Seeing the wood for the trees in Neolithic Orkney

by Michelle Farrell (@DrM_Farrell)

As I mentioned in my first GEES-ology blog post, palynology can be applied, along with a whole host of other scientific techniques, to help answer archaeological questions. One of my main research interests lies in understanding how people interacted with their environments during prehistoric times – not just the ways in which human activities may have impacted upon the environment, but also the effects that environmental conditions may have had on the development of human culture and society. I am particularly interested in how these human-environment relationships may have differed in areas that are currently perceived to be marginal for human settlement, and especially in island environments where finite natural resources would have been available.

To date, my research in this field has focused on the islands of Orkney, situated about 10 km off the northern coast of Scotland. This apparently open, hyper-oceanic environment would presumably have provided quite marginal conditions for human settlement, yet Neolithic communities flourished and the islands contain some of the most spectacular remains of this period in north-west Europe. The importance of these monuments is reflected by the designation of the Heart of Neolithic Orkney World Heritage Site, which includes the settlement of Skara Brae, the chambered tomb of Maeshowe, and the ceremonial sites of the Stones of Stenness and the Ring of Brodgar.



One of the houses at the Neolithic village of Skara Brae,
occupied between about 3200 and 2500 BC

The Stones of Stenness in west Mainland



Berriedale Wood in northern Hoy: Britain's most northerly natural woodland,
and the only patch of native woodland surviving in Orkney today

It has generally been argued that the Neolithic structures of Orkney have survived so well because they were built in stone - the use of stone for construction seems to have been rare elsewhere in Britain at this time. Orkney today is largely treeless – in fact the only natural woodland to be found on the islands is that at Berriedale in northern Hoy, which actually represents the most northerly natural woodland in the British Isles. There is a long-held assumption that Orkney has been devoid of substantial woodland throughout much of the Holocene (the period of time since the end of the last ice age, approximately 11,500 years ago, to the present day). Was the use of stone for construction in Neolithic Orkney therefore an environmental necessity?



Yesnaby in west Mainland serves to demonstrate why the islanders
might have preferred to use flagstone for construction even if plenty of
timber was available! The flagstone easily breaks off along the
bedding planes in perfect, evenly sized slabs ready for building.

Palynological investigations carried out in the 1960s and 70s suggest that Orkney did once have quite extensive tree cover, although high percentages of birch and hazel pollen have led this to be dismissed as ‘scrub’ or ‘shrubland’ rather than true woodland. These studies have often been used to provide context for the Orcadian archaeological record, the story being that the islands were covered with birch-hazel ‘scrub’ during the earlier part of the Holocene, which was then almost entirely cleared for agriculture around 5500 years ago. This apparently forced the islanders to the readily available Orcadian flagstone for their construction materials.

Many of these early palaeoecological studies were hampered by poor dating of the sequences investigated, and when I plotted the dates of woodland decline from previous reliably dated studies, along with dates from new cores that I worked on for my PhD research, it became clear that the timing of woodland decline in Orkney differed between locations. At several sites woodland loss occurred in multiple stages, with fragments of woodland persisting into the Bronze Age in places. So it seems that woodland was present in parts of Orkney throughout the whole of the Neolithic period – but how valuable a resource would it have been to the islanders?

The tendency to dismiss prehistoric Orcadian woodland as ‘scrub’ has led to the assumption that it would not have been particularly valued as a resource by the inhabitants of the islands. Whilst it is true that the woodland was probably largely made up of species such as birch and hazel, even birch-hazel canopied woodland can be a useful and rich resource. In the North Atlantic region, environmental archaeologists have identified the management of birch woodland as one of the most pressing issues in the Norse and medieval periods. The uses of birch wood range from domestic fuel to the production of charcoal for iron smelting, and there is palynological evidence from Greenland that birch woodland was being sustainably managed, indicating the importance of the resource to the human population. In Iceland, woodland was managed by coppicing and access to woodland was controlled by the more powerful members of society. Coppice management of woodland has been practised in Europe since the Mesolithic period (c. 9000-4000 BC), with evidence provided by artefacts such as fish traps found in Ireland and Denmark. There seems to be no reason why the birch-hazel woodland of Orkney should not have been similarly valued for the range of resources that it would have provided. In fact, there may have been greater diversity in some areas, with the possibility that species such as oak and pine also grew on Orkney, and this would only have increased the range of possible uses and value of the resource. More on this in a future blog post!

