Saturday, 28 February 2009

Seasons for Coastal Sydney


For a while I’ve been mulling over the ‘seasons’ in Sydney, and the inadequacy of the traditional autumn-winter-spring-summer system. Of course every place in Australia has its own seasons, and no one system would work across a county of our size and environmental variability. For that reason I’ve contracted my thinking to the Sydney region, and more specifically that lowland strip near the coast where most people in New South Wales live.

I present this table to stimulate debate and discussion. Soon (very soon!) the Botanic Gardens will begin a community monitoring program to get some good data on environmental change in New South Wales, so we can not only nail down the regular seasonal changes but establish a baseline against which we can measure the impact of accelerated climate change. We also hope to use our extensive herbarium collection (of over 1.2 million preserved specimens) to track changes in flowering times and other seasonal behaviour over the last two hundred years.

But for now, I provide the table at the start of this post, with the following footnotes...

*These were my first thoughts on this topic, based largely on the fact that ‘spring flowering’ around Sydney really starts in late July or early August, and autumn in Sydney is not a dramatic change in the way it is in temperate Northern Hemisphere or places like Melbourne and Hobart (and many inland country areas). Of course once you head up into the nearby mountains the seasons are different again – spring is later and autumn does have more meaning.

**Based on the concepts of Rick Kemp (pers. comm.) – Rick has tried to balance climatic and ecosystem changes but accepts that these two don’t always coincide. There are also transition periods between each of these seasons, and subtleties that I haven’t included here.

***While it may be difficult to change the widely accepted four seasons we have inherited from the Northern Hemisphere, as an alternative we could celebrate the start of more relevant seasonal changes around Sydney with celebratory days – for me, of course, I’d select plants for this purpose! Ideally we would use plants that grow locally in the bush but are also grown in our gardens. The Hyacinth Orchid can’t be grown in gardens but it is so distinctive and evocative of the Sydney Summer that I had to include it in this first rough draft… Different Banksia and Grevillea species flower at different times through the year but May is the usual time for the delightful Hairpin Banksia (Banksia spinulosa) and the striking Red Spider Flower (Grevillea speciosa) tends to start flowering in June. But I’m sure there are better plants to use for these seasonal markers and these are party to provoke debate. And a note about Wattle Day – it was gazetted nationally (in 1992) as 1 September, but 1 August seems (to me) to have more resonance as the beginning of ‘wattle season’ in most parts of Australia and would serve to separate the beginning of the ‘spring flush’, again in most parts of Australia, in late July and early August rather than September.

Thursday, 26 February 2009

The Empress of Brazil flowers again..

You have until friday to see the impressive Empress of Brazil (Worsleya procera) in flower again. We had one flower a month ago (see picture and notes under 19 Janaury post), but this time Gareth Hambridge reports there are a couple doing their thing in the montane section of the Tropical Centre, and a half dozen more in pots in the foyer.

Wednesday, 25 February 2009

Going extinct

Photo: One of Emma Robertson's earlier works (more images)

A week ago I said a few words at the launch of 'Ascendent and Descendent', an exhibition by our 2008 Artist in Residence, Emma Robertson. You can view the exhibition in the Red Box Gallery (off Mrs Macquaries Road) until 27 March. They are beautifully executed drawings - complex, creative and with a strong conservation message.


So at the launch I took my lead from Emma's catalogue and talked about conservation, and particularly plants close to extinction. What follows is a slightly edited version of my speech:


Ascendent and Descendent... Every species, in fact, ascends and descends in a sense. In most cases, species become extinct – the ultimate descent. Extinction and evolution feature strongly in the catalogue and in the artwork – all part of the Darwinian story we are celebrating this year.

The focus here is the Australian flora, but also our science and collections at the Botanic Gardens.

The Australian flora is under threat. Nearly 80% of our plant species grow here and no where else, but 1 in 20 are under threat of extinction. That is, if we do nothing, and current trends continue we lose 1,000 or so species.

Does that matter? A fascinating question.

