Wollemi Pine research projects
Find out more about our collaborative research projects, including how the Wollemi Pine grows, how it is being protected, and the relationship between these ancient plants and their living Araucariaceae relatives.
Our research project aims:
- Understanding how the Wollemi Pine grows in the wild and in cultivation
- Investigating germination requirements and seedbanking potential
- Banking seeds that can be conserved by seedbanking and developing alternative conservation measures
- Providing plants for display, interpretation and reintroduction
- Passing on lessons learned to the wider community
When was it discovered?
In September 1994 David Noble, an officer with the NSW National Parks & Wildlife Service, discovered some trees he didn’t quite recognise. In a deep, narrow canyon of the rugged Wollemi National Park, he discovered what we now call Wollemia nobilis or the Wollemi Pine.
Find out more in this clip by ABC Catalyst: Horstman M et al (19/5/2005) Wollemi Pine. ABC Catalyst.
Why was it so extraordinary?
The dramatic discovery of an evolutionary line thought to be long extinct is even more remarkable with these tall and striking Wollemi Pine trees growing only 150 km from Sydney, the largest city in Australia. They were found in the extremely rugged Wollemi National Park, a largely undisturbed wilderness area.
Find out more in this clip by ABC Splash: Content Mint, 'Prehistoric Wollemi Pine discovered', ABC Splash
Where is the Wollemi Pine found?
The Wollemi Pines grow in the Wollemi National Park, north-west of Sydney, the state capital of New South Wales (NSW), Australia. The park covers about 500 000 hectares and is the largest wilderness area in the state - a very rugged mountainous region of ridges, cliffs, canyons and undisturbed forest.
The sandstone ridges and canyon walls are covered by dry sclerophyll woodland and shrubland dominated by Eucalyptus species. A warm temperate rainforest in the deep canyons is dominated by Coachwood (Ceratopetalum apetalum) and Sassafras (Doryphora sassafras), with an understory dominated by ferns such as Sticherus (Sticherus flabellatus). The Wollemi Pines grow on ledges in these canyons.
Given the degree of interest in the Wollemi Pine, protecting it is crucial, and this is done through both legislation and site management. Under the NSW Threatened Species Conservation Act (1995) a fine of up to $220,000 and imprisonment of up to two years can be imposed for any damage caused.
What is the ecology of the Wollemi Pine?
The Wollemi Pine grows in a sandstone canyon in a ferny warm temperate rainforest. It grows on the steep lower slopes and ledges of the canyon on an acidic, sandy loam soil with pH of about 4.5. The main vascular associate plant species are Coachwood (Ceratopetalum apetalum), Sassafras (Doryphora sassafras), Lilly Pilly (Acmena smithii), Soft Treefern (Dicksonia antarctica), shield ferns (Lastreopsis spp.) and Umbrella Fern (Sticherus flabellatus).
Population parameters
- Fewer than 100 trees at several sites
- Average 4.7 stems per tree
- Average stem height is 11 m
- Average stem diameter is 118 mm
- Tallest tree is 38.5 m
- Widest stem is 0.67 m
Growth
The Wollemi Pine is bisexual (monoecious), with both male and female cones on the same tree. The round female cones produce the seeds, and the long male cones produce the pollen. The female and male cones start growing in mid-summer. In late spring the male cones release masses of pollen, which is carried by the wind, to fertilise the egg cells in the female cones. The female cones then take about 18 months to ripen, when the fertilised ovaries develop into seeds and they then fall apart high above the canyon floor, releasing winged seeds that float to the ground - research has been conducted into embryological (seed) development. If a seed falls in a suitable position and the weather is favourable it will germinate. Over time, if the light conditions are right, the small seedling may grow to become a majestic emergent rainforest tree.
Over 200 seedlings have been counted in the wild. Some of these are tagged and are being monitored for survival and growth rates. The seedlings grow on average only 1 cm per year and most are less than 30 cm high. Many of these seedlings will die unless there is a canopy opening that allows light in penetrate to the ground - thus providing energy for the seedlings to grow.
