Expanding native woodlands
- await colonisation or plant?

by Peter Quelch, Native Woodland Adviser, FC Scotland

A dubious background!
Some good-natured criticism was directed at me while chairing a discussion at the Woodland Restoration 1999 conference of the Scottish Woodland History Group. I was blasé about the need for deer fencing in woodland expansion schemes in the western highlands. For 20 years I was responsible for planting of conifers on thousands of hectares. Fencing protected both new planting from hill deer and restocking from forest deer. It might have been ecologically better, and possibly cheaper in the short term, to have carried out all that planting without fencing. But foresters are essentially practical people - they have programmes to meet with limited resources, and they work out practical solutions. To achieve well stocked commercial plantations on hill ground with large red deer herds on neighbour's land (over which you have little or no control), then we simply fenced them out.

To deerfence or not
A similar fencing philosophy is applied today to many (but not all) new native woodlands for more or less the same reasons. Implied in the decision to fence is a need to achieve a good result - quickly, and with some certainty.

Fortunately forest deer management has now reached the stage in many areas of Scotland that the deerfencing of restocking is rarely needed. Being able to do without fences on hill planting or regeneration does however depend on co-operation over deer control with neighbours, (unless your ownership is on such a scale that your own deer control dominates the relevant deer catchment area). Sometimes that co-operation is achievable, sometimes not, in the short term at least. In many areas it is an aspiration to be worked towards through negotiation within deer control groups. With deerfencing now being seen as a real threat to the rapidly declining caper population there is a strong incentive to fence only when absolutely essential.

Why do I dwell on the deerfencing issue when the title of this article is about planting and regeneration? Because I believe the same sort of thinking implicit in the 'fence: no-fence' decision, also divides those who would rather plant from those who would rather wait for natural colonisation.

Planted new native woodlands
A good example of the mainly planting approach is at Cashel (RSFS) on Loch Lomond. For lots of good reasons, including a financial opportunity, the trustees decided to plant the majority of bare land suitable for tree growing on an ex-hillfarm within protective deerfences. The results after 5 years or so of the earliest planting, (which included a lot of Scots pine just south of its recent natural range), are really very impressive and must be a source of satisfaction to those involved. Extensive areas of new native species woodland have indeed been created in a very short space of time.

Wisely, extensive patches of wet and peaty soils were not planted, either to stay as open glades and bogs, or in the case of lower flushes to be gradually colonised with grey sallow. The recovery of bog myrtle and many other wetland plants in these site types is heartening. Existing seminatural woods have a (rather modest) buffer zone to allow scope for regeneration. This model of native woodland expansion has been repeated all over the highlands, especially with new native pinewoods.

A large natural regeneration scheme
At Craig Meagaidh NNR, Loch Laggan, woodland restoration is proceeding without either deerfencing or planting. The great advantage of the resulting regeneration is that is about as natural as the circumstances will permit. Some terrific birch regeneration is occurring from the poor and scattered remnant trees, and sometimes surprisingly far from those seed trees - (a pity that new public roadworks have wiped out some of the nicest old birch and regen!) However equally large areas are not regenerating - with trees anyway.

But then we foresters are obsessed with getting 'full stocking' of trees, whatever that is in a natural situation. It is I suppose only to be expected that forestry grants are linked to a minimum stocking rate, with pro-rata reductions for achieving less than the standard - but do we really need wall to wall woodland cover? It is one's view on this question that will sway you towards either planting or regeneration.

Defining success
It is also partly a question of what you define as success. Are you happy with the idea of achieving scattered patches of birch and eared willow over 20 years through natural regeneration? Or do you want to plant and ensure you have the full panoply of tree and shrub species that nature intended (according to the NVC anyway) from day one?

But be realistic when planting- don't choose a species mix that is impossible for prevailing site conditions of soil, elevation and windyness. Use a tool like ESC to help decide what is indeed feasible. The target natural woodland types at high altitude or in exposed conditions, especially on acidic soils, are indeed species poor, with birch dominant.

Natural succession?
Or do you believe more strongly in the role of the natural succession of woodland types, starting off by planting large numbers of pioneer species like birch and pine, and then waiting for other species to add to the mixture. This is a nice idea in theory but one wonders how often it works out in practice. So many factors, especially grazing, can prevent that succession from happening.

We are a bit short of the tree species typical of late succession forests in mainland Europe. Beech, spruce and silver fir never made it to Scotland naturally after the ice age. We have some shade bearing shrubs like holly, wych elm and yew, but few shade bearing taller trees able to come up as advanced regeneration, just waiting for gaps in the canopy to let them get away.

Planting missing tree species
But what if seed sources of certain native trees are completely missing from the restoration area's catchment? There are not many choices here: either you plant some new seed sources of the missing species, or wait a long time and so perhaps never recruit them. You cannot depend on colonisation to bring say aspen, or even hazel or bird cherry - there is a large element of chance in natural processes. Whether this matters is debatable - my view is that we have a duty to prevent our natural origin woodlands declining any further in condition and species richness. [However, few people would advocate mass planting of rare trees and shrubs - see page 19 of FC Bulletin 112]

One thing is certain, that if species do arrive naturally, for example bird dispersal of yew as can be seen in crags on east Loch Lomond, the result is all the more welcome and valued. Perceived wisdom about the re-introduction of missing tree and shrub species constantly changes, simply because I don't think there is any right answer. My own opinion is to reintroduce in some woods. So heavier intervention (like planting missing species) becomes both more appropriate and justifiable, the poorer the existing condition. The nearer the site is to being ideal, the less one should intervene. Just modify it by gentle nudges to enhance the site's condition. This seems to me to be a reasonable compromise, whereby existing naturalness is protected within regeneration only schemes, but a real boost is given to native woodland expansion and the restoration of degraded habitats through planting schemes.

An elitist attitude?
Opponents of planting would rather have a slow and simple natural result than any amount of planted new native woodland. I can understand this viewpoint. Have you ever looked at a clump of wood anemones or violets growing in the fork of a tree? A whole woodland full of anemones would not please so much once you knew they had been planted. It is the spontaneous and unpredictable wild results of nature that delight us. But is this an elitist attitude which is rapidly becoming a luxury in a world of threatened habitats and species? Will our successors in 2200 be able to tell which oak trees had been planted, any more than we can tell for certain which were planted in 1800?

The upland landscape is very obviously not all in a state of ecological health and fitness, with all the tools in place for nature to do her job. To me this is the point about 'restoration forestry' - it is about man intervening, sometimes quite strongly, to help set natural processes back on course. And don't tell me that man is not part of the ecosystem! I think the more you look at the history of man's use of woodlands the more you realise how important traditional land-use has been in forming the character of today's 'seminatural' woodlands.

The choice is yours
I suggest you consider the philosophy discussed above and simply decide which route you want to go down. It would be dull if we all agreed to follow the same route! Above all decide how natural a result you want to achieve, and be realistic about the chances of achieving it. Or maybe you will decide that in your case the means justifies the end.

Planting, though an artificial action, almost guarantees that you will see visible progress towards your aim of complete restoration in what is left of this lifetime! Or are you happy just to help nature on her way. At the end of the day you pays your money and takes your choice!

Collecting tree seed and growing it on in native tree nurseries is one of the most satisfying ways in which people can get involved with natural type woodlands in the 21st C, and I wish TreeTrader a successful start in the year 2000.

Peter Quelch
Native Woodland Adviser
FC Scotland
Sept 00