At the launch of Emma’s year here at the Gardens I noted that the loss of any species is a sad and dramatic event. Not something we should just allow to happen as we go on with our lives.

Species go extinct all the time and over 3.8 billions years of evolution we’ve lost uncountable numbers. But as it says in the catalogue, the species we live with today are the ones we evolved with as a species.

Some of these species are ones we depend on now, or may need for the future. We don’t know which species are necessary for our survival and it’s a courageous step to lose them one by one…and at a rate of 100-1000 times the average historical rate of extinction. And we might say that extinction always happens so why not let a few species go. Well which ones? Do we really know enough to make these decisions? What about ‘forgone benefits’, to use an economic term – that potential for life-saving drugs, for new foods, for surviving change…

Scientists today [e.g. Brian Walker from CSIRO and Resilience Alliance, on Radio National Big Ideas] also talk about ‘response diversity’, ‘adaptive capacity’ and ‘resilience’ of a community. They point out that what might appear to be redundancy – e.g. half a dozen species in the pea family that can all have bacteria associated with them for trapping and fixing nitrogen – is in fact a strategic approach to change. And don’t we need that now, with climate change adding to our own direct impact on our flora and fauna. When it comes to what are called the ‘tipping points’ – when an ecosystem will change or be wiped out – having some diversity and resilience will be critical.

In fact one of our scientists, Peter Weston, is co-author on a paper in the latest issue of the prestigious scientific journal Nature talking about the constraints on plants in a changing world – can they adapt, can they move outside the vegetation type they have evolved in? The answer is generally not, at least at the big 'biome' scale.

On top of these practical considerations for us, the species on earth today are also the ones we have got to know and appreciate – part of our world family. Each is a unique outcome of evolution. It won’t evolve again. As Steve Hopper from Royal Botanic Gardens Kew has said, do we really want to lose the equivalent of De Vinci’s Mona Lisa?

But it’s a complex business. We have limited resources, climate change may mean that we have to decide which species are important to us. I have no problem with us deciding to conserve the Wollemi Pine or a helmeted honeyeater, but as I noted last week at the Darwin dinner this is may be a cultural or social activity rather than something we or the world needs to do to survive.
Which is fine, and something as important as retaining our language, artworks and culture – we just have to be clear about why we are doing it.

So conservation is a mix of our survival as a species and a commitment to not pushing to extinction species that otherwise (with us not here) would still be happily thriving…

* * *

So how has Associate Professor Emma Robertson from the University of New South Wales, and our Artist in Residence for 2008, responded to this challenge?

Emma was born and educated in Scotland, moving to Manchester for her post-graduate study. She has travelled throughout the world, at first with her parents who moved to South America and the Middle East.

She has works in public collections in four countries. As well as being short-listed and winning major art prizes, Emma continues to teach and do research.

It was a great honour to announce Emma as our Artist in Residence in Feburary last year, and particularly to learn of her desire to focus on rare plants and the way the Botanic Gardens responds to their plight.

Tonight we can enjoy the fruits of her work!

* * *

Emma has clearly brought immense style and talent. These artworks can be appreciated for their exquisite design and almost ephemeral beauty.

But Emma has put much more into these works than style alone. For her they have important things to say.

The Sydney Harbour seaweed – Vanvoorstia bennettiana – is something that struck a chord with Emma. This species has been lost to the world since 1886. Back then is was apparently common but changes to the harbour, presumably due to our settlement, have removed it from earth, forever…that’s a long time.

But who noticed? Have there been grainy pictures of sightings from divers, reports of shadows passing in the night – I guess no scat analysis?? This seaweed is arguably as important as the Tasmanian Tiger but not only has it been forgotten, but very few people know about it in the first place.

Emma in her art is celebrating the importance of our collections here at the botanic gardens. And this is a place where species – common, rare or extinct – are appreciated. With a sense of hope, I would add. We document and study life around us with a real sense of not only understanding how it evolved and how it works, but also of its intrinsic value. We work on both sides of that conservation decision – the practical and the emotional.

