Category Archives: Biodiversity and culture

Photograph and poem: the only alien here

2018-11-01 23.21.44

Wind the propagator propels air-borne seeds

To urban refuge and new opportunity

Where they germinate, elongate, grow, and flower,

Roots seeking soil, making do with mortar and render,

As, persistent in its invader role,

Buddleia grips a gable cliff, dispensing offspring

From house wall warmth into frigid space

And a clear night of stars backdrops the only alien here.

 

Advertisements

2 Comments

Filed under Biodiversity and culture, Personal biodiversity, Poetry, Urban biodiversity

The biological mutualisms at the heart of sourdough bread

20181026_120748

During the road trip to Denmark that I mentioned in a post back in September – see “There ain’t no b(ee) in Starbucks” – my wife Karin received a special gift from her sister Pia.  It was a small jar containing a starter culture for sourdough bread, a culture that Pia has been using since she received it from a friend, who long ago received it from another friend.  I didn’t know much about sourdough bread and did some reading. That Wikipedia link is a good introduction but don’t be put off by the complexities of “refreshment” – we’ve kept the starter culture in the fridge since early September and it’s been fine.  Karin used the culture for the first time this morning and made the rye bread you see above.

But on to the biology.  In essence the sourdough culture is a mix of wild lactic acid bacteria and wild yeasts, plus flour and water.  When added to the bread mix (which in our case contained water, salt, seeds and molasses, as well as rye flour) the yeasts feed on some of the sugars within the mix and the lactic acid bacteria feed on other sugars that the yeast cannot metabolise.  During that bacterial fermentation, byproducts are also produced on which the yeasts feed.  The yeasts in turn produce carbon dioxide which serves to leaven the dough, and the bacteria produce lactic acid as another byproduct, which gives the bread its slightly sour flavour.  This lactic acid also lowers the pH of the environment and, together with the production of anti-fungal chemicals, the lactic acid bacteria prevent the growth of other bacteria and moulds.  The yeasts, however, can tolerate these conditions and they thrive.

At least six species of yeast and 25 species of lactic acid bacteria have been shown to be  involved in this process, often as multi-species mixtures.  The exact biodiversity of the culture is dependent upon its source: micro-organisms vary a lot across the world.  But the heart of the relationship between yeasts and bacteria is always the same: they each facilitate the growth and reproduction of the other, and so the relationship is mutualistic, much like (most) relationships between plants and pollinators, birds and berries, and sea anemones and clownfish.

Of course there is a third organism involved in this mutualism: Homo sapiens.  By producing the resources on which these organisms feed, and then distributing the starter culture, we are providing the right conditions for the yeast and lactic acid bacteria to increase their populations.  In turn the yeast and bacteria play an important role in producing food for us, and in fact this way of making bread is thousands of years old.  Microorganisms and people all benefit: what could be more mutualistic than that?  Indeed, these interactions could be classified as a rare example of a ménage à trois mutualism.

There’s also a social-cultural dimension to all of this as the passing of gifts such as the starter culture binds friendships.  If any of our local friends are reading we’d be happy to share the sourdough culture once we’ve bulked it up.  The bread that it makes is delicious and from now on we’re going to try to give up buying the shop-bought kind.

If you want to read more about all of this, and have a try at making your own starter culture from scratch, there’s some great information and links on the Microbial Menagerie blog.

Many thanks to Pia for sharing the starter culture, and to Karin for baking the bread!

5 Comments

Filed under Biodiversity, Biodiversity and culture, Mutualism

The explosion in orchids as houseplants: what does it tell us about how flowers evolve?

Orchids 20180512_112533.jpg

One of the major trends in horticulture over the last 20 years or so has been the rise in popularity of orchids as house plants.  Orchids used to have a reputation as being delicate, choosy, costly things that needed expensive glasshouses, heating, and humidity systems to grow.  Some groups of orchids are certainly like that, but many are not (Orchidaceae is one of the two largest families of plants, after all).  These days it’s impossible to walk into any supermarket or department store and not see orchids for sale at a reasonable price, orchids that are tough and can withstand the relatively dry, centrally heated houses in which most of us in Britain live. 

