Store and flux – it’s a game

Ecosystem stores and fluxes. Local-scale exchanges of energy and matter. Human as well as Biophysical stores. The threat of the big global flux. The basis of a computer game.

SEDA Land [1] – a part of the Scottish Ecological Design Association (SEDA) – has been working with students at the University of Abertay Dundee [2] on a computer game in which- after catastrophic events – communities are striving for survival.

Figure 1. The Ring of Brodgar, Orkney, built by early settlers who tilled the soil and grazed pasture, opening the way to today’s agriculture. Soils and essential biodiversity are degrading here, but it’s not the dust bowl yet. Images by Squire, inset shows a record (LP) cover – Dust Bowl Ballads by Woody Guthrie (more below).

In the game, the communities have to provide a minimum of three things from the land – food, shelter and power. They have to grow crops, grass and livestock, make houses and barns from rock and trees, and generate power from turbines and other sources.

Land is in short supply. The communities have to work together or they fail. But there’s something else – a recent cataclysm opened portals to the other side. Standing stones, some with obscure icons carved into them, appeared in the landscape. The ‘veil’ thinned and fantastical creatures passed through, some to help the communities, some to cause mayhem. How will they cope!

Well the first thing (GS said) is to understand ecosystem stores and fluxes [3], first the real, then maybe the metaphysical. Here we look at stores and fluxes at two scales. But first a quick look at another portal, described in a work of poetry by Dante and portrayed by the artist William Blake [4].

From William Blake‘s illustrations of Dante‘s Divine Comedy, Inferno III [4] as Dante and Virgil are about to step through Hell-Gate (from one world to another), where they come across the tortured souls of the INDIFFERENT (those who did nothing?).

Figure 2. At Hell-Gate, between one world of soft leafy trees and another where souls move forever along rising paths through red and blue shards (fire and ice – climatic cycles?). Image taken by GS at the Blake Exhibition, Tate Modern, London, January 2020 [4].

Store and flux at local scales

All ecosystems are subject to large environmental ‘fluxes’ that are essential for life, but that can destroy life if not regulated. Most land-based ecosystems build a ‘store’, which consists of soil, plants, microbes, invertebrates, higher animals, and the ‘dead’ organic matter produced when these organisms shed tissue or die. The organic matter is ‘worked’ by the living things into forms that bind soil particles and hold water and the nutrients essential for life.

The main inward fluxes (Fig. 3) are of solar radiation, water, and in some cases deposition of dust, ash and chemicals carried by moving air. The store processes these fluxes to enable (for example) photosynthesis by plants in which carbon dioxide from the air is converted to plant matter, and fixation of nitrogen from the air by a symbiosis of soil microbes and roots.

Figure 3. Diagram representing ecological stores (in the box) including soil (mineral particles, dead organic matter, etc.) and living matter (plants, microorganisms, invertebrates, etc.), and fluxes of energy and matter into (black lines) and out of (orange lines) the store. Based on Squire & Hawes, 2024 [3].

The main outward fluxes (Fig. 3) are long-wave radiation from the plants and soil that have been warmed by solar energy, evaporation of water (termed transpiration when this moves through plants), gaseous emissions to the air from breakdown of organic matter, further loss of water and materials as surface runoff and drainage to bedrock, and the loss of store particles by the same forms of air movement that also deposit material.

For a system to have resilience, its stores and fluxes have to be balanced. The store must regulate the fluxes to survive. It mostly does so in a natural system. But when people came to use the land, to cut trees, grow crops, and graze animals, they added two extra fluxes: inputs such as cultivation, controlled burn, new seed, livestock, fertiliser and more recently big machines; and offtake of material for food, clothing and timber.

Over time, the inputs and offtake have become so large that they commonly lead to imbalance in the system, generally to its detriment. While managed ecosystems can in principle last for many thousands of years, they can also be destroyed in a few decades by mis-management. Imbalance in store and flux and subsequent destruction of the store for short-term gain, whether intended or through ignorance, is named extractivism. The US Dust Bowl is a classic example (Fig. 4).

From the Dust Pneumonee song by Woody Guthrie

I went to the doctor and the doctor said my son (repeat), You got that Dust Pneumonee and you aint got long, not long.

My good gal sings the Dust Pneumonee Blues (repeat), She loves me cos she’s got the Dust Pneumonee too.

Figure 4. Cover of the classic Woody Guthrie record of songs about the US Dust Bowl released by Folkways some decades ago. The people most affected by such environmental catastrophe are usually the poorest, the vagrant, not those who encourage the change or set the policy. The words above left are from one of the songs; those below from inside the record sleeve [5].

The pioneering ax and plough rapidly upset the interplay of natural forces that had formed and preserved rich soils ….. The same tide that rolled the frontier forward from the Atlantic rolled back nature’s stabilising mantle of trees and grasses and bared virgin soil to weathering.

John Asch

But something is missing from Fig. 3 – the knowledge and experience that people have in managing land is also part of the store …. and no matter how good the management, the store can be affected by distant forces.

The store of knowledge, continuity and community

The diagram in Fig. 3 therefore represents only one part of a managed ecosystem. The other part of the store is held by the People that live and work on the land (Fig. 5). The People not only give to and take from the biophysical store but they form an additional store in terms of their knowledge, experience and social connections.

Figure 5. Diagram to represent an ecosystem in terms of its biophysical components and its communities of people (orange boxes), both under constant threat from large global fluxes, here divided into Biophysical and Human (blue boxes).

Probably more so that at any other time, ecosystem stores are now under threat from extractivism. Inputs and offtake have become so great that they dominate the store. This need not be, and we can learn from those examples of successful stewardship.

Yet well managed systems are under threat from things well outside their control. In talking to the Abertay students, these threats came to be called ‘Big Fluxes’ (Fig. 5).

Threat of the Big Flux

The Big Fluxes can be divided broadly into those having Biophysical and those having Human causes. The Biophysical, such as volcanic eruption, tsunami, flooding, and cycles of global cooling and warming, are outside the control or influence of any parcel of land and its people. Many of the Human causes are also outside local control – take war, blockade, nuclear fallout and the acts of occupying ideologies to force mass starvation and genocide. In some cases, the controlling hands are physically closer to the scene – take the evictions and clearances that depopulated rural Scotland in the 1700s and 1800s.

But some Biophysical forces can in principle be influenced by Human intervention, both inside and outside the land in question. For example, disease epidemics (and pandemics) may have originated well outside the land, but their spread to and within the land could have been limited, more than they have been recently, through better understanding of the infection process and more effective control.

Can anything be done to make the local stores and fluxes in Fig. 3 resilient to a Big Flux? To a degree it can, for some of the Big Fluxes. For example, if agricultural or grazing land is denuded of perennial vegetation, its soil over-cultivated or over-grazed, the organic matter allowed to degrade and the surface left exposed, it will suffer more under flood and storm than if it was properly cared for (Fig. 6). And fire-prone forest and bush can to a degree be protected by creating breaks and reducing the store’s burnable material.

Figure 6. Erosion gulleys like this form in many parts of the world, mainly when gradual soil degradation over a long period (which may be unnoticed) is scaled up to catastrophic erosion during extreme rainfall and flood. Most organic matter, including roots, in the photograph above occupies the upper 10 to 20 cm of soil (short vertical bar). Some roots, mainly of the shrubs, can penetrate the red soil layer to 0.5-1.5 m (long vertical bar). Arrows show the ends of roots exposed after the collapse of the soil into an erosion gulley 5 m deep. Photograph by Squire, south-east Asia, 2014.

Forgetting the Big Fluxes

The situation that needs to be faced, in reality and in the game, is that People forget about the Big Fluxes. There will be another, there’s no doubt, but People fail to prepare for it.

Some Big Fluxes are so infrequent that generations, sometimes centuries, even millennia, pass without experience of them. The last major tsunami to hit Scotland was thousands of years ago and the last volcano to throw its ash this way was Laki, in Iceland in 1783-84.

Others Fluxes are more frequent but governance repeatedly fails to act. In Scotland, and in the UK as a whole, home-grown food production fell well short of feeding the people in the run of bad-weather years in the late 1870s. Rather than giving long-term technological support for agriculture, the government filled the void by importing food from north America, leaving agriculture to suffer and its people to leave the land.

A few decades later, and in the face of blockades in 1914 and 1939, the country again had to rely on imports. Even now when its advanced agricultural technology could in principle feed the people, it would still fall well short in a face of blockade. Extreme climatic events elsewhere could have the same effect. Imagine that drought destroyed the vegetable harvest in Spain and north Africa. Where would the UK get its veggies from?

So ‘memory’ of the big fluxes needs to kept by people, by their communities and in their shared history.

It’s a game

How is all this going to be realised in a computer game? Well not all of it, at this point, but things like soil, vegetation, livestock, rock and power sources can be represented spatially. People have a choice as to whether they build their stores and extract materials sensibly, or let them degrade and ultimately fail.

They might be succeeding, and all looks good, but then what’s the chance of a Big Flux! Can other forces help them? It’s a work in progress.

Continued ….. click on the page number links at the bottom.

Page 2 More on soil degradation under agriculture and forestry and ways to avoid it by Lorna Dawson and Geoff Squire.

