Seed collectionCan we improve the unimproved seeds?

UPSC 070510

Dag Lindgren

Plants in Sweden dominated by Norway spruce and Scots pine.

Less than 0.5% decideous trees and around 3% ”other conifers”

Very few clones, less than a permille are Norway spruce cuttings!

Only collections of Swedish Scots pine and Norway spruce considered

Considerations are on a link which can be reached from my web:http://www-genfys.slu.se/staff/dagl/Frotakt/Utredning.htm

Source of Scots pine plants in Sweden

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Source of Norway spruce plants in Sweden

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Seeds from Swedish unimproved stands give raise to 1/4 of Swedish plants!

In addition import of stand seeds (mainly spruce from Belarus and Baltic states) 10-15%.

Seed consumption is predicted to increase

• Reforestation after the storms Gudrun and Per increase the plant need!

• Direct seeding of Scots pine raises

• Forest production becames a higher priority and thus possible more planting

• Good spruce seed harvests the last years because of weather add some seeds, but this is not sustainable

• Radical decrease of need of unimproved stand seeds first when the third batch of seed orchards become mature around 2025.

EU category

Svenska English Example

Känd härkomst Source identified

Åmsele300 000 ha pine

Beståndsutvalt Selected

Individutvalt Qualified SkaholmaPine seed orchard

Testat Tested AlvikPine seed orchard

A forest reproductive material must be derived from an approved basic material to be marketed. It can be a seed orchard, a seed collection stand or a seed collection area. Information is kept on record by Skogsstyrelsen, currently Lennart Ackzell is responsible.

For Scots pine and Norway spruce there are no approved seed collection stands except a few seed orchards, which were not up to standards for ”qualified”.

Till a few years ago there were exceptions and transition extempts, but now the rule is in full force.

Cones and seeds can not be collected without the permission of the owner.

Most cones are harvested on felled trees after final felling.

The annual time window for cone collection is rather short. In August the seeds are not ripe and in December where is snow.

Only some years are suitable. Cone set and seed maturation varies. A rough estimation can be made from metheorological records, based on that it is decided if further actions are needed (identification of candidate stands and analyse of cone samples)

Seed maturation is often unsatisfactory for pine in cold areas. Insect damage can be a large problem in spruce. Many of these factors can be evaluated only on seed and cone samples, and there is little time for decisions between analyses and execution.

Seed dealers without forest buy often cones from the private person arranging for the timber harvest ”on the market”.

The large companies prefer to collect cones on their on land: • they can coordinate the activity of cone collector and timber harvest;• need not agreement with land owner;But sometimes no object in approved seed collection areas is not available. They can apply for making it permitted and this is likely to be given, but it is a process which takes time and administrative effort. The benefit is seen as doubtful it is just seen as a disturbance. That was initiating this review of the system.

The approvement procedure takes some time and administrative effort, and someone must pay for it.

• We know more now• The authorities experience difficulties with

the current system.• The “natural” forests are reduced and the

increase in planted forests make the origin and the pollen source more uncertain.

The idea with seed collection areas is historically and mentally anchored

• Tree provenances were known since some centuries. Provenances are different!

• Bad Scots pine seed imports from Germany caused ban on foreign provenances on state land and seed taxes around 1880.

• Mendel and race biology were important concepts in the end of the 30ies when forest tree breeding started.

• Anyone knows that heredity matters, good trees certainly get good progeny!!!

• To get anything else than suitable areas for seed collection takes lots of time and effort if at all possible

• Bertil Lindqvist wrote the first textbook about forest tree breeding 1946. It give much emphasize on seed collection areas, thus expeditions and procedures to identify good forests.

• There was no alternative.• Spruce was imported and when it could be

important that Swedes actually looked at stands (authoctonity, size, homogeniety, records etc.). We got accustomed to inspections.

• The last major inspections were done 25 years ago, if someone want this extended they probably have to pay for it.

Frötäktsområden GranCirkelns yta är proportionell mot arealen

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Frötäktsområden TallCirkelns yta är proportionell mot arealen

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The areas of seed collection areas as a function of latitude and altitude

Spruce to the left and pine to the right

There is no very northern spruce. For pine it is desirable to move southward and the seed maturation in the north is bad. There are few seed collection areas under

100 m

Seed collection areas for pine (orange) and spruce (green)

”Approved seed collection areas” (millions of hectar)

Pine Spruce Forest area in Sweden Percent

8.5 3.8 21.2 58 %

Most forest area is approved as seed collection area! The rule is not very limiting.

