In other News: Spring is here

During the winter, nature goes into lockdown. Trees have shed their leaves and stand to attention …. birds scrabble around desperately searching for their next meal ….. insects live as eggs, larvae or cocoons. Waiting … patiently waiting for longer and warmer days.

And now spring is here! Birds are singing their heads off in anticipation of imminent breeding and the raising of a new family, butterflies are pursuing the same goal but rather than singing they are flittering. Trees are beginning to come into bud, leaves are magically beginning to appear.

But this is not a normal spring, we are part of nature, whether we think so or not, yet we now find ourselves in lockdown when the rest of nature is not. I am reminded of a poem …. The Waste Lands by T.S. Eliot, written in a different century about a far bigger catastrophe – World War One. Two of the most famous lines spring to mind ‘April is the cruellest month’ and ‘I will show you fear in a handful of dust’. The next few weeks are going to be difficult and traumatic for us, but, and I don’t want to sound trite, as a nation, we will get through this and life will go on, as The Waste Lands shows us.

Of course, elsewhere life is going on and watching it unfold is my favourite hobby, because whilst I think I know what is going to happen nature doesn’t always read my script. For many years now, I have been looking at the oak and ash trees in my garden, prompted by the old country expression ‘oak before ash – we are in for a splash and ash before oak – we are in for a soak’, I want to see who wins the race to be the first species to come into leaf.

In reality oak pretty much always comes into leaf before ash. In the last fifty years oak has always leafed before ash. It has not always been this way – in the 18th century when it was less mild ash did often produce leaves before oak – thus the quote.

Climate change has changed all of this – usually oak comes into leaf in late March-May which is about two weeks earlier than 30 years ago. Ash usually comes into leaf during April and May, about 7-10 days earlier than 30 years ago.

However, first in 2017 and now again this year, it is pretty much a dead heat – the ash is early. I’ve got 5 different oak trees in the garden and one big ash (seriously affected now by ash dieback). The oaks appear genetically different so I think they have come from different parent trees as the come into leaf at strikingly different times. One is way ahead of the others – the same happens every year. This particular oak has ‘beaten’ the ash, but the ash is ahead of the other four. I can’t really explain this as it has been a very mild winter in a warming world so oak should have beaten the ash by quite a distance.

When this pandemic madness has passed, at least for now, and we begin to reconstruct our lives and rebuild the economy, we need to remember that the global climate and biodiversity crises have not gone away and still need to be urgently addressed. If we learn one thing from all of this, it is that we live in a very connected world, and actions taken in one place can impact detrimentally elsewhere. Who would have thought three months ago that fruit bats and pangolins (the presumed original source of COVID-19) would play such a key role in our lives but we also need to remember that in reality they are the victims and not the villains in this whole saga.

The role of social sciences in environmental and conservation conflicts

It has been long recognised that an understanding of human interests and positions is important in better understanding and delivering conservation policies. Environmental issues and conflicts do not consist solely of matters which can be addressed by the natural sciences. The involvement of those who specialise in the social sciences in environmental and conservation conflicts will often provide insights into the way people behave which are key to ensuring effective actions and outcomes follow.

Bennett N.J. et al (2017) have recently published a review paper of how a broad range of social sciences can contribute to and help deliver conservation outcomes which are more ‘legitimate, salient, robust and effective’. The paper ‘Conservation social science: understanding and integrating human dimensions to improve conservation’ is published in Biological Conservation and is open access – it can be downloaded here.

I have recently read How culture shapes the climate change debate (Hoffman 2015) which is a good example of how the social sciences can provide context, understanding and potential approaches for conflict resolution in the polarised debate around the issues of climate change, science and anthropogenic global warming in the United States.

Hoffman argues that climate change is not really about carbon dioxide and complex mathematical models, it is really about opposing cultural values and worldviews.

The book describes how we all use cognitive filters to look for information that supports our pre-existing beliefs. These cognitive filters reflect our cultural identity known as cultural cognition. This leads to us developing ‘worldviews’ are consistent with others in our group. This cultural identity can overpower scientific reasoning. Our cultural identity is also influenced by economic, political and technological matters and this creates our own political economy which creates an inertia for change.

