Tree-mendous trees: planting the right tree in right place

Aller Woods - Mark Green

Trees provide secure homes for wildlife whether hunter or prey, shelter from the elements, secure passage across our landscapes and enrich food sources for all manner of species. They capture carbon, protect and provide strength and structure for our soils, help reduce flooding and contribute to mitigating against air pollution.

Whilst they have been doing these jobs since the beginning of time without a big fuss, it doesn’t come as a surprise that the humble, hardworking tree has been put under the media spotlight and lauded as the ‘instant fix’ for the environmental challenges – both climate and ecological – that our world faces going forwards. 

There’s no doubt that we need to increase and improve the quality of tree cover in the UK to address falling biodiversity and rising global temperatures.  However, at Somerset Wildlife Trust we believe that restoring wooded habitats – and thus any tree planting activity – must be based on the principle of ‘right tree, right place’.

Before you pick up your spade – remember: nature’s ecosystems are complicated. Planting a tree changes an ecosystem and has a significant impact on the physical characteristics of an environment, such as shading, water cycling and soil pH. Whilst many of these changes are beneficial, in some places tree planting might negatively impact biodiversity in the medium to long term and in time reduce the value of existing ecosystem services or the quality of wildlife habitats.

Beech trees

Beech trees - Heath McDonald

One… two… tree… four… five

When it comes to your tree-mendous plans, whether on your own land or with your local community group, what should you be doing to make sure you have the impact you want, and how do you make it work within the bigger landscape picture? Here are our top 5 points to consider…

Talk about flowers first! (Yes, we did mean to say that!)

Quite often we see trees planted, with the best of intentions, on grassland areas that support a range of native wildflowers. The ‘scrappy corner’, steep bank or field that doesn’t produce as much grass often seems the ideal spot for tree planting, as it is less productive or harder to access. But it is these places that are most likely to support native wildflowers, which can only thrive in such low-nutrient conditions. Grasslands are also very capable of storing carbon, particularly where a long history of no fertiliser inputs has allowed a thick soil layer to develop. Wildflower grasslands are particularly vulnerable and in decline – as are heathlands and wetlands. These valuable wildlife-rich habitats already store carbon and planting trees on them can dry them out and cast shade, resulting in a net loss of wildlife value.
 

Would your site regenerate quicker naturally?

There’s almost an automatic assumption that if we need more trees, we need to plant them! Tree planting is right for some areas, but natural tree regeneration is often much better for both carbon storage and wildlife, as well as being significantly less expensive. Allowing natural regeneration on sites that are adjacent or near to existing woodlands is much more likely to result in more biologically diverse woodland habitat than planting new trees, as the tree species that establish will be locally adapted. A naturally regenerating woodland is also likely to develop a more natural structure, including establishment of woodland ground flora species and support a much wider range of wildlife. Last time we checked, trees were pretty good at seeding themselves – albeit not in the tidy way we have become accustomed to expect!

  • If there are nearby hedges, scrubby areas or woodlands that could provide a seed source of native trees and woodland plants, then it is generally best to simply cease any grazing or mowing and wait for nature to ‘move in’
  • Natural regeneration is less expensive and removes the need for use of tree guards necessary to provide protection from grazing deer and the need to operate machinery – though in many cases deer fencing, which can be expensive, is still needed to protect new growth.
  • In urban areas or places with few nearby woodland habitats or with visiting deer, it may be a good idea to plant trees with plastic-free biodegradable tree guards to get things started.

 If planting is the way forward and it is the right place, next be sure to plant the right tree!  

  • Look around you – what tree species are already growing in similar conditions to your site?
  • Collect local seeds to grow local native trees – a fun activity and a great way to be sure you are planting suitable species.
  • If buying ‘whips’ from a commercial supplier, be sure to ask for native species that are suitable for the soil type and pH.

Planting a variety of (locally suitable) tree species is likely to create more resilient woodlands in the long term, as species will respond differently to climate change and other environmental factors.

It doesn't have to be a woodland...
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  • Another great way of planting trees is to restore and create hedgerows. Our native hedgerows provide a vital source of food and shelter for many species, as well as providing an important wildlife highway through our busy modern landscape, helping species to move and respond to environmental change. It’s now more vital than ever to re-establish these important wildlife corridors.
  • Create or restore an orchard – Somerset is the land of scrumpy after all! As well as storing carbon and providing a great pollen source for your neighbourhood bees and butterflies, you will the have a very local source of food and drink to enjoy!
  • Plant trees and hedges in urban and community spaces such as parks, gardens and in unused areas of recreational space. Expanding tree cover in towns and villages can help increase carbon storage, reduce atmospheric pollutants, soak up water, provide a shady space to rest on a hot summer’s day and generally enhance where you live.
     

Plan ahead!

Create a management plan from the outset, including initial aftercare as well as a long-term plan for how the trees will be managed to create a well-structured, semi-natural woodland over time, supporting a rich diversity of wildlife. Well-planned aftercare is essential to ensure your tree planting is successful, this could include:

  • A period of watering may be necessary following planting of larger trees
  • Spiral tree guards (biodegradable guards are available) can help protect tree whips from grazing by rabbits, but need clearing out of grass and dead leaves annually; as the trees grow, larger tube guards may be needed on sites where deer grazing is an issue
  • Removal (and recycling) of tree guards once the trees are big enough

Accept that some trees will fail to establish, but also that as the trees mature, some may need to be removed to provide the room and freedom from competition for the ‘keepers’ to mature into healthy trees.

When planning larger sites, include open spaces such as glades and rides from the outset, as these provide vital variation in light levels, supporting woodland wildflowers as well as butterflies, bees and other wildlife.

Canopy of trees

Canopy of trees - Brian Phipps

Finally, planting trees does not immediately create a woodland. Even if you have done it all right and ticked every box above, let’s not forget that trees still take the same amount of time to grow before they can crack on with the job. First and foremost, we must protect the woodland (and other wildlife-rich) habitats that we already have and see planting trees, or enabling natural regeneration, as the start of a long but vital process towards development of semi-natural woodland.

Other useful sources of information: 

Tree planting methods, including when is the best time of year to plant
Which species to plant
Which trees grow on different soil types