Although I’m not entirely certain I think that this lovely flowering shrub is a Knobthorn Acacia (Acacia nigricans). It is currently flowering near to Lazenby House behind Hope Hall at the University of Exeter.
The weather has turned mild and for a few hours yesterday the sun shone. I therefore decided it was time to get the moth trap out again. It has been rested for the last couple of months. I gave it a little service which included that now old fashioned technique of re-wiring the old plug which had become loose.
Only one animal in the trap this morning – a Dotted Border. The adults are on the wing from February to April. This is a male, the female is flightless and has tiny stumpy wings. The caterpillars of the Dotted Border feed on a wide range of deciduous tree leaves. The caterpillars will hatch from their eggs in April and feed until June. The caterpillars will then pupate and over winter until emerging as adults next February. An early spring specialist!
The other animal I found yesterday in the garden was a Western Conifer Seed Bug – the first time I have ever seen one. Originally from Western North America it arrived in Italy a few years ago presumably as a result of ‘world trade’ and has now spread throughout the Continent. It first arrived in Britain in 2007. The larvae and adults feed on the flowers, cones and seeds of various conifers including Scots Pine. As of yet it hasn’t turned into a pest in the UK but it can be a problem in seed nurseries.. For more information on it see here.
Friday night saw two lunar events – a New Moon and a lunar eclipse.
The February Full Moon is known as a Snow Moon as some native American Indians used this term historically as it was the time of the year when snow was most prevalent in their homeland. It is also known as a Hunger Moon – signifying the time of the year (due to the snow) when it was most difficult to hunt animals which often resulted in periods of malnourishment.
The eclipse, known as a ‘penumbral lunar eclipse’ was a rather subtle affair! It is when the Moon travels through the outer part of the Earth’s shadow and it can be mistaken for a normal full moon. What makes this different from a normal full moon is that at least some part of the full moon will be darker than it typically appears. Here are three photos I took.
Looking at these photos of the moon reminded me of the NASA pictures taken from space of the earth on the Apollo 8 mission in 1968.
Such pictures changed forever the way we see our world. No longer could it be argued that we were at the centre of the Universe – we were now Spaceship Earth floating in deep space – a biophysical unit and a depiction of nature.
But what is nature and what is now natural in the 21st century? Nature used to be all the processes and phenomena that allowed life on Earth for us and our non-human co-habitees.
Historically nature was thought of as divine, then it became seen more as a creature or a machine which was constant and if disturbed returned to a stable equilibrium (see Daniel Botkin’s Discordant Harmonies and Bill McKibben’s The End of Nature for more on this).
Geologists now tell us we have left the Holocene and have now entered the Anthropocene (see here) – a nature no longer natural but one influenced all be it unwittingly by the actions of humans. Our modification of the climate along with the other forms of pollution and habitat destruction has put us on a course which is now unstable and not in equilibrium to an unknown destination.
It really is now time to take some responsibility for the situation.
I’ve been reading a great little book about the return of the beaver to Scotland written by wildlife writer Jim Crumley. I can really recommend it if you are interested in this amazing animal and the role it can play in shaping and creating wetlands whilst also ‘slowing the flow’.
You might also be interested in participating in a survey being carried out by a researcher, Roger Auster, at the University of Exeter ‘Attitudes Towards Beaver Reintroduction in Great Britain: An Evaluation’
If you want to help with this research press here – it will take you about 10 minutes and you might even win an iPad Mini!
I went deliberately to Waitrose yesterday in search of some English lamb mince – what I thought would be straightforwards turned out not to be so. No English lamb at all of any sort was to be found, instead the shelves were full of New Zealand lamb …… This led me to investigate why this might be.
It is quite complicated! Firstly as a nation we don’t eat that much lamb and mutton – apparently about 5kg per person per year – see here, and we are basically self sufficient in lamb. Defra told us that the national sheep flock in 2015 was estimated to be around 23.1 million animals – see here and Monbiot calculated that sheep occupy around 4 million ha. of land – the majority in the uplands – see here.
So if we are self sufficient in lamb why do we import lamb from New Zealand?
Firstly UK sheep farmers export around the same amount of lamb / sheep products as the UK imports (which mostly comes from NZ). So if we didn’t import lamb there wouldn’t be the supply to meet the demand.
Secondly lamb is a seasonal product, the UK is in the northern hemisphere whilst of course NZ is in the southern hemisphere. As a result their seasons are complimentary. UK lamb is mainly available from June – December, whilst NZ lamb is in season from December to early June.