The majority of these orchids are varieties of Phalaenopsis, the moth orchids.  Intensive hybridisation by commercial growers has meant that there is an almost inexhaustible range of flower colours, shapes, sizes and patterning available.  Take a look at this gallery of images and you’ll see what I mean, or go into a shop that sells such orchids and observe that almost no two are alike.

This is the stuff of natural selection: genetic variation in the phenotype that can be acted upon by a selective agent.  In this case it’s the growers of orchids who choose the most attractive types to sell and discard the others.  If this variation emerged in wild populations most of it would disappear over time, but some, just occasionally, would be selected for by a different group of pollinators and go on to form a new species.  This is much more likely to happen if the individuals with this variation are isolated from the rest of the population in time or space, for example if they flower later or have been dispersed to a distant valley or mountaintop (termed allopatric speciation).  But it can also happen within populations – sympatric speciation.

Back in 1996, near the start of this orchid explosion, one of my earliest papers was a speculative commentary in Journal of Ecology called “Reconciling ecological processes with phylogenetic patterns: the apparent paradox of plant-pollinator systems”.  It generated some interest in the field at the time and has picked up >250 citations over the years, mostly other researchers using it as supporting evidence for the discrepancies we see when trying to understand how flowers evolve within a milieu of lots of different types of potential pollinators selecting for possibly diverse and contradictory aspects of floral form.  In that paper I made a passing comment that I expected the reviewers to criticise, which they did not.  Once it was published I thought that perhaps other researchers in the field would critique it or use it as a jumping off point for further study, which has not really happened either.  This is what I wrote:

         “It appears that pollination systems are labile and may evolve quite rapidly….plant breeders can obtain a fantastic range of horticultural novelties through selective breeding over just a few generations.”

This is horticulture holding up a mirror to the natural world and saying: “This is how we do it in the glasshouse, look at the variety we can produce over a short space of time by selecting for flower forms; can nature do it as quickly, and if so what are the mechanisms?”  

I still believe that pollination ecologists could learn a lot from horticulture and there’s some fruitful (flowerful?) lines of enquiry that could be pursued by creative PhD students or postdocs.  Here’s one suggestion: part of the reason why these Phalaenopsis orchids are so popular as house plants is that they have very long individual flower life times, often many weeks.  Now we suspect that floral longevity is under strong selection; see for example research by Tia-Lynn Ashman and Daniel Schoen in the 1990s.  This showed that there is a negative correlation between rate of pollinator visitation and how long flowers stay open.  Plants with flowers that are not visited very frequently stay open much longer, for example the bird-pollinated flowers of the Canary Islands that may only be visited once or twice a day, and which can remain open for more than 20 days.  Is the floral longevity shown by these orchids (or other groups of plants that have been horticulturally selected) beyond the range found in natural populations?  If so, what are the underlying physiological mechanisms that allow such extreme longevity?  If not, does this mean that there is an upper limit to the lifespan of flowers, and if so, why?  

In the mean time I’m going to enjoy the orchids above that sit on our kitchen windowsill.  They actually belong to my wife Karin who has developed something of an interest in them in recent months.  The big spotty one is a late birthday gift for her that I picked up this morning from a local flower shop, and which stimulated this post as I was walking home.  I’d bet that we never see another one like it!

15 Comments

Filed under Biodiversity, Biodiversity and culture, Birds, British Ecological Society, Evolution, Gardens, Personal biodiversity, Pollination

Why conservation is like paella: thoughts and photos from our Tenerife field trip

 

A couple of days ago I posted a photograph on Facebook with a comment that “after a hot day of collecting data there’s nothing better than a nice big Tenerife paella!”:

Karin and the paella.jpg

My wife Karin and I had ended up in the small town of Candelaria, tired and hungry after sweating our way through the Malpais de Guimar  counting and measuring plants.  Big plates of hot food were just what we needed!

