Melbourne School of Land and Environment

Potential Honours Topics in Forest Science

The topics listed on this page are a selection only! Please check also the research section of the Department of Forest and Ecosystem Science or the group pages indicated below and browse for topics that are of interest to you. Do not hesitate to contact all staff directly!

Forest Science Honours Coordinator is Dr Peter Ades (petera@unimelb.edu.au) and Creswick Campus Coordinator is Michael Tausz (michael.tausz@unimelb.edu.au).

Research areas in Forest Science

(click on the text to go to honours topics or on the link to the right to go to the webpage of the research group)

Ecophysiology and Ecosystem Processes

Restoration of native woodlands: understanding soil-based feedbacks of exotic and native herbs

Invasion of Australian native woodlands by exotic herbaceous weeds is often associated with soil nutrient enrichment resulting from increased nutrient inputs in the surrounding agricultural landscape.  Studies elsewhere indicate that, once established, exotics can enhance their invasiveness by creating positive feedbacks that maintain high soil nitrate concentrations, which are inhospitable to native plants.  However, limited Australian data indicate that native perennial grasses might also create positive feedbacks that lead to sustained decreases in soil nitrate. Using controlled glasshouse conditions, this study will compare changes in soil nitrogen forms under two invasive exotic herbs with those under two native perennial grasses. It will improve understanding of exotic plant effects on soil nutrient processes and will examine mechanisms for tipping the scales in favour of native herbs.
Contact: Dr Lauren Bennett, Tel. 5321 4192, ltb@unimelb.edu.au

Enhancing revegetation opportunities through improved understanding of native acacia seed germination and storage requirements

Broad-scale revegetation programs rely heavily on efficient and effective seed protocols.  In the case of native acacias, there is much scope for improvement since current seed pre-treatment methods are cumbersome and time-consuming.  In collaboration with the Ballarat Region Seed Bank Inc., this study will examine effects of current and new seed treatments on survival and initial growth of three to four acacia species (native to central Victoria).  Interactive effects of seed treatment and storage conditions will also be considered.  The study will provide clear protocols for acacia seed treatment and storage, as well as indications on native acacia seed ecology (e.g. fire requirements).
Contact: Dr Lauren Bennett, Tel. 5321 4192, ltb@unimelb.edu.au

Effects of forest landscape restoration on the molecular diversity of soil fungal communities

Restoration of 2000 ha of Pinus radiata plantation to native eucalypt forest near the Delatite River in northeast Victoria is the largest project of its kind, with 1100 ha revegetated to date. The land-use history is complex, with pines originally established on agricultural land, or on forested areas cleared specifically for plantation establishment with adjacent land uses including native eucalypt forest, secondary forest, and a range of revegetated sites (to seven years). Using the PCR-based molecular technique ‘Terminal-Restriction Fragment Length Polymorphism’, this project aims to investigate whether the soil fungal composition of revegetated sites approaches that in the surrounding native eucalypt forests, and whether historical land-use and proximity to target vegetation play a role.
Contact Dr. Sabine Kasel, skasel@unimelb.edu.au
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Fire Ecology and Management

Do underground fungi influence floral visitation rates of pollinating insects?

Arbuscular mycorrhizal (AM) fungi are beneficial to host plants by providing access to soil nutrients, increasing drought, herbivore and pathogen resistance as well as  influencing the biomass of floral structures.  These benefits can enhance the fitness of plants and provide an advantage during adverse environmental conditions.  This study will investigate the indirect benefits of AM fungi colonizing annual heathland species from the Asteraceae family.  It is hypothesized that plants supporting AM fungi will appear more attractive to insect pollinators through an enhanced floral display compared to plants without AM fungi.  High rates of pollinator visitation will result in increased reproductive success and plant fitness.
Contact Dr. Fiona Christie, fjc@unimelb.edu.au

Effect of fire on tree hollows and hollow dependent fauna.