Working on threatened species might seem a little depressing, for a scientist or an artist. Emma focuses on the living dead and living fossils…As Dr Vaughan Dai Rees says in the introduction to the catalogue, ‘there is a sense of loss’ – a sadness. Dr Rees ends by saying there is a ‘hint of hope’.

I see more than a hint here. I see a recognition that our collections – our living plants, our seeds, our herbarium specimens are all part of us solving the problem. Not really dead collections but collections that reflect and respond to the world around us.

The ‘living dead’ – species that are critically endangered and survival is dependent on humans intervening in some way – are an interesting group, and either something to give us hope or to feel depressed, depending on how you view them. We have a Eucalyptus copulans growing outside the Maiden Theatre to remind us of one species that clinging to existence – two individuals in the wild – and needing us to prop it up. And the Wollemi Pine is close to this.

But what Emma reminds us is that each of these species is important and if we lose it, it’s like losing a friend or family. How could we possibly sit by while this happens? That social element again.

‘Living fossils’ are another disturbing group of organisms. Adapting to change is what evolution is all about. If you don’t change, you go extinct. Our so-called ‘living fossils’ are species that seem to have changed very little for millions of years and they don’t have many close relatives alive today (either because they went extinct, or the species didn’t diversify into new species over that time). Perhaps it didn’t have to? But a living fossil often doesn’t have much potential to survive change so they need a little care and attention.

Again we have to make tough decisions about which ones to conserve. Emma includes them in her ‘Book of Hours’. We can contemplate them as the clock ticks through hours, days, months and years.

Can we conserve them all? How important are these long unbranched twigs of the tree of life? No easy questions and the artwork, to me, has this same complexity.

Throughout all the works, and then particularly in ‘Collectors’, Emma recognises the role of the botanic gardens and its staff in inspiring people to appreciate and conserve plants. This is done through stories about plants, which Emma appreciates and interprets, and in our collections, from living seeds and plants in the gardens, through to the pressed seaweeds and pickled plants in bottles.

I’d have to say that my own pickled algae and the slides I make of them are not as pretty as those Emma has seen, but I beauty is in the eye of the beholder – and think they are pretty special.

And that, perhaps, is a good place to end today. Emma’s pictures will mean different things to different people.

To some they will represent how important all life on earth is and the need to make sure we lose no more of it.

To others it will reflect the complexity of making decisions about conservation, about which species are more important than others – the living dead or the living fossils perhaps?

Others will appreciate the beauty of the artwork and be mildly surprised to learn of the stories behind each picture.

For everyone, though, I’m sure they will stop and think, and their life will change a little by visiting this exhibition - and that’s absolutely what a botanic garden is all about.

So I formally declare the exhibition open, and thank Emma for her wonderful contribution to our Botanic Gardens.

Friday, 20 February 2009

The World's Best Botanic Garden?

Photo: Medicinal garden beds in the Orto Botanico Padua, established in 1545

To anyone working in a botanic garden this is an easy question to answer - your own. And the three gardens run by the Botanic Gardens Trust are certainly some of the better ones in the world!

But the more interesting question is what makes a botanic garden great. I spoke about this yesterday to the Friends of the Australian National Botanic Gardens in Canberra. It's a talk I've given a couple of times, in various guises, but it's one I enjoy giving.

I start with a brief history of botanic gardens, from their origins as medicinal gardens in monastries through to an era of university sponsored physic gardens with an underlying scientific basis - where most people see the beginnings of the 'botanic garden'. At first they displayed the wonders of creation, later they celebrate evolution.
From there it's into the difficult task of defining what makes a garden a botanic garden, let along a great one. There are a few definitions around but the best is from the International Agenda for Botanic Gardens in Conservation (2000): 'Botanic gardens are institutions holding documented collections of living plants for the purposes of scientific research, conservation, display and education'. It's slightly flawed, and leaves out some of the great things botanic gardens do (like art and performance, and interpreting the history of their site) but it gives the general idea.