Page 3 Early project ideas and descriptions offered to the Abertay students by SEDA Land and James Hutton Institute (Geoff Squire, Lorna Dawson, Gail Halvorsen and Pete Iannetta) – in progress, to go ‘live’ soon.

See [5] and [6] below for links to related articles on curvedflatlands and livingfield webs.

Author | contact: For this article: or For SEDA Land and development of the game:

Sources | Links!

[1] SEDA Land:

[2] Abertay University: School of Design and Informatics

[3] Store and flux and related agri-ecosystem processes are described in a book chapter to be published ‘open access’ in August: Squire GR, Hawes C (2024). Biodiversity for Agriculture – the role of integrated farm management in supporting agriculture through biodiversity. In Managing Biodiversity in Agricultural Landscapes. Burleigh Dodds Science Publishing.

[4] William Blake (1757-1827) made many illustrations based on events in the Divine Comedy by Dante (1265-1321). Some were shown at an exhibition William Blake at Tate Modern in 2019-2020 and the complete set is now available in a book – Schutze S, Terzoli MA – William Blake – Dante’s Divine Comedy – The Complete Drawings, published by Taschen. The Divine Comedy is available in paperback and in online translations at Project Gutenberg and Digital Dante.

[5] Dust Bowl Ballads by Woody Guthrie, Folkways Records, 1964: see Smithsonian Folkways. More on the Dust Bowl at livingfield web: Dust Bowl Ballads which includes links to the pioneering work on soils by Hugh Hammond Bennett, e.g. Bennett HH, Chapline WR. 1928. Soil erosion a national menace. Circular No. 33, United States Department of Agriculture. 

[6] William Blake and the Dust Bowl were both referred to in an earlier presentation and web resource viewable on the curvedflatlands web at Soil: healing the skin. The healing remedies include Bandage (e.g. coverings) and Ointment (e.g. exudates and other organic matter from grass-crop-tree mixtures). Click for a PDF file of the presentation

Systems Framework 2011

Back in 2011, several people at the James Hutton Institute were working to develop a general ‘systems’ approach to measuring and modelling managed ecosystems [1]. We constructed a diagram to place and connect the main components of the system and the internal and external forces that influence its workings.

The framework diagram was used and adapted for various purposes in the following years [2], and has recently been re-interpreted for a book chapter to be published 2024 on the role of biodiversity in supporting agriculture [3].

We thought the original diagram should be available so collaborators could appreciate where the structure originated and how it evolved. Here it is. The main author was Cathy Hawes.

Here are some explanatory notes dated 16 August 2011:

“This diagram represents an initial stab at describing the context, the likely main elements and the scale of a generic ecosystem services framework. It is intended only to kick off discussion and is by no means a final approach to the problem!

“It starts off at a global or national scale influenced by global food/fuel/fibre markets and national policy goals (e.g. food security, biodiversity, sustainable development). These factors influence local markets and specific government policies at the regional or landscape scales. These, in turn affect farmer/landowner decisions and behaviour at the local scale. Finally, the end result is the impact on the interactions between individual organisms within a management unit (field, forest or hillslope).

“It is these interactions between organisms that produce many of the ecosystem services that are required for sustainability. The goods and services included in the boxes at each scale are taken directly from the National Ecosystem Assessment, but we will need to agree exactly where they should sit in the system and whether there are others that should also be included.

Balanced against these goods and services (benefits) are losses from the system or costs. Analysis of the trade-off between costs and benefits resulting from a particular policy/market goal then feed back to decisions made at each scale.”


Sources | links

[1] Research funding from the Scottish Government to the James Hutton Institute.

[2] The framework was used in EU projects to interpret multi-scale phenomena. For example, a much simplified version was published in the final report of the EU AMIGA in 2016.

[3] The diagram has been adapted for a book chapter to be published in 2024: Squire GR, Hawes C. Biodiversity for Agriculture: the role of integrated farm management in supporting agricultural production through biodiversity. Details to follow.

Community mapping – food, climate

SEDA Land’s mapping initiatives. Communities, landowners, science, technology, computer gaming. Food sourcing and food security. Local vs global. Spatial data and the need for local knowledge. Building resilience to global disruption.

SEDA Land arose from the Scottish Ecological Design Association’s 2021 Land Conversations as an active and inclusive grouping intent on exploring and then influencing the way we value and manage land and water [1].

One of the first developments from the Land Conversations was an idea to ‘map’ the land around a place or community for its capacity to provide for the people, now and in the future. That capacity included food, water, wood, open space and a sense of place. The ideas quickly developed and by early 2022 took form through collaborations between many people and organisations in a project called Mapping Future Food and Climate Change.

A map of fields (inset) on a farmed landscape, Aberdeenshire (original photograph by GS).

Community – land – science – art – gaming

A pilot study began in 2022, based on the locality of Huntly, comprising a range of community groups, schools and local landowners [2]. Scientific institutions are providing knowledge of soil, crops, food, carbon storage, greenhouse gas emissions [3] and expertise in computer gaming [4]. The main elements of the pilot study are as follows.

  • The land in and surrounding the town, and its nature, shape, occupancy, community involvement and ownership.
  • The biophysical status of the land, its climate and weather, bedrock and soil, carbon storage, biodiversity.
  • Structure of the land – mapping ‘parcels’ or units of management (e.g. fields, woods) and what they produce or contribute.
  • The community’s use of locally-grown products versus the import of things grown on resources elsewhere.
  • The meaning of the land to the people, expressed through tradition, art craft, music [1].
  • Definition and analysis of spatial and temporal ‘layers’ (e.g. area, soil, climate, use, inputs, outputs) to understand the current value and limitations of the land and its future potential for delivering benefits such as food security, C sequestration, biodiversity and community involvement.
  • Expressing all of the above through computer gaming.

But where do we begin … ?

Fig. 1 Map of the Climatic Conditions in Scotland, published 1970-72 by Birse and colleagues at the Macaulay Institute for Soil Research [5].

Mapping the biophysical, economic and political landscape of Scotland has a history going back several hundred years. The climatic maps produced in the early 1970s from the Macaulay Institute for Soil Research (Fig 2) are among the most spectacular. The arable-grass agricultural land lies mostly in the red and yellow areas around the east coast and across the central belt.

In the half-century since Fig. 1, digital maps have become the norm, now available online for many features – including land classification, soil and soil carbon content, erosion and compaction risk, and land suitability for agriculture and forestry [6]. The study based around Huntly will be able to use the maps, and the data behind the maps.

Fig. 2 An area of land, a few kilometers in diameter, in which the individual parcels are identified, each having the potential for distinct and different land use [7].

Mapping land and land use

The patterning of the land is one of the first things to appreciate, and in particular the division of the land into the units of management. Why is this important? Well … suppose three fields have similar soil, slope (etc.) but one is woodland, another is grassland and the third is cropland. They all differ in what they produce, their agrochemical and mechanical inputs, the carbon they store, the biodiversity they support and what they conserve or release to the wider environment. Therefore the management of the field is just as important as its underlying qualities.

Mapping fields and other land parcels in fine detail is now possible (Fig. 2). Their shapes can be made visible and to a large degree, but not completely, the use of the land in each parcel can also be defined. Without even visiting the area, the parcels containing established vegetation such as woodland and marsh can be identified from remote sensing and each of the agricultural parcels can be separated into grassland and arable (or cropped land) using data from government census.

The sequence of crops grown in an arable field can also be defined, and from that, combined with data on soil, climate, outputs (yield, etc.) and inputs (agrochemicals, etc.), the capacity for carbon storage end emissions can be estimated or modelled.

Let’s get on with the mapping.

Fig. 3 The parcels of land in Fig. 2 supporting grass for livestock grazing (left), crops such as barley (centre) and a variety of other uses in agriculture and forestry (right) [7].

Given the right information [7], the shapes can be coloured to show the different forms of land use. In the example in Fig. 3 – based on the field patterns in Fig. 2 – the first to go in is grassland (Fig. 3 left), then tilled or arable land (centre) and third, the remaining areas consisting of woodland, vegetables and fruit, minor crops that occupy relatively few fields, and also semi-natural vegetation (right).

When all land parcels have been identified, the map looks as in Fig. 4: a complex mosaic of land use types that gives the Atlantic zone maritime its unique features. Some of the patterning originated hundreds, even thousands of years ago. Like much of lowland Scotland, and despite removal of the original vegetation, the fields are diverse in size and shape, with little evidence of prairie agriculture that continues to degrade so much once-natural land in many parts the world.

Fig. 4 The three parts of Fig. 3 brought together, where each colour represents a distinct type of land use [7].
Limits to data – the need for local knowledge

Because of the way land use has been recorded historically, the arable fields can be defined by the crops grown in them, such as barley, oats, wheat, beans, peas, oilseed rape, potato, turnips, and so on. However, grassland – which often occupies the most land in regions of lowland Scotland – tends to be lumped in just a few categories. In the current census, the two categories are grass present in a field for under 5 years and grass in its fifth year and over. This lack of definition in grassland obscures the great variation found across Scotland’s managed grass in terms of biodiversity, soil carbon content, fertiliser inputs, greenhouse gas emissions and grazing potential.