While much research has outlined the relationship between fire and plant community composition and structure, less is known about the role of fire in the formation and destruction of tree hollows.  Many vertebrate species rely on tree hollows for shelter, nesting sites and as a foraging substrate with many hollow bearing tree communities existing in fire prone environments.  This project aims to investigate how fire regimes have influenced hollow formation in the brown stringybark woodlands of western Victoria and determine optimal fire regimes for a range of hollow dependent fauna.  Contact Dr. Fiona Christie, fjc@unimelb.edu.au

Is the home range shape of swamp wallabies (Wallabia bicolor) affected by topography?

Many studies of animal space use quantify home range size, but few have investigated home range shape.  Observations during previous research indicate that the shape of swamp wallaby ranges may be influenced by topography, in particular, the orientation of major gully systems.
The objective of this study is to quantify the influence of topographic features on the home range shape of swamp wallabies.  There is potential to compare results from populations living in different habitat types (unharvested native forest vs. regenerating coupes), and between sexes.  The project will involve two components:
1.Field work in the Pyrenees State forest ground truthing previously defined home ranges and gaining an appreciation of the landscape
2. A desk-based exercise establishing relationships between home range shape and topographic features using home range outlines overlayed onto aerial photographs. The project will be supervised by Julian Di Stefano from the Department of Forest and Ecosystem Science, Creswick.  The successful candidate will need to spend some time at the Creswick campus during the course of the project.
Contact: Dr Julian Di Stefano, juliands@unimelb.edu.au
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Forest and Climate Change Research

Salinity tolerance of eucalypts – importance of apoplastic solutes

Osmotic adjustment and intracellular compartmentation are important mechanisms for salinity tolerance of trees. This project will investigate the importance of osmotic adjustment and salt stored in the apoplast in field grown eucalypts that are exposed to salinity. Samples will be collected in national parks and plantations and analysed in the laboratory.
Contact Dr. Stefan Arndt, sarndt@unimelb.edu.au

Mechanisms of drought tolerance in eucalypts – active or passive osmotic adjustment

Plants can adapt to drought by lowering their osmotic potential in the leaves. This can either be achieved by a net increase of solutes (active) or an adjustment of the water content (passive). This important mechanism of drought adaptation has scarcely been studied in tree species in Australia. This project will study osmotic adjustment in field grown eucalypts and acacias in different climate zones in Victoria and will consist of two field campaigns (one in Feb/Mar and one in May/Jun).
Contact Dr. Stefan Arndt, sarndt@unimelb.edu.au

How greenhouse friendly is phytoremediation?

The heavy metal contaminated sludge in the Western Treatment Plant (WTP) in Werribee is treated by phytoremediation. Willow trees are grown at the WTP and are fertilized with contaminated sludge, thereby removing the heavy metals. Is process actually greenhouse friendly? Or is the carbon benefit of growing trees offset by other soil based greenhouse gas emissions? Greenhouse gas emissions will be measured in a number of campaigns at the WTB in order to establish a complete greenhouse gas audit.
Contact Dr. Stefan Arndt, sarndt@unimelb.edu.au

Forest soil fertility management and trace gas emissions

Method: Soil from an ‘N-deficient' and an ‘N-sufficient' plantation will be laboratory incubated to measure trace gas flux (N2O, CH4 and CO2) with and without fertilizer, at different soil moisture and temperatures. From this a seasonal/annual greenhouse gas budget can be constructed using climate data.
Background: Soils can be a significant source or sink for both N2O and CH4 depending upon environmental and soil conditions: oxygen availability, soil water content, soil temperature, soil C/N ratios and organic/inorganic N content and input. In the last decade, Eucalyptus globulus has been planted extensively throughout the southern states of Australia, predominantly on land previously used for grazing. Following harvesting, fertiliser input has become a key management option to maintain productivity in nutrient deficient sites. Fertiliser addition can greatly alter soil N status and microbially-mediated processes that control N2O production (nitrification, denitrifiction) and CH4 uptake (methanotroph oxidation), potentially offsetting the carbon sequestration benefits of tree growth.
Contact Dr Stephen Livesley, tel: 92506818,  sjlive@unimelb.edu.au

