Bertil Lindquist wrote a book published 1946, which received much attention and thus probably became a major fundament of “early thoughts”.

Focusing on my evaluation of the book in the light of the current situation

Seeds should be collected stands where historic factors speaks for that they are less genetically degraded by human interference than alternatives and which looks phenotypically good. The first step in that process could be a country-wide mapping. The seed collection should be directed to the best looking trees within stands. I believe Lindquist is right in principle but give an impression of that the effects of those actions would be much larger than they are. The genetic leveling out of differences caused by pollen flight had not been analyzed and was not considered. It was not recognized that only a small share of the genetic variation is useable by the available tools, the most important is the continuous provenance variation, and this is taken care of anyway. Besides that, results have shown that the genetic variation is less important than the environmental. Lindquist emphasizes external quality more that rapid growth, but our experiments show that the response to growth rate has been larger than that to quality.

Lindquist mentions a number of Swedish locations where (staffed) forest tree improvement is going on (Stockholm, Uppsala, Källtorp (=Ekebo), Linköping, Brunsberg, Dalfors, Sundmo, Kratten and a number of provincial forest boards. Of these only Uppsala and Ekebo remains today six decades later. However, Uppsala is no example of continuity as it was abandoned some years in the 70ies and when built up from scratch again. The average life time of a forest genetic location seems to be in the magnitude 30 years, and as trees and impact of ideas have a much longer life than that, this gives an unsatisfactory low link to the history.

The focus at Ekebo at its foundation was triploids, others abroad worked much with hybrids, when Gustafsson became professor 1948 attention was given to mutation breeding, it is remarkable little written about any of those “side lines”.

Looking in “föreningen” yearbook since 1938, I could not find maps with “plus” and “minus” stands as in Lindqvist (1946) (only a few for individual counties).

Lindquist seems to trust in a rather rigid governmental control, in particular about the seed orchards.

Lindquist seems to have worked only a decade as forest geneticist, after that he become manager of the botanical garden in Gothenburg.

There are no quantitative calculations or predictions of expected gain by the different activities suggested. The phenotypic superiority of selections is quantified, but there are no suggestions of genetic superiority based on quantitative reasoning, just a few highly speculative statements of 50 or 100% superiority. In chapter 8 (national economy) he mentions 20%.

A passage from the still more than two decades after its publication probably most used tree improvement text book by Zobel and Talbert (1984) says (slightly modified): It is of interest how three different incidents triggered the establishment of large, well-organised, and adequately financed tree improvement programs in the south-eastern United States over 30 years ago. The first was the publication of a book on forest genetics by Bertil Lindquist. The book was translated into English (and many other languages) and was circulated widely among foresters. It was written in a manner that caught the interest of foresters, and from it many obtained their first insights into the use of genetics in forest trees…

This book must have had a large World-wide impact and particular in Sweden and the influence may have been indirect. Thus it is of interest what is written in it, and not only historic interest. It may not be read nowadays but thoughts of it have probably been deeply rooted in the administrative and legal World. Thus it is of interest what is written in it. I try to shortly review it, (inserting some own comments in hindsight).

The book appeared at a time when Race Biology was still more touchy than today. It had political implications. The Nazis supported their policy with Race Biology arguments. The Commies claimed the reverse (that would make humans more modifiable to scientific Marxism-Leninism). Not that we are so very objective towards genetic change today (“Creative design…”)…

The book is structured in nine chapters.

There are no direct references (although the persons are often mentioned and there is an appendix with relevant literature). Thus the degree of speculation in statements is difficult to verify.

There are 60 photos, many of them suggestive showing trees or stands which look very superior (or sometime inferior) to other trees and stands. There are no formulas and only five “scientific looking” graphs and tables. One understands Zobel’s comment that it was written in a manner that caught the interest of foresters.

Chapter 1 about facts. Lindquist states that the subject is a difficult matter and we are often forced to rely on probabilities or analogies. There are examples there it seems very likely that differences between tree populations in e.g. bole form and branching habit are caused by genetic factors. That has also been proven by controlled crosses.

Chapter 2 is titled “Deterioration of the genetic quality of Sweden’s forests as a result of earlier forest exploitation. Human has had a significant effect of forest. This has happened in most places in the world, in Sweden probably this means since the end of last glaciation. Timber of a high quality was required, the largest trees with the highest quality was cut, the other left. This practice stopped almost a century ago for spruce and pine, but may still be important for hardwoods. This meant generally a negative selection for a long time. That meant that tree improvement should make an effort to start from the least degenerated stands far from settlements. The northern pine has a higher quality than the southern and Lindquist guesses that this may be a consequence of less human impact for a shorter time in the north. The pressure on spruce timber has been less intensive, so spruce can be expected to be less degenerated. Seed collection was usually done close to the villages, where deterioration is worst, and it was done from isolated, wide-crowned, wolf-pines with abundant flowering. Thus the negative impact of human exploition have probably spread (for plantings before the book was written). However, also large areas of bad pine at high altitudes in the far north were identified. Here Lindquist suggests that other selection factors than Man may also be important. E.g. where pine is mixed with spruce, broad crowned varieties may be more competitive and thus selected.

Chapter 3 about immediate measures (mainly choosing seed collection areas). Many plantations of local provenance show a remarkable bad type of branching and bole, Lindquist ascribes that to the genetic quality of the used local seed sources, later research has made it probable that it is plantation in wide spacing itself which is the main culprit. Lindquist suggests a country-wide inventory and describes much of a variation which might be genetic of pine in middle and Northern Sweden. Over half of Gävleborgs län (county most carefully inventoried) pine forest were regarded unsuitable for seed collection. (Similar comments are not given for spruce) Schemes for acceptable transfer are given, in the light of what we know today we would be less tolerant to moving pine from the south to the north in harsh northern areas, and consider the altitude of the plantation site more. Gains could be made by grading nursery stock. Seeds should preferable be collected from selected trees within the selected stands. Seed stands could be thinned to improve pollen quality and amount of seeds. Besides seed collection, silviculture matters, in particular the selection of seed trees in natural selection and pre-commercial thinnings.

Chapter 4 about long-term measures (mainly establishing clonal seed orchards). It is noted that the annual seed demand is 60 tons, but only 25 tons are produced. (Today about ?? tonnes are used). For seed production in a grafted seed orchard there is a guess (referring to Larsen and Jensen) of a yearly seed crop of 50kg/hectare. Girdling, root pruning and grafting were suggested to improve flowering. Today we know that nothing of this works and grafts produce more seeds than similar managed seedlings only in the establishment phase. Seed production has been raised from initial 4 to 7 kg per hectare by relevant management procedures. 6-10 clones were suggested for a seed orchard and 100 clones were considered sufficient for the need of Sweden (for pine). Lindquist suggests 10 orchard zones for pine and 6 for spruce, more than double as many will be used for third batch of seed orchards. I think it would have worked with the lower number but it is worth the extra gain with the present zones.

Chapter 5 is about plus trees. Plus tree selection and progeny-testing were discussed.

Chapter 6: best utilization of the elite material

Chapter 7 effect on forest management

Chapter 8 National economic consequences

Chapter 9. Realisation in Sweden

Lindqvist, B. 1946. Den skogliga rasforskningen och praktiken. Svenska Skogsvårdsföreningens förlag, Stockholm. Available in English. Chronica Botanica, Waltham, Massachussetts, 1948.

Zobel, B. and Talbert, J.T. 1984. Applied Forest Tree Improvement. John Wiley & Sons. 505 pages.