After I posted the image a Spanish colleague commented that the dish was “closer to being an arroz con cosas than a paella”.  The term translates as “rice with things” and is used to convey the fact that the original Valencian dish of paella has been bastardised and changed across the Spanish-speaking world, and no longer reflects its culinary tradition.  Knowing nothing of that culinary tradition I took a look at the Wikipedia entry for paella.  It makes for interesting reading, not least the fact that in the original dish one of the main ingredients was the meat of water voles and that the dish was cooked on an open fire fuelled by wood from orange and pine trees to give a distinctive smoky flavour.  There was also a lot of geographic variation in the dish, so what constitutes an authentic paella is debatable.

Although there was no sign of rodent flesh or naked flames in the dish that we ate, it was certainly delicious!  But the comment about arroz con cosas got me thinking about shifting baselines in cooking and conservation.

The idea of a shifting baseline is that expectations of what is “correct” or “normal” or “natural” change over time depending upon what each generation has experienced.  It’s been mainly applied in conservation; for example, the Lake District of England is seen by many as a “natural” landscape of rolling hills and low mountains, but originally it would have been covered in deciduous forest.  Likewise large parts of Tenerife contain a high proportion of alien plants (such as agave and prickly pear) but local people and visitors see this as natural.  The baseline of “naturalness” has shifted for people.  Returning these landscapes to their original condition would mean a drastic shift in the composition of the vegetation.  And what point do we return that condition to?  One hundred years ago?  One thousand?  Ten thousand?  It’s an issue that is widely debated in the conservation literature, especially in relation to rewilding.

Likewise, over time paella has evolved and been adapted by different chefs, and what is currently cooked in restaurants only partially reflects how the dish was originally cooked.  Other than for epicurean purists, our culinary expectations have changed.  There’s been a shift in the paella baseline.

Anyway, enough metaphorising, here are some photographs from our trip.  To set the context, University of Northampton students and staff, including Pablo Gorostiague who is visiting from Argentina, and colleagues from the University of Sussex (Maria Clara Castellanos and Chris Mackin), were out with us last week.  Then we bade them farewell on Sunday before moving on to do some field work.

Field work on the lava fields at Santiago del Teide:

Santiago del Teide 2018-04-28 11.21.30.jpg

Santiago del Teide 2018-04-28 11.23.30.jpg

Santiago del Teide 2018-04-28 12.20.48.jpg

The landscape of Malpais de Guimar, which actually probably hasn’t changed much in the last 10,000 years:

P1040129

 

How many people can you fit around Pino Gordo, the largest Pinus canariensis on the island:

Pino Gordo 2018-04-24 12.10.41.jpg

Pino Gordo 2018-04-24 12.10.50.jpg

Pino Gordo 2018-04-24 12.11.09.jpg

The endemic Tenerife Blue Chaffinch:

P1040195.JPG

The cold, damp laurel forest:

P1040222.JPG

Team Nicotiana!  Helping Chris with locating Tree Tobacco populations for his PhD work:

Team Nicotiana - 2018-04-27 11.52.15.jpg

Team Nicotiana 2018-04-26 10.13.13.jpg

Pablito takes a break:

P1040235.JPG

 

 

 

5 Comments

Filed under Biodiversity, Biodiversity and culture, Rewilding, Tenerife, University of Northampton

Split the kipper: snowfall thoughts of breakfast, fish and childhood games

Kipper 2018-01-21 10.39.16.png

Karin and I had kippers for breakfast this morning, a satisfying and warming treat on this cold Sunday as we watched the snow fall into the garden, softening the edges and hedges:

Snow in the garden 2018-01-21 11.20.48.png

I do like a nice kipper!  Smoking fish to make it last longer has been repeatedly discovered and transmitted as an idea across cultures, and represents a fascinating intersection where wild biodiversity meets human ingenuity.  The north east of England, where I grew up, has a great and ancient tradition of smoking herrings to preserve a portion of the catch, a practice that may have originated with the Vikings who colonised that part of the country over one thousand years ago.

Of all of the North Sea’s edible biodiversity I feel most comfortable eating herring; although there were issues with over-fishing in the 1960s and 70s, current stocks look to be being managed sustainably.  The most up to date information I’ve found is in a Norwegian government report from which I took this graph:

Print

Kippers have had subtle, but interesting, influences on culture, spawning phrases, songs and games. To be “done up like a kipper”* is to be taken advantage of by someone or bamboozled, whilst a “kipper tie” is a fashion hangover from the 60s and 70s, named for its broad proportions.  Of course Supertramp sang about having kippers for breakfast, particularly in Texas “cos everyone’s a millionaire”.  That strikes me as an odd line as herrings (in whatever form) have always been considered a cheap dish. Though I suppose importing them from Craster to Dallas could be quite expensive.

