Australia’s native rhododendrons hide in the high mountain forests



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Rhododendron lochiae, photographed on Bell Peak.
Image by Dan McLeod

Stuart Worboys, James Cook University

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The 1800s was a time of colonial expansion across the globe. During this time the great and the good of Britain filled their grand gardens with exotic novelties from all corners of the world.

Amongst these were many species of Asian rhododendron, a diverse and colourful genus of shrubs and small trees, whose high altitude origins made them well suited to the cool temperate climate of England and Scotland.




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Throughout the 19th century, commercial collectors and field naturalists discovered rhododendron species in southern China, the Himalayas, on the high peaks of Borneo, Java and especially New Guinea.

These finds lead Victoria’s government botanist of the time, Ferdinand von Mueller, to speculate about finding rhododendrons on the high tropical mountains on the northeast coast of Queensland. He wrote:

When in 1855 [I] saw… the bold outlines of Mount Bellenden-Ker, the highest mount of tropical Australia, towering to 5,000 feet, [I] was led to think, that the upper region might prove to be the home of species of Rhododendron… forms of plants characteristic of cool Malayan sylvan regions.

But the lofty heights of Mt Bellenden Ker were unknown to European Australians. It would be another 32 years before an expedition led by naturalist W.A. Sayer reached its central peak.



The Conversation, CC BY-ND

Sayer’s expedition, accompanied by two indigenous assistants, reached the mountain’s high ridge after several mishap-filled attempts. It was here they confirmed Mueller’s suspicions. Sayer’s account of its discovery is interesting:

The top of the range is razor-backed, and on travelling along the range beyond the spur by which we ascended, I could not see the sides, they being, if anything, hanging over. We tumbled rocks over, but could not hear them fall.

It was here that I observed the Rhodendron Lochae growing, and asked the Kanaka to get it; but he remarked, ‘S’pose I fall, I no see daylight any more; I go bung altogether;’ so I had to get it myself.

Mueller received the hard-won specimens and named the species Rhododendron lochae (later corrected to R. lochiae) after Lady Loch, the wife of the Victorian Governor.

Since then, rhododendron plants have been found on nine peaks and tablelands in the Wet Tropics region of north Queensland. Populations on peaks south of Cairns are called Rhododendron lochiae, whilst plants growing on mountains to the north of Cairns are considered by some to be a distinct species: Rhododendron viriosum.

Australian rhododendron at Smith College Botanical Garden.
Ren Glover/Flickr, CC BY-NC

Both northern and southern plants are straggly shrubs that grow in thin soils or rock cracks, sometimes in open cloud-swept boulder fields, sometimes in deep shade along creeks, or rarely as epiphytes on moss-covered trees. They produce bunches of gloriously red, bell-shaped flowers, followed by dry brown capsules filled with small winged seeds that are apparently spread by wind.

They grow slowly but with relative ease from cuttings, and are often cultivated in gardens and nurseries in temperate Australia. However, over time knowledge of the precise origin of these cultivated plants has been lost, which means they are unsuitable for detailed scientific investigations.

All of Australia’s rhododendron populations are located at altitudes above 950m in National Parks within the Wet Tropics World Heritage Area. Most are difficult to access, requiring arduous climbs on rough foot tracks through leech-infested rainforest. And yet, although isolated in protected areas, they are threatened by human activities: loss of habitat due to climate change.

Recent climate modelling research published by scientists from James Cook University and the CSIRO predicts significant reductions in suitable habitat for a suite of mountaintop flora species in Australia’s tropics (our rhododendrons were not included in the analysis, but occupy the habitats assessed).

The habitat of many of these species is predicted to disappear altogether well before the end of the century.

Conservationists are racing to preserve samples of native rhododendrons.
Author provided

Using rhododendron as a model, the Australian Tropical Herbarium at James Cook University is working to save these threatened species through “ex situ” conservation – cultivation in temperate zone public gardens, well outside their natural range. Because the threatening process – climate change – is not readily mitigated, establishing precautionary ex situ collections is the only viable conservation intervention for these plants.

With funding from the Australian Rhododendron Society Victoria Branch and the Ian Potter Foundation, and the support of traditional owners, Queensland National Parks and the Wet Tropics Management Authority, we have mounted expeditions to collect samples from most of the known populations.

