The scent of winter

Posted on by andy.winfield

The last remnants of snow that recently blanketed Bristol, and indeed most of the UK, have been washed away by what seems like relentless rain. In the Botanic Garden, the staff and volunteers are seeking shelter in the potting shed and glasshouses, turning to indoor work during this inclement weather. Yet, despite grey skies and soggy soil, the Garden still has some delights to offer the senses.
Prunus mume in bloom at the Botanic Garden
Just outside the welcome lodge at the Botanic Garden, there is a delightful fragrance emanating from the Chinese plum, which is also known as the Japanese apricot (Prunus mume). This is an incredibly important plant in China and Japan and the delicate pink flowers feature prominently in much of the art from these cultures. Beneath the Chinese plum, Helleborus is in bloom – purple, pinks and whites – offering a beautiful winter display of colour.
Andy, a botanical horticulturist at the Garden, has taken time out of his busy schedule to show me around today…in the rain. As we enter through the main gate, all the borders are looking incredibly tidy. Now that the last leaves have fallen, the volunteer and staff gardeners have taken the time to sweep and rake up the remains of autumn.
Snow drops have finally made their appearance.
Andy takes me past the pond to an area at the back of the garden where the gently sloping grass bank is scattered with spring bulbs that have broken through. Andy explains plans to make a bee hotel. There is already a good stack of wood and bamboo started, which will be added to over the next while to provide habitat for solitary bees. There are also plans to use some planks to create a city skyline sculpture that is also fully functioning bee habitat – a ‘Bee-tropolis’ if you will. Good gardeners always treat their pollinators well!
Winter sweet (Chimonanthus) looking a little soggy.
We stop at the winter sweet (Chimonanthus) and have a smell of the small white flowers that are growing along the bare branches. Andy tells me that most of the winter flowering plants are incredibly fragrant in order to attract the few pollinators that are out and about at this time of year. Unlike the sweet smelling Chinese plum, the winter sweet has a more nutty or spicy scent, which makes me wonder what sort of pollinator it’s trying to attract. Generally speaking, flowers with a spicy or fruity smell tend to attract beetles, while sweet smelling flowers attract bees and flies.
The winter flowering honeysuckle (Lonicera purpusii) is in full flower. The flowers are…subtle. In fact, Andy needs to point one out to me. It has a strong citrus smell that is really lovely.
Winter flowering honeysuckle (Lonicera purpusii) 
has a lovely citrus fragrance.

Without a doubt, however, the amazing winter display is the evergreen Daphne bholua ‘Jacqueline Postill’. It is in full bloom and is incredibly fragrant. This species grows wild in the Himalayas and belongs to a group known as the paper Daphnes as the bark was once used to make paper and rope.

Beyond the Daphne, in the corner, there are a number of very large wheelbarrows filled with branches and cuttings that are evidence of how much cutting back and clearing has been done in the garden recently. There is also a pile of branches and a bush, which are all victims of the recent snowfall.
Daphne bholua ‘Jacqueline Postill’
offers an incredible winter display.
“Winter is a time for keeping our fingers crossed,” says Andy, “hoping that everything makes it through and that all the winter protection we did helps.”
As we cruise by the compost heap, I can’t help but think of the rotting robot parts.
Beyond the compost and the vegetable patch, there are piles of Hazel branches. The gardeners have been collecting these in preparation for the new growing season. They are used as pea sticks to support herbaceous plants. It’s one of many winter tasks in the garden.  
Andy explains that winter is when much of the landscaping and development is done in the garden. However, right now with such sodden conditions, it simply can’t be done. But, in the meantime, there’s lots that can be done indoors. Let’s hope the winter pollinators have more luck with their outdoor tasks!

Ro-botany: rotting robots in the garden

Posted on by andy.winfield

There’s something really exciting going on in the compost heap at the Botanic Garden. Don’t believe me? What if I told you that buried deep within the hot and humid milieu of the compost, lay the components of future robots that could help clean up environmental disasters such as oil spills. It might sound like a piece of science fiction, but in fact it’s part of a two year project by the Bristol Robotics Laboratory that is looking at the development of a biodegradable robot.

The aim of the project is to build a robot that is self-powered, can move and biodegrades at the end of its life.  It’s an idea that was conceived by Dr. Jonathan Rossiter from the University of Bristol and Dr. Ioannis Ieropoulos from the University of the West of England (UWE). Rossiter is an expert in the development of artificial muscles and Ieropoulos is an expert in the development of microbial fuel cells. So, when these two put their heads together to think about the future and the biggest challenges that lay ahead, they came up with the biodegradable robot.

Look out – there may be a future robot rotting in the
Botanic Garden’s compost heap!
Robots have the potential of conducting large scale clean up of the environment in order to minimize the risk to humans. However, releasing the number of robots necessary to clean up an environmental mess within a reasonable time frame isn’t currently feasible as there is too much effort required to collect them all afterwards. If the robots aren’t collected, they themselves pose a toxic threat as batteries and other components degrade and release chemicals into the environment. The solution? A completely biodegradable robot.

