Katinka works in Paganoni, Ludlow Forest and Yalgorup National Park on the methods of management and restoration of Tuart woodland ecosystems. Tuart woodlands are limited to coastal areas in the south west and have been considerably fragmented by clearing for agricultural land and suburban development. As well as these threats there are the challenges of invasive species and changing climate including a significant decline in rainfall since the 1970s. This has also resulted in a decline of inflow into dams and the groundwater level in some areas has dropped eight metres. 2010 was the driest year on record and is considered an extreme event.

Katinka presented diagrams showing the weather patterns in the last few decades, demonstrating the lead-up to the collapse of the Tuarts in the Rockingham area in 2011. This collapse affected both trees and seedlings, there was recovery but there will be no seed for years. There were two areas of differing health and density: the trees in lower- lying, high density areas showed little collapse while 90% of Tuarts on higher ground, with low density, collapsed. This collapse of the trees in the higher area may have been caused by decreasing rainfall over many years, dropping levels of groundwater, shallow soils and hot and dry weather.

Katinka suggested that often revegetation comes at a high cost and often is not very successful. A lot of kangaroos and rabbits affect growth of revegetation. The main issues looked at were with regard to seed and ashbeds. Tuarts like the ashbed for regeneration. Small clearings with created ashbed were tested in Paganoni Swamp Bushland. When the ash cooled the areas were hand- seeded. The hand-seeded areas did very well, almost as well as naturally occurring generation. Natural regeneration occurred in most areas containing Tuarts with low-hanging branches with high seed loads, in sites containing Allocasuarina fraseriana, which, we think, provided a suitably high temperature fire from its leaf litter for regeneration. The slightly lower (but not significant) seedling number in the created ashbed could be due to a number of factors including the lack of mature trees in the area, not enough seed being used, or seed predators such as ants removing many of the seeds.

Another consideration is when to plant. Early versus late planting! Research has shown that planting in late July can reduce survival, growth and health. Planting in early June is the best even if there has not been a decent amount of rain. Artificial watering is out of the question because of the large areas for the experiments as well as sourcing the water.

When it came to site preparation it was found that ripping the soil benefited the plants by facilitating greater rooting depth. The voluntary involvement of various groups from the community is essential to help with the large amount of work and the monitoring of results. An example of the benefits community/restoration interface is a bus turn-around site that was seriously degraded.

This site is near the Perth-Mandurah railway line and Paganoni forest and was a project undertaken by members of the Friends of Paganoni. The revegetation was organized with a plan that listed tasks with guidance as to when they were to be carried out, for example plant in June.

Questions followed the completion of the presentation. The first acknowledged the enormous number of seedlings growing quite tall soon after a fire in the Rockingham area several years ago. Do the Tuarts self prune? Unlike many Eucalypts Tuarts grow very quickly and after some years a few will send up leaders and dominate others around them. There is also a wood borer that attacks some as they form bark at around four years so this can lead to some thinning. Another question regarded evidence of climate change. It seems these forests are exhibiting step change rather than a steady change. The bigger trees suddenly show signs of severe stress, and rainfall is clearly declining. There is much discussion on how to manage our forests, for example should we thin them to allow fewer trees to prosper.

The next question was about Tuarts growing outside their natural area. There is a big plantation down at Esperance which, evidently, is doing very well. Plantations in Israel are being watered with salt water, and they are a declared weed in South Africa. This very interesting presentation had us all enthralled and was to be followed by an excursion to a Tuart Forest at Rockingham.

Lynette Davies