 

Remains of one of the wooden structures at Braes of Ha'Breck: the large
post holes which would have held the timber uprights are clearly visible

The final question to be answered is whether the woodland of prehistoric Orkney would have been capable of providing timbers that were substantial enough for construction. Until recently, the only early Neolithic settlement known in Orkney was that at Knap of Howar on Papa Westray, which was built in stone at a time when early Neolithic houses elsewhere in Scotland were constructed from timber, thereby apparently supporting the suggestion that the predominance of stone architecture in Neolithic Orkney was a consequence of a lack of timber resources. In recent years early Neolithic buildings have been discovered at several other locations in the islands, with a wide range of architectural styles now recognised from this period. The remains of wooden structures at Wideford in west Mainland and the Braes of Ha’Breck on the island of Wyre clearly demonstrate that timber resources were exploited during the earlier part of the Orcadian Neolithic. Whilst it is probable that at least some of this timber was derived from driftwood, recent palynological evidence has shown that local woodland could have provided a more reliable resource. The archaeological evidence from Braes of Ha’Breck suggests that whilst in some cases timber buildings were directly replaced with stone structures, others may have been contemporary with them. Although stone buildings appear to have been predominant in the later phases of occupation at this site, large structural timbers continued to be used within them. A small domestic quarry on the site appears to have been exploited for its stone during the early Neolithic, when buildings were being constructed from wood, and was apparently filled in and no longer used during the later Neolithic, at a time when it has been suggested that people were turning to flagstone as a substitute for timber. This was also a period of rapid social change, and the combination of palynological and archaeological evidence suggests that the shift from timber to stone construction in the mid 4^th millennium BC in Orkney can no longer be explained simply as a consequence of a lack of timber resources. Rather than being an environmental necessity, it more likely reflects underlying social and cultural changes. 

This blog post is based on the following article, which can be accessed here:

Farrell, M., Bunting, M.J., Thomas, A. and Lee, D. (in press) Neolithic settlement at the woodland’s edge: palynological data and timber architecture in Orkney, Scotland. Journal of Archaeological Science (2012), doi:10.1016/j.jas.2012.05.042.

Sustainability exchange

By Dr Lindsey Atkinson (@LJA_1)

In August/September the University of Hull welcomed two visitors from the University of the Western Cape, South Africa.  Desleen and Hestelle had travelled on an Erasmus Mundus scholarship to spend some time looking at how universities in the UK and other parts of Europe were integrating sustainability into their activities.

The University of the Western Cape (UWC) is located in Belville, a suburb of Cape Town and has recently been awarded the African Green Campus of the Year Award (2012).  Desleen works in Services and Operations within UWC and is their green team leader.  Hestelle is the manager of the UWC Nature Reserve and takes a lead on environmental education and nature conservation.  They met with many people from around the University including our Environment Manager, Grounds and Gardens Manager and academic staff to discuss approaches to sustainability in Higher Education.  We found contrasts (not just in climate!) but also some common themes.  Both universities are taking measures to improve energy efficiency, sustainable purchasing, recycling etc but we have some different resources available to us.

UWC is privileged to have its own designated nature reserve:  the Cape Flats Nature Reserve which consists of 33 ha of critically endangered Cape Flats Sand Fynbos and endangered Cape Flats Dune Strandveld.  It has a number of endangered species (Red Data Book species) and is managed to minimise invasive species.  In addition there is a nursery for indigenous plants, an Environmental Education Centre and the reserve is also used for research.  Have a look at the Cape Flats Nature reserve website for more information and some great photos.