Back to the north east and my childhood, where we played a game called “Split the Kipper”. This involved standing opposite a friend on a grassy field and taking it in turns to throw a knife near to your opponent’s foot.  If it stuck into the ground then your opponent had to slide their foot to that point.  This continued until one of you had your legs so far apart that you fell over – the kipper had been split!  Not the safest game for kids but I never knew anyone to get injured playing it. Like all the best games the point was not just to win but to win beautifully: inching your adversary’s legs apart with accurate knife throws gradually ramped up the tension of the game.  I wonder where the game originated? Is it too fanciful to imagine that it was brought over by the Vikings?

The snow is still falling – wonder what’s for lunch….?

 

*Whatever you do, don’t search the Urban Dictionary for the definition of the word “kippered”….

15 Comments

Filed under Biodiversity, Biodiversity and culture, Gardens

Vermicide: how do you deal with earworms?

P1020258

Warning: biodiversity content almost nil; bad language content significant.

——————————————————–

Language fascinates me, and one of the things that I find particularly intriguing is the way in which metaphors and analogies from the natural world find their way into our writing and speech.  We talk of a “bird’s eye view” or being as “slow as a snail”; say that “from little acorns large oaks grow”, and we are as “ravenous as wolves”.

Which leads me to earworms.  Nothing to do with real worms of course, but fragments of music that worm their way into your consciousness and stay fixed there, repeating over and over and over and over…….

According to Wikipedia other names include brainworm, sticky music, stuck song syndrome, and Involuntary Musical Imagery, but I’ve always known them as earworms.  And I’ve suffered from them for as long as I can remember; typically every couple of days I’ll have part of a song stuck in my head that I can’t get rid of.  In recent days it’s been “Long-haired Lover From Liverpool” by Little Jimmy Osmond (which I heard on a Top of the Pops Christmas Special); Joni Mitchell’s “River”; and “The Rain Song” by Led Zeppelin that featured on a YouTube playlist on New Year’s Day.

Earworms get worse when I’m stressed or when I have a hangover: indeed if I have drunk too much the night before (a rare occurrence these days) I will wake up with a headache, nauseous, AND SOME FUCKING SONG BOUNCING LOUDLY AROUND IN MY BRAIN LIKE A KANGAROO* ON AMPHETAMINES!

At their worst these earworms can last for days and be very hard to shift.  They can also wake me up in the middle of the night and stop me from getting back to sleep.  The only method that I’ve found that can suppress them is to sing another song to myself that masks the offending song.  After much experimentation I find that “In My Time of Dying”, another Led Zeppelin track, is the most effective, perhaps because it’s slow and not especially catchy.

(Bugger, my son James is tidying his bedroom and playing music and Queen’s “Bohemian Rhapsody” has just come on – almost guaranteed to get stuck in my head!)

If you also suffer badly from earworms I’d be interested to know what methods you use to shift the little blighters: what works for you?

 

*See what I did there?

12 Comments

Filed under Biodiversity and culture

The holly, the mistletoe, and the pollinators: an update on an old story

holly-and-mistletoe-20161211_103252

Holly and mistletoe are two of Europe and Scandinavia’s most iconic plants, steeped in folklore and cultural significance, and redolent of the dark days of mid-winter and its festivities.  Last year, together with my colleagues Jim Rouquette and Tom Breeze, I published a study of the value that pollinators add to the wholesale auction prices of these two plants using data from the UK’s largest holly and mistletoe auction that has been held in the town of Tenbury Wells for 160 years.

Holly and mistletoe are excellent subjects for a study of the added value that pollinators bring to a crop as they are 100% reliant on pollination by a range of wild bees, flies and other insects.  This is because both species are dioecious with separate sex plants, therefore any berries produced on a female plant must be due to the activities of pollinators.

