Wollemi pines are dinosaur trees



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Wollemi pines once covered prehistoric Australia.
The Conversation/Wikipedia

Cris Brack, Australian National University

Welcome to Beating Around the Bush, a series that profiles native plants. Read more about the series here or get in touch to pitch a plant at batb@theconversation.edu.au.


There’s a tree that once covered the whole of Australia, then dwindled to a dozen examples, and is now spread around the world. We call it the Wollemi pine (Wollemia nobilis), but you could call it the dinosaur tree.

Fossil evidence indicates that between 200 million and 100 million years ago, Wollemi pine was present across all of Australia. A dryer, more flammable continent is likely to have driven the tree to near extinction over the millennia, leaving just a very small remnant of the Wollemi in a secluded deep gully not far from Sydney.




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And there these trees remained, hidden, until they were discovered by a canyoning National Park worker in 1994.

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A spectacular discovery

The reaction to the discovery of this tree, thought to have disappeared 100 million years ago and only known through its fossils, was spectacular. Great secrecy was maintained around the site of the find. Because there were so few, the individual trees in the gorge were given their own names to celebrate their importance and acknowledge the efforts of those trying to protect them.

Scientists, arborists and botanists swung into action to discover ways to propagate more trees and establish other colonies of the Wollemi as insurance against that single refuge being lost.




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There was a great sigh of relief when it was discovered that trees could be successfully cloned, and new trees were potted up in the Sydney and Mount Annan Botanic Gardens. The interest in these original cloned offspring was so great that they were auctioned off by Sotheby’s, with the profits going back to support more research into this little-known living fossil.

Students and staff from my school at the Australian National University pooled together to bid for a clone of the Wollemi, christened the “John Banks” – named for our colleague Dr John C.G. Banks, who was one of the first researchers to describe the tree’s dendrology. We planted our tree in memory of John, with a cage around it because it was so rare and valuable.

Sent around the world

In 2006, just over a decade after the original discovery, huge numbers of cloned Wollemi Pine seedlings were released from the official nursery in Queensland.

Every major nursery in Australia stocked potted Wollemi Pines for sale to a public who were keen to own a piece of ancient life and help ensure it didn’t go extinct. Enthusiasts around the world also bought their own dinosaur trees.

But it’s not just gardeners who have spread the Wollemi back to all corners of Australia and across the seas. Special Wollemi pines are also in the diplomatic service, having been presented by Australian prime ministers and foreign affairs ministers to various dignitaries.

Seedlings are an obvious choice to represent long-term friendship and trust, as the act of planting a tree is one of hope for the future and a common good. A seedling that can trace its history back more than 100 million years, and which represents the reversal of an extinction, is even better.

Wollemi were thought to be extinct long before humans arrived in Australia, so there is no opportunity for humans to have used it in any specific way. However, ancient species may have properties or traits that are no longer present in evolved plants and these may be useful. For example, extracts from Wollemi pine leaves have been found to be successful in inhibiting a pest that affects winter wheat production – which may help control an expensive problem without herbicides.

Scientists found that extracts from the leaves of the Wollemi contained chemicals that had never previously been described, and which suppressed annual ryegrass (Lolium rigidum). The ryegrass, like many modern weeds, has evolved in the absence of Wollemi and thus was unlikely to have developed resistance to its chemistry.

How does it grow?

Little was known about Wollemi pines when the remnant was found. We knew the conditions of the gorge where they grew, but not whether these were optimal. Could the tree survive in hotter or cooler, drier or wetter, more clay or gravelly soils?

We now know from planting experience outside the National Park that Wollemi pines can grow on exposed rock slopes, surviving frost and temperatures lower than -5℃ with the help of a waxy coat it puts on top of its growing buds. They can also survive heat greater than 45℃ in full sun.

Some Wollemi pines have been known to happily sit in small pots on verandas or decks, growing to over 3 metres – only to die within weeks of being transplanted into carefully prepared holes. They can be slow-growing, but given good light and moisture they can grow more than 50cm per year. Horticulturalists and the Sydney Royal Botanic Gardens continue to work on finding the best ways of tending these pines.




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Wollemi pines, unlike their nearest neighbours in the Araucariaceae, can also produce coppice or epicormic shoots in response to drought or fire. It is likely that this ability is responsible for the survival of the original remanants in the National Park, with new upper stems regenerating from below-ground stocks century after century.

A potential issue with clonal reproduction is the lack of genetic diversity, which could make the pines susceptible to further environmental changes or pests. However, many trees are maturing and producing viable seeds, and there is certainly diversity in the phenology with some Wollemi of the same age producing female cones, some male cones (and some both).