In the case of the polarised debate in the US around climate change it means that different groups view the same science but see different things which creates a cultural schism. For example, those who dismiss climate change as a threat to society, see policies brought in to lessen the impacts of climate change as an interference with the market, the overpowering hand of Big Government which diminishes personal freedoms – a threat to their livelihoods, their wealth, their way of life and perhaps even their religious beliefs.

This leads to the use of ideological filters which are influenced by our belief systems and creates motivated reasoning and our cultural cognition. Greater weight is given to evidence that supports our pre-existing beliefs and causes biased assimilation or confirmation bias. Conversely, we refute evidence that challenges our pre-existing beliefs and this is known as disconfirmation bias.

These biases are exacerbated by our bounded rationality i.e. we are limited by the type and amount of information we can access and by our cognitive ability to process it. As a result, we are cognitive misers only spending time on things that are important to us.

Hoffman goes on to suggest that there are four main reasons why people disagree about climate change.

  1. Distrust of the messengers – e.g. Al Gore for example is seen by neo-liberal Democrats as a left wing liberal environmentalist who is using the issue to make himself money. A ‘watermelon’ – green on the outside, red on the inside.
  2. Distrust of the process that created the message – e.g. the scientific review process is corrupt (peer review = pal review), Climategate, distrust of the IPCC and the United Nations. Scientists only do the research to get grants to keep them in employment.
  3. Distrust of the message itself – e.g. carbon dioxide is good – it makes plants grow, environmental disasters as a result of climate change are simply not possible, climate change challenges their notion of God.
  4. Distrust of the solutions that come from the message –g. interventions to reduce climate change lead to an intrusive Government, impacts our personal lives and the free market.

In effect both sides of the argument are speaking different languages: science verses neo-liberalism.

As such there are three options for resolution:-

  • The optimistic path – a technological solution will be invented which means we can maintain our lifestyles and levels of prosperity without needing to use fossil fuels.
  • The pessimistic path – a combative path in which the battles will continue until one side eventually wins.
  • The consensus based path – a consensus based approach to conflict resolution.

Tactics for bridging the cultural schism – a social science approach

  1. The messenger is as important as the message – choose leaders carefully – ones that can bridge the divide
  2. Address the process by which the message was created – rather than trying to address the issue in its entirety e.g. the IPCC Consensus Statement, break it down into a number of discrete pieces e.g. are greenhouse gases increasing?, does this lead to a warming of the planet?, has the climate changed?, are humans responsible?, what is the environmental and social impacts? Gradual consensus building.
  3. Choose messages that are personally acceptable – messages needed to be framed to specific audiences and need to be made personal e.g. some may prefer a risk management approach i.e. what will happen to our insurance premiums; others may prefer public health threat approach as it is personal and salient.
  4. Present solutions for a commonly desired future – rather than focusing on what must be sacrificed concentrate on solutions, innovation and current successes

Defining a social science theory of change

  • Build the trust of those we are trying to influence
  • Create a vision for where we might go
  • Understand how to overcome people’s fears

Building trust is vital and something that is sadly lacking at the core of many conflicts. Creating a joint vision can only occur once there is trust and dialogue led by a trusted messenger. Understanding people’s fears again can only come from dialogue and research.

Hoffman finally states that there three central points to a theory of change.

  1. Focus on the middle – not the extreme scenarios like 6m sea level rise
  2. Employ the radical flank – there are those with radical positions – use them to create a bigger and more attractive central ground
  3. Never waste a good crisis – in the aftermath of recent hurricane events the costs of insurance have been monetised by the Markets and this makes climate change current and real in people’s minds and makes them more likely to act.

These four quotes from the book seem very pertinent to me.

“More science, though important, will not by itself change people’s minds and create the collective will to act”

“It is about competing worldviews and the cultural beliefs of people who must accept change even when it challenges their beliefs”

“When engaging in the debate we must think not only of the science but also about the socio-political processes and tactics necessary to get people to hear it”

“Know your theory of change and enact it”

I found How culture shapes the climate change debate a fascinating book which helped explain to me why climate change science is so divisive in the US.