Given the right conditions the trees grow quickly for the first 15-20 metres until they reach the canopy, they then put more of their energy into the bulk of their trunks and root systems.
Coppicing
Through the millions of years of population decline, the Wollemi Pine has maintained its ability to sexually reproduce but has adopted a secondary reproductive strategy - that of self-coppicing.
Coppicing also helps the tree to survive disturbance. While tree ring analysis has revealed that trees with a diameter of 0.8 m may be 350+ years old, the coppice roots may be thousands of years old. The extensive root system of the Wollemi Pine may also explain how it has survived droughts - the roots penetrate into creek beds and into cracks in the sandstone cliffs.
Disturbance
All populations have been burnt or subjected to rock fall or windstorm damage. It is postulated that if these disturbance events happen too often they may reduce or eliminate the Wollemi Pine's population. On the other hand, if there is no disturbance the other rainforest plants may dominate the glades and prevent the Wollemi Pine's seedlings from growing into adult trees.
Some big ecological questions
The long-term aim of the ecological research into the Wollemi Pine is to track the survivorship of the trees and the seedlings. This may reveal some insight into how to manage disturbance such as wildfire at the sites.
- How old are the coppice trees and how long can they live?
- Could too-frequent wildfire destroy the stands?
- How frequent and what type of disturbance would ensure survival of the Wollemi Pine?
- How do we manage illegal visitation to minimise impacts?
How old is the Wollemi Pine?
To determine the age of the Wollemi Pine trees, a scientific team cut cross-sections from one of the fallen trunks (a large mature, 35-40 metre trunk) at the original site in Wollemi National Park, and sent them to the Australian National University Forestry Department for analysis.
One of the most intriguing things that can’t be determined, due to coppicing (the unusual branching habit which leads to old Wollemi Pines having many separate trunks), is how old the original tree was before this particular trunk was produced. It may have been hundreds, or perhaps thousands of years since it was a seedling!
By counting the growth rings from cross-sections of the trunk and combining this with carbon dating, the best estimate for this sample trunk is about 350 years old. This means that this trunk started growing around 1650! See also 'Determining its age' and 'If Trees Could Talk...'.
Family ties?
The Wollemi Pine belongs to the conifer family Araucariaceae, and its closest living relatives in this family include the Kauri (Agathis species), Norfolk Island, Hoop, Bunya Bunya and Monkey Puzzle pines (Araucaria species). Morphological, wood anatomy and DNA analysis suggest that the Wollemi Pine is a new genus, falling between the two previously known living genera: Agathis and Araucaria.
Ancestry?
Conifers date back to the Carboniferous age, more than 300 million years ago. ‘Modern’ (evolved) conifers, like the Araucariaceae family, are known from the Triassic period, more than 250 million years ago.
There are Triassic fossil examples of the Araucariaceae family, which reached maximum diversity during the Jurassic and Cretaceous periods, between 200 and 65 million years ago, with worldwide distribution. At the end of the Cretaceous, when dinosaurs became extinct, so too did the Araucariaceae in the northern hemisphere.
Until about the middle of the Tertiary (30 million years ago), plants in the Araucariaceae grew in the forests of the southern super-continent of Gondwana (which included Australia, Africa, South America, Antarctica and India). The Araucariaceae family then began a slow decline in range and diversity as flowering plants, better adapted to climate change, began to evolve and gradually displace conifers. The last fossil record of the Wollemi Pine is dated at about two million years ago and so the Pine was thought to be extinct. See also 'Tracking through time'.
What does it look like?
In the wild Wollemi Pine trees grow to about 40 metres and their trunks can grow up to 1 metre in diameter. Like other conifers, it bears cones (male and female), which appear at the very tip of branches with adult phase leaves. The bark is particularly unusual, looking very much like ‘chocolate crackles’ or bubbling chocolate, making it quite different from the bark of other related species.
