Bernard Dell

Mediterranean type forest ecosystems commonly experience an extended dry period during summer months. In recent decades many Mediterranean regions have experienced elevations in temperature and decreases in rainfall, which have led to large-scale forest die-off events. This has also recently occurred in the Northern Jarrah Forest (NJF) (Matusick et al. 2012) and was closely associated with increased infestations by borers. These borers caused severe damage to jarrah and marri trees and contributed to increased tree stress and tree mortality.

Blue-stain (Ophiostomatoid) fungi, which attack woody tissue, can be closely associated with bark beetles. These fungi have been found in Eucalyptus species, invading the sapwood (van Wyk et al 2007), and appear to be present in the jarrah forest of Western Australia.

In this study, the occurrence and relationships between borers and blue-stain fungi in jarrah forest under drought conditions, is being investigated.

There have been widespread climate induced impacts in natural and plantation forests both within Australia and overseas, and modelling suggests a markedly different future climate. New thinking and approaches to forest management may be required. In Australia there are over 149 million ha of forests; in the approx. 8 million ha of managed natural and planted forests foresters have always dealt with climate-induced uncertainty. These past experiences may help to deal with future conditions although the limit to which this will be constrained by finance and public opinion is unknown. This paper will examine how forests respond to climate, past climate change impacts in forests, the management responses to those events, the role of climate change mitigation (reforestation, forest management, bioenergy) and then explore how this aids the development of future climate change adaptation strategies.

Short rotation energy crops have the potential to provide sustainable sources of biomass, but the efficient use of nutrients will be crucial to ensure that these systems are sustainable. In dryland environments 3- to 5-yr rotations of tree crops integrated with agriculture represent a major potential bioenergy feedstock and a means to restore landscape hydrologic balances, while maintaining food production. In soils with low natural fertility, the long-term viability of these systems is critically affected by site nutrient status and subsequent cycling of nutrients. A nutrient assimilation index (NAI) was developed to allow comparison of the nutrient assimilation between tree species and tree components, to optimise nutrient management, and to quantify different strategies to manage nutrients. Biomass, nutrient export, and nutrient use efficiency were assessed for three short rotation tree crop species (Eucalyptus globulus, E. occidentalis, Pinus radiata). Component NAI was generally in the order of leaf

Tall, dry sclerophyll forests characterise parts of south-western Australia with a mediterranean-climate. The jarrah forest is managed for multi-purpose use including conservation, water supply, mining, timber harvesting and recreation. This paper will briefly describe the historical setting of land-use and then examine recent climate events impacting on forest health. These include a decline in rainfall and groundwater levels, reduced stream flow, increased incidence of drought, increased forest dieback and mass collapse. Finally, measures to manage forest decline are considered.

Stem rot disease caused by Sclerotinia sclerotiorum has emerged as a serious problem for canola (Brassica napus L.) production in Western Australia (WA) over the past few years where crop losses can be up to 40% in the worst affected crops. The biological characteristics and pathogenicity of the pathogen in WA is poorly understood. Also the potential for local biological control agents (BCAs) to be used in the management of the disease has not been explored. This paper provides preliminary data in these fields. One hundred and forty isolates of S. sclerotiorum were collected from WA canola growing regions for identification of biological characteristics which include colour of mycelia, growth rate, production of sclerotia, and pathogenicity. Other fungal isolates with potential biological control activity were collected from southern regions of WA. Colour of mycelia of Sclerotinia isolates varied from white, yellowish white, greyish white, brownish white, grey, dark grey to brown. Each isolate had its 24 and 48 hour growth rate recorded after sub-culture on PDA + ampicillin medium. ANOVA showed highly significant differences between growth rates of isolates 24 and 48 hours after being sub-cultured (P≤0.001). There were significant differences in number of sclerotia produced by each isolate. Two potential fungal biological control agents were found in WA, namely isolate KEN1 and isolate MTB1. These local fungal BCAs were found to be effective in inhibiting in vitro both the growth and ability to produce sclerotia of S. sclerotiorum.

Background
• in situ deeply weathered granite profiles (Fig. 1) are common in South-Western Australia (SWA) (Fig 2).
• Roots of native trees penetrate up to 40m (Fig. 3) to access ground water.
• Deep soil carbon (>35 m) has recently been quantified in SWA (Fig. 4). This deep carbon accounts for up to five times more carbon than current world estimates (<30 cm).
• Deep rooted native vegetation in SWA has been replaced by shallow rooted annual crops (20.5 m ha) (Fig. 2iii).
• The composition, age and stability of this deep carbon is unknown. The impact of agricultural practices on deep carbon is also unknown. Here we report on the composition of deep soil carbon for one profile.

Stem rot disease caused by Sclerotinia sclerotiorum has emerged as a serious problem on canola (Brassica napus L.) production in Western Australia (WA) over the past few years where crop losses can be up to 40% in the worst affected crops. Hundreds of isolates of S. sclerotiorum have been collected from different canola growing regions of WA. As the majority of WA isolates of S. sclerotiorum have not been analyzed for their genetic characterization, analysis of genetic variation of WA isolates will be undertaken using classical and molecular techniques such as pathogenicity test, mycelial compatibility groups (MCGs), ITS sequencing, and cluster analysis. The experiments which started in March 2013, aim to use classical and molecular tools to identify groups of WA isolates of S. sclerotiorum from which isolates will be selected for the main studies on the management of S. sclerotiorum in canola. Accurate information of genetic diversity through research on characterization of the pathogen will lead to better understanding of the pathogen and will also benefit the breeding programs particularly aiming at breeding for disease resistance and moreover, could lead to developing better techniques for managing the disease. The paper provides an outline of the experiments and preliminary results.