The woodland-salt marsh-mangrove transition along Western Port Bay - nutrient cycling, losses and disturbance

Method: Through seasonal soil sampling, water sampling and trace gas measurements the biogeochemistry cycling of N will be investigated along transects through the woodland-salt marsh-mangrove transition as compared to the agriculture to mangrove transition.
Background: The vegetation matrix and transition along the fringe of the Western Port Bay is unique as being the most southerly extremity of temperate mangroves in the world. Its integrity has been under threat from the conversion of adjacent woodland and saltmarsh to agricultural and residential uses. This may alter the ability of this mangrove fringe to filter nutrient flows between land and water, especially when adjacent agriculture relies on fertiliser N inputs as well as producing excreta and urine N inputs. This may also alter the integrity of the mangrove vegetation itself.
Contact Dr Stephen Livesley, tel: 92506818,  sjlive@unimelb.edu.au
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Plantations and health

Impacts of forest thinning practices on invertebrate fauna in Eucalyptus regnans (Mountain ash) forests of the Victorian Central Highlands.

The aim of the study is for the candidate to examine the impacts of thinning practices in ash forests on various invertebrate taxonomic groups. Results obtained will assist in developing management strategies and monitoring programs suitable for application within ash forests that both preserve and enhance invertebrate biodiversity.
Contact Nick Collett, ncollett@unimelb.edu.au

Effects of microclimatic conditions on litter invertebrate populations

Litter invertebrate activity is dependent on a range of variable factors. Potentially important amongst these are the combined effects of litter, temperature, rainfall and humidity. This study would examine key indicator invertebrate groups to determine the impacts, if any, of these various factors, either singly or in combination, on litter invertebrates in a number of forest conditions.
Contact Nick Collett, ncollett@unimelb.edu.au

Comparison of different types of pitfall sampling methodologies.

This study would examine the efficiency of transect pitfall trap line compared to other pitfall trap layout configurations. Different invertebrate taxa would be examined, as well as whether accuracy of data is maintained using different pitfall traps in various designs over different exposure periods. The study will assist in designing future invertebrate experimental work.
Contact Nick Collett, ncollett@unimelb.edu.au

Family-level variability in Eucalyptus globulus coppicing ability.

In Eucalyptus globulus pulpwood plantations the coppice developing after harvest may be either managed for a second crop, or require removal/control where the site is replanted. Continual tree improvement through selection and breeding may have changed coppicing ability in deployed germplasm for this species. The study will utilize recently thinned E. globulus age 5 years family trials (c. 100 families) on contrasting sites in western Victoria and Gippsland. Conventional measurements of growth and vigour could be supported by physiological studies, with quantitative genetic analysis of heritability of observed traits.
Contact Dr. Tom Baker, tgbaker@unimelb.edu.au

Tree improvement for species for lower rainfall environments.

Tree improvement for species suitable for plantations in lower rainfall areas (400- 600 mm MAR) such as Eucalyptus cladocalyx, E. tricarpa, E. sideroxylon, E. occidentalis, Corymbia maculata is relatively undeveloped. The study can access a range of family / provenance trials of these species established in Victoria under the auspices of the Australian Low Rainfall Tree Improvement Group. Conventional measurements of growth and stem form traits could be supported by physiological studies, with quantitative genetic analysis of sources of variation.
Contact Dr. Tom Baker, tgbaker@unimelb.edu.au

Tree- and stand-level biomass relationships for Eucalyptus globulus plantations.

Tree- and stand-level biomass relationships/equations are required for a variety of purposes, ranging from bioenergy production, to estimation of carbon sequestration in plantations to calibration / validation of  process-based growth models. The study will draw on a large body of Eucalyptus globulus data from individual studies for development of robust compatible biomass equations that are applicable across a range of sites.
Contact Dr. Tom Baker, tgbaker@unimelb.edu.au

Calibration of fertiliser responses in eucalypt plantations.