The Wollemi Pine has two types (or phases) of leaves. It does not have needles like pine trees in the northern hemisphere. Its young broad-based juvenile leaves are bright lime-green and grow in low light under the rainforest canopy. The adult leaves, which grow in much harsher conditions above the canopy, are tougher and a deeper bluish-green.
The leaves at the beginning and end of a growing season are shorter than those formed during the middle of the season, creating a repeating diamond shaped pattern along the branch. The leaves also have an in-built system to help reduce water loss.
Its leaves have a thick cuticle (a very thin film covering the outer, or epidermis, layer of the leaf), a fibrous hypodermis (a layer of cells just under the epidermis) and sunken stomata (pores), a survival characteristic which helps it reduce water loss.
Further reading: Leaf Anatomy of Wollemi Pine (Wollemia nobilis, Araucariaceae), by Geoffrey Burrows and Suzanne Bullock, Australian Journal of Botany, 47(5): 795-806 (1999).
Most flowering plants, though not conifers, have dormant buds in the axils (the angles between the upper side of each leaf and the stem) - so if a plant is damaged by insects or pruning, these buds can sprout. In the genus Araucaria and in the Wollemi Pine, each axil has a small group of cells that’s somewhere between a fully formed bud and no bud at all. A unique feature of the Wollemi Pine is that these buds on upright branches develop normally to form a multi-stemmed and multi-branched tree.
Further reading: The Wollemi Pine (Wollemia nobilis, Araucariaceae) possesses the same unusual leaf axil anatomy as the other investigated members of the family, by Geoffrey E. Burrows, Australian Journal of Botany, 47(1): 61-68 (1999).
There are two types of branches on the Wollemi Pine: 1 - one grows upright (orthotropic), forming a stem or another trunk, depending on where it starts. 2 - the other grows sideways (plagotropic) from an upright branch and the leaves develop on these branches. Unlike trees in the genus Araucaria, the sideways branches do not divide unless the growing tip (apical meristem) is damaged.
Upright branches start from buds borne along the trunk, eventually maturing with foliage and a branching structure resembling the initial trunk, so that older trees develop a branched crown. Upright branches that develop from buds at the base of the trunk, referred to as coppicing, form a multi-trunked tree.
Young seedlings, from as early as one year old, can develop more than one upright branch - unlike Araucaria trees where additional upright branches develop only after the growing tip has been damaged or wounded.
Some dormant buds may sprout along the trunk or from the base of the trunk. This is called coppicing, resulting in large old plants with multiple trunks of different ages - see age and ancestry. This may be a defence against damage from drought, fire or rock fall in the steep canyons where they grow. It‘s probably the reason that the Wollemi Pine has survived the increasing aridity of Australia over millions of years.
Further reading: Architecture of the Wollemi Pine (Wollemia nobilis, Araucariaceae), a unique combination of model and reiteration, by K D Hill, Australian Journal of Botany, 45(5): 817-826 (1997).
The leaves don’t have stalks (petioles) to attach to the branch. Instead, the whole base of the leaf wraps halfway round the branch. So the tree sheds entire lateral branches rather than individual leaves, which is another unusual feature it shares with the genus Araucaria.
Using samples from a trunk collected by the NSW National Parks and Wildlife Service rangers we have been able to examine the anatomy of the wood. See our Image Gallery for these spectacular images taken using a Scanning Electron Microscope.
Further reading : Wood anatomy of Wollemi pine (Wollemia nobilis, Araucariaceae), by R D Heady, J G Banks & P D Evans, IAWA Journal 23(5): 339-357 (2002).
Where can you see the Wollemi Pine?