One obvious application of such a robot is in the event of an oil spill. “There are hydrocarbon-degrading organisms that will utilise crude oil,” said Dr. Ieropoulos, a Senior Research Fellow in Engineering Design and Mathematics at UWE. “A futuristic scenario is to release these robots with guts full of microbes that use the crude oil. The robots swim about and the microbes in the fuel cell utilise the crude oil to power the swimming action. By the time they have finished, the robots have biodegraded gracefully into that very same environment without harming it.”

The hard bits, soft bits and active bits…

The workings of a robot can be divided into three main components: 1) the stomach – where energy is generated, 2) the body – which enables movement and 3) the brain – which can receive information from the environment and potentially make decisions. For this project, Rossiter and Ieropoulos are concentrating on developing the first two components – the stomach and body.

The ‘stomach’ is a critical component of the project as it enables the robots to be self-powered. Microbial fuel cells, are a technology that uses microorganisms to directly convert organic matter into electricity.
For the body, the researchers have to identify a range of biodegradable materials: hard bits to give it structure, soft bits that act as skin to hold it all together and active bits to help it move. For this, they are looking to both human-made materials as well as biological materials (such as cellulose).

“There are two approaches really,” said Dr. Rossiter, a Senior Lecturer in the Faculty of Engineering at Bristol. “We take man-made materials that we know work as artificial muscles and see if they degrade and we take materials that we know biodegrade and see if we can build muscles out of them.”

What’s happening in the compost heap…

The researchers are looking at the behaviour of a range of biodegradable materials in different environments. They will compare how the materials decompose in the lab, exposed only to room temperature and air, with how they decompose in the compost heap, and finally how they decompose in a bacterial broth, which replicates the microbial fuel cell environment.

Each week, the materials are weighed to determine how much mass has been lost over time. The results from the compost heap will be compared with those from the lab to determine whether the bacterial broth in the lab is accelerating the biodegradation process, and if so, how much electricity is being generated through that biodegradation.

“We can feed the microbes in the fuel cell things from the environment,” said Ieropoulos, “but if there are biodegrading organisms inside the fuel cell, then at the end of the robot’s lifetime, we want them to consume the chassis and muscles of the robot itself.” 

The project began in August 2012 and will run over two years with support from the Leverhulme Trust. At the end of the two years, Ieropoulos and Rossiter hope to have a proof of concept to show that a self-powered biodegradable robot is possible.

So, next time you visit the Garden and happen to be by the compost, bear in mind that there might be a future robot lurking in there!

Volunteers in the spotlight

Posted on by andy.winfield

This is my first day visiting the garden on a Tuesday. It’s a whole new set of faces around the coffee table as each day of the week brings with it a new set of volunteer gardeners at the Botanic Garden.  I’ve brought some home-made cookies – a sort of bribe or peace offering I suppose. You see, I want to drag a few of these lovely volunteers away from their work for a few minutes to ask them about what motivates them to keep coming back to the garden, donating their precious time, week after week, year after year.
Colin Bolton has been a volunteer gardener for nearly
ten years.

After some discussion around the coffee table, Colin Bolton becomes my first volunteer interviewee. I’m not entirely sure he has actually volunteered himself…it rather seems that his fellow volunteers around the table have ‘volunteered’ him. He’s willing to go with the flow though.

