Category: rare plants

‘Tis the season…or is it?

Posted on by andy.winfield

By Helen Roberts

As I sit at my desk this morning, staring out the window, the weather is dire. There is slanting torrential rain and high winds, a typical December day perhaps.
Here in the UK, the seasons are changing and we are experiencing extremes of weather. For example, we have had wetter, milder winters in the southwest over the last couple of years along with increased flooding, particularly on the Somerset Levels. And then there was the very slow start to spring this year, with temperatures well below average in April. This was followed by a very hot end to the summer and warmer-than-average temperatures throughout autumn.
These changes to the seasons are linked to global climate change and are throwing the UK’s wildlife into disorder and affecting the fine balance of habitats and ecosystems. This is not a good scenario for biodiversity in the UK. Seasonal timing is off. When seasons start and end is shifting, and the length of the season itself is changing, making ‘growing seasons’ a more fluid concept. There is also increased risk for most gardeners of a ‘false spring’. Many plants and animals are changing their geographical ranges in order to adapt to these changes.
One of the most significant effects has been the disruption of lifecycle events and these are manifesting themselves in different ways. Bird migration, insect emergence, incidence of pests and diseases and flowering times are being thrown out of kilter.  
Researchers from the University of East Anglia recently analysed 37 years worth of data from the UK Butterfly MonitoringScheme (UKBMS) and found that extreme weather events were causing population crashes of butterflies. Uncommonly high rainfall events during the cocoon life stage affected 25% of UK butterfly species. And more than half of species were affected by extreme-heat during the overwintering life stage, possibly due to the increased incidence of disease or the effect of a ‘false spring’, causing butterflies to emerge too early only to be decimated by a return to cooler temperatures.
Warm temperatures are not all bad for butterflies though, as they will benefit from hot temperatures over the summer months when they are in their adult form and resources are plentiful. However, if populations crash more frequently than they expand, these extreme weather events could threaten UK butterflies.
The spider orchid (Ophrys sphegodes).
Photo: Jacinta Iluch Valero via Flickr [Creative Commons]

Changes in seasonal timing are also knocking the relationships between plants and animals out of sync, including the delicate balance between plants and pollinators. Thiscan be detrimental to the balance of entire ecosystems. An elegant study carried out by scientists from Kew and the University of East Anglia found that earlier springs brought about by rising temperatures are affecting the relationship between a rare spider orchid (Ophrys sphegodes) and its sole pollinator, the solitary miner bee (Andrena nigroaenea).   

This particular orchid has a flower that resembles and smells like a female miner bee and it uses this deceit in order to lure the male miner bee in. The male attempts to mate with the flower and by doing so, pollinates the flower. The plant has evolved to flower at the same time as the male bees emerge, but before the females do.
What the researchers discovered, by looking at the data set going back to 1848, was that rising temperatures are causing the relationship between orchid and bee to break down. Although rising temperatures cause both the bee to emerge and the orchid to flower earlier, the effect on the bees is much more pronounced. The male bees emerge much earlier and the orchids now flower as the female bees emerge. This means the males are not “pseudocopulating” with the flower because the real thing is already available and so the rare spider orchid is having fewer pollinations.
However bleak this picture may seem, plants and animals do have the ability to adjust to seasonal changes caused by climate change, it is just whether they can adapt quickly enough for these intricate ecological relationships to remain intact.
Helen Roberts is a trained landscape architect with a background in plant sciences. She is a probationary member of the Garden Media Guild and a regular contributor to the University of Bristol Botanic Garden blog.


References

Plants and war

Posted on by andy.winfield

By Helen Roberts

For centuries plants have been closely entangled in the complexities of wars and hostilities. Shortages of food during periods of conflict are one of the most pronounced impacts on humans. Conflict can impede our ability to grow and harvest crops as well as distribute food. Restricting the movement of food is a tactic that is used to control territories and ultimately bring down enemies. 
In the 1990s, in sub-Saharan Africa, many countries suffered famine as a result of conflict and this was primarily due to the different sides using food and hunger as political tools. As well as immediate famine in those areas of active war, there were indirect impacts as people were displaced by war and could not return home to plant their crops. Even more recent examples include the siege warfare occurring in many parts of Syria where the act of starvation is used to make opposing sides submit. The devastation and suffering as a result of food shortages to humans is untold during conflict, but the ultimate survival of certain plants can be threatened too.  

