are based on the vegetation communities’ management needs (see Map 3). Zone 1 and 2 are Snow Gum Woodland areas which vary in tree and shrub cover across the Conservation Area. Zones 3 and 4 are areas of dry and wet Natural Temperate Grassland" (p.11). We have in mind to declare Zone 5 - Wet Areas, because they have distinctly different ecologies, have quite different vulnerabilities and probably risks, and need quite different management. Grass growth is greatest in the wet grassland areas (Zone 4). But we need to check that all areas within Zone 4 are comparable to one another. It appears to us that the dry grassland (Zone 3) varies a great deal. We need to map the parts with more vigorous grass-growth (and that presumably have better soil and/or are subject to more frequent watering and/or less frequent or intensive kangaroo-grazing). The Snow Gum Woodland (Zones 1 and 2) is mostly quite sparse. We need to check whether any parts of it warrant grazing at this stage. We may need to specify for-grazing and not-for-grazing segments.

2. Consider Controlled Burning

It may be that the high-grassgrowth / high-fuel-load areas can be controlled by learning the technique of doing low-temperature acre-sized burns, or inviting the local Rural Fire Service to come and do a practice-run. ("Without grazing or fire, the native ground cover at ‘Bunhybee’ Grasslands may become less diverse" – Plan of Management, p. 14).

An attempt at a systemic explanation of this might be:

• grasslands existed before white man's sheep and cows (although, admittedly, whether this particular grassland did we don't know)
• fire is natural
• the kinds of high-intensity fires that occurred in Canberra in 2003 and in Victoria in 2009 aren't natural (or at least didn't used to be)
• but low-intensity fires are natural
• the fires that seem likely to have been lit by aboriginals may have been generally of low intensity (on the assumption that they would have not done it in high-danger periods)

Hence:

• if kangaroos can't graze it fast enough, then the nearest thing to a natural control isn't white man's animals but low-intensity fire

3. Consider differential controls in different segments

Zone 4 appears to be most at risk of loss of species diversity, because that is where the native grasses are very dense, and forbs appear to have been already squeezed out. (But is this natural anyway?). On the other hand, this area appears not to be a significant fire-risk in the current, reasonable conditions.

The 'lushest' segments of Zone 3 may be both at some risk of loss of species diversity and higher fire-risk.

So a mix of grazing and controlled burning in different segments might be more appropriate than one or the other.

Mowing and patch burning are other possibilities.

4. Investigate means of controlling agisted stock:

• portable fencing, to keep them on intended sections and off others (particularly the dams and the waterlines, but possibly also areas in which grass-growth is neither threatening forbs nor creating a significant fire-risk)
• means of watering stock without providing them with access to the dams and the pools in the waterlines (e.g. troughs, pipes and pumps)

5. Investigate the practicalities of agisting stock:

• what are the water requirements for 150 head for 3-4 weeks?
• where do we get a standard agistment agreement? [This is essential, in order to be clear about questions concerning the recent locations of the stock and/or quarantine, watering, the preclusion of hand-feeding, and responsibilities and risks, e.g. fence integrity, fence maintenance, liability for animals on the road]
• who is a likely agister? [At this stage, Di Izzard for sheep. If we consider cattle (e.g. by putting up temporary electric fencing to protect the dams and water-lines, and coming up with alternative watering arrangements), then David O'Connell is a possibility]
• what are normal agistment rates, and how much less convenient will this kind of arrangement be for the agister?

Our Current Intentions

Hold off on grazing in autumn 2009.

Map the areas in which grass-growth is an issue.

Track down David Eddy, who has written a book on the topic, and discuss it with him.

Probably do, or arrange, a small trial controlled burn.

Research fencing and watering, and build and maintain our local contacts, so that grazing can be arranged quickly if we change our minds.

Reference:

Eddy D. (2002) 'Managing Native Grassland: a guide to management for conservation, production and landscape protection' WWF, 2002

Contact: Linda or Roger

Created: 23 February 2009; Last Amended: 1 March 2009