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3 Dimensions of Nature Recovery

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3 Dimensions of Nature Recovery
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Once you understand the 3 D’s, you’ll start to think about land management differently and see the landscape in a different way. You’ll realise that every project can be designed to maximise the value for nature, and start to come up with original solutions on your own.

While these three dimensions first gained ground in rewilding, the idea is relevant to every aspect of nature recovery.

Are you a different kind of learner? We also have a video lecture and a podcast which explain the concept of the 3 D’s.

The 3 D's
Habitats with high value for nature have moderate disturbance, high dispersal, and high diversity.

Backstory

It’s easiest to understand the 3 D’s if you know where they came from. Rewilding started out in the U.S. – over there, they found that reintroducing large Carnivores to huge Core areas of wilderness, then joining these areas up with wildlife Corridors led to the dramatic recovery of nature across wider landscapes. This was called the ‘3 C’s’ – cores, corridors and carnivores.

The classic example of the 3 C’s is Yellowstone National Park – wolves had been wiped out by overhunting in the early 20th century. This led to the park becoming dominated by Elk (a big deer), which ate all the trees.

A reintroduction programme in the ’90s found that wolves scared Elk away from scrub and rivers. This led to a surge in tree growth, especially along river banks, which enabled locally-extinct beavers to return. The beavers created new wetland habitat, boosting aquatic biodiversity, including fish. This series of events, where a carnivore reintroduction had an effect all the way down the food web, is described as a ‘trophic cascade’.

But in Europe, the 3 C’s don’t often work – we don’t have undisturbed core areas of wilderness, as our land has been colonised at high intensity for much longer. With denser populations of people, carnivore reintroductions are politically difficult, and some of our carnivores, like the cave lion, are long-extinct.

The 3 D's Emerge

In the 21st century, a few rewilding projects in Europe began to see a lot of success, and scientists tried to understand what it was that they had in common. The most widely-accepted answer was a theory from a 2019 paper (Perino et al, 2019). This proposed a framework for rewilding – the basis of ‘the 3 D’s’…

The paper describes how 3 key properties are the foundations of ecosystem health:

‘Trophic complexity, stochastic disturbance and dispersal’. 

In 2021, to make this a bit easier to understand, we renamed these three dimensions as ‘the 3 D’s’ – ‘diversity, disturbance, and dispersal’. We’ve also taken a few liberties and added a bit more context to the explanation, to make this theory more relevant to all nature recovery and regenerative agriculture projects.

 

Grassland habitat with late successional scrub
Knepp was one of the earliest rewilding success stories in the UK, although this model was heavily subsidised by the landowners.

What Are the 3 D's?

We’ll explain what each dimension means in detail further on, but first, let’s take a look at the bigger picture.

In a healthy ecosystem, there is a high level of diversity, with high dispersal (movement) of animals, plant seeds, fungal spores etc from place to place, and moderate levels of disturbance from animals and natural processes.

In contrast, in degraded ecosystems, these three dimensions may each be at a low ebb. However, disturbance tends to be bad for ecosystem health at both very low and very high levels, especially when it comes from non-natural processes like farming, building or warfare).

Each one of these dimensions is intrinsically linked to the others…

  • Disturb the land and you’ll see improved diversity if new animals and plants can easily disperse into your project.
  • Improve herbivore diversity and you will disturb the soil in more ways, creating opportunities for incoming dispersal of plant seeds onto the bare earth.
  • Increase dispersal opportunities by coordinating your activity with a neighbour, and you’ll see higher diversity of animals, which create more disturbance on your land.
Heathland habitat with late successional scrub
Some patches of countryside are deliberately rewilded, while others fall out of regular use and low grazing pressure results in high biodiversity, like this patch in Devon.

Diversity

How diverse is the ecosystem right now?

There are several different types of diversity, all of which contribute to a healthy ecosystem. We’ll go through them from large to small scale.

Habitat Diversity
The number of different habitats in a landscape. 

A habitat is a community of organisms – plants, animals, fungi etc – which coexist in the same environmental conditions. Acid Grassland is one example, where low pH soils and grazing create suitable conditions for a sparse community of grasses, wildflowers, reptiles, birds etc.

At the edge of a habitat, where it blends into the next habitat, there is often an ‘ecotone’ – a transition zone. This combines species from two different communities, creating high biodiversity. So a mosaic landscape with a patchwork of different habitats and lots of edges (ecotones) tends to be good for biodiversity.

Structural Diversity
The variability in vegetation and terrain height. 

A flat grassland has low structural diversity, but allow a few shrubs to pop up and this will improve. These provide perches, shade, wind and rain protection, hunting and foraging spots. The taller, dense scrub allows vulnerable species dependent on cover to avoid predators, as they move across the open, exposed grassland. These are the many benefits from adding only a few bushes – this demonstrates the importance of variety in vegetation height within an ecosystem.