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The ConversationDespite the ability to survive cold and heat and even recover from damage using epicormics, Wollemi Pines may not make ideal street trees, as the branches on the trunk shed relatively quickly. Shedding leaves, bark or branches are regularly complained about by residents in cities. But in the right place in a backyard – with low frost intensity, warm summers and enough moisture – you can grow your very own dinosaur tree.

Cris Brack, Assoc Professor Forest measurement & management, Australian National University

This article was originally published on The Conversation. Read the original article.

How our research is helping clean up coal-mining pollution in a World Heritage-listed river



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The Wollangambe River’s canyons are loved by adventurers.
Ben Green

Ian Wright, Western Sydney University

The Wollangambe River in New South Wales is a unique gift of nature, flowing through the stunning Wollemi National Park, wilderness areas and the World Heritage-listed Blue Mountains. It’s an adventure tourism hotspot, with thousands of people clambering through the river’s majestic canyons each year.

So it was with a sense of irony that bushwalkers noticed unnatural flow and discolouration in the river and suspected it was pollution. In 2012 they contacted Western Sydney University, which has since conducted ongoing investigations.

The pollution was traced back to the Clarence Colliery, owned by Centennial Coal. Our recent research confirms that this is one of the worst cases of coal mine pollution in Australia, and indeed the world.

For four years I and other researchers have been investigating the pollution and its impacts on the river. The NSW Environment Protection Authority (EPA) has verified our findings. In exciting news, the mine was in March issued a revised environmental licence, which we believe is the most stringent ever issued to an Australian coal mine.

This is appropriate given the conservation significance of the river and the current scale of the pollution. We are now hopeful that the pollution of the Wollangambe River may soon be stopped.

Water pollution damages the river and its ecology

The Clarence Colliery is an underground mine constructed in 1980. It is just a few kilometres from the boundary of the Blue Mountains National Park.

Clarence Colliery and Wollangambe River.
Ian Wright

Our research revealed that waste discharges from the mine cause a plume of water pollution at least 22km long, deep within the conservation area. The mine constantly discharges groundwater, which accumulates in underground mines. The water is contaminated through the mining process. The mine wastes contributed more than 90% of the flow in the upper reaches of the river.

The EPA regulates all aspects of the mining operation relating to pollution. This includes permission to discharge waste water to the Wollangambe River, provided that it is of a specified water quality.

Our research found that the wastes totally modified the water chemistry of the river. Salinity increased by more than ten times below the mine. Nickel and zinc were detected at levels that are dangerous to aquatic species.

We surveyed aquatic invertebrates, mostly insects, along the river and confirmed that the mine waste was devastating the river’s ecology. The abundance of invertebrates dropped by 90% and the number of species was 65% lower below the mine waste outfall than upstream and in tributary streams. Major ecological impacts were still detected 22km downstream.

We shared our early research findings with the NSW EPA in 2014. The authority called for public submissions and launched an investigation using government scientists from the NSW Office of Environment and Heritage. Their study confirmed our findings.

Progress was interrupted when tonnes of sediment from the mine were dislodged in 2015 after heavy rainfall and the miner and the EPA focused on cleaning the sediment from the river. This incident has resulted in the EPA launching a prosecution in the NSW Land and Environment Court.

We recently compared the nature and scale of pollution from this mine with other coal mine pollution studies. The comparison confirms that this is one of the most damaging cases of coal mine water pollution in Australia, or internationally.

Even 22km below the waste outfall, the Wollangambe is still heavily polluted and its ecosystems are still degraded. One of the unique factors is that this mine is located in an otherwise near-pristine area of very high conservation value.

New licence to cut pollution

The new EPA licence was issued March 1, 2017. It imposes very tight limits on an extensive suite of pollutant concentrations that the mine is permitted to discharge to the Wollangambe River.

The licence covers two of the most dangerous pollutants in the river: nickel and zinc. Nickel was not included in the former licence.

The new licence now includes a sampling point on the river where it flows into the World Heritage area, about 1km downstream from the mine. The licence specifies vastly lower concentrations of pollutants at this new sampling point.

For example, the permitted concentration of zinc has been reduced from 1,500 micrograms per litre in the waste discharge, in the old licence, to 8 micrograms per litre.

It can be demoralising to witness growing pollution that is damaging the ecosystems with which we share our planet. This case study promises something different.

The actions of the EPA in issuing a new licence to the mine provide hope that the river might have a happy ending to this sad case study. The new licence comes into effect on June 5, 2017.

The ConversationOur current data suggest that water quality in the river is already improving. We dream that improved water quality, following this licence, will trigger a profoundly important ecological recovery. Now we just have to wait and see whether the mine can improve its waste treatment to meet the new standards.

Ian Wright, Senior Lecturer in Environmental Science, Western Sydney University

This article was originally published on The Conversation. Read the original article.