Interestingly a great many of the ideas set out in the book are directly relevant to our own conflicts in the Uplands here in England and on Dartmoor along with the search for consensus. We need to spend a great deal more time working out tactics for bridging the cultural schisms, building trust, focusing on the middle, employing the radical flank(s) and not wasting the good crisis that is Brexit.

Nathan J. Bennett, Robin Roth, Sarah C. Klain, Kai Chan, Patrick Christie, Douglas A. Clark, Georgina Cullman, Deborah Curran, Trevor J. Durbin, Graham Epstein, Alison Greenberg, Michael P Nelson, John Sandlos, Richard Stedman, Tara L Teel, Rebecca Thomas,
Diogo Veríssimo & Carina Wyborn. (2017) Conservation social science: understanding and integrating human dimensions to improve conservation. Biological Conservation 205: 93-108. Open Access.

Andrew J. Hoffman (2015) How culture shapes the climate change debate. Stanford Briefs. Stanford University Press.

Air pollution and climate change from aviation and shipping

I have recently been writing about atmospheric pollution from nitrogen and ozone (see here and here). According to a report from Natural England (NE 2015 p10) around a third of the nitrogen pollution on Dartmoor comes from long range nitrogen sources. This means the nitrogen comes from international sources and includes pollution from aviation and shipping.
Easyjet over Exeter

Currently carbon dioxide emissions from aviation account for around 2% of global emissions but these are set to rise by up to 400% according to the UN. As well as emitting carbon dioxide jet engines also emit nitrogen oxides, sulphur oxides, soot and water vapour.

Globalisation and our one-liberal economic model means shipping is also a group area

Shipping accounts for 2% of total global emissions and this could rise by between 230-350% by 2050. As well as emitting carbon dioxide shipping engines also emit nitrogen oxides, sulphur oxides and soot.

Neither aviation or shipping are explicitly covered by the Paris Agreement on Climate Change but their continued growth will pose a serious threat to Dartmoor and elsewhere as a result of carbon dioxide, ozone and nitrogen pollution.

Natural England (2015) Atmospheric Nitrogen Theme Plan. Developing a strategic approach for England’s Natura 2000 sites. Improvement Programme for England’s Natura 200 Sites – Planning for the future.

The oak and ash race

Ash before oak – we are in for a soak

Oak before ash we are in for a splash

In reality oak pretty much always  comes into leaf before ash. In the last fifty years oak has always leafed before ash. It has not always been this way – in the 18th century when it was less mild ash did often flower before oak – thus the quote.

Climate change has changed all of this – usually oak leafs in late March-May which is about two weeks earlier than 30 years ago. Ash usually leafs during April and May, about 7-10 days earlier than 30 years ago.

Not this year though.

I have 5 oak trees and a number of ashes.

Four of the five oaks are just coming into leaf but so are all the ashes – it is a dead heat.

Ash coming into leaf

Oak buds

I can’t really explain this as it has been a mild winter in a warming world so oak should have beaten the ash by quite a distance – any ideas?


The problem with Heather Beetles

The Heather Beetle (Lochmaea suturalis) is a native Chrysomelid leaf beetle which feeds almost exclusively on heather (Calluna vulgaris). It is common in areas whether heather grows from the south of England to Orkney in the north (Duff 2016).

Heather beetle populations are well known to fluctuate greatly from low numbers which have little over impact on heather plants to very high numbers which can lead to the widespread defoliation of heather and can cause its death.

Heather Beetle damage on Ryders Hill March 2016

Heather beetle outbreaks have historically been problematic for grouse moor owners and the issue of heather beetle and its control has been championed by the Heather Trust who have produced a short document on the species (Heather Trust undated).

In addition the Heather Trust commissioned a literature review of the species (Rosenburgh & Marrs 2010) which summarises the ecology of the beetle, its impact as a pest and strategies for control. This work has been updated (Gillingham et al 2015a and 2015b) and published as Natural England Evidence Reviews on its ecology and its management.

