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Tuesday, 17 March 2015

The Friends of the University of Bristol Botanic Garden celebrate their 40th anniversary

By Helen Roberts


It can be a little difficult to pin down one of the Friends of the University of Bristol Botanic Garden for an interview these days. Between organising the extremely popular Art and Sculpture Festival, planning for 40th anniversary celebrations - which includes a concert this coming Saturday (21st March) - and their own busy lives, the Friends are hard at work. I spoke to Pat Davie, the Chairman of the Friends, about how the Friends began, their role over the years and what they hope to achieve in future.

Pat joined the Friends group in 1995 after she attended some courses on Garden History at the Botanic Garden; it was then that she learnt about being a volunteer. Since then, she has taken on a number of roles and very much enjoyed being part of the working life of the Garden.

“I am extremely busy volunteering doing various jobs but I wouldn’t have it any other way, the Gardens are a very special place.”

The Friends are an essential part of the Botanic Garden with 1,900 members and over 200 of these members actively volunteering in the garden. They provide valuable resources for the gardens in many different guises, be it the organisation of events and activities to providing funding for trainee horticulturists.

How did the Friends start?

The Association of Friends of the University of Bristol Botanic Garden formed in 1975 when the Botanic Gardens were threatened with closure due to a financial crisis at the University of Bristol. The Friends needed to raise the profile of the garden and persuade academics, administrators and the community at large of the importance of the gardens as a teaching and research resource. Peter Haggett, Emeritus Professor in Urban and Regional Geography at the University of Bristol, was one of the founding members; “Our primary purpose was to get the University to change its mind and retain Bracken Hill”, which was the Botanic Garden site at that time. “The formation of an organisation of ‘Friends of the Botanic Garden’ was a key tactic in that strategy,” explained Peter.

As well as Peter, the original committee included the curator of the garden at the time, Dr David Gledhill (Botany), Keeper of the Garden, Dr Mark Smith, and local campaigner Mrs Anne Hewer (daughter of Hiatt Cowles Baker, a former Pro-Chancellor of the University).

The inaugural meeting was held on 8 December 1975, where the draft constitution was accepted. The aims of the group were to:

promote interest in botany and horticulture,
provide a meeting ground for persons with these interests,
give members opportunities to see and cultivate scarce and unusual plants, and
further the development of the amenities and educational services of the Botanic Garden.

A photo from a 1976 edition of the Bristol Evening Post,
showing Mark Smith in the Botanic Gardens.
The annual fee to be a Friend then was £3 (it’s now £25 for an individual or £35 for a family, which is still good value for money). Membership included free access to the gardens at weekends and public holidays, a number of rooted plants and seed packets, lectures and social events.

Initially, 200 people joined and membership has gradually increased over the years to 1,900. Now, to celebrate 40 years of supporting the garden, the Friends would like to see that membership break 2,000 for 2015.

One of the popular events in the early days of the Association of Friends, was the plant sales started by Dr Mark Smith and from 1984 developed further by Nicholas Wray. According to Pat, the sales were, “extremely popular and queues started early and were very long”. The sale became an important source of income, but with the decision to move the garden the last of the major plant sales happened in
A photo from the sponsored walk from
Bracken Hill, across Clifton Suspension
Bridge, to The Holmes.
2001, after which all efforts were put into preparations for the garden’s move to The Holmes allowing Bracken Hill, to be sold for redevelopment.

The move from Bracken Hill to the Holmes was a huge undertaking and one memorable aspect of the move involved a sponsored walk from Bracken Hill to The Holmes in May 2005 across the suspension bridge with wheelbarrows full of plants! This was to raise the profile of the Botanic Gardens and help raise funds for the move.

The Friends in more recent years

The basic costs of the design and development of the new garden (now in its 10th year) were covered by the University, but many other projects over the years have been funded by the Friends. These include the Welcome Lodge, which was part funded by a long standing member, the replacement of tree ferns in the evolutionary dell when the originals died during a particularly hard winter, purchase of new plants for various displays in the garden and development of the tropical pool in the glasshouses.