Several other factors important for the study cannot be gained from current surveys. It is not possible to know from remote sensing or census data the quality and purpose of the product and whether it is consumed locally or exported from the area. For example, a field of cereal (barley, wheat or oats) could be used for malting (alcohol), livestock feed or milling to produce flour. The cereal feed might be given to livestock on the same farm or sold to a merchant to be used in another place. Even much of the grain used for milling – though small in quantity compared to malting and feed – will be sold to merchants for distribution elsewhere.

And it’s not possible to know what the landscape means to the people who live in the area. So for these unknown or uncertain features, we must add in local knowledge ….. that provided by the general community and the people that manage the land.

Next steps

SEDA Land, the Huntly Community interests and the academic partners are now looking to obtain grant funding. In the meantime, several of those involved will be scoping the digital mapping and other background data available online and members of the mapping group (1-4] will be getting to know each other through meetings, real and virtual.

By way of introduction to the project, SEDA Land is preparing a set of questions asking people’s perceptions of what the land around Huntly provides – for example, how much food and timber is grown locally rather than imported. The questions are intended primarily for schools but will be available to any in the community.

Fig. 5 Map of a region in Scotland showing land in broad categories: the lower altitudes support arable (crops) and grass, shown in green and yellow; the higher reaches, especially to the top of the image holding mainly rough grazing. Map prepared by the James Hutton Institute as a contribution to Nourish Scotland’s work on food systems [7].
Spatial scales and land categories

One of the first things the group will consider is the spatial scales at which data will be recorded and the categories into which land is divided. An example of broad land use categories is given in Fig. 5, which represents a tract about 30 miles at its widest. This sort of mapping gives a quick guide to the general possibilities for food and timber production. Green and yellow is already under managed agriculture. Orange, which covers more than half the area, is of low productivity, mostly used for extensive grazing of sheep, but offers possibilities, for example, of woodland regeneration.

Fig. 6 An area of land, lower altitudes to the bottom-right containing many small fields (average area around 7 ha), rising in height to large units of more open moorland at the top [7].

Much finer detail can be defined, as in Fig. 2-4, giving clues as to how local topography, soil, microclimate and past management determine the patterning of fields and what can be grown in them.

The fields and other units in a tract of land a few kilometers wide are shown in Fig. 6. The area to the bottom of the image, comprising many small fields, has been in agricultural use for thousands of years, but records exist of its conversion into high-quality arable and grass from the time of the monastic improvements beginning in the 1200s. The top of the image is higher land which would have been woodland in prehistory, but now comprises large units of open moor or rough grazing. The strands of small fields running down from the moorland identify water courses. Fig. 6 is taken from the upper left of the larger area shown in Fig. 7.

The scientific contributors will assist with defining scales and data, but anyone with interest in the project can begin now with online and free-to-use mapping through the National Library of Scotland and Ordnance Survey [8].

The curvedflatlands web site will be publishing further news, posts and comment over the coming months and maintains a growing inventory of relevant data sources [9]. The SEDA Land web pages [1] will be the formal point of contact for the project.

Fig. 7 Fields and other land units delineated over a landscape bordering the sea (in white), two crop types identified by orange and yellow colour; width 47 km. From work by Nora Quesada, Graham Begg and Geoff Squire at the James Hutton Institute [7].

Sources | Links

[1] SEDA Land is part of the Scottish Ecological Design Association: A working group within SEDA Land, including all the participants, is taking forward the work on community mapping. Primary contact for the project: Gail Halvorsen, email: As in the Land Conversations, writing, poetry, art, craft and music will be integral. Contact: Sophie Cooke (

[2] Primary contact: Huntly Development Trust Email: Jill Andrews ( Local schools and landowners are active in the project.

[3] The scientific input is guided by the James Hutton Institute and Scotland’s Rural College (SRUC). Contacts at JHI: Lorna Dawson ( and Cathy Hawes ( Contact at SRUC: Mads Fischer-Moller (

[4] The University of Abertay, Dundee, will be working towards gaming design through a post-graduate student group starting later in 2022. Contact: Kenneth Fee (

[5] E L Birse and colleagues at the Macaulay Institute for Soil Research (now part of the James Hutton Institute) produced three classic maps on the Assessment of the Climatic Conditions in Scotland. The one shown is the last of the three, credits as follows:

[6] The James Hutton Institute’s online resources: Scotland’s Soil Data and other maps accessible from that page .

[7] Data for defining land use (crops, grass, etc .) in Fig. 3, 4, 5, 6 and 7 came from EU’s Integrated Administration and Control System (IACS) and was spatially analysed by Nora Quesada, Graham Begg and Geoff Squire at the James Hutton Institute. The maps in Fig. 4 and 7 were published some years ago on the Living Field web site at Scaperiae. Contact:

[8] Online map resources The National Library of Scotland has an increasing range of historical maps available online at the Map Images Homepage. The Ordnance Survey’s extensive downloadable resources are at Open Data Downloads and for education, see Free Education Resources for Teachers, and Digimap for Schools.

[9] curvedflatlands is compiling an inventory of mostly online data on land, soil, vegetation, biodiversity, climate, etc., which will be updated as new material becomes available: Sources of Information.

Author / Contact: GS has been working with SEDA to develop the 2021 Land Conversations, is on the steering group of SEDA Land and keeps (honorary) links with the James Hutton Institute. email: or

[Page online 10 March 2022, minor edits 27 March 2022]

Degradation-restoration: defining a safe space

Work with the Scottish Ecological Design Association (SEDA) over the past year [1] led to an invited, short article in SEDA’s autumn 2021 magazine [2]. The topic chosen was the integrity of ecosystems, their degradation through mismanagement and their possible restoration. This short article expands on some of the topics raised in the article.

Transitions in the state of land

Production ecosystems can be placed in one or more categories defining their state on a scale of degradation and regeneration. All agriculture and forestry began through change in a primary or original ecosystem (1) that was largely untouched by human activity. In many places, the original was slowly transformed into production land (boxes 2, 3). Some such systems have remained in production for hundreds, even thousands of years. More generally, sustainable production gave way to extractive production, which if intensified reduced the functioning of the system to the point where it could no longer support economic output (5). Land might have further degraded to a state that no longer supported agriculture and forestry (6). An alternative route from (1) to (6) is through rapid and excessive exploitation, as is happening in parts of the world that have lost primary ecosystems in only a few decades.

Figure 1. Transitions in land use from natural ecosystems (1) to systems managed for economic output (2, 3, 4), to exhausted or degraded land (5, 6), and then through regeneration to sustainable production (2, 3) or through wilding to a system much removed from (7) or similar to (8) the original. Brown arrows represent degradation, green arrows regeneration, dashed arrows a difficult transition and uncertain outcome. Green boxes – where productive land in agriculture and forestry should be.

Many past civilisations have reached 5 or 6 and then faded away as they lost the ability to produce essential food and materials. Others have decided to repair and regenerate ecological processes. Regeneration might attempt – where the land and climate permit – to move back from 4 or 5 to a sustainable state, whether extensive production (2, low management input per unit area) or sustainable, economic production (3).

Relative stability in categories 2 and 3 is possible in many different soils and climates (some examples in Figure 2) but the prevailing trend in much of agriculture and forestry has been continued transition from 3 to 4, 5 and 6.

Figure 2. Examples of productive land use in categories 2 and 3: upper left, c’wise, wetland rice, northern Laos; seasonal hill grazing, Slovenia; terraced vegetable fields, Burma (Myanmar); and mixed woodland and grazing, Romania (photographs by the author).

Recognising that land has degraded to 4 or 5 is a first and necessary step to regeneration. The Improvements in Scotland after 1700 accepted that much land had been exhausted of nutrients and found ways to re-stock soil. In the 1800s, the design and trialling of complex ‘grass’ seed mixtures, comprising grasses. legumes and other dicot plants, aimed to improve nutrition of both the soil and the livestock that fed on the grass [3].

An even greater challenge is to move severely degraded land back towards the primary state (from 6 or 5 to 2). That is possible but it takes a long time, decades, centuries. Some shifting cultivation in Asia is in many respects of this type. The forest is felled and burned, crops are grown on the nutrients from the trees, and after a few years, agriculture moves to a new area, the land left to return to scrub or forest. Shifting cultivation of course needs a lot of land and a small population to feed and when those conditions are met, can be sustainable to a degree. In many cases, the land simply cannot get back – for example, its soil might have been lost, its functional biodiversity extinct – and it ends up in what is here termed a reduced system, a desert for example (7).

Proportioned stores and flows

Natural ecosystems evolved to balance their ‘flows’ and ‘stores’. The big universal flows of solar radiation and water allow plant life to turn carbon dioxide in the air to living matter – the basis of an ecosystem store. Microbes and small animals feed on the plant products, creating a more diverse store and allowing it to combine with the earth’s inorganic materials, to create soil or coral, for example. A balanced ecosystem can last for millennia, but the balance is delicate.