Saving seeds in Svalbard

Svalbard Global Seed Vault, Norway.
Photo credit: Amber Case [via Flickr CC licence]

Seed banks – facilities that specialise in collecting and storing seeds that society has deemed worthy of cultivation – are critical in preserving and potentially restoring the plants lost as a result of war. In 2015, researchers made the first ever withdrawal of 38,000 seed samples from such a bank in order to rebuild a seed collection to replace one lost to the conflict in Syria. 

In 2012, when war reached Aleppo, Syria, researchers from the International Center for Agriculture Research in the Dry Areas (ICARDA) shipped seeds representing 87% of their collection to the Svalbard Global Seed Vault in Norway (a subsequent blog will follow on this unique seed bank facility). The remaining seed was shipped out to other international seed banks. The ICARDA facility in Aleppo hosted seed from 150,000 specimens of significant agricultural importance from the Fertile Crescent – the birthplace of agriculture. Many of the plant varieties do not exist in the wild any more, including unique landraces and wild relatives of cereals, legumes and forages and are only represented in seed banks. 
Having fled Aleppo, ICARDA researchers, now in Terbol, Lebanon, have withdrawn some of this seed from Svalbard in order to recreate the collection lost in the war torn city of Aleppo. Seed was also sent to another ICARDA facility in Morocco. The seeds will be planted and allowed to germinate, grown up and seed collected and sent back to Svalbard to continue the loop of important seed conversation and diversity. At the facilities in Lebanon and Morocco, agricultural research will continue on the seed samples with germplasm being distributed worldwide to plant breeders. 

Russian scientists protect seeds with their lives

It is not the first time that scientists have battled for seed survival. Russian scientists during the Second World War were so desperate in their unerring determination to protect an internationally important seed bank from devastation that lives were lost. The man in charge of the collection was Nikolai Vavilov, a Soviet botanist and geneticist most famous for his work on the evolution of domesticated plants. As a child, he had witnessed first hand the horror of food shortages and this spurred him on to a follow a career in the plant sciences concentrating on plant breeding in order to help combat famine in Russia. He has long been considered the founder of modern seed banks. 
Unfortunately, Stalin who foolishly sought short-term solutions to Russia’s problem of famine, did not support his work. Vavilov fell from favour and whilst on a plant collecting expedition in the Carpathian Mountains was taken and incarcerated, slowly dying in prison of starvation in 1943. Vavilov’s vast seed bank survived the 872-day Siege of Leningrad. Dedicated scientists bent on protecting this valuable collection, barricaded themselves into the seed bank building and guarded it against looting. Sadly, they succumbed to either starvation or disease. This was an ironic tragedy considering they refused to eat any of the seed they were so intent on protecting. 

Plant-based resources in short supply

Not only does conflict cause basic food shortages and threaten plant species survival but it can affect the availability of important plant-based resources. Commodities such as rubber, coal, paper, timber, drugs, cotton and hemp, all derived from plants, have played a key part in conflicts. Of course, control of these critical resources has also propelled countries into war, including tea, spices, salt, grain, flour, bread, sugar and rice. 
One of the many ‘Dig for Victory’ posters
of the Second World War.

War also pushes the agricultural and manufacturing boundaries in the production of food and plant materials. One major commodity during the Second World War of vital importance was rubber. Natural rubber supplies from the plantations of Southeast Asia were severed at the start of the war and American forces were faced with the loss of a hugely important resource even though rubber had been stockpiled in the years preceding the war. With the fall of Singapore and the Dutch East Indies in 1942, rubber exports came to a complete standstill. The Americans invested heavily into developing synthetic rubber, but one of the twentieth century’s greatest ethnobotanists, Professor Richard Evans Schultes, was sent into the remote Amazon basin to hunt for wild rubber. For Schultes, this resulted in 12 years of exploratory research deep within the rainforest. 

People in Britain were growing their own to combat food shortages during the Second World War – spurred by iconic posters emblazoned with the words ‘Dig for Victory’. A staggering 1.4 million people dug up their gardens and lawns to grow vegetables and fruit in Britain. It was similarly successful in the US – by May 1943, 100 acres of land in the Portland area of Oregon was being cultivated by just children!