The precision of predictions of fertiliser responses in eucalypt plantations can be improved by using plant tissue and/or soil nutrient analyses. The study will draw on a large body of rotation-length growth and response data coupled with foliar analysis, and climatic and edaphic data from field trials established across a range of site types throughout Victoria. Empirical and/or process-based response modelling approaches may be taken.
Contact Dr. Tom Baker, tgbaker@unimelb.edu.au

Tree growth in relation to salt accumulation in soils in irrigated plantations.

Wastewater re-use into tree plantations in low rainfall areas has been of long-standing interest to promote growth and avoid disposal of nutrient-rich water to natural water bodies; and now most recently has a bioenergy emphasis. The study will draw on a large body of rotation-length growth and response data coupled with climatic and edaphic data, including profiles of soil salinity development with time, from irrigated field trials established in northern Victoria. Empirical and/or process-based response modelling approaches may be taken.
Contact Dr. Tom Baker, tgbaker@unimelb.edu.au

Reducing tree water use by pruning (foliage removal)

Pruning of lower branches enables the production of knot free wood. However, pruning can remove more than half of the canopy leaf area and thus slow growth and reduce the amount of water used by the tree. This project would estimate water use by measuring rates of sap flow and the cross sectional area of conducting tissue (sapwood).
Contact Dr. David Forrester, davidif@unimelb.edu.au

Growth of a mixed species plantation of Blackwood and Douglas fir

The interactions that occur between different species in mixtures can lead to significant improvements in growth rates, tree form and wood quality, particularly when one of those species is capable of fixing nitrogen (such as Blackwood). This project will examine the growth and interactions in a mixture of Douglas fir and Blackwood. This could involve measurements of growth (diameter, heights, volume), and the resources for which trees compete, such as light, water and nutrients.
Contact Dr. David Forrester, davidif@unimelb.edu.au; Mark Stewart, marks@unimelb.edu.au

Designing a silvicultural regime for Poplar plantations

Several decades ago a couple of poplar trials were established to examine the effect of spacing on tree growth. These stands have now reached maturity and provide an ideal data set to examine the growth dynamics and competitive processes of this stand. This could involve relating tree growth to the competition it experiences from its neighbours. Measurements of crown size and leaf area may also be useful.
Contact Dr. David Forrester, davidif@unimelb.edu.au

Regeneration and growth of native forests

Due to the differing shade tolerance of natural vegetation, species regeneration is influenced by the size of gaps in forested areas. For example, eucalypts require larger sized gaps for seedlings and saplings to develop, while wattles and other understorey species are more favoured by shading. Ideal gap sizes vary depending on the shade tolerance of the species. Young trees growing on gap edges, next to adult trees, will be shaded and hence grow more slowly or even die. This effect is often ignored when estimating species composition and growth rates of regenerating patches of native forests, but a high proportion of young trees can be affected by this competition, particularly if the gaps are small. This study will relate the growth and frequency of young eucalypts and understorey species to their distance from the gap edge in order to better understand ‘edge effect’ and the partitioning of productivity. Study sites will focus mainly on mountain ash forests near Tanjil Bren, in the Central Highlands, but could include mixed species forests at Cabbage Tree Creek, in East Gippsland.
Contact Dr. David Forrester, davidif@unimelb.edu.au; Simon Murphy, scmurphy@unimelb.edu.au

Biomass, litter and soil carbon changes following reforestation of agricultural grassland with Eucalyptus, Acacia and Pinus

The impact of reforestation on soils continues to be a contentious issue, particularly with respect to plantation monocultures and potential deleterious long-term impacts on soil quality and productivity. This project will utilize a 6 year-old field experiment planted in south-western Victoria providing for replicated comparison of Eucalyptus globulus, Acacia mearnsii and Pinus radiata . The work will require tree growth measurements together with application of existing (or newly developed) tree biomass allometric equations to estimate biomass, and litter and soil sampling and analysis.
Contact Dr. Tom Baker, tgbaker@unimelb.edu.au