Terrain height has a similar effect – and the presence and absence of water is also covered by this category. Existing ponds, wetlands, lakes, ditches etc provide enormous value to both wildlife living in and around the water. Bare earth and exposed rock can also be valuable in small amounts within an ecosystem. 

Lumps and bumps on every scale provide similar effects to vegetation structure – creating shade, humidity, sheltered sunny patches and a diversity of soil conditions which leads to higher plant diversity. A structurally diverse ecosystem tends to look ‘messy’, rather than ‘neat’ – but it’s the kind of mess that nature thrives in.

Functional Diversity
The different functions performed in a habitat. 

A wild boar is good at disturbing compacted grassland, turning over turf and creating opportunities for plant seeds to germinate. But so are pigs – they do about the same thing – they are ‘functional equivalents’. But pigs can be farmed for meat, and they’re less dangerous to handle, so we tend to use them on rewilding projects.

Similarly, domestic Apple trees are basically the same as our native Crab Apple, but the fruit they produce is edible, so we can grow the edible domesticated species and make a bit more money.

An ecosystem with a degraded food web isn’t just missing species, but also the functional roles they play. Rather than try to restore every species, we can first build out the missing functions, which will bring the ecosystem back to health much quicker. 

As time goes on and the ecosystem recovers, each function will be performed by multiple species. Or a role may continue to be served by a functional equivalent (like pigs) if the species is extinct, locally extinct or difficult to acquire.

Species Diversity
The number of different species in a habitat. 

Large herbivores – keystone species – have gone missing from our landscape, but we’re slowly bringing them back – beavers, wild boar, bison etc. These ‘ecosystem engineers’ change the habitat they live in, creating niches for other animals and plants, disturbing the ground and vegetation, and building diversity around them.

But in smaller projects, introducing a beaver is a bit much, and it can be easier to start at the bottom of the food web. Plants create a trophic cascade by acting like a magnet or an advert, pulling in the rest of the food web above them with sight and smell. So planting native trees and wildflowers can attract a diverse community of animals (and even fungi!). Visit the Tree List to find out which trees might be worth planting on your land.

Genetic Diversity
The diversity in genetic code of species in a habitat.

We’re aware that inbreeding can cause health issues, and that this is also the case in animals, which is why a large and diverse population (‘gene pool’) is healthier. However, there’s also the benefit that, with more genes, you’re more likely to have, somewhere in your gene pool, resistance to a new threat, whether it’s a disease like Ash Dieback, a new predator tactic, or a change in the climate.

A large population is not always the same as a genetically-diverse population. A genetic bottleneck is when a species declines to just a few individuals (a small gene pool), and then recovers again. This results in the loss of much of the genetic diversity. It has happened to Cheetahs, and Bison, and has had long-lasting effects on their health.

Planting a huge population of trees which are all clones reduces their resilience to future threats like disease and climate change. Many trees bought from nurseries are propagated from cuttings, which are genetically identical to each other, whereas every seed is unique. Planting additional saplings grown from the seed of local trees can protect long term woodland health.

Salt Marsh grazed by sheep
There are exceptions to the rule of high structural diversity being good for ecosystem health - salt marsh (pictured) and bog.

Disturbance

How much does diversity change over time?

While diversity and dispersal usually improve ecosystem health as they get higher, disturbance can be damaging at both very low (gardens, fenced enclosures) and very high levels (overgrazed fields, dog parks, warzones). Getting the right amount of disturbance is a balancing act, which usually requires a bit of experimentation with livestock density and/or management.

There are basically two types of disturbance – the kind you need to establish a habitat (artificial disturbance), and the slowly increasing influence of wild/rewilded/domestic herbivores (natural disturbance). 

The British landscape is very heavily degraded, so we need to undo a lot of damage to restore it to health. These are a few of the most common issues that are caused by, and/or solved by artificial disturbance:

  • Pesticides
  • Chemical, Microplastic, Pharmaceutical Pollutants
  • Fertilisers
  • Liming (neutralising acid soils)
  • Ploughing & Erosion
  • Draining (mole drains, gripes, ditches)
  • Channelisation (straightened, dredged watercourses)
  • Soil Compaction (‘poaching’)
  • Pond Infilling
  • Development (roads, housing)
  • Resource Extraction (quarries, mines)
 

While some of this damage can be undone in the same way it was created, like removing soil from old ponds, other artificial disturbance requires more effort to reverse. Nature-based solutions – like Treatment Wetlands – exist, that can remove pollutants from water, while soil stripping may be necessary in extreme cases when dealing with heavily-polluted ground.

Tackling artificial disturbance is best done on a habitat-by-habitat basis. So it’s worth reading through the ‘Protect’ and ‘Restore’ sections of relevant Habitat pages.