These reviews state the following regarding heather beetle outbreaks:-

  • ‘Considerable damage to heather can occur with complete death in the worst cases’.
  • ‘Large scale vegetation change can follow’ (heather outcompeted by invasive grass species).
  • ‘The occurrence and severity of heather beetle attacks appears to be made worse by increased levels of nitrogen in the soil and plant tissues, which has been blamed on high nitrogen pollutant inputs from the atmosphere in recent years’.
  • ‘The high nitrogen in the leaves provides the beetles with more high quality food to consume’
  • ‘Climate change is expected to lead to increased winter survival of heather beetles’

On Exmoor heather beetle is considered a major problem, and the National Park Authority report that outbreaks are common and are spreading from the south to the north of Park. They also suggest that in areas where Purple Moor Grass (Molinia caerulea) is absent the heather plants recover fully and rapidly but where Molinia is present this quickly swamps the heather and replaces it (ENPA 2015).

I have written before about the loss of heather that had occurred on the National Trust’s land in the Upper Plym valley on Dartmoor (see here). In 1995 there was a serious outbreak of heather beetle which killed off the heather in the area known as Hen Tor Fields. At the time it was assumed that overgrazing was the cause although no increase in stocking levels had taken place for a number of years.  In this specific instance the heathland communities (H12 Calluna vulgaris-Vaccinium myrtillus) were replaced by upland grass communities (U4 Festuca ovina-Agrostis capillaris-Galium saxatile) which do not naturally contain Molinia. On the wet heaths of the Upper Plym Estate there were numerous other outbreaks on heather beetle during the 1990s and 2000s (Helen Radmore NT tenant pers comm) and in these habitats Molinia now dominates (my observations).

There has been no systematic survey of heather beetle on Dartmoor and Goodfellow et al (1997) only briefly mention it “Outbreaks of heather beetle cause local declines in heather”, however my recent observations on the moor suggest that heather beetle damage is very widespread and extensive.

Heather Beetle damage on Ryders Hill – March 2016

I would be very interested to hear from anyone with information about heather beetles on Dartmoor in recent years – it is an issue which is begging for more research.

Duff A.G. (2016) Beetles of Britain and Ireland. Volume 4 Cerambycidae to Curculionidae. A.G. Duff (Publishing) West Runton.
ENPA (2015) Exmoor Swaling Review 2014/15. Seminar Notes ENPA. Dulverton.
Gillingham P., Diaz A., Stillman R. & Pinder A.C. (2015a) A desk review of the ecology of the heather beetle. Natural England Evidence Review, Number 008.
Gillingham P., Diaz A., Stillman R. & Pinder A.C. (2015b) Desk review of burning and other management options for the control for heather beetle. Natural England Evidence Review, Number 009.
Goodfellow S., Wolton R. & Baldock N. (1997) The Nature of Dartmoor: a biodiversity profile. English Nature / Dartmoor National Park Authority publication.
Heather Trust (undated) Heather Beetle. Download from Heather Trust Website
Rosenburgh A. & Marrs R. (2010) The Heather Beetle: a review. Report to the Heather Trust.

The problem with bracken

Bracken (Pteridium aquilinum)  is a contentious species which is almost universally hated on Dartmoor (except in the handful of places where it harbours the nationally threatened butterfly, the High Brown Fritillary (Argynnis adippe).

Bracken was once harvested as an important crop and used for animal bedding and as a roofing material. These practices dropped out of favour as other more modern materials were used instead and as a result bracken was no longer managed and began to spread.

This spread of bracken can be damaging to the historic environment as its dense network of rhizomes can seriously interfere with any sub-surface archaeology. It is also a species which is very unpopular with hill-farmers as it spread reduces the area of palatable grazing for livestock. Likewise conservationists do not like the species as its spread can reduce areas of inherently interesting vegetation communities e.g. heather stands (Marrs and Watts 2006).


Bracken tends to grow on deep well drained soils which do not become waterlogged. As a result it is absent on Dartmoor from the blanket bog and wet heathland communities as these are too wet. These deeper better drained soils on the moor support heathland (NVC H8 Calluna vulgaris-Ulex gallii heath) and upland grassland communities (NVC U4 Festuca ovina-Agrostis capillaris-Galium saxatile grassland and U5 Nardus stricta-Galium saxatile grassland). Bracken can encroach into wet heath communities (M15b Trichophorum cespitosus, Erica tetralix wet heath and M15d Trichophorum cespitosus, Erica tetralix wet heath, Vaccinium myrtillus sub-community if these have become drier as a result of hydrological changes, over grazing or burning (Marrs and Watts 2006).