An autumn day at
Thwaite Gardens

We can’t boast a nature reserve but we do have a botanic garden consisting of approximately 10ha with ornamental gardens, a lake and some mixed temperate woodland. Unfortunately the day Des and Hestelle visited it was a very autumnal, cold and damp day!  Known as Thwaite Gardens, the site is listed as a Grade II Garden of Special Historic Interest by English Heritage and contains an exotic collection of trees representing North America, Europe, the Mediterranean and China. There is also a collection of native hawthorns and greenhouse displays of desert plants and ferns maintained by the Friends of Thwaite Gardens.  Biodiversity in the gardens has been enhanced with cultivation of a meadow area and provision of bird and bat boxes. The main campus grounds are also managed with biodiversity in mind working to a Biodiversity Action Plan (BAP) which links in to the local area BAP. Although there are many contrasts between UWC’s nature reserve and our botanic garden, both are oases for wildlife in urban areas and both are used in education (and both have problems with invasive species!).

Thwaite Gardens on a sunnier spring day

An interpretation board
overlooking the lake

We also discussed the importance of effective communication in rolling out a sustainability programme to staff and students.  We looked at ways of raising awareness, for instance, in both universities we include a talk about sustainability in our induction programme for new staff.  Des and Hestelle particularly liked our interpretation boards which highlight habitats and species that can be found on campus and describe how we are managing the grounds for biodiversity.  While they may have left the UK with lots of ideas I think we also learnt a lot from what they are doing at UWC.  Oh, and they are thinking of starting a blog....

What's 'appening' with DE:FT

By @deftfood

Progress so far 
Now that we are six months into the project we thought it was time we let you all know how things are progressing. We have prototypes of three apps - FoodCloud, ShopStamp and Gradeback - which are on our website www.deftproject.org.uk as power point slides.  For those who left comments on the forum page of the website, many thanks!  Any further comments would be most welcome too! We have also designed a questionnaire survey, https://www.surveymonkey.com/s/DDZWC9K which is looking at shopping habits and technology.  Again please feel free to complete it.  There is also the chance of winning some Amazon vouchers for those who do.

Following on from some of the feedback we have received we have slightly modified the FoodCloud prototype, removing the quiz and simplifying some of the links that we had built into it.  Just to recap, the idea behind FoodCloud was to develop an app which would show people how they were ‘surrounded by food’ so, for example, what was growing in the fields, how food was moving all around them, the routes it was taking and the outlets available to them.

Progress to date 
David Grey from Computer Science at the University of Hull is one of the co-investigators on the project and he has been busy turning our paper prototype of FoodCloud into a working app.  The app has, of all things, a ‘back end’, which can be found at http://foodcloud.deftproject.org.uk so please have a look at it and tell us what you think. The link will take you straight to the log in page and once logged in it is then possible to input descriptions of what the fields are used for using the fields tab.  David has built in a link to ‘MyFarm’ so that anyone who logs in as a farmer can locate their farm using the map which will be displayed, zoom into their fields and label them accordingly as well as providing a brief description of their farm and any farm gate sales they offer.  It’s amazing what a campus can be used for as in order to test how well the ‘back end’ works we have turned the Hull site into a virtual arable farm. The Cohen building was a field of wheat which has been harvested and will be made into biscuits.

Opening up the app 
This information is stored in the ‘back end’ of the app and when the app is opened up it uses GPS to locate any fields that have been added to the ‘back end’ data base.  

Image of smartphone screen and field ‘flags’

Once the fields are located a small ‘flag’ appears on the phone screen (see image above),and by touching the ‘flag’ labelled, wheat, for example, an image of a wheat plant will appear together with the information that was loaded onto the ‘back end’.  We now have a working prototype which is exciting which we can take out ‘into the wild’ and demonstrate to people something we have just started to do and if anyone else would like to see the app working please get in touch at Deborah.butler@hull.ac.uk.  Any feedback is invaluable and will help us in making the app more responsive to the needs of user groups.

Next steps.
At present we are in the process of trying to develop extra ‘layers’ to ‘FoodCloud’ so that it can be used to make the link between food and sites of historical interest. We have also been thinking about a broader ‘FoodCrowd’ concept which would involve children, for instance collecting and inputting data on their local area thus learning about their localities and how they are surrounded by food.