Here’s a link to last year’s blog post about that paper and here’s the reference for the paper itself, with a link to the journal where you can download it for free:

Ollerton, J., Rouquette, J.R. & Breeze, T.D. (2016) Insect pollinators boost the market price of culturally important crops: holly, mistletoe and the spirit of Christmas. Journal of Pollination Ecology 19: 93-97

The data set in that paper only developed the story up to 2015 as the 2016 auctions took place too late to include within our analyses.  However I’ve collected the auction reports for 2016 and 2017 and added them to the data set.  The results are graphed below*.

The auction price for holly with berries is rather volatile, but on average over this time period, berried holly has twice the commercial value of holly without berries.  Indeed in the last auction of 2017, holly without berries failed to sell, hence the value of £0.00.  The very wintry weather on the auction day reduced the number of buyers, but nonetheless, to have no one bidding for the unberried holly was unprecedented.

Holly auction prices plot

The pattern for mistletoe is rather similar, but in this case the value of berried material is less volatile than that of holly, and the average value is around three times greater than for auction lots of unberried plants.

Mistletoe auction plot

This data set offers a unique insight into the value of pollinators for two culturally important crops (all other such studies have focused on food or, rarely, fibre crops).  I’ll continue to archive the auction reports and to update these analyses every few years in the run up to Christmas.  If anyone is interested in accessing the data, please drop me a line.

If you want to learn more about the botany of different types of mistletoe follow this link to Mike Fay’s blog post on the Kew website.

Also worth checking out is Manu Saunders’ recent piece highlighting some old Christmas-themed blog posts.

Yesterday was my last day in the office, I’m now officially on leave and looking forward to a restful Christmas and New Year break.  Season’s greetings to all of my readers and thank you for your continued support and interest in biodiversity!

 

 

*There are three auctions each year and therefore three data points per annum, except for 2016 when only two auction reports were produced.

6 Comments

Filed under Biodiversity and culture, Ecosystem services, Pollination

Spiral Sunday #33 – an Aeonium from Tenerife (for Karin’s birthday)

Aeonium.png

Over the past couple of weeks we’ve been extremely busy doing field work and not had great internet connections, hence no postings on the blog.  But this weekend we are staying in a lovely little hotel in a restored 18th century Canarian house in Icod de los Vinos.  So things have slowed down, though the internet is not much better.

I have managed to capture a few images of spirals along the way that I will use for upcoming Spiral Sunday posts.  As it’s Karin’s birthday today, here’s one of an Aeonium species, the group of plants that’s been the main focus of our recent field work.

Happy Birthday Karin!

3 Comments

Filed under Biodiversity and culture, spirals, Tenerife

Spiral Sunday #29 – a pair of guest photos

Spiral from Alex Laws.png

Spiral Sunday this week features a couple of photographs I’ve been sent recently.  The first is from one of my PhD students, Alex Laws, taken on a trip to Cornwall earlier this year.  The artist is James Eddy, not a name I was familiar with, but definitely worth checking out, especially as he is a land artist too.

Which leads us to the second picture, sent to me by a Polish colleague, Marcin Zych, of a spiral-shaped piece of land art he found near Olomouc, in the Czech Republic.  It reminds me (on a smaller scale) of Robert Smithson’s amazing sculpture Spiral Jetty (of which I was unaware until it was kindly introduced to me by Carrie McLaughlin of the Texas Pollinator Powwow).

Spiral from Marcin Zych

Many thanks to Alex and Marcin, and to Carrie too.

 

 

4 Comments

Filed under Biodiversity and culture, spirals

Spiral Sunday #28 – hearts and vine

P1030350

The sun was illuminating the coloured glass of a window ornament and I noticed two things: (i) the lovely juxtaposition between the metal spirals of the ornament and the spiral tendrils of Cyphostemma simulans, a member of the vine family (Vitaceae) that I grew from seed many years ago; and (ii) the fact that our front windows really need washing….  No time for that this weekend, though, been too busy working in the garden with Karin!  That’s Spiral Sunday, enjoy the weather while you can.

5 Comments

Filed under Biodiversity and culture, Gardens, spirals