Canopy efficiency of eucalypts growing in mixtures with nitrogen fixing acacia trees

Mixed species plantations of Eucalyptus with a nitrogen fixing species such as Acacia can be significantly more productive than Eucalyptus monocultures. This results from increased nutrient availability via nitrogen fixation and accelerated rates of nutrient cycling, and reduced competition for light. However, these factors only explain part of the growth response, there appears to be another factor that is also responsible, which is likely also to be linked to increases in canopy efficiency. This has not been examined in mixtures and would be the focus of the proposed project. This could involve gas exchange measurements of maximum rates of photosynthesis, electron transport, carboxylation efficiency and dark respiration. Additional data quantifying leaf nutrition and canopy shape and size would also be collected. This knowledge will provide information required for the growth modelling of mixed species plantations and would fill a knowledge gap currently existing in mixtures research.
Contact Dr. David Forrester, davidif@unimelb.edu.au

The influence of competition on tree form in eucalypt plantations

The value of wood from trees is related to growth rates, wood quality and tree form. Many studies examine the effect of thinning, pruning or mixing species together on growth but few examine the influence of these treatments on tree form. The proposed study aims to examine the effect of neighbourhood competition on the form of individual trees by calculating competition indices and relating this to a trees size, branching habit and height to diameter ratio. This technique could be applied to several Eucalyptus plantations that have a range of thinning or pruning treatments or to mixed species plantations containing Eucalypts with Acacia mearnsii or Acacia melanoxylon. The results will be used to design planting patterns that will facilitate the development of well formed trees.
Contact Dr. David Forrester, davidif@unimelb.edu.au

Modelling stem form response to thinning in eucalypt plantations.

Tree stem taper models have been commonly used in many computer-based decision support systems in forestry (forest yield models or simulators) to estimate various wood products (e.g. pulpwood, sawlogs, veneer logs). Traditionally, stem taper has been modeled as a generic, species-specific mathematical relationship between the relative underbark stem diameter and relative height along the stem of trees. Such generic taper models cannot account for the variation of stem form in different forest stands, particularly plantations with intensive silvicutural interventions (e.g. thinning, pruning). This study aims to: (1) investigate different biometric modelling approaches for improving the predictive ability of taper models in responses to thinning of eucalypt plantations, and (2) to explore error structures of taper models under different modelling approaches. The project may require taking field measurements on stem tapers of sample trees, and associated tree or stand characteristics from eucalypt plantations with known silvicutural treatment histories.
Contact Dr. Yue Wang, yuewang2@unimelb.edu.au

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Tree Developmental Biology and Forest Biotechnology

Ecotypes of local Acacia species

Plant species develop ecotypes in response to local environmental conditions.
Seed will be collected from natural populations of the species and grown in a common garden study. Variation in morphology and fitness will be examined and information used to guide seed sourcing for revegetation projects.
Contacts: Paul Nevill, p.nevill@pgrad.unimelb.edu.au; Dr. Peter Ades, petera@unimelb.edu.au

Cold tolerance, field survival and the effects of climate change on E. regnans and E. delegatensis

Low temperature tolerance is one of the main traits controlling the natural distributions of the major ash species and it may affect field performance when seed is moved off-site or as a consequence of climate change.
This project is to investigate the effects on field survival and growth associated with variation at a genetic locus that has been shown to affect frost tolerance in laboratory studies.
Contacts: Paul Nevill, p.nevill@pgrad.unimelb.edu.au; Dr. Peter Ades, petera@unimelb.edu.au