The Hot Potato: Starch, Thermal Adaptation and Enzymes

By Karen Scott (@DrKarenScott)

When the word geography is mentioned, microbiology is not always the first thought, however this was probably the main focus throughout my PhD studies. Being able to understand the microbiology of the environment can greatly assist in putting together the bigger picture, especially where sustainable organic waste management practises are concerned, as they rely ultimately on understanding the mechanisms that control organic matter decay.

This study builds upon my earlier findings on gully pot waste degradation and enzyme activity (see my previous blog) assessing the effect of starch on degradation rate and enzyme activity (α- and β-glucosidase) under mesophilic (moderate temperature typically between 20 and 45 °C) and thermophilic (relatively high temperature between 45 and 122 °C) conditions. A key focus was to assess how the enzymes potentially adapt to different temperature regimes to assist in understanding whether the effect observed was an acclimatisation effect, or it is in fact a true temperature effect that is a result of the composting process. This reciprocal design measured the differences between increased or decreased assay temperatures compared to the temperatures the waste was composted at. The enzyme activity was measured to assess the degradation dynamics. The experiment took place over a 6 week period where mesocosms (a mix of water and sieved gully waste) were incubated under mesophilic (30ºC) and thermophilic (50ºC) conditions, a starch additive was added to half of these mesocosms.

The messy job - mixing the slurry ready for the experiment

This study confirmed previous findings showing that the waste was able to decompose under both sets of temperature conditions. Interestingly though, the losses observed were similar throughout, indicating the losses were temperature independent, which appears to contradict the general literature, where temperature has been shown to be a main controlling factor during composting. However, many other studies have indicated that temperature is not necessarily the driving force in every situation.

The results for the enzyme activity did not follow the same suit, showing greater activity in those that had the starch addition, confirming that a starch addition significantly increases the activity of both α- and β-glucosidase, albeit weakly for the β-glucosidase. Whilst β-glucosidase activity is on average higher with the higher assay temperatures, this was not statistically significant in this instance, indicating neither in situ temperature or assay temperature are significant explanatory variables. However, the effect of increased activity of β-glucosidase with increasing temperature is consistent with previous results. Interestingly, the interactive effect of assay and in situ temperature on α-glucosidase activity is weakly significant which would be indicative of an adaptive effect of temperature on the enzymes responsible for this activity. 

The mean activity for b- and a-glucosidase over the sampling period. the labels for each bar shows the in situ temperature followed by the assay temperature.

Similar results were obtained when α-glucosidase activity was investigated with the starch amended samples only. Therefore, the data for α-glucosidase assay provides evidence for thermal adaptation in this environmental system. The results presented here would be consistent with α-glucosidase being under selection (in an evolutionary context). Whilst α-glucosidase activity is on average twice as high when assayed at 50ºC than 30ºC for the 50ºC starch amended samples, it is only 20% higher when assayed at 30ºC as compared with 50ºC for the 30ºC starch amended samples. Therefore it appears that as enzymes become adaptive to increasingly high temperatures, they become increasingly less adaptive at lower temperatures.

This study demonstrates a positive association between enzyme activity and its putative substrate (starch) and also the effect of temperature appears to have an adaptive selective influence on enzyme activity. Examining these temperature variables provided a better understanding of the processes occurring and displaying the wastes ability to decompose, to a degree, under conditions similar to those that it would be subjected to if using ex situ management system. Whilst complete agreement between enzyme activity and in situ degradation was not observed, it does leave scope for more investigation into enzyme parameters which could potentially shed more light on these issues.

The paper which this blog was based on can be found here

Adams, J. D. W. and Scott, K. M. (2013). Enzymatic analyses demonstrate thermal adaptation of α-glucosidase activity in starch amended gully waste. Bioresource Technology 127(0): 231-235.

Conferences from the inside

by: Drs M. Jane Bunting and Michelle Farrell

Between August 5th and 9th, we were the hosts and organisers for a small conference with associated workshops (small = 35 people on the busiest day).  Organising a conference makes the experience of being at the event quite different - for a start, some days you don't even get close enough to the coffee table at break to grab a biscuit!

The meeting was supported by the Crackles Bequest Project, which pays Michelle's salary at the moment.  The goals of the conference are described here.  We'll write more about the research later as we get final results and work on the papers; this blog post is about the experience of organising a small conference.