Colin has been a volunteer gardener at the Botanic Garden for nearly ten years, coming in one morning a week. He is a chemist by training and is a retired lecturer from the University of Bristol’s Faculty of Medicine. He heard about the opportunity to volunteer through his son Mark Bolton, who is a well-known garden and flower photographer and has worked with a number of people in the Botanic Garden for various projects. Colin thought he would give volunteer gardening a go.
However, immediately before he was about to start, Colin was struck with meningitis and was very seriously ill in hospital for about six weeks.
“The medical staff were amazed that I came out of hospital, I was so ill,” Colin tells me. “I began volunteering for the garden right after that as a bit of therapy.”
For Colin, it seems to be the people in the Garden that he works with that have kept him coming back all these years.
“They are such nice people to work with and it’s lovely to work with people who know what they’re doing. They’re good teachers and everyone is very friendly, right from Nick [the curator] downwards.”
Colin began volunteering a couple of years before the Garden moved locations and he recalls the move well.
“The move was quite a performance…moving so many plants that were really well established. I can still remember seeing Andy digging around the roots of a really well established tree. He was digging down six feet and across just as much.”
When I ask him whether he was a big gardener before volunteering here, Colin tells me that he and his wife do have a fair size garden at home. He claims that his wife is really the creative genius in their own garden though. Then with a smile on his face, he describes his role as the unpaid labourer.
Judith Moore (second from the left) started her own
gardening business after she became a
volunteer gardener.
Next, I head off to find Judith Moore. She is sweeping leaves with a few of the other volunteer gardeners, Judy, Zaria and Marion, and I can hear the laughter and chatter long before I spot them.
Judith began volunteering as a gardener just after the garden had moved. She was a social worker and found herself between jobs and looking for something to do. Having visited the Garden at the old site quite a lot, Judith felt quite an attachment to it. She had always had an interest in gardening, so she began volunteering one morning a week. That was over seven years ago.
Volunteering in the Garden inspired Judith to start her own business and become a self-employed gardener, which she’s been doing now for about six years.
“I’d never thought about doing paid work as a gardener, but being here made me think about it. It just made me think, ‘well yeah, I could do this’. So I did.”
Judith completed horticulture training courses through the Royal Horticultural Society at the Botanic Garden and spoke to me about many of the other benefits she receives being a volunteer gardener: “It’s a fantastic network here. [The Botanic Garden] is a source of lots of things – information and ideas, but also work.”
People often phone the Botanic Garden inquiring about gardeners and they refer them to Judith. She’s acquired two of her clients this way. But, it’s more than this that has kept Judith coming back over the years.
“I’m sure everyone will say this to you, but the paid gardeners here are such nice people. Day to day it is just such a pleasant environment to be in, but also you feel that they’re all very supportive of us.”
When I point out that Judith’s volunteering commitment means hours that she can’t put toward building her business and her paid work, she simply replies, “I think that highlights how good it is coming here, because I really didn’t want to stop this connection. It sort of feeds you.” 
I couldn’t have said it better myself.
Iris unguicularis in bloom in the garden on January 15th.
Before I leave, I take a whirl around the garden to see what’s going on. There are some irises in bloom, which offer a beautiful splash of colour against the winter back drop and I stop to take a photograph. I run into Martin Webb who is working hard. Martin and his wife Carole started volunteering with the Botanic Garden about seven years ago, when it moved to its current location. Like many of the volunteers, Martin and Carole span the different groups of volunteers and are volunteer gardeners, volunteer guides and are also very involved with The Friends.
“ We’ve seen the garden grow up in this location,” says Martin, “which means that from a gardening point of view you feel as though you own a little bit of it because you can say, ‘I did that’ or ‘I helped with this’. It also helps with the guiding because when people ask questions you can tell them an anecdote because you know where things have come from and how things used to look before.”
Martin immediately slips into his role as a guide without knowing it and points to an area beyond where we’re standing and starts drawing upon his anecdotes: “When we first came, all of this wasn’t planted and you had to take your cue from Nick, who painted a picture of what things were going to look like and then we had to try and see what he was seeing.”
Martin enjoys being on the interface between the garden and those who come to take pleasure in it. He and Carole both give tours for both adults and children and he spends some time telling me about how touring children about the garden requires completely different techniques.
“You get them to pick up a few leaves and have a look at them – some are glossy, some are prickly, some are waxy, some are furry – and you get them to have a feel. We talk about why the leaves are different and we basically have a mini botany lesson.”
Martin Webb is both a volunteer gardener
and a volunteer guide.
Martin says that the worst fear among the volunteer guides is that they will be asked a question they can’t answer. However, he claims that almost never happens.
“Even if they’re a very well informed group, you can always explain things in the context of this garden and what’s going on here. A good disclaimer is to just say up front that you are a keen amateur and encourage others within the group that might be more knowledgeable about specific areas to speak up and share their knowledge.
“In the end, you usually come off a tour on a bit of a high because you feel as though people have appreciated it, asked good questions and learned something.”
Martin and Carole decided to start volunteering after they retired. They were looking for something to do together and they were both interested in gardening and seven years later they are both very involved volunteers at the Garden. Martin pauses just long enough for me to take a picture of him in the winter sunshine before heading back to work.
So there you have it – a few of the stories behind the volunteers who are so integral to the Botanic Garden. I’m sure that every volunteer at the garden has a different reason for why they started volunteering and a unique motivation that keeps them coming back. However, as an observer, watching them work away on a cold winter day, I can safely say that all the volunteers look happy doing what they’re doing. And quite frankly, there’s a lot to be said about being somewhere that brings you happiness.   

Love, hard work and a lot of volunteers…that’s what makes the garden grow

Posted on by andy.winfield

Two weeks ago when I was at the Botanic Garden learning about the tremendous amount of work involved in putting the garden to bed, I was invited to join the team for morning tea. Of course, I leaped at the opportunity to warm my hands and to meet some of the other staff and volunteers. It was a Friday and there were about 8 or 9 of us sitting around the table. After introductions were done it took no time at all for the conversation to return to a friendly banter that put me in mind of a family gathering. It was all very insightful. There was talk of books, movies, a case of being mistaken for a celebrity, the perils of driving an E-Type Jag with a heavy foot, and cakes…there was lots of talk about cakes. You see, it would seem that as well as all the other things the volunteers do at the Botanic Garden, many of them can also bake a mean cake.
Volunteers helping at a fundraising event.

