Preparing to search
John Matthews was appointed to initiate work in forest genetics and took up residence at Alice Holt in September 1948. Considered as a possible venue for a Forest Research Station as early as 1942, Alice Holt then consisted of the original Lodge itself with a range of outbuildings and garden facilities rapidly filling with a number of specialists; Matthews was allocated a desk in the library.
Reports of earlier work in Sweden by Lindquist and in Denmark by Syrach Larsen formed the basis of initial planning, together with a comparative study of the methods used by the Welsh Plant Breeding Station in forage grasses, another perennial outbreeding crop. Other benefits also came from liaison with the John Innes Institute, Norwich and East Malling and Long Ashton Research Stations in which plant genetics of woody species were studied.
Initial investigations of the practical techniques of grafting, rooting of cuttings and controlled pollination took place at Alice Holt in one small glasshouse and the original fig house, and a small area of arable land was made available for outplanted trials.
By the spring of 1950 there was a staff of two foresters and two forest workers and the section was housed in a second-hand military bunk-house and boasted a cherished if unreliable official car. They had developed plus-tree selection criteria together with basic competence in grafting, rooting cuttings and raising progeny, and had initiated a small clone bank and demonstration area.
The way was now open to build up a major programme of work, concentrating on the selection of seed stands and plus-trees.
Much benefit for this work came from the 1947-49 Census of Woodlands, work on which was nearing completion. The detailed information assembled and the knowledge and experience of its staff, notably those who transferred into Genetics Branch, gave a major impetus to the systematic surveying for stands and plus-trees which was now in place. Early surveys had been centred on Corsican pine, Douglas fir and Sitka spruce from a wide range of forests.
After a short programme of beech selection in the Cotswolds and South Downs, work began to be concentrated in the North with detailed surveys of Forestry Commission (FC) plantations and the large private estates of the Laigh of Moray and North-East Scotland. The work was allocated to a different FC Conservancy in each year, the four into which Scotland was then divided occupying the period 1951-54. This coincided with the time in which Alan Carlisle was heavily involved in the original survey work of native Scots pinewoods prior to the publication of his definitive work with Prof. H.M. Steven (Steven and Carlisle, 1959). This influenced the selection of over 200 clones in native woodlands, a number of which have been combined into production populations for the creation of seed orchards to produce native Scots pine seed.
This method of surveying continued through the 1950s, covering the five English Conservancies and starting the new decade with all of Wales in 1960. Selection was based on a wide range of species though Scots pine received the most attention. Among other major conifers, Corsican pine, Douglas fir and European larch figured prominently but Japanese larch, western red cedar, western hemlock, Norway spruce, oak and ash were also considered during those years together with some quite obscure species. It is important to note, however, that, apart from just over 300 trees selected in 1950, no effort was devoted to selecting any further material of Sitka spruce, other than a small number of seed stands.
While records of plus trees amassed and specimens painted on their trunks with bright yellow bands and large numbers began to proliferate throughout the forest estate, a register of seed stands had also been initiated. Increasingly, Genetics Section surveyors became agents of an adequate and regular supply of home-collected seed.
The importance of quality was also recognised and a system of classifying stands into four categories soon emerged. These provided a basis for sourcing seed in better quality stands, resorting to stands of lower quality only in years when the supply was inadequate.
A Tree Seed Association was established for Scotland and a separate one for England and Wales. These organisations, whose aim was to improve the quality of planted material through the use of the best-known appropriate sources, involved both state and private sector participation. More details of the early work on seed stands.
Throughout these years of survey work, there was major consolidation taking place in vegetative propagation. Techniques established at Alice Holt had been continued there and on a small scale at Tulliallan (Aberfoyle) and Newton (Moray) nurseries, but in 1951 the walled Garden and glasshouse facilities at Grizedale (Lakes) were acquired for development as the main grafting facility which operated with a staff of up to three foresters over the next 15-20 years.
Grafting was carried out both under glass and in open ground, in both instances using 2 or 3 year old rootstocks (Lightly and Faulkner, 1963). The side-veneer graft evolved as the preferred type among many originally investigated and remains so today. It was found that leaving a sap-drawing branch on the upper part of the rootstock was beneficial and this is still standard practice. Grafts were bound with raffia and coated with hot wax specially formulated from tallow, beeswax and Venetian red, a mixture with explosive properties not unknown to those involved.
The early grafting work was the precursor of the original clone banks which were established for Scots pine at Alice Holt and Newton together with Larch at Drumtochty (Kincardine) and Douglas fir at Glenfarquhar (Kincardine).
