Tree planting and natural regeneration

Do we need to plant nursery-grown ‘whips’ in our UK woodland creation projects, or can we allow nature to create woodlands by standing back (natural regeneration), perhaps with a subtle helping hand (assisted natural regeneration)?

I’ve been having a bit of a debate on Twitter recently about the relative merits of tree planting and natural regeneration as an approach to woodland creation in the UK. This was sparked by posts from the Woodland Trust, World Wildlife Fund-UK and the Rivers Trust.

My interest has been sparked by numerous Tweets from the Woodland Trust, celebrating its woodland creation endeavours, which always seem to be illustrated with photos of plastic tree tubes, affixed to treated wooden posts with a couple of plastic ties. I posed the question: why not allow either natural regeneration (where one simply stands back and allows natural woodland growth to take its course) or assisted natural regeneration (in which we can give nature a helping hand by clearing grasses and scrub from around tree seedlings that appear naturally, or plant seedlings grown by school kids).

In response, the Woodland Trust stated that planting whips in tubes is necessary to ensure trees get away in the face of grazing and grazing voles, rabbits and deer. They also alluded to funder preferences for planting.

Barbara Young, the Chair of the Woodland Trust who I hold in great esteem, suggested in a tweet that planting is needed now because natural regeneration wont be quick enough to deliver carbon sequestration benefits, which need to be delivered within the next twelve years.

Now, don’t get me wrong. I accept that planting of small whips (nursery transplants) can be an effective approach and is sometimes needed. It’s also a great way to engage communities in woodland (plantation?) establishment.

But I fear that planting of imported whips is the default approach adopted by organisations like the Woodland Trust.

So what? For starters, should we be using tens of thousands of plastic planting tubes and plastic ties? These will remain in the environment fo thousands of years, far longer than the tree they accompany, even if it does survive to live a ripe old age. How long can an oak really hope to live? Plastics could be recovered and an attempt made to recycle them. But they are often degenerated by the sun, caked in muck and often just collapse to be lost among emergent scrub. And surely the Woodland Trust should observe the ‘Reduce, Reuse, Recycle’ rule: surely we should look to Reduce avoidable plastic waste, only using plastic when it simply cannot be avoided – then re-using it if possible, and recycling it as the last resort?

What of the statement that woodlands cannot regenerate in the presence of voles, rabbits and (over-abundant) deer? This is true in some situations. But a look at the Northern Forest region, in which the Woodland Trust plans to plant hundreds of thousands of trees, reveals a network of tree and shrub lined railway corridors. The fact that these are celebrated wildlife corridors – with deer not an infrequent sight from the train – suggests that trees are quite capable of getting away throughout the area without much planting.

What of Barbara Young’s assertion that planting is needed urgently because natural regeneration cannot deliver carbon sequestration quickly enough? I can see the argument: planting whips at least guarantees that a mix of native trees will establish at a given plot quickly. I’m not convinced, though, that assisted natural regeneration wouldn’t do the job just as well, and just as rapidly.

The Woodland Trust also state that planted trees form natural woodlands. My experience is the opposite. It’s very easy to tell a planted oak wood, 100 years later, from a naturally regenerated woodland. That’s my experience, at least.

So, what do I suggest? How about a Hierarchy approach:

First, assume natural regeneration, unless the site is so far away from seed sources that trees and shrubs simply wont arrive any time soon.

If that’s demonstrably not possible…

Second, undertake assisted natural regeneration, in which naturally-appearing seedlings are ‘liberated’ by keeping competitors at bay in their immediate vicinity, and with some planting of small seedlings of, say, oaks, grown on by kids at school.

If neither of those two options are demonstrably appropriate at the site in question…

Finally, plant nursery whips.

It would be relatively easy for the Woodland Trust, and other natural woodland creators to adopt such an approach.

6 thoughts on “Tree planting and natural regeneration

  1. Yes Steve, the Woodland Trust are obsessed with planting rows of tubed trees 2m apart with little scope for anything natural such as successional stages, scrub growth or diverse structure and natural clearings etc.. in my experience they are not prepared to listen to experienced local ecological expertise but just go ahead with these uniform rows with little appreciation for diversity and it is rare for any later management to be undertaken. they need to take ecology and nature more seriously.
    Planting of small areas to encouraged a quick start may be justified but natural regeneration and appreciation of scrub should be encouraged and made the norm. The Knepp rewilding project shows the incredible richness of scrub habitats and onward succession to woodland also. Locally, Woodland Trust plantings now 20 years old are often tall, even aged, closely planted tall lolly pop tree plantations, though they do hold some wildlife value. Naturally re-generated areas adjacent to these invariably have far greater wildlife interest, lots of bramble, open areas amongst thorn species and great structural and ecotonal diversity. Higher densities of breeding birds are evident too.

    Liked by 2 people

    1. Thanks for your reply, Barry – I thoroughly agree with all you say. I wonder if there are any studies comparing structure, species richness, abundances, growth rates etc etc, of paired samples of planted and naturally regenerated areas in the UK at different time-steps – after 5, 10, 20, 30 years etc? And associated biodiversity – breeding and wintering birds, invertebrates etc? Your observations about the value of all successional stages is important: near me, chalk scrub is amazing just on account of the number of shrub species, let alone all the hoverflies, crickets etc.

      Liked by 1 person

  2. Jon Gurr

    Steve, I agree with all your points made in the article. It certainly feels to me that funding I.e. money is what is driving the WT tree planting model. It is quite remarkable that an organisation filled with experts and dedicated people focused on woodland conservation have effectively got it so wrong on tree planting and tree establishment . I work as a tree specialist in a rural local authority and even in my team I’m having a hard time convincing them that it’s not all about tree planting. It’s now a culturally driven model that is probably going to be hard to break. I hope some quality research is being undertaken on tree planting vs NR and ecological outcomes. Cheers, Jon

    Like

  3. Pingback: Rewilding will make Britain a rainforest nation again | George Monbiot – Hobbit Worldnews

  4. Pingback: Rewilding will make Britain a rainforest nation again | Newyorrk.com

  5. carolynfmills

    Hello, I have just come across your post and you say exactly what I have been thinking recently, so was good to hear. Given the scale of reforestation needed in Britain, I think it is mad not to rely on natural regeneration wherever possible. Apart from the ecological benefits you mention, it is also much cheaper and does not involve the carbon emissions associated with propagating trees, site preparation and planting, that must cancel out some of the initial carbon uptake when the trees begin to grow. There would still be no shortage of sites where trees could and should be planted due to lack of seed sources, or for new productive woodlands managed for quality timber for the future. Concentrating planting schemes on these sites and using natural regen elsewhere would seem a more effective use of resources.

    Liked by 1 person

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s