With this out of the way I travel through various gardens in Europe - botanic and otherwise - and assess how well they inspire and inform people about plants and gardening. As someone said to me after the talk, those gardens with lots of money seem to do a better job whether or not they carry the adjective 'botanic'. But the message I try to give is that there are lots of ways to do botanic gardens and it would be a dull (and ineffective) world if they were all the same. The important thing is to do it well, rather than to tick the boxes and do it all.

I intersperse the pictures of gardens with a few quotes, including the intriguing views of
Robert Dessaix’s from his book ‘Night Letters’, when he decides to not visit arguably the first botanic garden in the world in Padua, near Venice.

In the end I admit to a list of things I think a good botanic gardens should do. While I'm happy if entities we call botanic gardens (or arboreta) don't do them all, I think the better gardens would try to tackle them all in some way. Without further ado, these things are:
  • A collection of plants with good record keeping
  • Mollycoddled interesting plants
  • Education, interpretation and stories
  • Visitors (you'd be surprised...)
  • Meaningful/inspiring landscape and design
  • Excellent horticulture
  • Environmental responsibility and leadership
  • Local relevance (flora, useful plants, desire)
  • And, for good measure, be challenging, stimulating and fun…

Relocating flying foxes

Photo: the Palm Grove four years ago when the flying foxes started to peak in the many thousands

Thousands of Grey-headed Flying Foxes still spend their days in the Royal Botanic Gardens. At last count there were about 6,000 in the camp, not the 22,000 or so reached at their peak late last year.

As most people in Sydney know, the Botanic Gardens Trust has applied to the State and Commonwealth Governments for approvals to relocate the flying foxes. Two weeks ago we got our approval from the State Government - it was decided that our planned relocation was unlikely to harm the flying foxes. There are conditions to the approval but we will be able to meet these in time to commence the relocation in May this year.

The Commonwealth Government has advised us that the same relocation does have the potential to harm the species so they will require further information. We are waiting for them to detail the process to follow and the information they'll need - hopefully they can use some of the information we are gathering for the State Government.

We have advised the Commonwealth Government of the urgency of our request and our need to get a decision before May if possible. The window of opportunity (when flying fox numbers are at their lowest, and to not interfer with breeding and nursing of young) is May to September. Already we have lost significant trees from our collection, and the heritage listed landscapes are severely scared. With 12 trees already dead and 60 more on our critical list, it's important for the future of the botanic garden that we commence the relocation this year.

Today I spoke with Jason Morrison on 2GB about the issue. He reflected the love that Sydney-siders have for the Royal Botanic Gardens and was encouraging immediate action. I explained that our proposal was using a proven technique (regular hourly noises during the day to disturb the camp and to eventually make our Gardens an uncomfortable place to roost) that would not harm the flying foxes, and it was important to get the approvals first. There is certainly some unrest out there and I know that many of our Friends of the Gardens are frustrated by the delays.

We have to do this right, but we have t do it as soon as possible.

(If you want to find out more about the relocation process or about flying foxes, see http://www.rbgsyd.nsw.gov.au/welcome_to_bgt/feature_stories/questions_and_answers.)


Sunday, 15 February 2009

Fast and furious taxonomy

We've been naming plants (i.e. doing taxonomy) for a long time - back at least to Ancient Greece, with Carl Linnaeus bringing a little more order to our systems in the eighteenth century. Like everything else in science, though, I wouldn't be suprised if China was doing a little taxonomy on the side in between.

After so many years you'd think we would pretty good at it and have most living things on earth named. Not quite. It's estimated we are about a fifth of the way ther e, although no-one is quite sure of the size of the problem - probably somewhere between 5 and 100 million species, with just under 2 million described.

So plenty of work to do. But every stage of the process is time-consuming - discovering, collecting, sorting, preserving, databasing, describing, conceptualising (the big intellectual step - working out where a species starts and finishes and why it is different), illustrating, publishing etc.