Fine scale spatial genetic structure of E. regnans

Spatial genetic structure (SGS) is the distribution of genotypes over space. Information on SGS is important for the design of conservation strategies and in the collection of seed for reforestation.
This project will investigate the fine scale genetic structure of E. regnans in both core and outlier populations using genetic markers. The project involves lab and field work.
Contacts: Paul Nevill, p.nevill@pgrad.unimelb.edu.au; Dr. Peter Ades, petera@unimelb.edu.au

Hybrid zones in the Otways Ranges

Many ash species readily hybridise and Eucalyptus regnans and Eucalyptus obliqua are believed to have formed extensive and stable hybrid zones in the Otways region of Victoria.
This project will examine some of the evolutionary questions associated with these zones using ecological and genetic approaches.
Contacts: Paul Nevill, p.nevill@pgrad.unimelb.edu.au; Dr. Peter Ades, petera@unimelb.edu.au

Genomic architecture of the Alpha Tubulin gene in Eucalyptus globulus

Alpha tubulin plays an important role in development of plant cells and, in trees, may influence wood quality traits including pulp yield, lignin content, growth and basic density.  To explore this hypothesis, this project will analyse the alpha tubulin gene sequences of 20 trees representative of the natural range of E. globulus, and a further 10 individuals of a breeding population.  This project requires the student to learn standard molecular genetic techniques including gene amplification and sequencing, and involves analysis of sequence data for signatures of selection and altered nucleotide diversity levels.
Contacts: A/Prof Gerd Bossinger: gerd@unimelb.edu.au, Dr Luke McManus, lmcmanus@unimelb.edu.au; Mr Saravanan Thavamanikumar,  s.tharvamanikumar@pgrad.unimelb.edu.au; Dr Josquin Tibbits, josquint@unimelb.edu.au

The role of cambium specific genes in wood formation

Over recent years the UM-SFES Tree Developmental Biology and Forest Biotechnology research group have isolated a number of cambium specific genes with potentially unique roles in wood formation.  Using Induced Somatic Sector Analysis (ISSA), the latest tool in functional gene characterisation developed in our lab, candidates can choose a specific gene and with the aid of over-expression and/or gene silencing help us to understand its contribution to wood formation.
Contacts: A/Prof Gerd Bossinger: gerd@unimelb.edu.au, Dr Antanas Spokevicius, avjs@unimelb.edu.au; Dr Josquin Tibbits, josquint@unimelb.edu.au

Understanding the composition of in vitro derived wood

Over the past several years the Tree Developmental Biology and Forest Biotechnology group have developed novel in vitro wood formation systems.  In these systems, stems from growing trees are placed in culture, and with the addition of specific hormones, begin to undergo cambium differentiation and produce new wood.  The candidate in this project will be involved in the production and assessment of the chemical composition of the new in vitro derived wood.
Contacts: A/Prof Gerd Bossinger: gerd@unimelb.edu.au, Dr Antanas Spokevicius, avjs@unimelb.edu.au
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Sustainable Forest Management

Monitoring aerial eucalypt seed sowing in Victorian native forests

Regeneration of harvested forest areas (coupes) is the responsibility of VicForests, being a requirement under the Code of Forest Practices.  As part of regeneration activities, VicForests oversees aerial sowing of eucalypt seed on 120-170 native forest coupes per year.  An important part of this process is to monitor seeding operations to assess whether sufficient seed is reaching the target area, and if seed is being distributed evenly.
This project will involve working with VicForests to develop a method and analytical protocol for post-harvest monitoring of aerial eucalypt seed sowing.  There will be three major components:
1. Comparing two alternative methods for monitoring seedfall (field work - Autumn 2008)
2. Conducting seed viability tests (laboratory work)
3. Determining adequate sample size for seedfall monitoring using alternative analytical techniques
The project will be supervised by Julian Di Stefano, Simon Murphy (both from the Department of Forest and Ecosystem Science) and Michael Ryan (VicForests).
Contact Dr Julian Di Stefano, juliands@unimelb.edu.au; Simon Murphy, scmurphy@unimelb.edu.au
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