However, one of the most interesting things I learned that day was that some volunteers have been with the University of Bristol Botanic Garden for more than 20 years. That’s an impressive retention rate even for paid staff, let alone volunteers. I had to find out more about the role of volunteers in the Garden and the ethos that manages to cultivate such loyalty.

First, some history…
Volunteers have been a part of the culture of the Botanic Garden for a very long time. There’s photographic evidence of their role dating back to 1970 and when curator Nick Wray joined the garden permanently in 1984 there were a handful of volunteers.
However, in 2002, when it became clear that the garden was going to move location, the volunteer numbers grew dramatically.
“We needed to increase the number of people to help us prepare for the move,” said Nick, “to propagate plants, lift and care for plants. It was clear to me that we were going to end up with thousands and thousands of plants in pots, bags and sacks. Just the shear job of watering in dry weather was going to take a vast amount of time.”
So, with one advertisement in the Friends of the Botanic Garden newsletter, the volunteer numbers grew from a dozen to twenty-one.  Those volunteer gardeners assisted with the preparation of the move as well as carrying out the move itself. It was four years of preparation and eight months of driving back and forth between the two sites to move 12,500 plants, all during a drought year. Volunteers supported all of it.
Volunteers planting on the ballast seed garden barge.
Where are we today?
Today, volunteers at the Garden take on any number of roles and often multiple roles, though gardening is still the most popular. There are currently between 41 and 43 volunteer gardeners working each week, which will probably drop to about 35 in the depth of winter. However, by next Easter there will be a four month waiting list of ready and eager volunteer gardeners, looking for the opportunity to get their hands dirty.
Besides volunteer gardeners there are about 30 volunteer guides who have completed a 10-session training program, which gives them the knowledge and confidence to guide groups around the garden. This training alternates each year and so the Garden will be recruiting and training a new set of volunteer guides in 2013.
There’s also a dedicated group of volunteers that welcome visitors to the Garden. They run the welcome lodge where they hand out leaflets, let people know what’s going on, what’s relevant for their visit in the garden that day and collect the small administration fee. They are on the front-line if you will and are the friendly faces that welcome and point people in the right direction at events throughout the year. There are about 35 people on the welcome lodge roster. 
So, by my count that makes over 100 volunteers and I haven’t even mentioned the volunteers that help in the office, mail out newsletters, distribute leaflets through doors, fundraise, work on plant records, tweet on Twitter…the list goes on!  Whatever the exact number, it is certainly more than a handful. 
To provide some perspective, there are ten paid employees, which equate to seven full time equivalents at the Botanic Garden. They are vastly outnumbered by their volunteers. This clearly has the potential of being a management nightmare. However, whether it’s the quality of the volunteers, the skills of the staff or some combination of both, it all seems to run very smoothly.
Creating the right culture
From an outsider’s perspective there seems to be a few key ways in which the Garden has created a culture that nurtures the growth and retention of volunteers:
  •          Every job is important – This philosophy seems to be instilled throughout the Garden team. Basically it doesn’t matter what people do, from washing pots to propagating plants, it’s all equally important in the bigger scheme of things because it all needs to get done. This is also reflected in the distribution of work, with everyone having their share of the monotonous as well as the exciting.  
  •            Self-sufficiency and autonomy are supported– Many of the experienced volunteers mentor those that are less experienced. The volunteer guides and welcome lodge volunteers are coordinated by the volunteers themselves, which shifts the responsibility of day-to-day management away from paid staff and gives the volunteers some autonomy as well as additional responsibility.
  •          Confidence is instilled through training – Whether the volunteers are pruning, or touring a group of enthusiastic gardeners about the garden, the staff at the Botanic Garden have put in place practices that give the volunteers the skills they need to be confident in what they do. This also means having the flexibility to let people learn through their own mistakes. Nicola Rathbone, better known as Froggie, manages the volunteer gardeners on a day to day basis and was telling me about her approach to providing instruction on pruning. She gives a summary that makes clear what needs to be done, but with enough flexibility that the volunteers have to exercise their own judgement and creativity, which helps them develop their own skills. She said, “Things always grow back. It’s more important that the volunteers are reassured about what they’re doing.”  
  •          Volunteers are valued – If you read last week’s post you’ll know that Andy Winfield claimed that without volunteers he’d be curled up exhausted in a corner of a mud heap somewhere. This attitude seems to be shared among all the staff I spoke to. Nick said, “They are the life blood of what goes on here. We simply couldn’t operate without them.”  