Plants used to commemorate lives lost

During and after conflict, many plants can hold particular meanings for people. The flowers of certain plants are commonly seen as peaceful elements imbuing a sense of calm and many plants are closely associated with the recognition and commemoration of those who have fallen in wars. The red poppy is one of the most emotive and unforgettable flowers because of war. A symbol of remembrance and hope, and worn by millions of people to remember those who have fallen in battle. The idea of using the poppies stemmed from one of the world’s truly poignant poems, ‘In Flanders Fields’ and is now inextricably entwined with the memory or war. It represents a powerful symbol of our relationship with a plant during and after conflict.

Helen Roberts is a trained landscape architect with a background in plant sciences. She is a probationary member of the Garden Media Guild and a regular contributor to the University of Bristol Botanic Garden blog.

Sources:

  1. Seed bank aims to protect world’s agricultural inheritance from Syria war. (2016). The Guardian. <http://www.theguardian.com/world/2016/feb/24/seed-bank-aims-to-protect-worlds-agricultural-inheritance-from-syria-war>
  2. ICARDA’s update on its seed retrival from Svalbard <http://www.icarda.org/update/icarda’s-seed-retrieval-mission-svalbard-seed-vault#sthash.5nrDjLb8.dpbs>
  3. Richard D. Bardgett. (2016). Earth Matters: How Soil Underlies Civilization.  Oxford: Oxford University Press.
  4. Wade Davis. (1996). One River: Science, Adventure and Hallucinogenics in the Amazon Basin. London: Simon & Schuster Ltd. 
  5. Kathy Willis & Carolyn Fry. (2014). Plants: From Roots to Riches. London: John Murray. 

Undergraduates get their first glimpse at the garden

Posted on by andy.winfield

By Alida Robey

I’ve been promising myself a visit to the University of Bristol Botanic Garden since I arrived in Bristol four years ago. Life has intervened. Yet when the opportunity came to join the new intake of students from the University on their first practical of their 3 year undergraduate degree, I leapt at the chance. 
Once there, the thrill of the plants, garden, stories and mysteries within, were hard to resist!  I joined the briefing given by the Garden’s curator, Nick Wray, as he introduced the day’s second group of 70 students (over 250 students attended the practical over two days) to their PhD student demonstrators – there to inspire the undergraduates about different aspects of the gardens.  

An introduction to the day

These biology and zoology students were visiting the garden as part of their ‘Diversity of Life’ module – taking a first-hand look at some of the adaptations that have enabled plants to diversify into the more than 400,000 species that exist today. Beyond this, however, the practical offers an opportunity for the students to get to know each other and learn to work collaboratively, gain confidence in sharing knowledge,  as well as orientate themselves to this incredible resource available to them.
Nick and the demonstrators were up against time and the logistics of manoeuvring 70 students around 6 ‘work stations’. Students were split into manageable groups and two volunteer guides were brought in to assist moving the groups swiftly through the rotation of topics presented around the garden.
Off we went. As a newcomer myself, I shared the sense of wonderment and awe one student expressed as she exclaimed at how much more there was at the Garden than she had expected. She pointed out how interestingly organised the gardens were, which effectively revealed the story of plant evolution – a set-up that Nick had explained was unique to the University of Bristol Botanic Garden.

Into the glasshouses for plants that eat and are eaten

I followed a group into the glasshouses where Edith showed us the adaptations plants have evolved to cope with extreme habitats. Plants from very different families share common features that are adaptive in similar conditions. Euphorbia, for example, which grows in the deserts of Africa is so similar to the form of cacti found in the deserts of America that they are often misidentified – this is an example of convergent evolution.
The striking Haemanthus coccineus – a native of South Africa -flowers and then sets seed in autumn to coincide with the first rains, giving the seedlings a full rainy season to develop. The leaves appear well after the flowers to reduce the amount of moisture lost prior to the rains. Edith pointed out carnivorous plants that have adapted to nutrient poor habitats. She showed us a plant that produces citronella to deter insects and a species that looked half eaten to make it less attractive to herbivores.
The group was then passed along to Nick who ushered us into the tropical greenhouse to reveal further wonders, such as the orchids of Mexico that require pollination by moths to produce vanilla pods. When commercially produced in the Comoros Islands, pollination is done by hand for every flower – a task often given to children in this struggling economy. We saw the giant lily pads of Victoria cruziana. Reminiscent of triffids, Nick pointed out that in summer they have to be cut back every three days to prevent them growing out of the pond.
Nick Wray shows the students the largest seed in the world.
Photo credit: Nicola Temple