These National Vegetation Classification (NVC) communities can change depending on the management regime they receive. Averis et al (2004) suggest the following changes to National Vegetation Classification communities which can all lead to an increase in bracken communities. The communities described below follow the NVC (Rodwell 1991 & 1992).

  • If H8 Calluna vulgaris-Ulex gallii heath or H12 Calluna vulgaris-Vaccinium myrtillus heath is over grazed or over burnt it can change into M25 Molinia caerulea-Potentilla erecta or U4 Festuca ovina-Agrostis capillaris-Galium saxatile
  • If U4 Festuca ovina-Agrostis capillaris-Galium saxatile grassland or U5 Nardus stricta-Galium saxatile grassland are under grazed then can turn to H8 Calluna vulgaris-Ulex gallii heath or H12 Calluna vulgaris-Vaccinium myrtillus heath
  • However all four of the communities mentioned above (H8, H12, U4 & U5) can be invaded by bracken and turn into U20 Pteridium aquilinum-Gallium saxatile

Bracken can be controlled either by cutting, rolling or the use of herbicides (asulam). However treatments must be repeated yearly if bracken is to be controlled, complete eradication is usually not possible. All these methods are time consuming and expensive. Rolling is often not possible due to the terrain or rocks and asulam can now only be used under an Emergency Authorisation licence as its use was outlawed in 2012 [1], there are also concerns that stocks of asulam are not in short supply as it is no longer being manufactured.

bracken-bruising-003Bracken rolling on Dartmoor by the National Trust

Pakeman et al (1995) showed that bracken had increased significantly over the past few centuries in Britain but they also showed that between 1970 to 1980 there had been a 3.4% decrease on Dartmoor (by 1.9km2 of bracken being gained but 3.8km2 being lost).

Pakeman et al. (2000) ‘concluded that the current abundance of Pteridium was less than, or at worst, equivalent to maximum historical records’. It is clear therefore that the abundance of bracken has fallen and risen depending on its harvesting or clearance by humans.

Werkman et al (1996) carried out experiments where bracken and heather and a mix of the two were grown in open topped tents to mimic climate warming and where different plots were treated with additional nitrogen inputs. They found bracken growing in the tents with additional nitrogen grew more vigorously and for a longer growing season than plants not grown in tents where no nitrogen was added. The bracken under the former conditions also encroached into the heather stands.

Werkman et al (2002) in another experiment found that bracken responded positively to increased temperatures but did not respond to increased nitrogen levels. They concluded that in a warmer climate bracken will continue to replace heather. They added a caveat that if climate change led to drier summers then water could be a limiting factor in the spread of bracken.

The implication of both papers by Werkman et al (1996, 2002) is that bracken will also spread into areas of upland grassland as well as areas dominated by heather.

Hill-farmers and other land managers on Dartmoor such as the National Trust spend considerable time and money attempting to control bracken on the moor, it would appear that in the future more effort will be required if bracken is not to spread further.

So rather like Purple Moor Grass Molinia caerulea, bracken does respond to anthropogenic changes to the atmosphere. In the case of bracken to increased temperatures caused by rising CO2 levels and in the case of Molinia to increased nitrogen levels caused by pollution from vehicles and agriculture (see here).

If a future climate change scenario on Dartmoor led to rising temperatures and reduced rainfall it is not impossible that the current areas of wet heath and those areas dominated by Molinia could become dry enough to allow the encroachment of bracken into these areas too.