The problem for land management and restoration is that main flows of energy and matter are very large compared to the stores. One of the crucial functions of an ecosystem’s store, therefore, is to regulate the flows that sustain it. In a perennial forest or grassland, high solar radiation is balanced by evaporation of water through vegetation to achieve an equable temperature, and layers of vegetation shield soil from the most intense rain. The store also allows a system to survive through adversity, whether seasonal dryness or flooding.

The problem is very simply illustrated in Fig. 3, which represents, on the left, a well-regulated system and on the right, one exhausted to destruction. The box shows the store, and the large downward arrow represents the main flows into the system. The store captures and partitions some of the flows (internal circular arrows) but most of the flows pass through the system. On the left, the large store is able to partition the inflows through several different outflow channels, whereas on the right the small store is ineffective to a degree that the inflow passes through in a single large outflow.

Figure 3. Diagrams to represent and ecosystem ‘store’ (box) and the flows of energy and matter (arrows) in systems that are left, well proportioned (large store compared to inflow and many dissipating outflows) and right, degraded (small store compared to inflow and single outflow).

In a place that experiences, for example, high inflows of rainwater, the left-hand diagram might represent be a multi-storied tree-crop system that collects and holds water, then channels the excess through evaporation, drainage, soil-surface flow and transpiration through the plants (e.g., Fig. 4 right); whereas the right hand box could be a degraded, weakly structured and sparse vegetation that intercepts little of the water, which then hits the soil and flows off mainly as surface wash, eroding soil at the same time (e.g., Fig. 4 left).

Figure 4. Examples of tea plantations in the same region of Sri Lanka, the right hand one able to contain, use and dissipate high flows of solar radiation and water, the right hand one unable to do so and losing its soil. The difference is due entirely to management. (Photographs by the author).

Scientific study can inform ecosystem restoration by quantifying the stores and flows in a system, assessing the current status of the system compared to a sustainable ideal and defining feasible transitions in Figure 1.

International efforts in restoration have been boosted this year by the UN’s Decade of Ecosystem Restoration 2021-2030 and its 10 Guiding principles [4] and by the Society for Ecological Restoration’s [5] intensified political activity, particularly in Europe, both of which will have further coverage on this web site.

Sources | links

[1] Background to the Scottish Ecological Design Associations set of 6 Land Conversations: Land Conversations – first ideas, SEDA Land Conversations – matrix and decision tree, and later in the year, a summary of the online discussion hosted with the John Muir Trust: Carbon tax land conversation?

[2] Sustainable Design for Ecosystem Restoration by G R Squire in SEDA Magazine Autumn 2021.

[3] Grass seed mixtures of 1800s Scotland are described on this site at Grass mix diversity a century past and the Agrostographia.

[4] UN Decade of Ecosystem Restoration 2021-2030 at and the UN’s 10 Principles that Underpin Ecosystem Restoration

[5] Society for Ecological Restoration (SER)

Carbon Tax Land Conversation

John Muir Trust – SEDA Land: online conversation on a carbon tax for land

The newly formed SEDA Land [1] organised an online conversation on 10 November 2021 in which the John Muir Trust [2] set out its proposal for a carbon tax on land. Several invited responders then commented on the proposal. Members of the audience asked questions via a chat line.

It was a much needed debate. Land is being degraded and losing its store of carbon in many parts of Scotland. The diagram below was constructed as a step towards completing my understanding of the complexity of interactions linking a carbon tax to land management and hence land-based carbon storage and GHG emissions.

Complex sets of processes are identified as single boxes, some grouped and some linked by arrows. Boxes shaded grey are those that (the author suggests) received most discussion during the Conversation.

Click to see a larger image

Figure 1. Decision trees (simplified) linking interventions on the right (taxation, inducement, management) though land type to biophysical processes (centre) and ‘pillars’ of sustainability.

Change in management inevitably leads to some alteration in the biophysical and social-economic parts of the overall ecosystem and so will have a range of outcomes other than those on carbon and emissions. Some of these outcomes may be unintended or unexpected. 

A general feeling at the meeting was that there should be a broad, holistic approach to defining the problem and executing the solutions. Less silo-ing among all parties involved is therefore needed.

Explanation of the diagram

The structure is based on a decision tree of the type created in DEXi software [3]. Starting from the left , the system is divided into biophysical and social-economic attributes (A, B) but there is nothing rigid or fixed in this – other categories could be placed here. Both branches subdivide into other branches (technically called nodes and leaves) which can be extended as needed to include the fine-scale workings of the system. Regulation of carbon and emissions (box C) can only work through the biophysical attributes (e.g. primary production, organic matter breakdown, microbial activity, food webs, element cycling, etc.) which are not shown in detail.

Carbon and emissions are of course not the only high-level attributes linked by biophysical and social-economic processes. All the others – food, industrial products, alcohol, wood, fibre, power – are represented by box D.

Three groups of  ‘interventions’ are shown influencing boxes C and D (and hence A and B). First, to the far right, are those related to taxation (G): the boxes within G indicate some of the topics discussed at the meeting, for example, area-thresholds and criteria for defining carbon in land. Taxation, etc. has to operate through land management (box F) – and while the current proposal is slanted towards land of low agricultural productivity, there are strong arguments not to exclude managed grass and arable lands, which can hold much more carbon and emit far less than they presently do. Management interventions operate through land types or classes which are shown in a separate box (E). Change in one land category generally affects what goes on in another.

External influences

A particular part of the diagram (at the bottom) alludes to a crucially important set of processes – those that act from outside the region or country but have a great effect inside it. So over-reliance on imports, and purchase of land by external countries and corporations as a means to carbon offsetting, will put a break on internal interventions designed to increase the biophysical and social-economic sustainability of land.

It is essential therefore to include within the set of interventions (G) explicit regulations – here termed global responsibility – that are designed to prevent aggressive purchasing of land within the country and despoilation (including ecocide) in other countries. Interestingly the international crime of ecocide was defined by lawyers earlier in 2021 [4].

Despite the complexity of the topic, the scientific and technical capability to set criteria and estimate C storage and emissions is within reach. Moreover, the examples given at the meeting of how energy-use can be graded (for example for appliances and domestic housing) and of how taxation has already reduced damage to society, show that the approach proposed by JMT could work.

GR Squire, draft for SEDA 12 Nov 2021, modified and uploaded to curvedflatlands 27 November 2021 (with minor edits 8 December 2021).

More to follow

Sources | links

[1] SEDA Land’s web site describes the formation of the organisation and gives information on recent and upcoming events

[2] John Muir Trust

[3] DEXi by Marko Bohanec: more on this web site on the functioning of decision trees and links to the software at SEDA Land Conversations.

[4] Ecocide – The Living Field web site under its DIARY21 lists developments during the present year by those intent on bringing the crime of Ecocide to public attention. DIARY21 gives links to reports and announcements.

SEDA Land Conversations – matrix and decision tree

The SEDA Land Conversations, online in March and April 2021, have taken place and the report on them is due in June. Updated matrix and decision tree, used to guide content and summarise developments, are described here.

The series of SEDA Land Conversations – A New Vision for Land Use in Scotland – was held online between 1 March and 12 April 2021. This post updates a previous description of the matrix and decision tree that were used to define the scope of the conversations.

SEDA’s approach for assistance with the Conversations at the end of 2020 was welcomed in a previous post – Land Conversations 2021 – which related some interactions with SEDA several years ago.


Two simple devices were used to assist development of the Land Conversations: a 2-D matrix and a decision tree. Each of these depicted connections between two of the several ‘dimensions’ through which land use operates and can be influenced:

  • Basal states (topography, soil, climate)
  • Land Use types
  • Outputs and products from the land – ‘What we get from land’
  • Governance and society (often two separate dimensions) including ownership, public needs, power balance, political will
  • External influences – mainly human causes – including global food system, import dependence, and then blockade, war, global pollution.
  • External influences – mainly ‘natural’ – e.g. volcanic eruption, mass-transfer by air.

These dimensions are presented for illustration here – they are not all-encompassing, not fixed. The first three in the list tend to be directly connected, in that Outputs and products depend much on basal states but can also influence basal states (e.g. several thousand years of deforestation, two decades of growing potato).


A spreadsheet was constructed (Fig. 1) to list, in rows, the broad types of land use, and in columns, their outputs and products or ‘What we get from land’. Not all cells in the matric are occupied, but where there was clear evidence of occupancy, the cell was identified by a colour and symbol (see later). 

Fig. 1 A matrix of land use types (e.g. wind power, livestock production, wild land) and products or ‘(what we get from the land’ (e.g. energy, food, peace of mind): the arrows indicate a cell where there is a strong connection or interaction between land use type and product.

The matrix evolved as topics of the Land Conversations were being developed – examples later.

Decision tree

The tree is a simple device which partitions various linked entities in a hierarchy that can be converted to a model using for example DEXi software. The tree has a main trunk – which might be a sustainable future for land use in the region, which divides into several main branches (perhaps Land Use types) which in turn divide into further subbranches and leaves. In a model the leaves and branches can be combined quantitatively to give the status at any point in the tree. Also, the tree can be interrogated, for example, to assess the extent to which current food supply can be satisfied by production.

Fig. 2  Decision tree of main land use types and sub-categories (rows in the matrix): each category can be rated in relation to delivering one or more ‘products’ and the ratings combined through utility functions.