Hmmm… time to escape back into the fresh air where things were growing at a more manageable pace for me, but Nick continued to show the group other commercially important plants, such as lotus, bananas and cotton. He held up a specimen of the world’s largest seed – that of the sea coconut or coco de mer (Lodoicea maldivica), which can weigh up to 30 kg.

The students were then taken into an area of the glasshouses that’s not open to the public and shown some very rare and unique plants, including Amborella trichopoda, which is of particular interest because molecular analyses suggest this is one of the earliest flowering plants. It is the last remaining species of a group that first appeared on Earth more than 140 million years ago, when dinosaurs still dominated the animal kingdom.  A sprawling shrub native to New Caledonia, Amborelladoesn’t cope with changes in humidity very well, so it is kept behind plastic to control the humidity.
Some students scribbled madly, while others just chose to listen as Nick enthusiastically explained what a unique experience this is for University of Bristol students.  ‘Until last year, Bristol was the only botanic garden in the UK growing this plant,’ said Nick. (The University of Cambridge has recently acquired one.)

New Zealand garden – survival of the species

In the New Zealand garden, Dave showed the radical ways plants survive difficult conditions; in this case, the attentions of the now extinct Moa bird. This was graphically illustrated by Pseudopanax, which starts off its first 10 years or so as a sapling with hard, spiky, downward facing sword-like leaves. Once considerably taller – namely beyond the reach of 3m tall Moas – the trees don’t invest as much energy into being unpalatable and transform into an unrecognisably different form, with soft and safely inaccessible leaves reaching to the light.

Angiosperm phylogeny explained

A group gathers around the pond to learn about angiosperm
phylogeny. Photo credit: Nicola Temple

I moved on to hear about angiosperm phylogeny; a new term for me, but more exciting and less daunting than it sounds. In the past, plants were classified into family groupings based on their physical characteristics. With the advent of DNA sequencing in the last 20 years, we can use genetic relatedness to help us understand how plants have evolved. James, our demonstrator, pointed out some of the oldest species of flowering plants, including star anise (Illicium verum). This area of the garden is organised into the two major groups of flowering plants monocotyledons (seed has single embryonic leaf) and dicotyledons (seed with two embryonic leaves). The monocots include plants such as orchids and grasses, including agriculturally important species such as rice, wheat, barley and sugar cane. The more familiar garden plants, shrubs and trees, and broad-leafed flowering plants such as magnolias, roses, geraniums, and hollyhocks are dicots.

Learning in the garden beats a textbook any day

Speaking with the students, they said they enjoyed being able to touch and feel the actual plants, make comparisons and learn within this physical context. They could see as James explained how even though Protea, lotus, Banksia and London plane tree (Platanus x acerifolia) looked very different, their DNA suggests they are more closely related than they appear. Genetic relatedness is traditionally illustrated using a cladogram – a branching tree with scientific names at the end of the branches, with no sense of what these species look like. What an opportunity to see what the diversity at the end of those branches can look like!
Students use pens to see how flowers are
adapted to distribute pollen on the
pollinators that visit them.
Photo credit: Nicola Temple

My time ran out before I could get as far as the sessions on pollination and plant evolution!  With my head spinning from this intensive and whistle-stop tour of some of the delights and extraordinary features of this garden, I sat on a bench in the autumn sunlight to reflect on the afternoon with fellow blogger, Nicola Temple, who had invited me take part in this day.

Like many of the students I spoke with as we went from location to location, I was delighted to have had the opportunity to understand the great thought behind the layout of the gardens.  There was far and away more here than I had bargained on.  I wanted to keep going but knew I could only take in so much on my first visit.  As we had gone around I had been surprised as an observer to note how quiet the students were, very few asking any questions.  Having stood back from it though I wonder if, like me, they were overwhelmed by the hidden depths to this exceptional garden. I’m certainly going to seek every opportunity to spend more time here, whether learning or simply enjoying the peaceful and stunning surroundings.
And I daresay I will come across many of the students from this day, pursuing their studies and enjoying the sheer delight and boundless wonderment that nature continues to shower upon us and that this garden so beautifully illustrates.