One of the most recent appeals has been raising funds for hosting a horticultural trainee full time at the Botanic Garden. The Friends achieved the remarkable feat of raising over £10,000 to fully fund a trainee for a year, thereby supporting and inspiring the next generation of horticulturists. Some of the fundraising events over the last year include an exhibition of botanic art, the Blue Notes Jazz concert and the Friends’ open gardens scheme.
"Without the consistent financial support and direct help by many individual Friends, the Botanic Garden would have simply not survived. Instead in the early years it did survive and as the years passed by and support gathered the garden has seen many investments in both people and plants. The huge task of moving the plant collections and developing the new Botanic Garden has been an immense challenge with the resources and pairs of hands available. The Friends’ financial and physical support has helped the new garden to establish so that those that use it can be enthused, inspired and excited about plants and the many roles they play in maintaining healthy ecosystems. Our students have one of the most modern and relevant Botanic Gardens in the UK to inspire them in their studies. The Friends have helped make this possible."  - Nick Wray, Curator

What are the benefits of becoming a Friend?

For starters, you receive free entry to the gardens! Other benefits include free horticultural lectures, special seed packets from the garden that are not available to the public, visits to private gardens of Friends, excursions to other interesting gardens, early booking and reduced cost entry to events, and a quarterly newsletter.

The newsletter, put together by volunteers, contains useful information with pieces written by the Director and Curator of the Gardens, and to further bolster links with the University, there are articles written by members of the School of Biological Sciences. Froggie also has a repeating section in the newsletter that includes fantastic educational activities for children.

A concert to start celebrating the 40th Anniversary

The Friends of the BBG are holding a celebratory concert with the Bristol University Singers and the Bristol University Madrigal Choir at 2:30pm on Saturday 21st March. The event will be held in the Victoria rooms, Queens Road, Bristol and promises to be a relaxing afternoon of music that includes popular opera choruses and summer madrigals. A team over the winter has been working tirelessly and collated 40 years worth of photographs, papers, committee meeting notes, newsletters and extracts of memorable moments, some of which will be on display at the concert and at other celebratory events throughout the year.

For more information about the concert please visit bristol.ac.uk/botanic-garden/events/2015/179.html

For Friends general information please visit bristol.ac.uk/botanic-garden/support/friends/


Friday, 6 March 2015

Plants more resilient than animals through mass extinctions

By Nicola Temple


The fossil record suggests that a diversity of land plants had evolved by about 472 million years ago (mya). There is evidence to suggest that plants made the move onto land as much as 700 mya [1], placing them in the midst of the five largest extinction events to have shaped life on our planet.

Researchers from the University of Gothenburg released a study earlier this year showing that plants have generally been more resilient to these extinction events than animals. They looked at more than 20,000 plant fossils to see how these mass extinction events affected plant diversity [2].

Ferns and horsetails dominated the
landscape by the end of the Devonian.
Credit: Nicola Temple
They found, not unexpectedly, that each group of plants fared differently through each extinction event – with some doing better than others. Though plants might experience mass extinctions, the researchers concluded that plants also began to diversify again quickly after such events, so that more new species were being generated than were being lost.

"In the plant kingdom, mass extinction events can be seen as opportunities for turnover leading to renewed biodiversity," said leading author Daniele Silvestro.

The big five

Scientists have identified five mass extinction events since land plants have evolved.

Ordovician – Silurian mass extinction (approximately 443 mya): This event wiped out approximately 85% of sea-dwelling creatures, such as trilobites. It has been hypothesised that a huge ice sheet in the southern hemisphere led to the alteration of climate patterns, a drop in the sea-level and a change in ocean chemistry.

Late Devonian (approximately 359 mya): This event is likely a series of smaller extinction events that happened over several million years, but the end result was a loss of 75% of all species on Earth. Changes in sea level, multiple asteroid impacts and new plants that were changing the soil chemistry have all been attributed to this period of extinction.