The matrix and tree were used to help guide discussion towards a set of concrete topics that would form the basis of the  conversations.

Matrix of Land Use types and five groups of products from the land

The Land Use types were a highly restricted set, presented in the first two left-hand columns in Fig. 3. The products and outputs were designated in columns under the descriptors ‘What we get from land’ and ‘Why we need land’ and were distinguished in five groups: 1) products from the land, 2) economy and employment, 3) losses and pollution, 4) wildlife and shared space and 5) human wellbeing and perception.  Where there was a clear interaction between row and column a cell was identified by a colour and an asterisk (explained later).

With reference to the dimensions listed at the beginning, Basal states and Land Use types are combined in the left-hand columns, while ‘What we get from land’ is condensed into the five groups listed in the previous paragraph. What about the other dimensions? Governance and society appeared as additional columns to the right of the matrix (under headings Ownership/influence and Political/administrative). The very wide range of external impacts was simply alluded to by the row in grey at the bottom of the matrix.

Fig. 3 Land Use Matrix: colours and asterisks define cells where a strong interaction exists between Land Use type and ‘What we get from land’; further dimensions are indicated by the grey shaded area to the right (ownership / political) and the grey row at the bottom (external influences). Zoom in to read detail.

The intention was that each Land Conversation would concentrate on a sub-set of cells in the matrix, and it was also envisaged that connections between cells or groups of cells would become apparent during the discussion. An example of connected topics in one Conversation is given in Fig. 4 (note – using an earlier form of the matrix).

Fig. 4 Example to show indicative topics in one of the land conversations. Note: the matrix above was based on an earlier draft and differs in detail from the final version depicted in Fig. 3.

Topics covered in each Land Conversation

The central Land Conversations LC 2, 3, 4 and 5 were intended to cover many of the topics of interest. LC1 introduced the concept behind the event and LC 6 considered next steps.

To compare coverage by the four central conversations, the matrix was adapted in the following way: if a connection (i.e. a cell) was covered then its colour and asterisk (see Fig. 3) were both left in place; but if a connection was not covered, the colour was removed but the asterisk left in place. The resulting coverage is suggested in Fig. 5. The result is highly subjective – one person (GRS) listening and noting – but from these observations, each Land Conversation was distinct and the overall coverage fairly comprehensive.

Fig. 5 Main topics discussed during the central four Land Conversations (author’s perception): LC 2, spread across green (products), yellow (economy/employment), orange (losses/pollution) and grey (wildlife/shared space); LC 3, mainly yellow orange and grey; LC4, mainly blue (human wellbeing) and grey; LC5, spread wide but concentrating on integration (shown by yello, blue and grey boxes).

Inevitably, as the base for the Land Conversations was land and its usage, the earlier conversations tended to be confined to specific sectors, but as the Conversations progressed, rows and columns began to be considered as complete entities. In LC 5 in particular, the columns ‘rural economy / jobs’ and ‘rural repopulation / housing’ and the lowest row ‘integrated/local – multifunctional’ were examined more as a whole than as discrete cells (as indicated by the outlined boxes around each row or column.

Extending to higher dimensions

The use of a decision tree can allow – in principle – the incorporation of the additional dimensions listed at the beginning. This is a complicated procedure that so far has not been completed for the Conversations, but the example in Fig. 6 shows the scale and the potential. A tree depicts Land use types (rows of the matrix) and suggests connections to ‘What we get from the land’ (columns of the matrix). The resulting tree, if constructed in these two dimensions, would be highly complex. However, the challenge lies in incorporating the other dimensions.

Fig. 6 Land use matrix presented as a decision tree with examples to show how Land use type connects with ‘What we get from the land’.

Querying the tree

Trees of the general form in Fig. 6 can be operated in both directions. We can ask what is the present system status, defined by how far the current land use types produce adequate products and outputs.  Or we can define what would be the ideal status and then ask how would land use types or the activities in them have to change to deliver the desired status.

The Land Conversations showed without question the need to invoke the second of these two. Speaker after speaker emphasised that the current system is not fit for purpose, in that few of the needed products and outputs, in any of the five groups, are currently provided by the land.

As an example, the links in Fig. 6 for first groups of products (green boxes) are expanded slightly in Fig. 7 to illustrate the question of how the present status of dependence on imports for staple carbs, wood and natural fibre can be lessened or removed altogether. Even a cursory analysis would conclude that the present status is a result partly of internal land use decisions and partly of higher-dimensional (some very powerful, mostly negative) influences. To achieve the aims, the present Land Use types and activities within them would need to be rebalanced, but that rebalancing could only be achieved by a complete reorganisation of current governance and public attitudes.

Fig. 7 Decision tree extended to include Products from the Land and illustrating some additional dimensions that would need to be incorporated if import dependence was to be removed.

A major bar to progress is that current land use is highly sectorised throughout the dimensions. Vested interests compete to keep things as they are. The Integrated/local land use type, though small in area at present, is given some prominence in Fig. 7 because – as discussed in LC 5 and 6 in particular – it can manipulate and rearrange the different land uses and products towards a desired blend.

As a further indicative example, links are shown in Fig. 8 between Land Use types and another of the groupings under  ‘What we get from land’, this one being Losses and Pollution. The tree could be extended via biophysical processes to link Land Use types to the categories of loss and pollution. 

Fig. 8 Decision tree extended to show main negative influences on the four categories under Losses and Pollution.

Final remarks

The main aims of constructing a matrix and decision tree were to assist in the selection of topics in the SEDA Land Conversations.

  • It is stressed that the examples given in Figures 3 to 8 are indicative and not intended to be final or fixed. While the examples have concentrated on Products from the Land, or ‘plant production’ in the tree, the other Land use types can be extended as necessary.
  • Dexi decision tree software is easy to use by people and groups who might wish to elaborate on Fig. 3, etc., or construct a different version (search ‘Dexi’ & ‘Bohanec’ to get to Marko Bohanec’s IJS-Slovenia web site and downloadable programme). Dexi has been used extensively in collaborations between the Hutton and EU groups.
  • A matrix and decision tree were found useful as simple visual aids but there are many other modelling systems that may be more appropriate to handle the complexity of what is being examined and proposed.


[Online 29 Jun 2021, minor edits 22 Apr 2022]

SEDA Land Conversations – first ideas

The Scottish Ecological Design Association has been progressing at pace with the organisation of their 6 Land Conversations. The first one will be held later today, details and booking at A New Vision for Land Use in Scotland.

Land use in Scotland and its immediate products are varied and spatially complex. They are influenced by matters of ownership and political will and a range of external agents of both human and natural origin. A matrix and decision tree are being developed as an aid to understanding the complexity.

[The tools were developed and updated during the conversations – later versions and examples of their use are given at SEDA Land Conversat-ons


A matrix of land use and outputs is is intended both to help set the scene and to summarise discussion over the coming weeks. The matrix as it stands at 1200 today 1 March 2021 is shown below (Fig. 1).

Land use is divided into broad categories of energy, water, urban/industrial, wild land, rough grazing, grassland, arable land, integrated/local enterprise and forest/woodland. The columns represent a second major dimension – things that the land provides or imposes as a result of management acting within local constraints. Categories include products from the land, economy/employment, pollution/losses, wildlife/shared space and human wellbeing.

Other dimensions are indicated outside the matrix. There are factors of land ownership and political will (columns to the right, left unfinished at this stage) and external influences (grey row below). The external influences can be further divided into those that are caused mainly by human interventions, such as the import-exports balance, wars and blockades; and those that can be classed as natural phenomena, such as weather and climate, storms and volcanic eruption. Pervading the whole, but not included in the matrix as shown in Fig. 1 is the biophysical baseline – geological and climatic history, topography, soils and our location on the Atlantic fringe.

Fig. 1 Matrix of land use classes (listed left, in rows) and things provided by the land, which are not all positive (coloured blocks, columns). A further dimension of ownership and political will is indicated by the grey columns to the right and the complex and varied external influences are represented very simply by the grey row at the bottom. Click for a PDF to view detail, including notes.

Each cell in the matrix is given a simple provisional score from empty, indicating little relation between the land use type (rows) and the output (columns), and then *, ** or *** indicating increasing relation or effect.

At this stage, the categories in rows and columns and the scoring in the cells are provisional and for illustration only. They are expected to evolve during the course of the Land Conversations in the light of discussion, comments and new understanding. The development of the matrix will be charted here with acknowledgements to those who have contributed.

Decision tree: a semi-quantitative assessment tool

The matrix is also being converted to a decision tree in DEXi software [1]. Like the matrix it will evolve with the Land Conversations. An initial description showing land use categories as branches of a tree and the other dimensions listed to the right is shown in Fig. 2.

Fig. 2 Diagram to illustrate the use of decision tree software as a means of organising the multiple dimensions of land use. The tree to the left shows the land categories, slightly modified from Fig. 1. The other dimensions, including the columns from the matrix, ownership/political will, and the various human and natural external influences are listed to the right. Each of the Other Dimensions interacts with the land use tree at many points, and any one interaction will affect other aspects of land use and other dimensions. Click for a PDF of the above.