Why do they keep coming back?
So what keeps someone coming back at their own expense, on their own time, week after week, year after year?  I asked Froggie what she thought kept the volunteers coming back.  Her reply, “It’s a family. The volunteers are part of this big team and we’re all working towards the same goal. The volunteers are amazing and they look after us, as much as we look after them.”
The notion of a team of employees and volunteers being a family is often rhetoric rather than reality. However, sitting around that table for tea, I couldn’t differentiate between staff and volunteer – everyone was equal – and everyone felt like family.
Of course to really understand why people commit so much of their time to volunteering, you really need to ask the volunteers themselves, which I intend to do for my next post. Besides, I need an excuse to go back and try some of those cakes everyone was talking about!
If you are interested in volunteering with the Botanic Garden, please click here, however, be aware that there is already a waiting list for volunteer gardeners.

Putting the garden to bed

Posted on by andy.winfield

We all have different approaches to our gardening. Mine is very much a ‘survival of the fittest’ style. You will not find any high maintenance plants in my garden and it’s not from a lack of interest – it’s merely a reflection of my personality and lifestyle. However, when you house over 4,500 species from all over the world, as the Botanic Garden does, there needs to be some serious plant coddling. Particularly at this time of year as the days get shorter, temperatures drop and rain is inevitable.  Plants that are adapted to winterless weather need some special attention and so the staff and volunteers at the Garden are very busy right now putting the garden to bed.
Andy Winfield, a botanical horticulturalist who’s been working at the Botanic Garden for nearly twelve years, toured me around last week to show me some of the special treatments the plants are getting in preparation for winter. The first stop…bananas!
A few weeks ago when I was here, these banana plants were lush and green and reminding me of tropical places. Now there is no sign of that lush foliage, and some intriguing looking tee-pees stand in their place.
The banana plants are prepared for
the winter ahead beneath many
layers of insulation.

 “We start with a framework of bamboo,” explains Andy, “then around that we put some stiff plastic to form a funnel, which we push loads of straw into, down around the trunk of the plant. On top of that we put a little plastic hat to stop the rain coming in and soaking the straw. The leaves of the plants have been cut right back, so it’s the trunk that we are protecting over the winter. If rain gets in and the plant isn’t putting on any growth due to the cold weather, the trunk will just turn to mush.

“Then around the plastic cone, we wrap some fleece. Finally, we wrap the bamboo supporting structure in green netting, which goes around and encompasses the whole lot. We also pile bark mulch around the base of the plant to protect the roots.”
This process will take two people nearly an entire day to wrap three trees. It’s a labour of love to be sure, but it’s also a tried and true method. They’ve been using this method at the Garden for years -through wet winters, cold winters, and even really cold winters, and the bananas have come through it all.
The leaves of the Gunnera manicata are placed over the
the crown of the plants as part of the winterising process,
which also gives an interesting display.
Next on the tour is the Gunnera manicata, commonly called giant rhubarb. The giant leaves of this Brazilian native, which normally dominate the pond area have all been cut back and inverted into what can only be equated to little hobbit-like homes.
“This plant wouldn’t normally have a dormant period where it’s from, but here we need to protect it through the winter,” said Andy. “It has a great big crown, which is the growing point and that is what we need to protect. So we cut off all the leaves, and cover the crown in bark. Then we keep the bark in place by using the leaves as a cover. We tie a number of them together and invert them over the top, then firm them in place with more bark around the outside. It’s functional, but it also provides a structural display.”
As we walk past some cloches placed to protect some dry-loving Mediterranean plants from our wet south west winter, Andy explains some of the process behind putting the garden to bed.
“We consider each plant individually – where it comes from and what its needs are. Then we have a think about how best to protect it over the winter.”
Cloches protecting plants from the
wet of winter.
In fact, they have a list at the Garden with every species named along with very specific instructions for preparing it for winter. I’ve seen this list – it’s 21 pages long! Each year, Nicola Rathbone one of the horticulturalists at the Garden, goes around with the previous year’s list and updates it – adding new arrivals to the list and taking the less fortunate off. Then, it’s a matter of setting to work and starting with the most vulnerable plants, like the cycads and bananas, first. Work starts just before the first threat of frost, which was October this year, and by November things are in full swing.
Next, Andy takes me into the evolutionary dell – one of my favourite parts of the garden. The tree ferns haven’t had anything done to them yet, but shortly they will have some straw stuffed into their crowns and a little plastic hat placed on top to protect them from any penetrating cold or frost. Andy and the other staff keep a close eye on the weather in the winter and if a prolonged cold spell is in the forecast, the tree ferns will also get wrapped in fleece to insulate their trunks from the cold.
Some of the cycads, which are buried in the garden in pots, have been lifted, pot and all, out of the ground and placed in the glass houses. A couple of these plants have been a part of the garden for over 60 years and are substantial in size, and so this is a considerable job to transfer these individuals, and it’s all done by hand. The more hardy cycads are left in the ground and given the same treatment as the banana trees.
Branches are swaddled to protect them from winter frost.
As we walk out of the dell, my eye finally starts to tune into the individualised approach that has been taken to protecting the Garden’s investments. There are ‘mummified’ trees and shrubs that have had their trunks and branches swaddled in cloth to protect them from the cold. Little glass domes peek out randomly throughout the garden and some of these cloches are filled with straw, to give protection against the cold as well as the wet. Some plants, such as the Daphne bholua ‘Jaqueline Postill’ have a wall of netting on only their north-facing side to protect them from cold north winds, while other plants are completely surrounded by netting.  One of the volunteers, Sue, is hammering in a netting screen as we walk by.
“It’s a huge job putting the garden to bed,” says Andy, “and it really comes down to the help of our volunteers. We can’t stress enough how invaluable they are to us. This garden was built on volunteers really, if they weren’t here, this would all be mud and I’d be lying somewhere over there exhausted.”
Once the plants in the garden have been protected for winter, the staff and volunteers will turn their attentions to the many projects that get pushed down the priority list in the busier seasons.  For instance, a section is being prepared for a new Somerset levels display.  So it would seem that not only is there always something to see in the Botanic Garden, there is inevitably always something to do – even once it’s been put to bed.