These early years, during which the Genetics Section grew steadily were not without occasions when progress took a major step forward. The most important of these can be traced to the single night of 31st January 1953 when extensive areas of the old North Scotland and East Scotland conservancies were devastated by a storm of terrific force. Many of the 165 plus-trees and about 20 seed stands selected in Scots pine in the 1951 and 1952 surveys were lost and a major exercise was mounted to collect both scion wood for grafting and cones to yield seed for progeny testing in this and other major species. It soon became clear that an opportunity presented itself to select further plus trees, even in a prostrate position, and, in addition, to make general cone collections for Conservancy use. Large grafting programmes at Grizedale, Alice Holt and Newton ensued from these collections and seed from many families was extracted and stored.
This single event led to two important pieces of work.
The first was a series of untested clonal seed orchards emerging from the grafting work.
Several were established for FC use and grafts from clones on their own estates were offered to a number of private owners. This secured for them a supply of seed based on plus-trees from their lost plantations. Seven Scots pine orchards and one of Douglas fir were established for the FC on part of Ledmore (Tay) nursery, a site of major importance in later years.
Most of the orchards were composed of 20 clones each represented by 20 ramets in a standard layout, arranged to ensure maximum separation of ramets of the same clone. The FC orchards at Ledmore (Tay) and Bradon (Forest of Dean), together with others established at the same time on private estates, contributed greatly to the Scots pine seed supply throughout the 1960s and 1970s and some of the private orchards remained in production until the early 1990s.
Secondly, the first major series of progeny-tests was planted in 1957 at four test sites.
The tests were composed of around 60 Scots pine families, derived from clones lost in the 1953 storm, the performance of which was compared with four commercial seedlots. Up to this time, the planting of progeny tests had been limited and sporadic, but this series laid the foundations for the systematic progeny testing which was to follow from the mid 1960s. The tests were laid out on low and high elevation sites at Glenlivet (Kincardine) and at Chillingham (Kielder) and Kilmory (West Argyll). Carefully designed experimental layouts incorporating triple-lattices were used, each family represented by a 16 plant plot (4 x 4) in 3 replications.
By the early 1960s the Genetics section was well established. There had clearly been some benefit in the early years from the support given by the FC Chairman, Lord Robinson, at a time when such a long-term financial commitment would have been difficult to justify. A future reliance on seed orchards, for Scots pine in particular, was now within view. The team consisted of a stable group of people, particularly specialist foresters who would staff the section almost unchanged over the next 20 years. Initially an individual staff member was responsible for all aspects of work within one species.
Major changes of emphasis began, however, following a section meeting at Benmore in the spring of 1963. Here the decision was made to concentrate on Sitka spruce, the species which until then had almost been ignored. John Matthews left later that year to take the Chair of Forestry at Aberdeen and was succeeded by Roy Faulkner who had led breeding work in the North for some years.
At the same time, Alan Mitchell had left the section at Alice Holt to concentrate on dendrological work within Silviculture(South) Section and Alan Fletcher was appointed in the North to lead the new work on breeding Sitka spruce. The first ‘Visiting Group’ of scientists to review the tree breeding programme made a positive report recommending more intensive and systematic work on progeny-testing.
Thus a major policy decision was made to concentrate on only the most important conifers, then listed as Sitka spruce, lodgepole pine, Scots pine, Corsican pine and hybrid larch.
With the exception of Sitka spruce and some later concentrated efforts on Corsican pine, the main work of plus-tree selection was also drawing to a close at this time. The table below shows the final numbers of plus-trees selected in all species, a process which continued until the late 1980s for special populations of Sitka spruce.
Summary of the numbers of plus trees selected throughout the breeding programme
|Species||Plus trees (1950-92)|
|Other pines (2)||43|
|Other spruces (6)||545|
|Silver firs (4)||207|
|Other conifers (3)||127|
The stage was now set for the next 25 years of routine but intensive activity on establishing progeny tests, grafting work, pollination programmes and field assessment schedules. Throughout this period, the experience gained led to constant refinements in techniques across all areas of work. Changes in plus-tree selection criteria, choice of progeny test sites and performance measures used in tests all led to considerably greater efficiency. The development of more successful methods of grafting, progeny raising and artificial pollination consolidated the high degree of expertise in tree breeding.
These pages review the work performed by the Forestry Commission and Forest Research on tree improvement following the 50th anniversary of its establishment which passed in 1998. The genetic background describes the scientific procedures of tree breeding and the technical terms used in the remaining pages. All species are referred to by their common name in English.