Should we stop planting trees?

 article by Nigel Watson

 Many well-intentioned people are pinning great hopes on tree planting as a way to either rescue the natural environment or soak up carbon emissions, or both.  But sadly this can make little ecological and practical sense. 

What can go wrong

 Problems with planting schemes can include:

1.  Unnecessary planting  There is no doubt that forests can make a great contribution to environmental wellbeing and human enjoyment, and establishing new ones can be a good idea.  However, actually going out and planting trees is often the wrong action to take.  As scientific ecologists and many gardeners know, in much of Britain it is simply unnecessary to plant trees.  Seeds disperse very widely and if the ground is suitable for trees, they will grow of their own accord.  It used to be widely understood that land taken out of cultivation will soon, in an old phrase "tumble down to woodland" if it is not mown or grazed.  Natural colonisation of land by trees can still be seen taking place on disused allotments, railway embankments and the like.

 Self-seeded trees usually grow readily, and faster than those that humans have uprooted and transplanted.  Two illustrations of this:  first, leave a lawn unmown for a month in spring, and you will find trees germinating in it.  Second, plant a five foot native tree from a garden centre near to a six-inch seedling of the same species - silver birch, for example - that has grown naturally.  After a few years, you will usually find the former seedling is bigger than the garden centre tree. 

 So to create a forest one should not succumb to the urge to set up a planting scheme; that would just be giving way to human impatience and the modern tendency for micro-management of everything.  Instead, one should merely fence the site of the new woodland, to prevent grazing animals eating the tree seedlings (and to control any human activities that may damage young trees).  Fencing has to be done in most cases, whether trees are being planted or not, so it is not an extra cost.  Thereafter, one just waits for natural succession to replace grass and herbs by scrub and then, after a few years, by trees. 

 2.  Poor aftercare  In many schemes too much effort is going into the actual planting and not enough into aftercare.  Trees that have been uprooted and planted somewhere else do not find life easy and many will die if they are not watered and weeded for the first few years.  However,  it is the initial planting of the tree that provides the tick in the box and the warm glow of a good deed, and too often the aftercare is skimped.  So all the work and cost of treeplanting is wasted.

 3.  The wrong sites  Not all "unused" land should be covered with trees.  Other habitats such as heathland or chalk downland have greater rarity value - and some such as peat bogs can also act as carbon sinks if properly managed.  On many nature reserves the correct management, as practised effectively in such places for many years, is to remove encroaching trees - not plant them.

 4.  The wrong trees  Planted trees are frequently obtained with little thought, often being what is cheap or readily available.   Such trees may be the wrong species or subspecies for the locality  and can dilute the unique genetic characteristics of nearby woodlands or old hedgerows.

 5.  Forests are not future proof  Establishing new woodland is a strategy for the medium to long term, but there is great concern about future climate.  Hence there is uncertainty whether any actions taken now will turn out to be the right ones.  Two examples:  first, some native tree species planted now (eg beech) may turn out to be unable to survive in warmer, drier summers.  Second, it is not completely evident that creating more British woodland is in fact the right way to go. 

 The climate crisis is imminent.  Future generations may be faced with agonising choices between long term and short term needs.  One such choice might be between conserving woodlands to try to prevent further climate damage; or felling and ploughing, to grow foodstuffs that are urgently needed straight away.  If global warming causes significant worldwide crop failures, pressure will become intense to grow more food crops in Britain to avert famine - including starvation of our own citizens, if food imports become scarce and expensive.  In such a scenario one would hesitate to bet that our forests will be left intact.

Forests yes, planting no?

 To sum up; objection no 5 is arguable and may be best put on one side.  Given the uncertainties over the future, most environmentalists would agree that at present it still seems worth creating new British forests - in the right places, where they do not overly damage existing habitats. 

However objections 1 to 4 provide ample reasons to question treeplanting, at least on the great majority of sites.  (There can of course be a case for planting in certain particular situations, e.g. where tree seeds may be unusually scarce, or where small seedlings cannot be protected from being eaten, trampled or vandalised).

 Time to change attitudes

Organisations such as the Woodland Trust have jumped into planting schemes in a big way.  The idea of treeplanting is popular with the public and thus has great appeal to some environmental charities as an easy way to raise funds and support.  Planting lets ordinary people participate in practical conservation, leads to few awkward questions and can help recruit new members. 

However the whole activity is, as discussed, based on a misconception.  Its main value, outside the garden context, is a purely symbolic one - e.g. planting a commemorative tree.   Larger scale planting of entire woodlands only "works" and seems popular because the urban public does not have a good understanding of natural  processes in the countryside.  Talking up the need for planting trees panders to this ignorance and feeds off it. 

It is not right to mislead the public in this way.  The resources wasted by unnecessary planting would be more profitably used on better management of existing and new woodlands.

Two red flags

 One should be particularly wary of carbon offsetting schemes, where a polluter is proposing to pay for trees to be planted.  The instigators of offsetting  schemes are likely to have little interest in the real outcomes.  Hence these schemes are especially likely to be open to objections 2 to 4 above, and may fail completely.

Another thing to be very wary of is any proposal to plant trees in an existing woodland.  This is usually totally unnecessary.  Even if the intention is to replace a conifer plantation by native broadleaved woodland, it is usually only necessary to remove the conifers and wait for natural processes to do the rest.

Questions to ask

For anyone considering whether to support a treeplanting scheme, the following questions are suggested:

• Is the proposed new woodland in a suitable place, and will any existing habitats of special value be damaged?

• Does the new woodland have full support from the local community?

• Is it necessary for trees to be actually planted, rather than waiting for them to grow naturally from seed?

• If planting is required, are the trees native species being obtained locally?

• Is any necessary treeplanting being done by volunteers - and if not, why not?

• Are there adequate arrangements for aftercare of the young trees, and for the long term ecologicaly sound management of the new woodland?

About the author :-

Graduated from Pembroke College, Cambridge in 1973 (BA (hons) in Natural Sciences, final year specialism being zoology).  Became environmentally aware at that time.  Did not pursue science as a career, but actively involved in practical conservation as a volunteer (with BTCV and various local groups) from the early 1970s to the present.