Thirdly, as a nation we are rather fussy about what cuts of lamb we like to eat, we tend to prefer legs and chops, as the result of this the rest of the meat cuts and products are exported to countries abroad where ‘lesser’ quality cuts are eaten. In addition much more lamb is eaten that mutton in the UK.
Fourthly, is the issue of currency rates. When Sterling is strong then lamb is uncompetitive on the continent and UK exports drop. However when Sterling is strong, this is the time when NZ wants to export lamb to Britain as they get good prices for their products, leading to a potential conflict with UK farmers – see here for an example from Wales.
Conversely when Sterling is weak (as now) lamb becomes competitive on the continent and exports rise, but imports from NZ drop.
Lamb is a favourite Easter food and of course at this time UK lambs are still growing on the hills and in the fields so the lamb that is available is from NZ and this has led to people asking why UK supermarkets don’t stock UK lamb – see here.
Interesting! But there is more …..
People often complain that lamb is very expensive and why should this be the case? Well a comparison with pigs and pork explains quite a lot. The average sow produces 8 piglets on a four month cycle and each piglet after 5 months will weigh 250lbs and can go to market. Pigs can be kept in a pen measuring 30 x 30 feet. By comparison a ewe can produce 1 – 2 lambs per annum and needs 0.75 acres per animal.
Finally, look how this might change after Brexit – the pound is now very low compared to where it was 7 months ago so conditions are ideal for UK farmers to export to the Continent and elsewhere – both markets come courtesy of the EU Single Market.
If negotiations to secure exporting access to foreign markets takes many years then UK farmers won’t be able to export.
The strategy for sheep farming may then have to change – one option might be, especially in the lowlands, to produce lambs which are less seasonal. For example Dorset Breed sheep can produce lambs throughout the year so an increase in this breed might allow lamb to become available all year round.
Difficult times ahead.
The Uplands Alliance held a meeting yesterday in Cumbria about the future of the uplands after Brexit.
Dame Helen Ghosh, the Director General of the National Trust was one of the speakers.
Here full speech can be read here. She finished her presentation with the following words ‘There is change coming and we need to face into this together. But upland farmers have proved over the centuries that they are resilient and adaptable and those traits will be needed again over the next decade. If we work together, with a clear sense of our common goals, there is a bright future for farming, landscapes and nature. You can count on our commitment and support.’
The National Trust and various Cumbrian farmers have recently been involved in a very public spat over Thorneythwaite Farm – see here and therefore this speech by Ghosh appears to have gone a long way to re-build bridges.
As I have said before – united we stand, divided we fall
In my blog yesterday I wrote about the the rise in abundance of purple moor grass (Molinia caerulea) on Dartmoor, the challenges of suppressing its dominance along with the role that aerial pollution may be playing in encouraging it – see here. Today I am looking at the performance of Molinia in situations where the water table has been deliberately raised so as to restore and rewet degraded peatlands.
Molinia ‘is most abundant and grows most vigorously on sites where there is ground water movement, good soil aeration and an enriched nutrient supply’ according to Taylor et al (2001). One might suspect therefore that on sites where the water table is high – reaching the surface, and constant Molinia might be at a competitive disadvantage to other wet loving species.
Over the centuries many peatlands in the UK have been drained either for agricultural purposes or for peat cutting. Today conservation organisations are attempting to restore many of the remaining drained fragments of these original peatlands. Thomas (2015) described such an approach in the Manchester Mosses Special Area of Conservation (SAC). It should be noted that the Manchester Mosses are lowland raised bogs and not upland blanket bogs such as we get on Dartmoor. Nevertheless these remaining fragments of peat had been drained and were dominated by Molinia. The restoration work carried out on a variety of reserves within the Manchester Mosses SAC was carried out by the Cheshire Wildlife Trust, the Lancashire Wildlife Trust and Warrington Borough Council. At all three sites it became impossible to maintain raised water levels as the adjacent land had been fully drained and all the sites had ditch networks which further facilitated drainage. The restoration work at these sites involved blocking ditches and installing plastic piles around the perimeter to stop the water from escaping. The three sites combined totalled 193ha and therefore such an approach although expensive was feasible. Once the water levels had been raised it had a dramatic impact on the Molinia dominated swards – in all cases the Molinia declined and was replaced by such plant species as Sphagnum mosses and cottongrass.