A day in the life of a WRAGS trainee…

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Matt Croucher, a Work and Retrain as a Gardener Scheme (WRAGS) trainee, talks to Helen Roberts about working at the University of Bristol Botanic Garden, what first got him interested in botany and his aspirations within the horticultural profession.

I met up with Matt mid morning in the potting up area of the Garden. He was delicately placing seed into pots to supplement what is already planted in the ballast seed garden, an area for which he has sole responsibility. As he carried on with the task at hand, I asked him what first drew him to study horticulture, having previously come from a background in website design.

“My girlfriend and I had moved house and decided to get an allotment. Plants became important to me when I first started working on our own allotment and my interest in horticulture just emerged from that. However, even as a child I always had a small piece of the garden to grow something; I think an interest was probably always there.”

Matt started volunteering at the beautiful 10 acre gardens at Goldney Hall in Clifton, owned by the University of Bristol, and from there secured a WRAGS traineeship at the Botanic Garden. WRAGS provides hands-on practical training in horticulture, with the trainee working under the guidance of staff at a host location. WRAGS trainees do not receive funding from the scheme itself; rather, the scheme acts as an organizer and coordinator, helping to find trainees suitable host placements. Matt is funded by Perennial, a charity organisation that helps to support people in horticulture. He has also gained experience at a number of larger estates, including the National Trust property of Tyntesfield.

Matt started his traineeship with the University of Bristol Botanic Garden in August 2014, and will work two days a week there for a year. When he’s not at the Botanic Garden, he is working for a local landscape firm and studying for the RHS Level II course at the Garden.

As we take a walk through the gardens I ask Matt about a typical day’s work and what it involves.

“A typical day at the Botanic Garden is never really the same. One of the first things I do when I arrive is water the tropical houses. After that, I could be working on a range of different tasks. For instance, last week I was helping to re-pot the water lilies in the main pond and apply a solution containing nematode worms to control vine weevils to different plants. No one day is the same and that makes the work really interesting.”

He also had the chance to go further afield with work when he took a trip down to Chelsea Physic Garden with fellow trainee, Zoe Parfitt, and curator Nick Wray to collect eight specimens of Welwitschia mirablis, a rare ancient cone-bearing plant from the Namib coastal desert.

Matt holding the Welwitschia mirablis.

Matt showed me the Welwitschia mirablis potted up very neatly and snugly sitting in a specially constructed heated planter. They are indeed very weird looking plants and although I thought they looked small and were therefore probably not that old, they are already 25 years old. Matt was obviously really pleased to be involved in the collecting and potting up of these plants, which are a valuable addition to the plant collection.

“It was amazing to go to the Chelsea Physic garden and have the chance to help out with the Welwitschia. Nick Wray said to me that I would probably only get the opportunity once in a lifetime to pot up something that is so unique.”

Matt’s deep-rooted (excuse the pun) fascination with horticulture was evident as we talked about the plants whilst strolling through the different areas of the gardens. He relishes the time he spends on his own allotment and is now successfully growing and selling plants from his plot to friends and clients. He is also an avid collector of interesting plants, taking cuttings whenever and wherever he can; his home is crammed full of greenery. Towards the end of the tour, Matt sums up his training at the Botanic Garden and tells me of his plans for his horticultural career.

“The experience I have gained at the Botanic Garden has been invaluable and has enabled me to secure work at large estates, such as Tyntesfield. Ultimately, I would love to secure a full time position at a botanic garden.”

WRAGS was launched in 1993 and was originally intended for women returning to work after starting a family. Though the scheme is still administered through the Women’s Farm & Garden Association, it is no longer just for women. Matt is among an increasing number of men applying for the scheme – many of which are career changers. To learn more about the scheme, visit wfga.org.uk.

