LIMITACIONES Y PUNTOS FUERTES DEL ESTUDIO

different times (when the

risk of flood is high, for

example, or to control

disease or parasites such

as fluke), can be a useful

management tool.

2. The duration of grazing

Continuous grazing (often called ‘set stocking’) gives the vegetation no chance to recover. Native vegetation will eventually die out and be replaced with unpalatable, weedy species32_{. Continuous} grazing (even at low grazing pressure) can be very detrimental to riparian pastures and other vegetation.

In contrast, studies have shown that riparian areas recover quickly in response to periods of rest, either as a result of complete exclusion or rotational grazing (including wet season spelling)33, 34_.

In high rainfall areas where cattle are grazed intensively, total stock exclusion from the riparian zone is recommended.

More frequent and longer spelling will benefit the land, and may also give you more options in respect of your riparian land. Allowing pasture to build up can provide you with an emergency feed source if feed is poor elsewhere. Or it can be used to fuel a burn to control woody weeds (if this is an appropriate weed control strategy in your area).

3. The intensity of grazing

Conservative stocking rates, and the ability to move stock out of the area in response to signs of damage, are critical for good riparian management.

Low vegetation cover, heavily grazed trees and shrubs, poor water quality and pugging all indicate the need to remove some or all of your stock from your riparian area immediately. Alternatively, if fire or weed control are your management objectives, increased growth may indicate the need to graze more intensely. Grazing young, lighter weight stock can be a way of reducing both grazing intensity and the trampling effect.

47

30 Roth, C.H., Prosser I.P., Post D.A., Gross, J.E., Webb, M.J., O’Reagain, P.J., Shephard, R.N. & Nelson, B.S. 2004, Keeping it in Place —

Controlling sediment loss on grazing properties in the Burdekin River Catchment. A Discussion Paper, p. 14.

31 Water Note 18, July 2000, Water and Rivers Commission (Western Australia), p. 4.

32 Price, P. & Lovett, S. 2002, ‘Managing stock’, Fact Sheet 6, Land & Water Australia, Canberra, p. 11.

33 Jansen, A. & Robertson, A.I. 2001, ‘Relationship between livestock management and the ecological condition of riparian habitats along an Australian floodplain’, British

Ecological Society, vol. 38, pp. 63–75.

34 Ash, A., Corfield, J. & Ksiksi, T.

The Ecograze Project — developing guidelines to better manage grazing country.

SECTION

10

Challenges — dealing with weeds, pests and fire

Excluding or restricting stock from riparian areas can bring significant benefits to a property, particularly over the long term. This has certainly been the experience of the farmers in our case studies. Unfortunately, as with any changed management practice, it can also throw up some challenges. These challenges include the risks that riparian areas will become havens for weeds, feral animals and wildlife, and that increased vegetation will pose a fire hazard. These risks often deter farmers from changing their riparian management practices. However, with some forward planning and special management, these risks can usually be avoided or controlled.

This Section contains general information on planning for and dealing with the most common problems encountered by farmers when they exclude stock from their riparian areas.

Weeds

The risk that riparian areas will become infested by weeds is a major deterrent for many farmers. The threat comes from at least two different fronts — first, that grazing will no longer keep undesirable species at bay, and second, that fenced off areas will be difficult to access for spraying or slashing.

The reality is that weed control is likely to become part of your ongoing management routine following the restriction or exclusion of stock from your riparian areas. Factoring in a few days in your annual management plan for weed control, particularly in the first years following restriction or exclusion of stock, will help you manage the issue.Your local Landcare officer may also be able to advise you on obtaining funding or other assistance to help with weed control.

Left: Artichokes, a problem weed in drier environments. Photo Phil Price.

Right: This rainforest area has become infested with blackberries.

It is important to remember that weeds find it difficult to invade and become established in areas where the natural vegetation is relatively intact. Maintaining a healthy mix of pastures and native vegetation, therefore, will provide a good barrier against weed infestation. You will probably find that as your riparian area regenerates, weed management will take up less of your time — provided you have kept on top of the problem early on.

Your riparian areas will be most vulnerable to weed invasion if they are degraded, or bare — following fire, flood or weed removal, for example. In these situations, taking immediate steps to revegetate the area, either by replanting or by encouraging natural regeneration, will help to prevent weeds becoming established.You can encourage natural regeneration by

excluding stock, deterring wildlife and removing any weeds as soon as they become apparent. Cessation of grazing and the associated nutrient inputs from dung and urine, will help to make your riparian area less suitable for many exotic weeds.

49 Above: To reduce weed problems, this area was replanted immediately following

the removal of willows. Right: Stem injection of poison is an effective method for killing willows.Photos Lizzie Pope.

Sheep carry the seed of