Through the eyes of bees

Posted on by andy.winfield

One of the many fabulous things about the Botanic Garden is that on any given day, you may find scientists out there conducting cutting edge research. There are currently at least seven research programs going on either directly or indirectly with the garden, making it not only a place of beauty, but also a place of scientific discovery.

I recently had the opportunity to speak with a researcher from the University of Bristol’s Ecology of Vision group, who was in the garden photographing flowers with the most bizarre looking camera. I generally take notice of cameras anyway, but this one could hardly be ignored. It was essentially a metal box perched atop a tripod with a lens protruding out one end and an abundance of wires to connect it to a laptop protruding out the other. It simply begged the question – “what is that and what are you doing with it?”
“It’s a POL camera,” said James Foster, a PhD student in the School of Biological Sciences, “we’re imaging the polarized light reflected off flowers. Humans don’t have polarization vision, so we use this camera to create an image that allows us to see what animals with polarized light sensitivity, such as bees, can see. We want to see what flowers are like from a bee’s point of view.”  
James Foster, a PhD student in the School of Biological Sciences,
is using a special camera, built by Dr. Shelby Temple
and Dr. Nick Roberts, to photograph flowers in the
Botanic Garden. The camera characterises and quantifies
all aspects of light polarization and will help researchers see
the flowers from the bee’s point of view.
If, like me, you aren’t confident in your understanding of polarized light, here are the basics. Light travels as a wave, oscillating as it moves through space. As it travels, the wave can oscillate in any number of orientations, up and down, side to side or any angle in between. Polarization refers to either oscillation orientation of the wave (the angle of polarization) or how many waves oscillate in the same direction (the degree of polarization).
Though humans aren’t sensitive to polarized light, many other species are, including many important plant pollinators such as bees.  It’s been known for about 60 years that bees use patterns of polarized light in the sky to navigate, but are they using polarized signals in other aspects of their daily behaviours?  This is the question Foster is trying to answer as part of his PhD.
“We know that it’s the upwards facing portion of the bee’s eye that is most sensitive to polarized light, so we’ve been looking specifically at downwards facing flowers,” said Foster. “Those that seem to be most popular with the bees are usually found as clusters on an inflorescence, often where there are less mature flowers at the top and more mature flowers at the bottom.  I don’t expect that the bee is using polarized light signals to identify the flower as a flower, but once it gets to the flowers it might be using those signals to optimize its foraging activities. For instance, it could influence the bee’s decision to stay on a lower, more mature flower that may be more depleted in nectar or move quickly up to younger flowers that may have more nectar.”
The research is still in its early stages, but if Foster can demonstrate differences in the polarized signals of mature flowers versus younger flowers that also relate to differences in nectar availability, this will be a first step in determining whether bees are using polarized signals for more than just navigation. 
Recent research conducted at the University of Bristol and the University of Cambridge, has shown that conical cells on the surface of the petals of many flowering plants help increase grip for visiting pollinators and are particularly important when the flowers are moving (as they often do in a naturally breezy world).
“Those conical cells would also reduce the degree of polarization of reflections coming off the flower,” added Foster. “What we predict is that there will be areas that will be rich in these conical cells, for gripping, but there will also be regions where the cells are completely flat and these areas will allow polarized reflections that may be important signals for pollinators.”
It’s a tricky thing trying to study a sensory world that we are essentially blind to. However, it probably means that you might see more of James wandering about the garden, POL camera in tow, trying to see the flowers through the eyes of bees.

