Plan for plantation management


The Pinjar pine plantation. Picture: Martin Kennealey
The Pinjar pine plantation. Picture: Martin Kennealey

MOST of the northern suburbs pine plantations will disappear within five years, a state planning document says.

The draft Perth and Peel Green Growth Plan for 3.5 million, out for public comment until April 8, outlines the future of the Yanchep and Pinjar plantations in the City of Wanneroo, and the Gnangara plantation in the City of Swan.

“This action plan provides guidance on the implementation of the harvesting of pines,” the plan said.

“It describes future land uses for the Gnangara, Pinjar and Yanchep pine plantations situated over the Gnangara Mound within State Forest 65 and the ongoing land use and management of the area post-harvest.”

Under review every five years, the action plan said the pine plantations were established between 1932 and 1994 for timber production.

Classified as State Forest, they are vested with the Conservation Commission of Western Australia (CCWA) and managed by the Department of Parks and Wildlife.

The Forest Products Commission (FPC) has harvesting rights while commercial pine is present, which Wesbeam is harvesting under the Wood Processing (Wesbeam) Agreement Act 2002.

“In 1996, the State Government decided to remove up to 23,000ha of pines at the Gnangara, Pinjar and Yanchep plantations and not replace them in order to increase water recharge on the Gnangara Mound,” the draft document said.

“Water recharge to the Gnangara Mound, and hence groundwater supply, is important for almost half of the public drinking water supply in Perth as well as for supporting groundwater dependent ecosystems.

“Removing the pines was one strategy to offset the impacts of the drying climate, helping maintain the long term productivity of the water resource, particularly meeting water needs for a population of 3.5 million.”

It said the original 23,000ha of pine plantations were progressively being harvested and there would be about 8000-8500ha left by January 1, 2017.

“Harvesting of pines will continue to occur at a rate of 1400–1800ha of clearfelling per year to meet the FPC’s log supply commitments,” it said.

Wesbeam will harvest most of the pines by 2020, but there are plans to replant 5000ha in Yanchep for Carnaby’s cockatoo foraging habitat.

“Widespread clearing of banksia woodlands, the predominant native food source for Carnaby’s cockatoo, has accelerated since 1950,” the document said.

“Pine plantations established from the 1920s have progressively replaced banksia woodlands as a major food source for the cockatoos in the region, mitigating some of the loss of native habitat.

“Before the commencement of the removal of the Gnangara, Pinjar and Yanchep pine plantations, these plantations provided approximately 57 per cent of the total food resource available to Carnaby’s cockatoo upon the Swan Coastal Plain.

“In order to avoid some of the impacts of harvesting and provide a continuous food source for Carnaby’s cockatoo, 5000ha of pines will be replanted in the Yanchep area – replanting commenced in 2012 at a rate of 500ha per year.

“Following harvesting a controlled burn is carried out across the land to remove the majority of the tree debris that is left behind.

“This process reduces fuel loads and minimises the risk of fire affecting adjacent landholders.

“Material that does not burn away is then raked into heaps and windrows for burning to reduce the volume of harvesting debris as far as possible.

“The ground is subsequently scalped and young Pinus pinaster seedlings planted in the scalp lines at a suitable stem density.”

The action plan said pines start producing food for Carnaby’s cockatoo about 10 years after planting, reaching optimum levels at 45 years.

“Considering that the prime objective of the 5000ha of pines is to provide food for Carnaby’s cockatoo, the pines will not all be planted as a traditional plantation,” it said.

“Some will be established over a wider area or in different arrangements so as to maximise the food resource while providing the same groundwater recharge.”

The plan says 16,825ha of the land not used as pine plantation in the future would remain State Forest and be converted to grassland or low water use vegetation.

“These ex-plantation areas have re-vegetated to form a vegetative cover that is a mix of native species shrublands, as well as pine wildings and introduced grasses and other weed species,” it said.

Future urban and industrial areas flagged

ABOUT 1175ha of the Gnangara, Pinjar and Yanchep pine plantations could be used for future urban and industrial development.

“Significant opportunities have been identified for the extraction of basic raw materials such as sand from strategic locations across the Gnangara Mound,” the draft Perth and Peel Green Growth Plan for 3.5 million said.

“The areas where basic raw material extraction is allowed to occur throughout the Gnangara, Pinjar and Yanchep plantation area (total) 12,170ha.

“In addition, new industrial areas have been identified on the Gnangara Mound in the Economic and Employment Lands Strategy (WAPC, April 2012) and new urban expansion areas have been identified.”

Pines have already been harvested in areas identified for urban and industrial expansion – Nowergup 1, Pinjar South and West Ellenbrook – and the report said they were suitable for transfer to a development land use, which required amendments to both the Metropolitan Region Scheme and local planning policy.

PINES PLANTATIONS FUTURE

Total size: 23,000ha

Clearing rate: 1400-1800ha per year

Potential urban land: 447ha

Potential industrial: 728ha

Retained for State Forest: 16,825ha

Replanted for cockatoos: 5000ha

Raw material extraction: 12,170ha

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Draft sets out conservation plan