These expeditions have put expert naturalists into rarely visited and challenging environments. Beyond gathering rhododendron samples, new moss species have been discovered and are being named, a fern previously thought extinct was rediscovered, and beautiful little epiphytic orchids have been found on a mountain where they’d not previously been recorded. Golden bower-bird bowers have been mapped in remote mountain rainforests, and a likely new species of snail has been discovered.




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Australia now has a well-documented and genetically diverse collection of native rhododendron plants thriving in the Dandenong Ranges Botanic Garden.

We plan to expand this work, ensuring the preservation and public display of rhododendron and many other mountain species threatened by climate change.

Sign up to Beating Around the Bush, a series that profiles native plants: part gardening column, part dispatches from country, entirely Australian.The Conversation

Stuart Worboys, Laboratory and Technical Support Officer, Australian Tropical Herbarium, James Cook University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

With the right help, bears can recover from the torture of bile farming


Edward Narayan, Western Sydney University

Bear bile farms, which exist in some Asian countries like Vietnam and China, are a terrible reality for Asiatic black bears (Ursus thibetanus).

The bears spend their lives confined in tiny steel or concrete cages. They are “milked” through permanent holes in their side that allow bile to be extracted from the gall bladder.

My research, published in the journal Animal Welfare, investigated the chronic stress created by these conditions. We found that with care and rehabilitation, rescued bears in animal sanctuaries can readjust to a normal lifestyle with a reduction in stress – a highly encouraging result.




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What’s so precious about bile?

Bile is a greenish-brown fluid produced by the liver in humans and most vertebrates. Bile acid aids digestion of fats – and one particular bile compound, called ursodeoxycholic acid, could have potential pharmaceutical applications.

Because of this, bear bile is highly sought in traditional Chinese medicine. It is believed to reduce gall stones and improve indigestion, among other things. However, non-animal-derived and synthetic alternatives exist for urosodeoxycholic acid and other bile components.

The use of Asiatic black bears as primary sources of bile is a significant animal welfare problem that needs global awareness. Most of the bears are introduced to the trade upon poaching from the wild, and cubs as young as a few months are caged and held captive for up to 30 years.

I worked with the international welfare organisation AnimalsAsia, which runs rescue and rehabilitation programs in Asia and has moved hundreds of bears into sanctuaries.

My research investigated how successful this rehabilitation is, and whether rescued bears can recover from their experiences.

Animal cruelty causes chronic stress

Stress is defined as any unpleasant physical or psychological change that creates an uncomfortable feeling and negative outcome.

Not surprisingly, bears at bile farms in Vietnam have significantly higher levels of stress hormones than bears living in sanctuaries. This is the first scientific evidence of the chronic stress created by bear bile farming.

Stress in vertebrates (like humans and bears) is a physiological response in the endocrine system, also known as the hypothalamus-pituitary adrenal axis. This is the body’s main control centre for all things related to stress.

Stress hormones like cortisol help regulate the metabolism, especially in times of short-term or acute stress such as “fight or flight” situations. In normal situations, sharp stress causes an increase of cortisol that allows an animal to react quickly to a dangerous situation. Once the danger passes, a negative feedback loop reduces cortisol production and keeps the body stable.




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But chronic stress can lead to harmful changes in the stress endocrine system. Long-term cortisol overproduction weakens the body’s ability to fend off daily challenges, and increases the risk of disease and death. In humans, chronic stress contributes to problems with the cardiovascular, immune and central nervous systems.

The presence of what we call “stress biomarkers” in faeces or hair can be a very useful tool for assessing animal welfare.

We measured cortisol levels in bear faeces to rapidly and reliably check their stress levels.

This was particularly useful because we did not have to restrain the rescued bears, a process that would understandably upset them more than their peers.

Reversing chronic stress in bear sanctuaries

Chronic stress is a massive challenge for the successful rehabilitation of animals into their new environment. Careful monitoring of stress is essential in animal rescue and translocation programs because it can provide information on the physiological resilience of each animal, and help rescuers understand how the animals might respond to humane interventions and veterinary checks.

Rescued bears are given special veterinary care and integrated into the bear sanctuary after several months of careful physiological and behavioural assessments.

