Saturday, August 20, 2016

What Would Happen if we Abandoned Britain's Farms and Left Them to Nature?

Now what? David Hughes/Shutterstock
by Christopher Sandom, University of Sussex, The Conversation: https://theconversation.com/what-would-happen-if-we-abandoned-britains-farms-and-left-them-to-nature-63951

Without farming, Britain’s countryside would be drastically different. Imagine walking through landscapes un-tilled, un-sown, un-fertilised and un-treated, nor grazed by cattle or sheep.

Following the Brexit vote, the government has to decide what to do about the Common Agricultural Policy (CAP), the EU’s subsidy scheme for owners of farmed land.

Some of these subsidies support food production while others support environmental protection on land suitable to be farmed. In 2015, British farmers received roughly £3.2 billion from the EU.

Agricultural land covers 70% of the UK. If all subsidies stopped, the National Farmers Union reports many farmers would go out of business and large swathes of land would come out of production.

This may be unlikely (and it’s certainly not what I’d recommend) but it’s still worth exploring an even more dramatic scenario: what would happen if Britain’s farmers sold all their livestock and equipment and abandoned their land?

There would be cultural, social and economic shock for sure. With less food grown and reared locally, prices would undoubtedly rise as supermarkets scrambled to secure foreign supply lines. But what would happen to the land itself? Without farming, what would happen to Britain’s nature?

Scenario one: land abandonment

With the hungry mouths of livestock gone, along with the farmer’s ploughs, the great wheels of ecological succession would be freed to turn. Ecological “succession” is the process of change from one set of species to another. In this case, it would begin with dormant seeds, native or otherwise, that would start to emerge. Plants best adapted to fertilised soil such as nettles will thrive.

In time, shrubs and trees will venture into abandoned fields from woodland and hedgerows. Then would come fast growing, light-demanding trees like birch and oak, turning scrubland into early phase woodland. In the shade of the new canopy, lime and elm, both tolerant of low light conditions, will slowly establish themselves until they outlive or outgrow the trees that came before them.

It is a textbook story of succession. The varying climates and soils across Britain mean different species will prosper in different places, and plants will grow at different paces, but in time, in most places, the result will be largely the same. More trees.

England’s green and pleasant lands would mostly look something like this – eventually. ukgardenphotos, CC BY-NC-SA

Herbivores could halt this process in places, and roe, sika and red deer populations would be likely to thrive post-farming. But Britain is missing the heavy-duty herbivores like aurochs (the ancestor of domestic cows) and wild horses that can help halt succession. Storms and fire would open up the canopy in other places, but it is likely that woodland would come to dominate eventually.

So how would this affect Britain’s wildlife more broadly? We can look to the past for insight. Agriculture arrived in Britain around 5,000 years ago. Early farmers cleared woodland to allow them to graze cattle and grow crops. The result of this transition was that plants and animals that favoured open areas thrived. Woodland associated species suffered. In fact, most of the known recent extinctions in Britain are of woodland species, such as the red-backed shrike or scarce dagger moth.

Farmland abandonment would reverse this trend. Species associated with open habitats, such as grey partridge, skylark, lapwing, as well as many bees and butterflies, would find fewer places that meet their needs. But scrub and woodland species, such as bullfinch, nightingale, and capercaillie birds, as well as other groups like moths, beetles, fungi and mammals would thrive once more.

Bullfinches would flourish without farms. f.c.franklin, CC BY-SA

Scenario two: trophic rewilding

What would happen if instead of just abandoning the land, populations of large herbivores such as bison, wild horse, European elk (aka moose) or wild boar were established, along with their predators lynx, wolf and bear?

This scenario is known as “trophic rewilding”. The starting processes would be similar, and succession would still swing into action. But the shrubs and trees trying to establish in fields will be grazed and browsed. Areas of intense grazing would stay open.

But even large herbivores can be less inclined to browse where spiky bushes of bramble, hawthorn and gorse have established. Predators too will mean some areas are relatively free from large plant eaters, who would soon learn to avoid places where they feel at greater risk of being eaten. These plant havens would allow trees to grow, eventually poking out from the protective cocoon of spikes, to emerge above the browsing height of herbivores.

This combination of vegetation-driven processes rising from the bottom of the food-web and predator and herbivore driven processes cascading down from the top can create rich mosaics of habitats. Some of these habitats would be open grasslands full of wildflowers, others mighty woodlands, and some caught in transition. These different habitats would provide for the full range of Britain’s plants and animals.

But, as far as I know, Britain’s farmers have no plans of quitting. Plus, Britain’s nature is well worth investing in to secure our food supply, safeguard biodiversity and restore resilient ecosystems that support society. But this juncture gives us a chance to think about our future and perhaps, in some places, the return of wild nature should be welcomed.

Christopher Sandom, Lecturer in Biology, University of Sussex

This article was originally published on The Conversation. Read the original article.

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