Some of the area not approved has for administrative reasons never been considered.

Finland has approved all their area.

No scientific support for advantage of selected seed tree stand or seed

collection area• There are – to my knowledge - no experiments

which clearly demonstrate that a gain is associated to collecting seeds from a seed collection area of relevance to the Swedish pine and spruce situation.

• Many non-genetic factors affect the appearance of a stand, so it is difficult to imagine that genetic factors should dominate or be visible, even if they were rather important.

Is where a genetic variation among “autotochtoneous” stands?

• Yes!!• There is a large scaled provenance variation, trees from a more southern latitude survive

worse but grow better (if unharmed). This is mainly caused by selection which act a long time over a large area (trees which utilize more of the vegetation period grow better but get more injuries, “the nature finds” a reasonable balance). This is utilized in provenance transfers. The question now is variation beyond this large scaled continuous clinal variation.

• The genetic remainder (not explained by the known provenance pattern, where latitude is important) may be guessed from many experiments to be in the magnitude 6% in value and “1- latitude” in optimal adaptation.

• It is logic that factors like different selection under different conditions and genetic drift and different migration patterns give raise to limited differences among stands of pine and spruce. However this variation of distances 100 km is unlikely to be extremely large, as it is likely to be an important gene migration by pollen reducing local variations.

• This benefit in “value” is probably considerable, but how to “see” it? I suggest area phenotype difference will often not be able to give more than a few per mille in gain. Perhaps stand within area also give some per mille and part of that is probably obtained anyway, as I guess directly bad looking stands (infected, forking etc) are often avoided.

• A considerable gain of the choice of stand is only possible after unrealistic tests. Some of the benefit in adaptation may perhaps be utilized using short term tests, actually sometimes annual harvests of seed orchards are tested for adaptation (freezing test). A test for adaptation may change the area of use, and may therefore be done on already collected seeds. Or the less hardy seeds could be used for seeding in the intended area but the hardiness is compensated by more seeds.

• The rule that the source (where the seeds were collected) must be given will be there and is guaranteed by the state. This is the most relevant information, and that is enough for customers to make their own informed decisions.

Planting and seedingProvenance transfer

• An increasing amount of forest is planted or seeded. Cones are typically collected from old felled stands. Felled stands in northern Sweden are almost always autochthonous. Even when forest culture started it was often rather small transfers.

Quantitative importanceIf we move a provenance one or two latitudes? • In the new place probably 15 % of the plants will be self-generation;• 50% of pollen will anyway be contamination;• Selection will make it more similar to the local provenance;• The difference among stands is anyway +-0.5 latitude or so;• Planted stands are probably better seed sources (adapted to

plantation, less inbreeding), so it may be disadvantage with stand• If the stand is an origin which differs 2 latitudes from the local, it may

behave as if it was one latitude different. It makes difference in both growth and survival, but partly compensatory from a production point of view, so the loss is of the magnitude a few percent of production, which is not a big problem.

• The chance is rather small and the trouble limited so I suggest accepting it.

Planting and seeding- imports to southern Sweden

• In southern Sweden, cultivation has been going on for several centuries. The results from pine plantations were so bad so import was forbidden on crown land around 1883. Measured as kilogram, we has imported as much for more than a century, but one kg gives more forest now. Still even in south Sweden rather much autochthonous forests still exists, but we can hardly identify them and we do not know how much. Anyway the area is declining.

• Some “foreign” provenances seemed to give a good progeny (hybrids).

• Even where seed collection areas has been identified (“Emmaboda”), their genetic character change over time.

Import av granfrö till Sverige (kg/år)

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For pine it is probably clear cuttings used local sources, the “Tysktall” episode is too long time ago to matter and affected a small area, and led to more local materials.

Anyway seed orchards are now dominating so it will be neglible seed collections.

For spruce where is little demand on domestic origins (a few hundred thousand plants at Skogsplantor). Imports will dominate.

So South Sweden may be too small problem to really matter.

Theoretically seeds could be obtained from planted stands with

the best provenances• As seeds are used for plantations, seeds collected from

plantations are expected to be better adapted to plantation.

• A local plantation get generally better locally adapted seeds than direct imports.

• There are cutting plantations, but the selection was to weak to make most of them genetically superior

• The provenances (e.g. Belarus) are not constant and probably becomes less reliable over time

• Planted stands with “the best” provenances are too young to be felled and too seldom well documented.

• The small benefit from avoiding the worst looking stands and areas where imports are especially suspected from historical records may probably be done anyway without rules.

• Finland seem in principle to have made all Finland a seed collection area.