Our data show that although not all bears fully recover from living on a bile farm, they generally manage to reduce their stress hormone levels under the rehabilitation program.




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Like humans, animals need love and care. Stress reseach has shown humane treatment can reverse chronic stress – and our study has found that is true even for animals who have experienced intolerable treatment.The Conversation

Edward Narayan, Senior Lecturer in Animal Science; Stress and Animal Welfare Biologist, Western Sydney University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Farmers’ climate denial begins to wane as reality bites


Sarah Ann Wheeler, University of Adelaide and Céline Nauges, Inra

Australia has been described as the “front line of the battle for climate change adaptation”, and our farmers are the ones who have to lead the charge. Farmers will have to cope, among other pressures, with longer droughts, more erratic rainfall, higher temperatures, and changes to the timing of seasons.

Yet, puzzlingly enough to many commentators, climate denial has been widespread among farmers and in the ranks of the National Party, which purports to represent their interests.




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Back in 2008, only one-third of farmers accepted the science of climate change. Our 2010-11 survey of 946 irrigators in the southern Murray-Darling Basin (published in 2013) found similar results: 32% accepted that climate change posed a risk to their region; half disagreed; and 18% did not know.

These numbers have consistently trailed behind the wider public, a clear majority of whom have consistently accepted the science. More Australians in 2018 accepted the reality of climate change than at almost any time, with 76% accepting climate change is occurring, 11% not believing in it and 13% being unsure.

Yet there are signs we may be on the brink of a wholesale shift in farmers’ attitudes towards climate change. For example, we have seen the creation of Young Carbon Farmers, Farmers for Climate Action, the first ever rally on climate change by farmers in Canberra, and national adverts by farmers on the need for climate action. Since 2016 the National Farmers Federation has strengthened its calls for action to reduce greenhouse emissions.

Our latest preliminary research results have also revealed evidence of this change. We surveyed 1,000 irrigators in 2015-16 in the southern Murray-Darling Basin, and found attitudes have shifted significantly since the 2010 survey.

Now, 43% of farmers accept climate change poses a risk to their region, compared with just 32% five years earlier. Those not accepting correspondingly fell to 36%, while the percentage who did not know slightly increased to 21%.

Why would farmers deny the science?

There are many factors that influence a person’s denial of climate change, with gender, race, education and age all playing a part. While this partly explains the attitudes that persist among farmers (who tend to be predominantly male, older, Caucasian, and have less formal education), it is not the full story.

The very fact that farmers are on the front line of climate change also drives their climate change denial. For a farmer, accepting the science means facing up to the prospect of a harsher, more uncertain future.

Yet as these changes move from future prospect to current reality, they can also have a galvanising effect. Our survey results suggest farmers who have seen their farm’s productivity decrease over time are more likely to accept the science of climate change.

Many farmers who have turned to regenerative, organic or biodynamic agriculture talk about the change of mindset they went through as they realised they could no longer manage a drying landscape without major changes to their farming practices.




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In addition, we have found another characteristic that is associated with climate change denial is whether farmers have identified a successor for their farm. Many farmers desire to turn their farm over to the next generation, hopefully in a better state than how they received the farm. This is where the psychological aspect of increased future uncertainty plays an important role – farmers don’t want to believe their children will face a worse future on the farm.

We all want our children to have better lives than our own, and for farmers in particular, accepting climate change makes that very challenging. But it can also prompt stronger advocacy for doing something about it before it’s too late.

What can we do?

Whether farmers do or do not accept climate change, they all have to deal with the uncertainty of weather – and indeed they have been doing so for a very long time. The question is, can we help them to do it better? Given the term “climate change” can be polarising, explicit climate information campaigns will not necessarily deliver the desired results.




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What farmers need are policies to help them manage risk and improve their decision-making. This can be done by focusing on how adaptation to weather variability can increase profitability and strengthen the farm’s long-term viability.

Farming policy should be more strategic and forward-thinking; subsidies should be removed for unsustainable practices; and farmers should be rewarded for good land management – both before and during droughts. The quest remains to minimise the pain suffered by all in times of drought.The Conversation

Sarah Ann Wheeler, Professor in Water Economics, University of Adelaide and Céline Nauges, Research Director, Inra

This article is republished from The Conversation under a Creative Commons license. Read the original article.