Every 'taxonomist' knows, and worries about, that if we don't get a move on, many species will become extinct before we even discover them. Discovering and naming them is all part of understanding how they work, how they relate to the world around them and how to manage them for long-term survival.

On friday I travelled to Canberra to be part of the Taxonomy Research and Information Network (TRIN) steering committee. The network is all about accelerating the taxonomic process, filling the gaps in our knowledge, using innovative approaches to taxonomy, delivering easily accessible taxonomic information, and growing the taxonomic effort in Australia.

The early results are very encouraging and we heard updates on weedy lantana, ants, aquatic insects, rats and mangrove communities, as well as improvements in the ways taxonomists communicate with each other and with everyone else, a series of interactive keys to insect families. A fascinating question raised was how a taxonomist decides enough is enough, and when to turn to a new project. This is a tough question for every taxonomist (and scientist generally) - inevitably we can't answer all the scientific, policy and management questions, and there comes a time when we enter a phase of diminishing returns.

Collaborating on the web ('Web 2.0') certainly helps collaboration and should speed up taxonomy. Molecular sequencing increases precision and allows us to crack some of the previously impenetrable conundrums (although it can also mean that we have more evidence to sort through and further delay decision-making). Interconnected databases are essential, as will be standardised and simple publication systems. But one of the great things 'TRIN' is doing, is bringing together our brightest minds to solve our most pressing taxonomic questions.

Thursday, 12 February 2009

Happy Birthday Darwin

Can you see Darwin?
If you went down to the Royal Botanic Gardens today (just near the Children's Fig, beside Farm Cove) - around 10.30 am - you would have scored yourself a cup cake as well as a place in our D-A-R-W-I-N written in people. It was a fun occasion, with cordial, fairy bread and lots of scientists.

It was the opening of our new installation, which interestingly also spelt out D-A-R-W-I-N, this time in large mirrored letters covered in erudite quotes (see the picture). It's part of our thinking path through our 30-year old 'Myrtales Bed', soon to become an evolutionary garden.

This was also the morning after the night before, when 160 darwinians dined and debated in the Pavillion Restaurant in the Domain - see our website (http://www.rbgsyd.nsw.gov.au/) for who was there and what they talked about.

Both events were perfectly placed. The botanic gardens are of course a celebration of evolution. They are also pretty to look at. In fact some of the few kind words Darwin had for Sydney concerned our wonderful institution. In 1836, he said the botanic gardens and domain have 'a number of pleasant walks - no fine trees, but the walks wind about the shrubberies and are to me infinitely more pleasing than the formal Alameda of South America'. (BTW, we now have plenty of fine trees.)

In welcoming (with Frank Howarth from the Australian Museum) our guests to the dinner last night, I mentioned a few other of Darwin's observations. Although he said he looked forward 'with more pleasure to seeing Sydney than to any other part of the voyage', he famously left saying 'I leave your shores without sorrow or regret.‘ (Wisely, he noted elsewhere that 'after so very short a visit, one's opinion is worth scarcely anything'.)

He talked of 'thin scrubby trees bespoke useless sterility'. Still, like everyone else from Europe, he enjoyed the views of the Blue Mountains around Blackheath - 'to me quite novel, and extremely magnificent'.

Darwin was quite capable of the odd wry comment and I repeated this one on radio during the day and at the dinner. 'I was told at Sydney not to form too bad an opinion of Australia by judging the country from the roadside, nor too good a one from Bathurst; in this latter respect, I did not feel myself in the least danger of being prejudiced'.

He was travelling through Australia in fire and drought, in the middle of summer...

Friday, 6 February 2009

Hot plants

Photo: Somewhere hotter and drier than Sydney, most of the time.

This weekend will test our gardens. If you don't have tank, ground or recycled water, a few strategic buckets of water would be in order to keep susceptible plants alive until the Sunday watering. In the Royal Botanic Gardens in Sydney we've had a few trees wilt and some browning of leaves - saved to some degree by a sprinkle of rain on Australia Day evening, and by some extra watering by staff and Friends' volunteers.