Grassland Disturbance

Our grasslands would naturally have been grazed by large roving herds of aurochs (wild cattle) and horses. Today, some of these habitats are overgrazed, while others are not grazed at all, but mown. 

Bringing livestock back to mown areas can introduce some soil disturbance and grazing activity, which greatly benefits local diversity and soil health. It creates variability in sward height, allowing reptiles to bask on short grass and wildflowers to grow through taller grass.

In areas which have been overgrazed for a long time, it may take decades for a diverse meadow to form when grazing pressure returns to natural levels. Hooves and rooting snouts (like native wild boar and pigs) break up matted turf, creating exposed patches of soil where wildflowers seeds can germinate. Dense grass is then opened up by moderate grazing to encourage a more diverse community to flourish.

Woodland Disturbance

Many of our woodlands are under-managed, or not managed at all, while there is an overpopulation of deer munching through the undergrowth. This creates a dense canopy, shading out the sparse scrub layer. By controlling deer numbers, and introducing cattle and/or pigs very infrequently, coppicing some areas and selectively felling trees, we can hugely improve the diversity of the woodland.

In managed plantations, allowing some deadwood to persist and some older trees to last from one generation to another can increase the survival rate of new saplings. It also boosts the local biodiversity, and improves the cycling of dead plant matter into nutrient-rich soil.

Aquatic Disturbance

Take a look at the average stream in Britain, and you’ll see that it’s a straight and deep, V-shaped ditch, with dense, lush bank vegetation that shades the water. But wild streams don’t often look like this. They’re wider and shallower, with riffles (exposed shallows) and deep sections, wiggling more freely across the landscape. Their banks have diverse vegetation, from trees to marginal plants. Beaver dams crisscross them at intervals, creating wetlands and ponds, rich in aquatic life, filtering out sediment, nutrients and pollutants.

Over time, we’ve dredged out the bottom of these streams and pulled them neatly into straight lines along field margins, while killing off the beavers. But water travels more quickly down these narrow, deep channels towards chokepoints like towns and cities, where it spreads out, causing millions of pounds in flood damage.

In our river systems, artificial disturbance means undoing the straightening and dredging of the Victorian era and 20th century. Natural disturbance means allowing beavers back in, felling trees across upland streams, and allowing these waters to wiggle once more over their forgotten floodplain.

Mushroom
Fungal spores are carried in the air, from fruiting bodies, but also in the digestive tract of some animals, being deposited in rich excrement far from the source

Dispersal

How does diversity sync-up across the landscape?

Animals, plants, fungi etc all move across the landscape, but in different ways, and at different speeds. Whether it’s as airborne spores, on legs, wings, swimming, via root suckers or in the digestive tract of an animal, movement spreads organisms from one place to another.

Organisms don’t just move from one habitat to another, but also within a habitat, so the ecosystem health will affect their ability to disperse. A wild, tangled scrubland is much easier for a vulnerable rodent to cross than hot, exposed tarmac in a car park.

Similarity is Key

Our landscape is made up of fragmented pieces of semi-wild space. Wildlife corridors are the ideal form of travel between these refuges, but travelling across hostile terrain is often possible, and it’s much easier when there is ‘stepping stone’ habitat in between. 

In the case of aquatic species; ponds, ditches, streams and rivers improve dispersal in a dry landscape. In fact, many pond-dwellers have an airborne stage in their lifecycle, allowing them to fly short distances in search of a new home. Regrettably, frogs are not known to do this.

You’ll probably realise that stepping stone habitat has to be similar to the animal’s home turf, to maximise its potential for dispersal. Woodland birds can benefit from individual trees, but grassland won’t help them; crickets benefit from grassland, but not ponds; dragonflies benefit from ponds, but not sand dunes.

This is why it’s crucial that the habitat on your land matches similar habitat in your local area. Otherwise, you won’t get many suitable species arriving, and your diversity will remain low over time. So, dispersal is not just dependent on the distance between wildlife-rich green spaces, but also the similarity of their habitats.

Hard Limits

There are limits to what most organisms can navigate across, and fences, walls, large blocks of buildings, crops (including forestry) and paved surfaces can pose a significant barrier for many species. The height, heat, lack of food and exposure can all force animals to turn back, while many plant seeds will fail on concrete, tarmac, or in an intensively-farmed system.

Plants travel on the wind or in the guts of birds, but seeds typically go no further than about 100m or so from the parent plant (acorns are the exception). This means that, while animals may travel from country to country in a matter of hours, plants typically take shorter hops, requiring safe stopovers on the way. It is possible for plant seeds to move further, piggybacking for long distances (sometimes literally) on animals, but creating new stepping stone habitat can be of huge value in improving seed dispersal across a landscape.