The process began in January when we sent out emails checking the availability of our project partners (a wonderful group of people who provided all sorts of support for fieldwork in different parts of Europe, arranging permits, translating, bringing their students and colleagues along to help our team with the actual work, and being enthusiastic about what we are trying to do, which really helps when you're half-way up a mountain in the driving rain or crawling around in a haymeadow in thirty degree heat trying to identify a lot of very small green leaves, which does tend to start you wondering why this ever seemed like a good idea). We then set the dates so that as many of these people as possible could come, and began to plan in earnest.

The 'who can come when' spreadsheet was just the first of many.  We had to work out how much to charge for registration at the meeting, to cover printing abstract volumes and lecture handouts, provide copies of software and pens, and of course the all-important regular infusions of caffeine (and biscuits) to keep everyone alert.  We got quotes for a conference dinner and developed teaching plans for the workshops.  We booked rooms on campus, contacted the local conference bureau to get their help with negotiating some cheap rates with local hotels, and put together an advertisement to send out to the pollen-counting community via various mailing lists.  We even had lists of the lists we needed to make!

Although it felt like we did a lot of planning in advance, and the deadlines for booking to attend the conference and to get the hotel rates were relatively early on the 31st of May (over two months before), the week before the event ended up being manic.  I really should be used to that by now, but it always takes me by surprise.

Michelle demonstrates field methods in a field

We had fun stuff to do, for example sitting down with the menus from the campus catering service and choosing the options for the lunches (why yes, there WAS a chocolate option on the sweet platter every day, and twice it was brownies).  Michelle had a never-ending stream of emails - the pricing policies of the UK's railway system are baffling at the best of times, but trying to help someone travelling from abroad to find the best value ticket makes you question the sanity of the person who came up with it (or maybe they were just feeling particularly misanthropic that day?), and advising people who come from locations with very predictable weather on the possible conditions during the field day ("honestly, it could be pretty much anything, although snow is unlikely") reminds us that our normal is not anyone elses.  Friday afternoon found us settled in the committee room in our building with piles and piles of paper all over the big tables, assembling the handouts for the workshops - I got a bruise on the palm of one hand from banging the hole-puncher (yes, I should have done smaller wodges of paper, but then I'd not have got home before midnight) and Michelle stuck name labels on folders, assembled badges, and cut out individual slips of paper showing the menu choices for the conference dinner (we decided that would be easier than taking the spreadsheet to the venue or hoping people would remember what they'd chosen).  We moved furniture and put up signs pointing to the various rooms being used, and finally got to go home.

Attendees in the quad

I remember how hot the computer room got during afternoon practicals, an Indian attendee huddled in a coat after the dinner while the rest of us enjoyed the cool of the evening (it was about 18^oC by my car's temperature gauge - pretty cold if you come from the tropics I guess), some fabulous pictures of landscapes in a presentation about new work beginning in South Africa and some lovely data from more advanced projects, talking about science until my throat ached (and if you know me that's a LOT of talking) and a lot of laughing.  So here are a few pictures:

Before a session starts (in the earth science lab)

A summer's evening in the Hull docks area

As usual for conferences, people began to travel home at different points on Thursday, and by Friday afternoon only those who'd both stayed for the last workshop and had further to travel were still around.  We decided to meet up at a pub in Hull's docklands, where people could have fish and chips for supper if they wanted - obviously pub fish and chips are not as good as those purchased from a van (or shop in obscure location, depending on your particular favourite) and eaten out of paper, but they do come with beer.  Sitting around a table talking, teasing and gossiping like a group of old friends even though we'd mostly been strangers at the start of the week really brought home one of the benefits of this job to me - meeting other people who share the same strange interests and curiosity about how the physical world works, and having them become friends as well as colleagues.

Organising this meeting was a huge amount of work - I think we've finally dealt with the last of the expenses claims and bits of paperwork, and can sign off on the last spreadsheet, now it's October.  However, it is also very rewarding - all the intellectual stimulation of a conference PLUS you still get to sleep in your own bed, and don't have to put your pets in kennels.  But maybe we can all go to India or South Africa next time?