At Mount Tomah Botanic Garden we are already rationing our water (from the dam and rainwater tanks), and if there is no rain in the next month or so we may have to truck in extra water. Some deciduous trees are colouring up and will undoubtedly lose some leaves, as has happened in Melbourne over the last few weeks (deciduousness - see posting below - is all about not supporting and exposing your leaves during tough times when there is little growth).


In Sydney we should expect burning of leaves and some leaf drop over the weekend. If the heat does kill parts of your plant, it's generally best to leave them there until all threat of hot weather has passed - why expose new leaves to the same burning?

Wednesday, 4 February 2009

Shedding leaves

Tomorrow I'll talk to a journalist from AAP about the Breen Sculpture Competition (to design a sculpture feature for our first children's garden at Mount Tomah Botanic Garden - have a look at our website http://www.rbgsyd.nsw.gov.au/, top right corner).

That's exciting enough in itself but we'll also talk about deciduous trees! Not important in Australia you might say. Well of course we have lots of exotic deciduous trees in our gardens. We also have a few deciduous natives.

The most well known, and most aptly named, is Deciduous Beech (Nothofagus gunnii) from Tasmania. The White Cedar (Melia azederach), growing north of Sydney, is another that loses its leaves in winter.

More commonly in Australia, we have plants that lose their leaves in the dry season or in drought. There are plenty of tropical examples, including eucalypts. The Deciduous Figs (Ficus virens) in the Domain usually drop all their leaves for a few weeks in October or November.

And why do trees drop their leaves all in one hit? Presumably to conserve water and better survive tough conditions by relieving themselves of fragile leaves when they are not actively growing. In bitterly cold northern hemisphere winters its better to not have your leaves hanging around. In tough Australian dry seasons why keep your leaves.

Sometimes its helpful to shed some or all leaves so that your flowers are easier for birds and bugs to find, and pollinate. The Illawara Flame Tree (Brachychiton acerifolius) and the Red Cedar (Toona ciliata) are two local examples.

Barbara Wiecek (who with Karla Davies checked this information for me) told me that during droughts her local northern hemisphere deciduous trees get their 'autumn colour' and drop leaves in the middle of summer, and then again in winter.

All very interesting.

Tuesday, 3 February 2009

In the ponds today

Photo: We found at least one cell that looked like this (a euglenoid, Phacus) in the Twin Ponds

I talked to our summer Herbarium Interns about freshwater algae and then we wandered down to the Twin Ponds, the main pond and to 'Cunningham's Pond' (near the kiosk/restaurant) to collect some of the subject matter.

Twin Ponds looks very green, almost bluey-green, but it had a reasonable diversity of green algae - some swimming around (e.g. Chlamydomonas) and some staying still (e.g. Pediastrum) - just lots of them.

A sample from the edge of the froth in the brackish Main Pond contained only a few diatoms.

Around Cunningham's remains there was a rich and varied mix of diatoms and a few other freshwater algae, mostly attached to stems and leaves of aquatic plants. There were also some aggressive animals trying to eat the subjects.

Monday, 2 February 2009

Make Darwin happy

You can see how much Darwin is enjoying his cup cake. Come along on 12 February and show Charles how to party.

Not only will there be cup cakes (200 to be precise, so be early), but also cordial. I know that for a 200 year old, this sounds a little bit like 'The Curious Case of Benjamin Button', but it should be fun.

You'll also be at the unveiling of our new temporary artwork. Let's just say it reflects our admiration for Charles Darwin and his legacy...



Sunday, 1 February 2009

Ginger Lily flower



A pretty average picture of the Scarlet Ginger Lily (Hedychium coccineum) mentioned in my posting just under two weeks ago. We water it with rainwater from a nearby tank, and every now and then with tap water as part of Sunday morning sprinkle on days like these.

Remember though that this species can be weedy if it escapes from your garden so perhaps look for a tough, but not so tough, ginger lily cultivar.