Anderson (2015) describes work carried out on the North Yorkshire Moors and the Peak District. Both these areas have been severely impacted by sulphur dioxide pollution (from heavy industry since the Industrial Revolution), this has led to acidified soils which ended up killing many of the sensitive plant species e.g. Sphagnum mosses. In addition these areas attract huge numbers of visitors and as a result these Moors have suffered from a large number of accidental and deliberate wild fires. These two factors combined with heavy sheep grazing led to erosion and gulley formation (which drained the otherwise wet peat) on these moors on a very large scale. Restoration work has been going on for several decades now in the North Yorks Moors and the Peak District to try to undo the damage caused by pollution, overgrazing and wild fires. This has involved blocking gulleys with thousands of small wooden dams and in many cases the aerial re-seeding of the Moors with heather. Prior to the commencement of this restoration many of these areas had become dominated by Molinia. The dams in many places have resulted in the raising of the water table which in turn has seen the Molinia decline and wetland species such as Sphagnum return.
Examples from the uplands and lowlands showing that where water tables can be raised sufficiently the rise and expansion of Molinia can be halted so that sites of conservation importance can start their journeys back to favourable condition.
The Exmoor Mires Project aims to deliver multiple ecosystem service outcomes by restoring peatland areas of Exmoor previously drained as part of historic conversion to agriculture or during peat cutting activities. Since 2006 the Project has restored around 2000ha of peatlands at over a dozen sites. Smith et al (2014) describe the results of their vegetation monitoring of the Project. On sites where water levels were successfully raised they have clear evidence which shows that the original Molinia dominated communities have been replaced more species rich wetland ones. At several sites the Molinia swards prevailed after the restoration work had been carried out but the authors blame failures in the ditch blocking and bunding works i.e. the water levels were not raised sufficiently to remove the Molinia.
More recently on Dartmoor via The Dartmoor Mires Project, a series of pilot projects have been carried out to rewet small areas where erosion had been taking place. The situation on Dartmoor regarding moorland erosion is very different from the situation described earlier in the Peak District and the North Yorkshire Moors. Dartmoor did not receive very high levels of sulphur dioxide from the Industrial Revolution on account of its south westerly location and the direction of the prevailing winds. Unlike Exmoor, the Commons of Dartmoor did not see the level and extent of agricultural drainage in the second half of the 20th century.
The pilot Dartmoor Mires Project has however successfully demonstrated at least at some of the sites that raising water levels via small scale dams in localised areas of erosion can lead to a reduction in the area of bare peat (at Blackabrook Head, Blackabrook Down and South Tavy Head ) and that the process of paludification re-commences, i.e. new peat is formed, along with an increase in ‘beneficial mire species’ (at Blackabrook Head, Blackabrook Down and Winney’s Down Area 1). However to date there has not been a decrease in the abundance and distribution of Molinia. In the control site (where no rewetting was carried out) however the abundance of Molinia did increase (Lunt 2015). It is however fair to say that the Dartmoor project has not been running for very long and when the sites are re-surveyed in the future it could be expected that Molinia will start to decline as has happened on the other sites discussed.
At the moment work on the Dartmoor Mires Project has been halted whilst an evaluation of the results to date is carried out. It will be interesting to see whether following the pilot scheme, work will recommence on a large scale which may then have a bigger impact on parts of the Molinia dominated moor.
Anderson P. (2015) Molinia – the importance of controlling water and other management techniques. In Meade (2015) pp39-54.
Lunt P. (2015) Dartmoor Mires Project Vegetation Analysis 2015. Download here.
Meade R. (ed) (2015) Managing Molinia. Proceedings of a 3-day conference 14-16 September 2015, Huddersfield, West Yorkshire, UK. National Trust. https://www.nationaltrust.org.uk/marsden-moor-estate/documents/managing-molinia.pdf
Smith D.M., Barrowclough C., Glendinning A.D. & Hand A. (2014) Exmoor Mires Project: Initial analyses of post restoration vegetation monitoring data. In the Bog Conference September 2014. Download here.
Taylor K., Rowland A.P. & Jones H.E. (2001) The Biological Flora of the British Isles: Molinia caerulea. Journal of Ecology 89: 126-144.
Thomas P. (2015) Problems with Molinea caerulea in the restoration of lowland peat bogs – Manchester Mosses Special Area of Conservation (SAC). In Meade (2015) pp127-133.