Acknowledgements | contributions
  • SEDA and in particular Gail Halvorsen and David Seel for continued interaction over the scope and use of the matrix.
  • Will McGee from Forest Policy Group for suggesting realistic categories for the forest/woodland land use types.
Sources | references

[1] Decision models in DEXi are widely used in ecology and system studies. DEXi from Marko Bohanec at the Josef Stefan Institute, Slovenia is available to download: DEXi: a programme for multi-attribute decision making

Contact: or

[Updates – 2 March with decision tree figure and 3 March with text edits.]

Land Conversations 2021

Scottish Ecological Design Association’s Land Conversations, spring 2021. Six online discussions on the future of land use in Scotland. Including all forms of land – urban, wild, agriculture, forestry, industry. A call for people to decide the future of land in Scotland. With some recollections of earlier work with SEDA.

Back in 2012, the Scottish Ecological Design Association (SEDA) got in touch with an invitation to join them at their annual meeting and give a presentation on some of our work on the state and future of land, particularly that used for agriculture [1]. The meeting proved to be a refreshing example of searching discussion by people with interests and professions that were mostly outwith the scientific disciplines typically associated with food and agriculture.

Following the meeting, Sam Foster from SEDA wrote an appreciative summary of the talk (left, click to see a larger version), then he and David Seel, also from SEDA, asked if we would edit an Issue of the SEDA magazine.

The issue came out in 2013 [2] and included articles from several Hutton Institute people, and also friends and collaborators in soils, ecological processes, human fallibility and their links to land use and food security (more on the issue below).

Land Conversations 2021

So David Seel’s call, seven years later, in autumn 2020, with a request to advise SEDA on their proposed series of online Land Conversations, brought back some of those memories. Over the last few months, there has been continued interaction with SEDA, mainly through Gail Halvorsen and David Seel, who are leading the Land Conversations project, and then with ex-colleagues from the Hutton Institute who will be offering their expertise. The programme for the Conversations is now published on the SEDA web site [3, and flyer below right], which gives more on the scope and purpose. Here’s why it appealed to me.

First, the coverage of land use is comprehensive. It included production land comprising agriculture, forestry, and rough grazing; wild land and rewilding; water, both visible on the surface and underground; but also urban land, industrial and residential, transport infrastructure including roads and rail, and then energy – wind, solar, hydro (fossil and nuclear coming under industry). This broad consideration will be particularly appealing to those (me included) who have repeatedly queried why even activities as close as agriculture and forestry have been treated separately in census, subsidy and planning.

Second, most people in SEDA, and their circle of related interests, are not specialists in food systems or land use, except where that cuts across architectural design. Yet they have an abiding interest in the future of the planet, and how things can be done differently. They also bring, in my experience to date, a professionalism and businesslike drive that derives from hi-tech, commercial business.

There is little difference, when it comes to the principles, between designing architecture and designing a food system or field [4].

The science of food and agriculture has tended to produce many reports and papers that summarise the present status and what needs to be done, but not enough (my view!) of integrated planning and putting that planning into practice. Special meetings and working groups, all charged with redefining policy, commonly achieve less that what is needed, often due to vested interests pulling in different ways.

There will be little progress until enough people come together to act and demand. The Conversations and their aftermath should make a major contribution to such progress.

In the meantime, some mild effort is going into structuring diagrams and decision trees based around each of the six Conversations (examples of which will appear on this site over the next few weeks).

The 2013 SEDA ISSUE on SOIL and natural capitaL

The conclusions of the talk at the SEDA AGM in 2012 were based on much field work on farm land, augmented by modelling and analysis over many years. The long history of agriculture and food production here was acknowledged, as was the diverse range of farming systems and the high productivity of the region, as good as anything else in north-west Europe. But the talk exposed threats due to the way some land is treated and to the dominance of external influences.

The field-based threats reside mainly in excessive intensification, which continued after the main phase of agricultural yield gain, 1960-1990, but with very little further increase in yield. The result was accelerating disruption of the essential cycles of energy and matter (carbon, nitrogen, phosphorus, etc.), leading to soil degradation, loss of functional biodiversity, and then loss of pollutants to water and to air as greenhouse gas emissions from both arable and livestock farming.

External influences arise from the pressures to serve national and international markets, ill-thought subsidy regimes and the late 1900s divorce between society and farming. The many consequences of such pressure included a degree of decoupling of much farming from food production, payment for destructive practices, money in the food chain going more to manufacturing and retail than the producer, and the country’s continued reliance on imports to guarantee food security.

Action needed at all scales

The solution required action at a wide range of scales, but the essential scale for future provision of food in decades and centuries to come must be that of the field. Fields must be treated not as an expendable workspace, but acknowledged as a complex ‘organism’, whose health and survival needs constant attention. Degrade the field and land will not feed the people when they next have to rely on it.

The choices may seem stark – but to continue as at present is not an option. There are many examples in Britain and abroad of very well managed land and rural enterprises that turn a profit [5]. One example that repeatedly comes to mind is a small tea plantation in Sri Lanka, visited in the 1991 [6]. The image below shows full ground cover of young tea, planted on mini-contours, shaded by several species and ages of tree. The trees provide shelter from sun and rain and most of them are legumes, fixing nitrogen from the air and otherwise stabilising and enriching the soil.

Contrast that with the field in the inset, not far away, in the same climate and on a similar slope, but ill-managed with no contouring and no cover, ensuring severely eroded soil and virtually no yield. In this case, the terminal state of this farmed land was due to poor management that had its origin in past politics.

The experience with SEDA in 2012 and 2013, including some joint writing with Sam Foster and David Seel, gave me a greater appreciation of ecological design in architecture. The understanding of the sun, the seasons and solar energy is an example – vital to modelling agricultural crops, grass and trees but also to the positioning of buildings and their windows [7].

The influence of architectural design and planning rubbed off onto our own research on design of ecological production systems. It strengthened my view of a system-first or system-led rather than innovation-led approach to the future of food production [8].

Sources / references / links / notes

[1] Presentation at the SEDA Annual General Meeting 2012: Design: crops, biodiversity and fragile ecosystems by G R Squire. Thanks to Mary Kelly for the kind invitation.

[2] SEDA Issue Spring 2013: Soil and Natural Capital. Available to members only. The issues contained articles from several Hutton Institute people including Cathy Hawes and Ed Baxter and also an appreciation of LEAF Linking Environment and Farming by GS. Page 2 of this article, in progress, will give a summary of the talk.

[3] A New Vision for Land Use in Scotland : 6 conversations – more at the Land Conversations pages of the SEDA web site.

[4] Design of arable and grassland systems based on bio-physical principles is far from new, being evident for example in the structuring of rig systems before 1700 and of multi-species grass-legumes mixtures in the 1800s. But by the end of intensification in the 1990s, the functioning and health of many fields in mainstream agriculture had been left to mis-chance, unsafe in the notion that they had been there for a long time and would remain however they were treated. Biophysical design continued to guide various ‘agro-ecological’ farming methods and increasingly does so, but they remain a minority. A well designed field has its main stores (of energy, carbon and plant nutrients) in balance and regulates fluxes between them, such that (for example) offtake is replenished and losses are minimal. Management achieves this by ensuring synergy and coexistence between the microbes, wild plants and invertebrates that determine the integrity of a field and the economic products (crops, grass, livestock) that they periodically sustain.

[5] One of the articles in the SEDA Issue of 2013 was on the early history and principles of LEAF Linking Environment and Farming. The James Hutton Institute, and the Scottish Crop Research Institute before it, was a LEAF Innovation Centre. LEAF is a broad church, with few rigid prescriptions, encouraging farming to move gradually to forms of sustainable management. The UK hosts a range of progressive farming organisations, some of which, including LEAF, will partake in the Land Conversations.

[6] For much of the 1980s and until 1992, self-employment in land use (measurement, assessment, recommendation) paid the bills. A visit to Sri Lanka to appraise some of the research there gave a unique opportunity to see some of the best (and the worst) of land management. But to be fair, the worst of land management can be found in almost any country.

[7] One of the most authoritative and accessible descriptions of the annual solar cycle, including the effects of the earth’s tilt and elliptical orbit round the sun, is given by an architect: Szokolay S.V. 1996 (rev 2007). Solar geometry. Passive and Low Energy Architecture International (PLEA) and Department of Architecture, University of Queensland.

[7] The contrast between innovation-led and system-led approaches to design was debated through EU projects such as AMIGA on environmental risk assessment. The prevailing approach to risk assessment was (and a to a large degree still is) innovation-led. An innovation such as a biotech crop or new crop-protection chemical is examined for its safety, but usually in comparison to current practice within an existing system. Such a comparison came to be considered (in our view) flawed if the existing system was itself not safe, for example if its soils and functional diversity were degrading. Far better then to define an ideal ‘safe’ system first and then consider which innovations would be needed to help move the existing system to this safe state.

Page 2 (in progress)

Interlacing: lessons for seed mixes today?

“… an allowance is made for interlacing.”

Stebler and Schröter’s 1889 handbook on grass and legume species and mixtures. Their method of estimating seed rate for each species in a mix. Was the recommendation of over-seeding justified? Lessons for regenerating complex forages today. An article in the series on crop-grass diversification.