Local limestone quarry receives a special collection of plants from the University of Bristol Botanic Garden

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By Helen Roberts


It’s a bitterly cold February morning and I’ve driven to the outskirts of the small village of Wick in South Gloucestershire to meet with Roland de Hauke. Roland is going to give me a tour of Wick Quarry and the local nature reserve. It is extremely claggy underfoot and parts of the road are submerged underwater, so I am extremely relieved when Roland shows me to his 4 x 4 vehicle in order to tour the vast 100-acre site.
First view of Wick Quarry. Credit: Helen Roberts.

Roland, a passionate botanist and conservationist, bought the quarry and nature reserve two years ago with the aim of restoring it with a mosaic of habitats to maximise biodiversity.
“I have always been interested in botany and conservation and I am fascinated by trees,” remarks Roland, “and I am particularly keen to introduce species of local provenance. In the past, a lot of quarry restoration has involved a broad-brush approach, with a view that what works well on one particular site will work for other sites too. This just simply isn’t the case and I want to change that perception.”
The quarry’s situation is extremely impressive with sheer rocky cliffs of loose exposed limestone and a huge quarry lake approximately 60 metres deep. It borders with the Wick Golden Valley Local Nature Reserve (also owned by Roland), which has locally important plants, including Viper’s Bugloss and Spleenwort, and wildlife, including a dozen or so different species of bats.  The reserve’s interesting geology has also earned it the designation of Regionally ImportantGeological and Geomorphological Site – with its excellent examples of stratification. The reserve is also part of a larger Site of Nature Conservation Interest called the ‘Wick Rocks and River Boyd’.
A second quarry lake where it is hoped floating reed beds 
will be established. Credit: Helen Roberts.

I was impressed by the quarry and as a landscape architect this was probably one of the most interesting sites I’d visited in terms of visual impact and biodiversity potential. I could imagine the site in 25 to 50 years time as a vital stepping-stone for local habitats as our landscape becomes further fragmented by development.

Propagating rare and endemic species

Within the University of Bristol Botanic Garden’s local plant collection are some special trees within the Sorbus genus, which are more commonly known as whitebeams, rowans and wild service trees. Two species, Bristol whitebeam (Sorbus bristoliensis) and Wilmott’s whitebeam (Sorbus wilmottiana), grow only in the region of the Avon Gorge.
The location of some of the plants donated by the
University of Bristol Botanic Garden. Credit: Helen Roberts.

The Garden maintains these rare endemic species within its collection as part of the ‘Global Strategy for Plant Conservation’. Threatened plant species are kept in ex situcollections so that they are available for recovery and restoration programmes.

The Botanic Garden has donated a number of Sorbus species to Roland in the hope that they may get established within his quarry and become a self supporting population, including S. aria, S. bristoliensis, S. eminens, S. anglica, and S. porrigentiformis. Both the Director of the Garden, Professor Simon Hiscock, and the Curator, Nick Wray, have given Roland advice on planting and species introduction. The donated plants were all propagated from wild plants in the Avon Gorge and Leigh Woods between 1996 and 1997 by the Garden staff.
“Actually, planting the donated plants has been an interesting and exciting task as accessibility is an issue and the rock faces are fairly steep and loose in places”, explains Roland.
Creating wetlands
The lake itself is problematic because its steep sides do not lend themselves to wetland creation; this is where Roland is concentrating his efforts over the next 5 years or so. He will make shallower shelved areas into the water with the idea of creating floating reed bed habitats, which will be planted in the spring. These reed bed habitats can support invertebrates and fish, which are food resources that will attract wetland birds.
Sheer quarry sides descend into the lake.
Credit: Helen Roberts.

“At the moment we are not seeing a lot of wetland birds using the quarry lakes for any long periods of time as there just isn’t the food available for them”, explains Roland. “After about a day or two, the water birds simply move on to find a better food resource and that’s where reed beds will provide a suitable habitat for [them] to stay for longer.”

The future of the quarry
Roland is also looking to develop huge areas of species-rich grassland and is seeking advice on species that will attract a diversity of invertebrates.
The site will likely be closed to the general public in order to reduce the disturbance by humans.  However, it will be open to specialist interest groups, including local schools, to help educate local communities about the importance of rare local species, illustrate effective quarry restoration and allow the long term monitoring and management of the site.
“This is a long term project that I’m really excited about and at public consultation meetings most people there have been genuinely excited about it too,” commented Roland. “I am very grateful to the University of Bristol Botanic Garden for the donated plants and look forward to working with them in future.”