For many years the primary strategy for biodiversity conservation has been to create reserves and refuges, places where nature is protected behind imaginary fences, protected from excessive human impact, certain activities completely forbidden and even, sometimes, places where humans are completely excluded.
Gradually it has become apparent that this approach does not provide an ideal solution - either for nature or for us.
For nature this can be a weak strategy for several reasons. One is that reserves can overlook flows or processes that are essential - animals need to migrate sometimes, meet and breed and to do this safely and effectively they need a wide well connected landscape, not isolated pockets. Another issue is that many forms of negative impact care nothing for our boundaries and can easily leap the fence. Pollution, wildfires, floods and climate change laugh at the idea of 'protected areas'.
To withstand these dangers animals and plants again need a wider connected landscape, giving them the opportunity to move to safer places in a warming world this may mean plants finding a higher altitude or more northerly location to grow in.
With these issues in mind ecologists have talked of the importance of landscape 'corridors', and, more recently, of large scale restoration and rewilding of land that had previously been turned to farming, industry or forestry - giving biodiversity more space back.
An opportunity for gardens and gardeners
What a wonderful opportunity this is for gardeners to contribute. On average one quarter of the area of a typical city, and half its green space, is private garden. Researchers have calculated that the UK has a total cover of private gardens of roughly 433,000 ha, which is a fifth the size of Wales and comparable to the area of the Norfolk Broads, and Exmoor, Dartmoor and Lake District National Parks added together.
So gardeners can make a huge contribution to protecting endangered species, especially insects, by allocating small patches of wild space in the land that we own. We can help nature become 'unreserved' to regain some territory and resilience in the face of future threats. By doing so we can let a little wild back in our own lives and maybe challenge our own biases - is that really a weed? Or a wildflower that had previously been underappreciated?. The definition often given for weed is "a plant in the wrong place' although more accurately it would be "a plant that dares to annoy a human".
At least these definitions make clear that weediness is a subjective evaluation, something that can change as we learn more about the value of the wild ones that jump our fences. In the recent Tatten Park RHS Flower Show a 'weed garden won a gold medal. The world is changing, hopefully in time for us to help nature thrive again.
For more about giving nature space in your garden look at the work led and and founded by Mary Reynolds.
Farmers are changing the way they see weeds too
Farmers have also begun a shift and weeds in fields are being re-evaluated too.
It has been identified by researchers that to some extent weeds can be good for farmers and growers.
The benefits that weeds bring are not unrelated to the potential problems but just require a different way of looking at what is happening. It is true that weed roots may be more effective at colonising the soil (especially difficult soils) compared to crops or domesticated plants but that can bring benefits as well as difficulties. Soil is not meant to be bare, it is much healthier and much better protected when covered in green canopy and woven through by roots with an active rhizosphere. Weeds protect soils from erosion and excessive drying. The roots also feed the soil by donating carbon that improves soil structure and this in turn can actually enable stronger rooting of our crop plants.
It has been shown that many weeds are better at deeper rooting and breaking compacted soils than cultivated crops. The more roots the better and if our weaker domesticated plants cannot do it all, the weeds will help them. Some researchers looking at techniques of organic and regenerative farming are now suggesting that a low weed cover enhances crop growth. This all suggests that a low weed cover in your garden is improving your soil whilst supporting wildlife too.
Moving towards a win win
In his book Win Win Ecology Michael Rozenweig proposes that the current strategies of conservation by creating reserves or by restoration of damaged ecosystems will prove inadequate.
He argues that there simply is not enough land for biodiversity through these approaches to do what is needed. He argues for what he calls Reconciliation Ecology; adapting human places in ways that make them suitable for wildlife too. Only by sharing the land we have allocated as 'ours' can we ensure that the wild things have enough too. In our gardens this can mean leaving undisturbed patches, deadwood and even a few 'weeds' too. Remember that weeds are just wildflowers we do not like.
