Prescher et al.1 Seed production in Scots pine seed orchards Finnvid Prescher, Dag Lindgren, Ulfstand Wennström, Curt Almqvist, Seppo Ruotsalainen and Johan Kroon. Syktyvkar 14 september 2005

Prescher et al.2 Seed set in nature Typical pine stands LocationSeeds/m2 Northern Finland 50 Middle Finland 100 South Finland 150

Prescher et al.3 How do we get more seeds? Some years after thinning High site class Annual variations Five years after releasing seed trees it may be >200 seeds/m2 (Karlsson 2000)

Prescher et al.4 Seed orchards versus stand Considerable heavier seeds Heavier cones Not more seeds per cone Less fluctuations among years Probably stands on similar sites and management intensity would produce similar amount of seeds

Prescher et al.5 Frequent reports about seed orchard harvests Harvest statistics may not reflect biological production, in particular in old seed orchards Little actual biological production statistics from Swedish seed orchards Seed orchards versus stand, cont’d

Prescher et al.6 Pine seed orchard Askerud KlockeLustnäset Latitude Age (two years) Grafts/ha Seeds/m

Prescher et al.7 Mature seed orchards It is more difficult to harvest all cones the older the orchard becomes Harvest statistics often drops by age, is this reflected in a biological seed drop? 2004 were all seeds in three grafts per clone of 12 clones harvested in two mature seed orchards, which never have been thinned nor pruned recently.

Prescher et al.8 Skaholma 2005

Prescher et al.9 Pine seed orchard SkaholmaLångtora Latitude6460 Age at harvest (oldest grafts) 4642 Age (typical graft)4041 Grafts/ha Seeds/m Adjusted by annual cone set statistic in stands in area

Prescher et al.10 Conclusion Seed production can be quite good in old seed orchards, no sign of decrease when orchard get old!

Prescher et al.11 Sävar The experimental seed orchard at Sävar has 16 large seed orchard plots, all with different treatment (thus no real replications). It is thus unreliable to separate an individual factor like spacing, many factors are confounded.

Prescher et al.12 Experimental seed orchard Sävar Latitude64 Age29 Grafts/ha Seeds/m Adjusted by annual cone set statistic in stands in area

Prescher et al.13 Dense spacing of grafts does not seem to promote cone production beyond 30 years, however this is very scarce and difficult to interpret data. Conclusion

Prescher et al.14 Cone observed from ground A rough cone count from ground with unaided eye in mature seed orchards revealed <10% of the cones. Thus estimating cone set in seed orchards require more accurate instructions.

Prescher et al.15

Prescher et al.16 Variation in female contributions Coefficient of variation among ramets for different seed orchards Seed orchard LångtoraSkaholma Filled seeds Weight of filled seeds Volume of cones Number of cones Cones observed from ground Seed weight Note that the CV are similar for all fertility characters, thus variation in female reproductive output can be reasonable estimated in any way. The variation in seed weight among ramets in a seed orchard crop is limited.

Prescher et al.17 Thank You!