Permian (approximately 248 mya): It is estimated that 96% of all species were wiped out during this mass extinction. Marine creatures were badly affected and it is the only extinction thought to have had an impact on insects. Hypotheses as to what led to the demise of so many creatures have included combinations of asteroid impacts, volcanic activity, methane releases and decreased oxygen levels.

Triassic – Jurassic (approximately 200 mya): A mere fifty million years after the Permian extinction, about fifty percent of life was wiped out again. Plants seem to have been largely unaffected by this extinction event, but many of the marine reptiles were lost as well as large amphibians and cephalopod molluscs. Large scale volcanic activity and asteroid impacts have both been credited for these extinctions.

This dinosaur can still be spotted in the Evolutionary Dell
at the Botanic Garden! Credit: Nicola Temple
Cretaceous – Paleogene (approximately 65 mya): This extinction event is well known for the loss of the dinosaurs, pterosaurs and ammonites. The prevailing theory for this extinction is the impact of a large asteroid off the coast of Yucatán, Mexico and the subsequent fall-out effects.

While each of these mass extinction events meant the widespread loss of species, they also opened up opportunities for diversification and new species. Had the dinosaurs not gone extinct, for example, mammals would likely not have diversified, compromising our own lineage as humans. Flowering plants experienced extensive diversification after the Cretaceous – Paleogene event and they remain a dominant group today.

The key to resistence might be in duplicate DNA

The Wollemi Pine (Wollemia nobilis)
on display at the Botanic Garden has fossils
dating back 200 million years.
Credit: Nicola Temple
The majority of plants have undergone one or more duplication events where an exact copy of their entire genome is created. This is known as polyploidy – multiple copies of the same genome. Bread wheat, as an example, is hexaploid as it has six sets of chromosomes. Research has shown that one of these doubling events coincides with the Cretaceous – Paleogene mass extinction, approximately 65 million years ago[3].

An extra set of chromosomes could be quite convenient during a prolonged period of stress, such as a massive asteroid strike and its subsequent effects.  Polyploids might be better equipped to resist harmful mutations or perhaps take on mutations that offer a selective advantage under new conditions. Polyploidy plants also tend to be self-fertilising or asexual reproducers, which would be another advantage at a time when finding a partner for breeding could be limited.

Looking forward to a time of inevitable change

The theory that polyploidy confers an advantage during times of change can be witnessed in today’s extreme environments. There is evidence from the Arctic that polyploid plants are more successful than diploid plants at colonising habitats left by receding glaciers [3].

The Evolution of Land Plants Display at the Botanic Garden
(wrapped up for winter) is a walk through time.
Credit: Nicola Temple
Looking into extreme and changing habitats, such as the Arctic, as well as back into the fossil record can give us some indications of which plant groups may be more resilient to the changing climate we are currently experiencing.

You can take a walk through time in the University of Bristol Botanic Garden’s Evolution of Land Plants Display. There you will see living representatives from the groups of land plants that lived from the Cambrian to the Cretaceous, including unusual plants like Wollemi Pine (Wollemia nobilis) with fossils dating back 200 million years.

References:

[1] ‘First land plants and fungi changed Earth’s climate, paving the way for explosive evolution of land animals, new gene study suggests’, Penn State Science < http://science.psu.edu/news-and-events/2001-news/Hedges8-2001.htm>
[2] Silvestro D, Cascales-Miñana B, Bacon CD, Antonelli A (2015). Revisiting the origin and diversification of vascular plants through a comprehensive Bayesian analysis of the fossil record. New Phytologist (in press).
[3] Yong E (23 Mar 2009) ‘Extra genomes helped plants to survive extinction event that killed dinosaurs’, Not Exactly Rocket Science [blog] <http://scienceblogs.com/notrocketscience/2009/03/23/extra-genomes-helped-plants-to-survive-extinction-event-that/>

Sunday, 1 March 2015

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

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 situ collections 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.”