Autumn in a new light

Posted on by andy.winfield

     Some of my fondest memories of autumn are as a child holding my parent’s hands on a crisp afternoon, watching as my little red welly boots swished through the dried fallen leaves of the season. Even now as an adult, I can’t resist shuffling a little when conditions are right, just so I can watch the warm colours roll across my feet and listen to the rustle of autumn. However, last Friday Nick Wray, Curator for the Botanic Garden, opened my eyes to a whole new set of autumn delights – from winged bushes to exploding seed pods – this season is about so much more than just falling leaves.

Fruit and flowers
The small orange fruits of G. tinctoria

     The first stop on our tour was the plant Gunnera tinctoria, which to the untrained eye looks very much like rhubarb on steroids, and as a result is commonly called giant rhubarb. This species is smaller than the one commonly seen in British gardens, Gunnera manicata, but otherwise looks the same. As the plant prepares for its dormant winter phase, the large leaves have started to bend to the ground, revealing a world of colour beneath. Wrapped in a sheath of red feathery tufts are the promises of next year’s growth – buds, which will grow over the winter months ready for next spring. Beside these are the large influorescences, rising up like staffs from the base of the plant. Here, thousands of tiny orange fruits are housed, each one the product of a tiny pollinated flower.

     Growing on the north side of the house, in constant shade, is proof that autumn is still a time for flowers – Begonia grandis. This is a woodland plant from southern China and its pretty pink flowers are only one part of this plant’s colourful display. Turn the leaves over and an extraordinary cinnamon red is revealed.

Flower of B. grandis with the colourful dark underside
of the plant’s leaves in the background. 

“This is an evasion strategy,” Nick starts to tell me, “plants can’t get up and run away from predators, but they can masquerade as something else. Herbivores mooching about through the understory are likely to think there’s something wrong with this plant as the leaves make it look as though it’s dead or dying.”

Nick then takes me around the corner to one of his favourite plants in the garden, Impatiens tinctoria – a balsam. I can instantly see why it’s a favourite as the flower is truly stunning. Native to the mountains of western Ethiopa, this plant is adapted to cold dry winters and warm wet summers. The plant towers above me and Nick tells me all this growth has happened since the second week of May – an extremely fast growing plant indeed!
Flower of Impatiens tinctoria.  

     This plant has been producing flowers since July and they are clearly built for bee pollinators. A deep crimson runway guides the bee toward its nectar reward and as it enters the flower, its back rubs along the anther, dusting it in pollen. The pollinated flowers produce a rather extraordinary seed capsule, which is of course another important aspect of autumn….dispersing the next generation.

Scattering seeds
     Like all balsams, I. tinctoria has an explosive seed capsule. Each one is about 3cm long (just over an inch) and resembles a tiny cucumber. Water pressure keeps the capsule extended, but when a little force is applied, the sides of the capsule spring into their natural curled state of repose and the seeds are literally catapulted out. This explosive dispersal method is partly why Impatiens is very successful as a genus. However, this beauty is not to be confused with Impatiens glandulifera (Himalayan balsam), which was introduced as a garden ornamental by the Victorians and is now found choking many of the waterways throughout the UK.
The bladder-like fruits of Colutea arborescens

     Another wonderful example of autumn seed dispersal in the garden is the Bladder Senna, (Colutea arborescens). Though this plant doesn’t bring any colour to the garden at this time of year, the fruits offer their own element of intrigue. Native to the Middle East – Turkey, Iran, Iraq – the beige fruit resembles slightly deflated balloons dangling from the branches. Open it up, however, and inside you find two rows of perfectly paired little black seeds. As winter approaches, these fruits will fall off the tree and be carried across the dry land by the wind, much like tumbleweed. As the fruit tumbles along, it starts to tear and break down and the seeds get released. This type of seed distribution is very successful, particularly in the seasonally dry climates where it is found.

Losing leaves
     Besides the fruits, flowers and seeds, there is no denying that the Botanic Garden also offers a colourful display of leaves at this time of year. All the autumn colours are represented – yellows, oranges and even vibrant reds.
     As the days get shorter, many plants stop producing a type of plant hormone known as auxin. Among their many roles, auxins prevent a specialised layer of cells at the base of the leaf stalk – the abscission layer – from developing completely and cutting off the internal tubes that connect the leaf to the rest of the plant. So, once auxin levels drop, the abscission layer functionally cuts the leaf off from the rest of the plant. The chlorophyll, which gives the leaves their green colour, disintegrates rapidly revealing the other pigments carotene and anthocyanin, giving the leaves their autumn colours.
The bright orange seed of E. alatus seems dull compared
to the vibrant colour of the leaves

     Nick brings me over to Euonymus alatus, the colour of which almost hurts the eyes. The leaves are a fiery fuschia colour. This species is from China and it gets its name alatus, which means winged, from the hard sharp protrusions from the stem that protect the plant from herbivores. In the summer it’s a pleasant green shrub, but this time of year it is ablaze with colour. If the leaves weren’t enough, scattered throughout the bush are tiny fruits, which have split to reveal a single bright orange seed – a delicacy for birds.