Imagine … you’re making a complex seed mixture by combining seed of each of the constituent species or varieties. You work out the best combination of species for the field – three or four for one-year’s hay and maybe 15 for long-term pasture – then gauge the ideal proportion of each in the resulting hay or pasture, e.g. 20% ryegrass, 10% red clover, and so on up to 100%. 

Four of the colour plates by L Schröter in The Best Forage Plants: left to right, kidney vetch, meadow foxtail, sweet vernal and alsike.

It was a complicated task. The composition of each species – in terms of protein, fat, fibre and so on – had to be known so that the mix would satisfy the purpose, whether hay or pasture, sheep or cattle. The amount of nutrients that each species would need from the soil had to be estimated. For example, a nutrient-demanding species might have a hard time in a nutrient poor soil or else starve other, less demanding species. Then the proportion of each species in the mix had to be calculated. And all this before science and farming were fully aware of soil-plant processes such as symbiotic nitrogen fixation. 

A major contribution to knowledge at that time was the work of FG Stebler in Switzerland. His book – The Best Forage Plants [1] – was written in German, co-authored by botanist C Schröter, translated into English by McAlpine [2] and the translation published in 1889.

There was great interest in grass-legume mixtures at that time. A shift from arable to grass had begun in Britain, initiated by serial bad weather and crop failure, coupled with unbridled cheap corn imports from the USA. It was the start of a long-term slump in arable farming and a rise in pasture husbandry [3]. 

The book described 30 species in detail: 21 grass and 9 legumes. Most would have been familiar in mixtures used in Britain, with few exceptions such as the legume Galega officinalis which they named Officinal Goat’s-rue (‘officinal’ because of its medicinal use in parts of Europe). 

Officinal Goat’s-rue, one of many colour plates by L Schröter in The Best Forage Plants, indigenous to south-east Europe but grown widely as a medicinal and forage, having a preference for warmth and deep soil, rarely sown as a forage in Britain.
How much seed of each grass and legumes species for a mixture

Stebler’s recommendations on seed rate (weight per acre) were not without controversy. He worked out from many field trials the seed mass of each species that would be needed to cover and produce good growth on an acre of field: for example, 38.6 lbs for perennial rye-grass, 18.5 lbs of cocksfoot, 22 lbs of lucerne and 15.8 lbs of red clover. (To convert to today’s units, 1 lb is 0.454 kg and 1 acre is 0.405 hectare.) So 7.72 lb of perennial ryegrass seed would be needed if its proportion was 20%.

His method went further by recommending that more seed of each component should be added than estimated by such simple proportion. The extra seed ranged from 10% to 80%, but was typically 50%. The reasoning was that the species in a mix occupy different parts of the space: roots exploring either deep or shallow soil layers, for example; or some species leafing early in the year, others later. 

This is what Findlay [4] in 1925, commenting on Stebler, meant by interlacing. The quote at the top of the page, from Findlay reads “As the roots and leaves of the different ingredients do not occupy the same places …. an allowance is made for interlacing.”

Grass specialists appreciated that roots and leaves of different species interlace: they enter each other’s space, they co-occupy ground. Several species might occupy the same area of ground but in doing so they are not always competing for the same resource or if they are then it is not in the same place or time. 

Is overseeding a waste?

Findley appreciated what Stebler meant, but went on to criticise the method. He wrote “at no time is there any connection between the proportion of the seeds sown and of the plants either in the hay or in the pasture”, and gave the example that a competitive grass will oust an uncompetitive one regardless of the proportions in the mix. 

Findlay was right in principle: the extent and type of interlacing depend on how the species react to each other in the local conditions. Yet over-seeding is not without merit. The aim of a seed mix was to get more mass or nutrition than could be had from any species grown alone. Stebler said that to do this you had to sow more seed of each component than that based on simple proportion. 

Take the very simple example of a 50:50 mix containing one grass or cereal and one legume. The legume fixes its own nitrogen (N) from the air, so will take little from the soil. Consequently, the cereal or grass has most of the soil N to itself, but if it were only sown at 50% of what it would take to cover the ground alone, then it might have a hard time extending its roots to get the N throughout the whole soil space, which includes that ‘under’ the legume. Therefore (Stebler would say) it should be sown at more than half the seed rate needed to grow it alone. 

That’s not the full story because the two species would also compete for other resources – solar radiation, water, the macro- and micro-nutrients. In a 15-20 species mix for permanent pasture, very many interactions would occur between the types, and some would result in the elimination of species. The ones that went would not be the same in all soils and climates. One purpose of a mix therefore was to build in redundancy, such that the mix would still perform well even if some components disappeared.  

Awnless Brome Grass, now named Bromopsis inermis Ssp. inermis, one of the many plates by L Schröter in the Best Forage Plants, capable on poor, drying soils, widely grown in Europe, also previously in Britain, but now rare here as a sown forage.
Postscript – Stebler’s influence ?

In his preface to the translation into English, McAlpine had the view that Stebler & Schröter, now accessible to English readers, would be seen as a major work of agriculture, leading to ‘a revolution in the forage culture of Great Britain’. Further on, he writes ‘I do not hesitate to affirm that if Stebler be destined as I believe he is to become a power in agriculture the effect will be to increase the production of good forage and to improve the practice of this most important branch of farming.’ 

Yet Findley in 1925 [3] found Stebler’s methods deficient in several respects and did not endorse them.  Whatever Stebler and Schröter’s influence on British forage might have been in the 1890s, it did not last. After the mid-1900s, mineral fertiliser would come to supply most of the nutritional needs of grass and supplant forage legumes such as clovers and trefoils. As described elsewhere, the diversity of grass forages became poor and probably the knowledge of how to manage multi-species grassland faded [5]. 

Recent decades have seen a part-reversal of that trend, in that grass-legume mixtures are increasingly available from seed merchants. Some of the mixtures are intended for grazed swards but the emphasis seems to be on restoration for wildlife conservation. 

The lesson from Stebler is that the basis of estimating seed rate in a mixed crop or pasture might need to be reconsidered. In many parts of the world, however, seed is not plentiful. The choice has to be made: eat the grain now or keep it to sow for the next crop.

To come …. More on Stebler & Schroter’s Tables on the nutritional value and needs of grass versus legumes. 

Sources / references

[1] Stebler FG, Schröter C. ‘The Best Forage Plants’. Translated into English by A N McAlpine, 1889. Publisher: Nutt, London. Available to read online through Google Books. The illustrations of grasses, some reproduced here, were by L Schröter, brother of the second author. A review of the book, Wrightson J. (1889). A Review of The Best Forage Crops. Nature 39, 578-579, tells readers that the treatise omits the common fodder crops such as vetches and brassicas, and deals mainly with pasture grass mixtures. 

[2] A N McAlpine, the translator of Stebler & Schröter into English, was Professor of Botany, New Veterinary College Edinburgh and Botanist to the Highland and Agricultural Society. 

[3] curved flatlands article: Food security in the pandemic.

[4] Findlay, W M. 1925. Grassland in Scotland. In ‘Farm Crops’ edited by W G R Paterson. The Gresham Publishing Company, London. 

[5] curvedflatlands articles: Grass mix diversity a century past – for reference to books by RH Elliott and H Stevens; and 1800s mixed crops – lessons from the Agrostographia – gives examples of the Lawson’s (Edinburgh) crop and grass mixtures. 

Acknowledement Thanks to K Owen for allowing the use of her depictions of interlacing on Pictish symbol stones.

Food security in the pandemic

Not long into the 2020 pandemic, Pete Ritchie from Nourish Scotland, wrote a blog [1] putting the case that once the initial panic has receded, the international food system would adapt, the empty shelves would be re-stocked and no one in this country ought to go hungry. Nourish, through their blogs, web sites and conferences are at pains to point out that no one should go hungry in the UK because of shortage of food. Should they be hungry or malnourished, it would be due to other factors, such as social inequality, not the amount of food available.

Nourish were correct, but they were not giving the thumbs up to the current state. The blog writes that the food system – “ … generates massive environmental damage, monumental food waste, exploitative work practices and a disastrous mismatch between what we need to eat for health and what we are being sold.”

Dysfunction and mismatch are not simply other people’s problems. The blog continues – “ … would be good if Scotland were to produce more of what it eats, and eat more of what it produces.”

The blog raises the greater issue of the choices that can be made – whether to create a more equitable food system or stay with the current dysfunctional mix of hunger and plenty. Analysis by the Food Foundation [2] shows the pandemic is driving more people into malnutrition and hunger: the food is there but many people are unable to afford it or get to it.

Yet on the continuity of supply during the pandemic, the food system has adapted. Would the same be true following any global emergency?

The food-feed system is resilient ….. but it could fail

The food system was able to recover because of particular features of this pandemic. Farming and food stocks in most parts of the world have been little affected so far. Only a few of the food supply chains have been seriously disrupted [3].  It is too soon to say whether more will be affected if lockdown and social distancing continue, but the chances are they will not be. However, other global crises could have far greater consequences.  