Exploring a rewilding project
Improving public access can be very rewarding as you get to see others enjoying the landscape and biodiversity you have helped to create.

People and Nature

The 3 D’s are just the scientific side of nature restoration. In a world without humans, you could optimise these 3 dimensions and end up with a thriving ecosystem. But also, without humans there wouldn’t be any need for nature recovery.

In the real world, ecosystems need to thrive in the context of society, culture, economy and history. Ignoring these will only result in long term failure – just as ecosystems are affected by dispersal, they’re also affected by human inputs, outputs and decision-making.

If a nature recovery project is to continue into the future (even beyond your generation), then you’ll want to consider its impact and legacy for your family, the community and the economy.

Gardens

For smaller projects, delivering value is all about making the land a place that offers many different benefits for the family. Creating diverse benefits will ensure that, whether you sell the land or bequeath it in your will, your legacy will continue to live on. This means thinking about the potential of a biodiverse small space and what it could and/or must provide, not just for you, but for the people who will come after you:

  • Access to and from your home
  • Fruit, vegetables, herbs, nuts and salad
  • Poultry and eggs
  • Coppice and weaving supplies
  • Play equipment, nature exploration, sports
  • Tool storage, bikes, bins, parking
  • BBQ, Patio, Seating
  • Drying clothes, washing kit
  • Solar power, green roofs
  • Housing and exercising pets

 

Smallholdings

Beyond the back garden, in allotments, fields, and smallholdings, especially where there is open access, or the potential for access, it is worth considering the perception of your space by the local community. This is for two reasons – firstly, neighbours and local councillors can make your life hell if you don’t get on (!), and secondly, you’ll probably get a lot of enjoyment out of seeing others appreciate your hard work.

Your project can deliver value in a number of different ways:

  • Improving access to nature for the local community
  • Creating a shared space for community gatherings, food production and events
  • Becoming a showcase for a specific style of land management, e.g. permaculture, agroforestry, rewilding – running outreach events and tours to increase public engagement
  • Producing food, timber and/or other products which increase the economic value of your land
  • Raising heritage breeds, and/or growing heritage fruit varieties to preserve this genetic diversity into the next generation
  • Conserving areas of special ecological or archaeological importance
 
Some of these options involve publicity, while others are more suitable for those who prefer privacy. All of them are easily achievable within a small area of land, and can be an extremely fulfilling way of delivering the value that will keep your project running into the future.
 
Farms

Beyond the examples given above for smallholdings, a farm has greater potential to deliver economic and social value. With such a large area of land, it is essential to consider the implications of any change of use, and how that might be maintained profitably into the future.

Job creation is a possibility here, and diversification can also safeguard a farm against economic shocks. But the financial side of things is second-nature to most farmers and farm owners. Many landowners are more interested in working out how to keep the local council and community happy. Conflicts are likely to arise due to public access, and planning permission/permitted development is required on a regular basis for infrastructure and farming work.

Here are some potential options for improving community relations:

  • Create additional permissive footpaths and nature trails
  • Improve signage and surface quality on existing footpaths
  • Make an effort to approach and chat with walkers
  • Contact the local Ramblers’ association and ask them to work together on improving access across your land
  • Create allotments on land near a built-up area
  • Host festivals and fêtes
  • Create nature areas around public footpaths
  • Offer community participation in tree planting, hedge laying and other traditional skills
  • Partner with local butchers and grocers to supply produce
  • Repurpose farm buildings for community events and shared working spaces
  • Offer tours of the farm to the local community each year
 

The golden rule of all these outreach opportunities on a farm is that it’s worth maximising the publicity benefits of every individual event. Contact the local paper, post on social media, print signs in advance. 

This will increase awareness in the community of your activities. While it may feel shallow or conceited (it’s not!), you have to consider that, on a farm, you’re running a small business. Taking time away from the business to run these events costs you in both time and money. The ‘payoff’ from these events is community engagement, so PR and marketing are core to their success.

 
Structural diversity
A habitat with very high levels of diversity, dispersal and disturbance, grazed by cattle at low intensity. A coastal grazing marsh at Wild Ken Hill.

Summary

We’ve covered a lot of ground here, so let’s go over the key points that are worth remembering:

  • A healthy ecosystem has high levels of diversity and dispersal, and a balanced level of disturbance
  • Diversity is the number of species and habitats, and the variety of genes, vegetation and terrain variability present in one place
  • Disturbance is the amount of change that happens over time, due to natural processes like grazing, trampling, digging and longer term things like death and decay
  • We need to disturb an ecosystem artificially to kick it back into a wilder state, by reversing damage like drainage
  • Dispersal is the size and connectedness of a habitat to similar habitats within the local area
  • People are key to the success of a project in the long term, so it’s worth designing your land around community, economic value, heritage and family needs

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