• To joke a bit about Finland. The seed collection areas do not extend beyond altitude 1310 meters, that puzzled me a bit as I thought Finland was flat, but actually there is that high peak on the border to Norway, where I guess the tree limit drops below sea level.

Heat sum (Finland)

Region of provenance (pine) for Finland

Regions of provenance for

Sweden

I would still like to share more fine-scaled in regions of provenance (which can not be mixed), but LA seems to think it can be still simpler.

Areas to avoid seed collection• Coastal areas are exposed to Mans activities since

much longer time than inland. Since Man got sailing technology year 600 I believe wood transports from wood felled in coastal areas were common even in far north. Coastal areas have a later phenology and therefore a more sporadic and unpredictable gene migration. Mans operation can be expected to be more small scaled and locally diversified at the coast. Therefore I suggest to avoid seed collection close to coast, it may be operational with an elevation 50 border.

• This is the only guess I can make, and it has little influence as little seed anyway is harvested in coastal areas.

• Evidently there are places unsuitable for seed collection like botanical gardens and trials.

There seem to be little reason to vigorously defend seed collection areas. But could we not

still keep them?• But still they may give a little gain and are established

by intelligent people and built on old wisdom, should all this work and energy be counted for nothing just as it is my guess?

• It has a definite PR value and makes the people to feel more confident that they trust the strict rules enforced.

• The areas will not be needed in some decades and freedom could be misused.

• It creates some further considerations to remove the idea of seed collection area (reduced region of provenance needed?) some other limitations (e.g. only forest land)

I would prefer a system so it was easy to extend the allowed area, thus it is actually enough to document what has been done to get it approved “retrospectively”.

An advantage with such system:• It forces documentation and thought “why”• It’s a motive for the forest authority to preserve some

production oriented genetic competence• It is not irreciprocal removal• It would be few cases each year (demand low) so not a

big effort needed.• EU and OECD believes that they make rule to help us,

all our effort should not go to discretely nullify rules and intentions.

“Total freedom”

• No paperwork at the forest authority;• Easier for the seed collectors;• The trend now is to remove governmental

restrictions from the industry.• Similar to the intelligent neighbors in the east

(Finland).• Even if “freedom” should we still have “regions

on provenance” and how should they look? Like in Finland or in current Sweden?

After this short introduction….

– The possibilities to get good seeds by choosing good stands seem neglectable

– But most of the genetic variation seems to be among trees within stands, not among stands or areas (within the same region).

– Could we not select the best trees for cone harvest? Perhaps! But difficult!

Magnitude of gain small by selecting the best trees

• Phenotypic selection gain of plus trees gave a gain of magnitude 6%. That was intensive (say 1 in 100) and careful (measurement of comparison trees), carefully done by experienced staff.

• This to select cone harvest trees can only be done with low intensity (say 1 in 2) and fast and sloppy. So the gain will only be in the magnitude 1-2%.

W 4009, the reproductively

most successful tree in Sweden

Thinning

• To remove inferior trees improves the pollen crop. Forests are thinned and sometimes the idea is to leave the best trees there the value growth is most important. Thus it is good if suitable stands which are thinned with the aim of improving the quality of the stand are registered at thinning, and considered as seed collection areas.

• Note that thinning away dying supressed inferior trees probably has small effect on the reproductive output. Thinning away the worst half of trees is not a selection 1:2 for genetic quality at seed collection.

• The gain is anyway low!

Selection of seed parents• In the far north pine seeds are sometimes collected

from standing trees (in rather young stands). Could the people doing this be instructed in some way?

• If the cone collection was very integrated with harvest, the harvester could mark good trees (e.g. by leaving tops sticking up) and the cone collector follow immediately after (so the harvester do not make the adjacent felling before cones collected). This type of coordination is demanding.

• The best trees could be identified and felled manually and harvested for cones. When the harvester can come later.

• The best trees could be identified and when harvested by cutting the tops down by helicopter before the final harvest of the stand. As helicopters nowadays are used for cutting tops in seed orchards, equipment and contacts with entrepreneours ought to be possible

Tops are cut down in a seed orchard with a helicopter and

cones collected from ground.

Could be done in stands also.

Seed tree stands of Scots pine

• They are drastically thinned. That improves seed production considerable.

• I believe cone collection cheaper but Jörgen Andersson doubted that.

• They could be identified and treated as potential seed collection stands already when the seed tree stand was created.– Selection of seed trees on assumed genetic

superiority– Fertilized for further increase in seed yeild– Harvest coordinated with cone harvest