A diagram (Fig. 1) is used to illustrate how food and feed systems are sensitive to global events. The system is divided into four parts (Ag-economy, Ecosystem, Primary production and Food-origin) and each of these into two further parts. Of course food systems are much more complex than this: these particular sectors are shown to illustrate how vulnerable the system can be when things get out of balance.

The particular quality of this pandemic is that it has not had a severe effect on any of the parts in Fig. 1.

Fig. 1 Food production simplified for illustration into four sectors, each of two unequal parts.

The agricultural economy, shortened to Ag-economy is split into farms and related businesses that are viable in terms of making a profit and those that only exist with support, for example through subsidy, such as provided by the EU’s Common Agricultural Policy [4]. The viable fraction is smaller than the supported. (This is true for most of the UK and large parts of Europe.)

The Ecosystem provides for agriculture (nutrients, air, water, biological pest control) and needs agriculture to nurture it. Its essential parts, including soils, food webs, biodiversity, and the cycles of energy, carbon, nitrogen and water, can be described as in a state of either building or degrading. While some parts of the cropland ecosystem are at least holding steady if not building, most parts are degrading, in terms for example of declining soil quality, loss of biodiversity, soil erosion and inability to regulate water flows.

Primary production is the fixing of carbon dioxide from the air into plant matter by photosynthesis.  In Scotland, production land is divided into managed pasture for hay or grazing and another sector here named feedstocks, which refers to the dominant use of arable land to supply grain for alcohol and livestock feed, rather than staple food directly for humans [5]. The arable also produces oats, potato, fruit and vegetables, but the land area planted with these crops is small compared to the rest. Feedstock land covers less area than pasture. A large part of the products of agriculture go to export, for example as whisky and quality meat.

Food-origin is divided into that produced locally and that produced somewhere else and imported. Imports of food are essential for the UK and its constituent parts because much of farmland supports agricultural exports and livestock feed. Nourish Scotland’s Food Atlas shows around 60% of food consumed in Scotland is imported, but imports account for almost all of some types of food such as bread [6].

So there are four parts in the diagram, each given one quarter of the pie chart, and within each quarter, one of the parts is shown larger than the other. (Exactly how much larger does not matter for the illustration.) It is these imbalances make the food system vulnerable to external events.


The tensions in and between Primary production and in Food-origin primarily determine whether a society can resist and adapt to global crises. Cereals and legumes have been the foundation of all settled societies. It is the balance between local and external sources of these, particularly the cereals, that most strongly determines vulnerability of a food system. 

In a subsistence agricultural economy, these staples are produced locally. Hunger and starvation may happen if agriculture is threatened by bad weather or an insect plague. As societies develop, they usually grow more products for export, which along with trade in mined and manufactured materials, raises wealth. That wealth allows them to import food and feed. A combination of local produce and imports then offers resilience to poor local harvests. If, however, the move to an export agriculture goes too far, then the society becomes reliant on imports for its staple food and therefore vulnerable to anything that affects imports. That is the state of the food system in Scotland and the UK as a whole.

The position is bleaker in reality because the four quarters of the diagram are connected. The international food system presently provides much of the staple diet, leaving Primary production free to concentrate on products for overseas markets. The intensity of agriculture in a competitive world is driving degradation of the Ecosystem, while an indifference of politics and society to the Ag-economy leads to low food prices and dependence on subsidy. 

Most major global cataclysms would be likely to cause serious disruption to the food supply in these circumstances. Blockade, for example: assume for whatever reason, imports stop suddenly due to the country being blockaded. Local production could not supply the needs of the people for food. The same would happen if natural phenomena damaged agriculture in those parts of the world that grow the food we rely on.

The right balance

The balance of imports and exports is crucial to food security, but lessons from the last 150 years show the complexity of it – there is no single solution.

The agricultural depression of the 1880s

The depression that began in the 1880s was a consequence of bad weather and cheap imports flooding the home market. The weather of 1879 was among the worst recorded. In Scotland livestock died on a massive scale, grain harvests were 20-40 days late in starting, wheat yields were 50-70% of the average and many cereal and tuber crops failed [7].  Shortage might have meant higher prices to keep farming solvent, but not this time. Grain produced elsewhere, was imported to fill the gap, and a downward spiral begun of poor home yields, more cheap imports and arable land converted to grass. Symon [7] compared wheat prices: 64s. 5d. a quarter in 1867, half that 20 years later, then down to 23 s. in the 1890s, the lowest for two centuries (s., shillings; d. pence).

Most parts of the UK were affected. Thirsk [8] writes: “A dramatic collapse of grain prices occurred in 1879, and continued in 1880, 1881 and 1882. Wet and cold seasons ruined one harvest after another, without bringing the usual compensation to farmers in higher prices. Instead, cheap grain flooded in from North America, and farmers were warned that if American supply fell short, then Australia could send much more.”

The main lesson of this time was that local yields were insufficient, but it was the unbridled agricultural imports drove home farming into deeper depression. A second lesson is that global events have a long reach. The areas of the main arable crops all declined from the 1880s and some kept declining until the 1930s, trends that affected the country’s ability to feed itself when imports were threatened.

Insufficiency in 1914 and again in 1939

The freedom to import food at the expense of local production continued after 1900. In 1914-1915 the government failed to appreciate the scale of the impending problem of food shortage due to restricted imports. Symon [7] writes that it was well into the war before defeat by starvation was considered possible and urgent action necessary to ensure food security. The author goes on to lament the lack of a plan, an unrealistic attitude and a ‘mood of complacency’ towards agriculture and food supply. Matters did improve, the State took control, and agricultural output increased. But self-sufficiency in food was never assured throughout this period.  Even after it, and contrary to pledges made, free trade in food returned and again drove down farming.

The response in 1939 was more immediate and effective than that 25 years earlier, but massive changes had to be made: the conversion of much grass to arable, restrictions on which crops could be given mineral fertiliser, rebalancing different types of livestock, adapting to a shortage of labour on farms and imposing food rationing [7]. The combined result of many such changes was positive in that total output and yield per unit area increased in most crops. Technology advanced also: farming became aware again of the need to apply lime to reduce acidity, to balance the main mineral fertilisers, to sow improved crop varieties and to rely less on the horse and more on tractors for cultivation. But even though writers like Symon felt the changes introduced in the early 1940s were positive for agriculture, the main technological advances in farming were yet to come.

The Agricultural Expansion programme and intensification

After the food insecurities of the 1940s, a post-war Agricultural Expansion Programme was initiated to raise production. The programme worked. It was aided by improvements in machinery, agronomy, and crop yield potential, but also a shift in areas sown to main cereals, oats being replaced by barley and wheat over much of the country [9].  Despite a rising population, the country was able in the 1960s to feed itself. Yet within a few decades, it was again dependent on food imports. Did it return to the 1880s – in one respect, yes, because the food system again took advantage of low-cost food imports, often of poor quality and nutritional value. In another respect, it was different: production was not lacking, as it was after 1878, but turned its attention away from food.

The choice

In an uncertain world, a country needs to keep its borders open for trade, both ways. But it also needs to ensure it can feed itself if it has to.

The balance needs to be redrawn: local production raised, more food than feedstocks, a shift to building rather than degrading the ecosystem and paying a fair rate for food to remove dependence on subsidy. All this is possible.

More about the topics raised here can be viewed online [10]. The Living Field web site also publishes related articles and notes [11].

Sources, references

[1] Nourish Scotland. 2020 Making the food supply chain work for everyone. By Pete Ritchie, 24 March 2020.

[2] The Food Foundation published some recent statistics on 22 May 2020: Food insecurity and debt are the new reality under lockdown

[3] Seafood in Scotland is one sector that suffered severe disruption due to the pandemic. The disruption in this case was caused to a large extent by an imbalance between export and home consumption. Most of the catch (80%) was exported, so when international trade was reduced or closed, the only sectors open to it were UK catering and retail. Then the restaurants closed and major UK food retailers shut their fresh fish counters. More at Seafood Scotland on the Crisis Stricken Seafood Sector.

[4] The EU web site gives a summary of the EU Common Agricultural Policy. The James Hutton Institute produced major reports on CAP Greening measures, available for download at Land Systems Research Team. GS structured the main arguments of a Scottish Government CAP Greening Review in the form of a decision tree at Greening with decision trees.

[5] The areas of land used to grow pasture and arable or horticultural crops is detailed on the Scottish Government web site at Agricultural Statistics in Scotland. This (curvedflatlands) web site gives links to further data on food and agriculture at the Scottish Parliament Citizen’s Jury pages.

[6] Food Atlas

[7] Symon J A. 1959. Scottish Farming – past and present. Oliver & Boyd, Edinburgh and London, UK.

[8] Thirsk J. 1997. Alternative agriculture – a history from the Black Death to the present day. Oxford University Press, Oxford, UK.

[9] A brief history of changing areas and yields of oats, barley and wheat over the past 150 years on this web site at Three grain resilience.

[10] To find out more about local food systems, try these organisations: Scottish Food Coalition and their Campaign for a Good Food Nation; the Food Foundation and Scotland the Bread.

[11] Living Field articles: City University’s food systems diagram: Five spheres around the food chain, and a look at the 10 crops from across the world that go into a simple meal of Beans on Toast revisited.