Marrs R.H. & Watts A.S. (2006) Biological Flora of the British Isles: Pteridium aquilinum (L.) Kuhn. Journal of Ecology 94, 1272–1321
Pakeman, R.J., Le Duc, M.G. & Marrs, R.H. (2000) Bracken distribution in Great Britain: strategies for its control and the sustainable management of land. Annals of Botany, 85B, 37–46.
Pakeman, R.J., Marrs, R.H., Howard, D.C., Barr, C.J. & Fuller, R.M. (1995) The bracken problem in Great Britain; its present extent and future changes. Applied Geography, 16, 65–86.
Rodwell J.S. (ed) (1991) British Plant Communities. Volume 2. Mires and heaths. Cambridge University Press. Cambridge.
Rodwell J.S. (ed) (1992) British Plant Communities. Volume 3. Grasslands and montane communities. Cambridge University Press. Cambridge.
Werkman B.R. & Callaghan T.V. (2002) Responses of bracken and heather to increased temperature and nitrogen addition, alone and in competition. Basic and Applied Ecology 3: 267-276.
Werkman B.R., Callaghan T.V. & Welker J.M. (1996) Responses of bracken to increased temperature and nitrogen availability. Global Change Biology 2: 59-66.


Weather warning: Britain’s Special Places under Threat

A new report was launched yesterday written by The Climate Coalition with support, analysis and weather attribution by the Priestley International Centre for Climate. It shows how recent extreme weather events are damaging some of Britain’s most iconic places – you can download and read the report here.


There is a video which accompanies this campaign by showthelove which would can watch here – amongst others it features Charles Dance and Miranda Richardson.


Dawlish Warren Beach Management Scheme

There are some big plans ahead for Dawlish Warren. The fear is that a strong southerly storm could cut through the Neck of the Warren and split the sand dunes into two. This will then increase storminess in the estuary and create a heightened flood risk in the village of Dawlish Warren.

This information board at the Warren explains the detail.

dw2Looking across to Exmouth

dw3One of the groynes that needs to be replaced.

dw4This is part of the first phase of the project that was completed a couple of years ago – an internal bund that will hold back the sea during storm surges.

Later in the year a new bund will be built near the Neck made of geotextile bags.

Coastal erosion at Leasfoot Beach

Apart from seeing the Desert Wheatear on Leasfoot Beach near Thurlestone last weekend I also came across the aftermath of the 2014 storms which hit the south coast of Devon.

The small road which runs down from the cliff top car park towards the golf course has been swept away

leasfoot-beach-1Looking back from the other direction you get a good impression of how much land the sea gouged out

south-milton-sandsFrom the top car park you look down onto South Milton Sands – the same storm removed a lot of the sand dunes and also took away the road at the far end of the beach where the buildings are.

Sea level rise and increased storminess resulting from climate change will make these kind of episodes more common in the future.

UK Climate Change Risk Assessment 2017

Yesterday the Committee on Climate Change published a 2000 page report setting out the threats faced by the UK from Climate Change. The report consists of a ‘Synthesis’ summary document along with 8 technical chapters. You can download the summary report here and the technical chapters can be accessed from here.

The report highlights six area of threat and these are summarised in the table below.

Screen Shot 2016-07-13 at 10.15.52

Lord Krebs who chairs the Adaptation sub-committee summarises the report in this video

There is a great deal in these reports and I can’t claim to have done more than skim the surface but it is clear that we face huge threats from flooding, we are not properly prepared for the rising temperatures and much of our agriculture is entirely unsustainable as it is degrading the soil that it depends upon.

Whilst the publication of this important report passed under the radar for most yesterday due to the shenanigans of the two main political parties it is important to see what our new Prime Minister had to say in 2008 about climate change.

“I am thrilled to see that after years of Conservative pressure, we have finally passed a necessary and ambitious piece of legislation on Climate Change. Britain is the first country in the world to formally bind itself to cut greenhouse emissions and I strongly believe this will improve our national and economic security. To stay reliant on fossil fuels would mean tying ourselves to increasingly unstable supplies which could endanger our energy security and the Climate Change and Energy Bills mark an important step for both the health of our economy and the health of our nation. It is now vital that we stick to these targets. I will continue to put pressure on the Government over the third runway at Heathrow as an extra 222,000 flights a year would undermine our national targets and seriously damage the health of the local community.”

The worry of course now is that with everything else that is going on this essential work won’t receive the time and attention that it needs.