A great example of a cultivated Wollemi Pine can be found behind the Visitor Centre at the Australian Botanic Garden, Mount Annan. Nearly 20 years old, this tree has been well-watered and protected from sun on the southern side of the building. It is well over ten metres tall and is covered with both male and female cones. Like plants in the wild, the tree is beginning to produce multiple branches from the base.
You can also see a Wollemi Pine in the Royal Botanic Garden Sydney, see here on the map.
How is it being protected in the wild?
After millions of years of evolution from ancestors in or before the dinosaur era, the Wollemi Pine is teetering on the edge of extinction. Human beings are the biggest threat to its survival. One visitor to the site could destroy the population by introducing pathogens, for example a root fungus.
Since there are so few specimens in the wild, a thorough management strategy has been developed to protect them - the Wollemi Pine Recovery Plan - which includes:
World Heritage listing (the Wollemi National Park is part of the Greater Blue Mountains World Heritage Area).
Protection under the NSW Threatened Species Conservation Act 1995 and the federal Environmental Protection and Biodiversity Conservation Act 1999.
Memorandum of Understanding between NSW National Parks & Wildlife Service and the Botanic Gardens Trust to manage the wild populations and develop a cultivation and propagation program.
Not revealing the exact location of the known stands to other than bona fide scientific research teams.
Minimising the number and duration of visits to the site and avoiding trampling seedbeds and seedlings, compacting soil and introducing disease.
Introducing special precautions during scientific field trips, for example anti-microbial foot baths to ensure the exotic root rot pathogen Phytophthora cinnamomi and other diseases aren’t introduced to the site.
Monitoring the sites to guard against unwanted and perhaps destructive visits by bushwalkers and collectors, and liaising with neighbours to the national park who help with site protection.
Studying the ecology of the species in the wild to identify issues critical for recruitment and the survival of the species under a range of disturbances such as fires, floods, rockfalls and treefalls.
Establishing botanical research and horticultural development projects. See also 'Growing Wollemi Pines'.
Why was the Wollemi Pine propagated for sale?
Humans pose the greatest threat to the survival of the magnificent Wollemi Pine in the wild. Ensuring the trees can be seen and grown by the public is a unique and exciting part of the strategy to protect the remaining trees. Having Wollemi Pines in homes, gardens and parks worldwide is safeguarding the species from becoming extinct and minimises the threat of unauthorised visits to the wild population. In conservation terms, this strategy combines in situ protection of the trees with ex situ cultivation and translocation as a 'back up' for the wild population.
Plants have been available from Botanic Gardens Shops at the Royal Botanic Garden, Sydney, the Australian Botanic Garden, Mount Annan, and the Blue Mountains Botanic Garden, Mount Tomah, on-line or from selected nurseries in Australia since 1 April 2006.
So far, the plant is proving to be an especially good pot plant and can be grown in many garden situations.
How do I grow my Wollemi Pine?
Wollemi Pines, like other Araucariaceae, grow in warm temperate rainforests and are adapted to a climate with low frost intensity and frequency, and warm summer temperatures. Wollemi Pines are the most frost tolerant and least heat tolerant of the Australian Araucariaceae, a response that is consistent with its current location and climate in a deep, protected gorge.
Understanding the natural growing environment, including light levels and temperature, of the Wollemi Pine has been important in ensuring cultivated and translocated plants will survive and thrive in their new locations. For example, cultivated plants thrive in protected positions, with exposed plants showing yellowing and leaf drop due to irreversible photoinhibition (light damage). This damage occurs with a combination of temperatures that are too high or low (exacerbated by wind chill and low soil moisture), and strong sunlight exposure to foliage (especially young delicate leaves).
Plants in more protected positions, especially those slowly adapting to lower temperatures going into summer or winter, will be more likely to survive with minimal damage. Our research has shown that Wollemi Pines grow best in climates with temperatures as low as -10oC in winter and up to 37oC in summer.
For more detailed scientific information on this topic, see Growth of the Wollemi Pine in the Wild and Growth of the Wollemi Pine in cultivation.