     Other plants, such as the witch hazel, (Hamamelis mollis ‘Pallida’), don more golden hues but are no less spectacular.
H. mollis glowing gold against the evergreen backdrop
of Atriplex humilis (Fat Hen family)

     Nick had to run to a meeting, but I stayed in the garden for another half hour, taking photographs and crouching down to look at plants from new angles and examine parts that are usually hidden by lush foliage any other time of year. It was a whole new way to experience autumn. Of course, I still shuffled through the fallen leaves on my way out…some things are sacred.

Remember – next weekend (26th-28th October) is the 25th British Orchid congress at Writhlington School!

“WOW! That’s a lot of bees!”

Posted on by andy.winfield

     I could hear my son’s enthusiastic voice coming from somewhere near the front. He had managed to squeeze through the crowd so he could see, while I stood at the back trying to catch a glimpse of what was going on. There were about a hundred of us gathered around a demonstration beehive in the University of Bristol’s Botanic Garden, listening to the beekeeper talk about maintaining beehives. He’d just pulled out a frame from the hive that was absolutely writhing. We all stepped in for a closer look, and despite having no fear of bees, I have to admit that I was grateful for the mist net that separated us. After all, 15,000 is a lot of bees!
An audience gathers around the demonstration hive to
learn about the art of beekeeping. Photo: Nick Wray.
     Last month, my son and I were on a long walk when we happened upon the annual Bee and Pollination Festival at the Botanic Garden. The festival is a joint effort between the Botanic Garden and the Bristol branch of the Avon Beekeepers Association and this was its 3rd year running. This year, the event also partnered with the Bristol City Council’s Allotments Team, who helped to build a small working allotment on-site to celebrate the event’s theme of vegetable growing and allotments. About 1,000 people visited the gardens over the festival weekend and judging by the faces gathered around the demonstration hive, it was a hit whether you were two or ninety-two.
     For my 4-year old, bees mean delicious sweet golden honey. However, for many of us with gardens or allotments, bees have a much greater importance and value in their role as pollinators and the Bee and Pollination Festival was a chance to celebrate this. In the UK, the hard work of pollination is mostly done by insects – bees, butterflies and hoverflies to name a few. Besides our domestic bee, Apis mellifera, the UK has 26 species of bumblebee and 250 species of solitary bee. While we’re at work making a mental list of things that need sorting out in the garden on the weekend, these pollinators are out there doing their thing. In the UK alone, the value of insect-pollinated crops is estimated to be £510 million annually; pollinators perform an extremely valuable ecosystem service that is critical to our future food security.
     It’s important to be reminded of the connection between food and insects, particularly when we consider the plight of our pollinators. Bee and pollinator populations are in decline largely due to loss of natural habitat; monoculture crops and well-grazed pastures do not promote the wild flowers that are essential food for our pollinators. Loss of nesting areas, widespread use of pesticides and disease are also taking their toll.
     The University of Bristol’s Urban Pollinators Project was on hand at the festival to discuss some of these issues. The project is taking a close look at pollinators in urban environments, surveying pollinating insects in the urban centres of Bristol, Edinburgh, Leeds and Reading. The researchers are comparing the biodiversity of pollinators in urban environments with that in reserves and farmland. They’re also trying to identify urban hot-spots of pollinator biodiversity and look at ways of improving diversity and abundance of pollinators in urban areas.
The small working allotment built for the Bee and
Pollination Festival. Photo: Nick Wray.
     While my son stood entranced at the observation hive, searching for the queen, I also had a chance to check out the Bees for Development stand. If you haven’t heard of them, this is an independent organisation that works largely in Africa and Asia promoting more and better beekeeping to help build sustainable livelihoods in developing communities, while also conserving biodiversity. Among other things, the group helps promote the value of bees as pollinators, linking beekeeping to improved crop yields and profits for farmers and stressing their importance for food security.
     We had unfortunately just missed a speaker from Writhlington School’s Orchid Project, but we did meander through the artist exhibits and local nursery displays. We stopped by the Riverford Organic and Butcombe Brewery displays, and of course we couldn’t leave without buying a jar of local honey from the Bristol Beekeepers.

      However, the highlight of the day for me was, without a doubt, seeing my son’s face as he wound his way through the crowd to find me and share his unbridled excitement at seeing all those bees. For him, the smell of the smoke, the hum of the bees and the thrill of spotting the queen among thousands of dancing bees was an incredible window into the world of bees. For me, it was a reminder of the many ways we’re connected to insects and pollinators in particular. For both of us, we’ll have fond memories to think back on each time we enjoy some of our local honey.