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Selective Harvest of Local Landrace Eucalyptus Seed: The Basics
"Eucalyptus seed quality" is a vast concept. It has many angles. And all of them have an effect on the next generation of trees raised somewhere to be planted somewhere else and later yield an expected amount of timber or non timber products, services and/or externalities. Few times so many big volumes are dependant on such a small weight.
Fig. 1 - Selective local landrace Eucalyptus seed harvest methodology. (Click image to enlarge)
When local landraces develop after the introduction of any Eucalyptus species to a new area of the world, the founder (limited) gene pool (more or less diverse depending on circumstances) starts a cycle of recombination. Many times, human action plays a critical role, either consciously or not, on this long term evolution. Without a minimal conscious effort towards the improvement of the local landraces at the time of seed collection and plant propagation, the results tend to be a decline in productivity after a couple of generations, a by-product of inbreeding.
There are at least two parallel paths to try to counterbalance this tendency. A first one is the introduction of well identified "fresh" genetic material brought from either natural Eucalyptus forests back in Australia or from advanced breeding efforts. Preferrably after testing its superior performance against controls of the local landrace, and preferrably as a part of a broader genetic improvement plan focused on the sequential operational deploy of advanced generations. A second one is trying to refine the local landrace and any subsequent newly introduced gene pool by selective seed harvest. Both paths can be combined.
Many times a parallel breeding program is not feasible due to the too many uncertainties of having as single basement the local landrace. Other times a multiple path combination with breeding efforts based on more newly introduced genetic material is not possible either. But in any case tree breeders, foresters and plant propagators alike should be aware of the importance of applying as simple as possible strategies to contain the advance of inbreeding effects in the local landraces around. Harvest the right seed. Harvest it right!
Fig. 2 - Selectively harvested local landrace candidate plus tree Eucalyptus seed ready for cold storage at GIT Forestry Eucalyptus Seed Bank (Click image to enlarge)
"Individual tree selection yields better results when good even aged tree stands of a convenient age are available. This allows efficient comparison between selected trees and control trees. Individual tree selection yields better results in monospecific even aged natural stands, or in tree plantations. This is, at a large distance from any other, the most common method for first generation tree selection and it has been applied worldwide"
Selectively Harvested Eucalyptus Seed from Northwestern Spain
Basic measures to help improve quality in the Eucalyptus seed trade chain
- Silviculturalist: Ask for details on the seed provenance used to raise the plants you are about to buy to start your Eucalyptus timber growing project. Use this criterium to help you select reputable forestry plant nurseries. Regardless of the level of genetic quality in seed, that information should be part of the archives of any serious forestry plant propagation enterprise.
- Nursery man: Source your Eucalyptus seed from reputable seed sources or specialised merchants, and try to get to know as many details as possible on the parent trees and seed collection methods. Plant propagation is just the last step to the release of genes stored in tree seed. Learn beyond propagation techniques, nursery practice and plant sales. Keep good records of the materials you use. And do not try to save on Eucalyptus seed if saving on seed means great looking seedlings but poor timber crops. Save elsewhere. As someone else well said elsewhere: "Good seed does not cost, it pays".
- Seed merchant: Try to focus also on quality of the product you sell and not only in the margin you obtain from your trade. Tree seed is not lettuce seed. And tree seed in general is not the same as tree seed for timber investment projects.Your actions might have a much longer term impact than for seed of annual crops. Learn about what you sell. Depending on your actions, there can be huge differences for the performance of third party timber investments.
- Seed collector: Try to identify candidate Eucalyptus trees to the plus tree status and collect seed from those and any other according to a minimal of technical criteria, so to help avoid the most obvious risks of poor plant performance. This does not mean you should only collect from plus trees if circumstances force to do otherwise to meet the demand. Bulk seed or individual isolated tree seed collection cannot be avoided sometimes, but keeping eyes well open to see the good trees and being well organised to extract different seed lots according to seed quality criteria, even if from the same seed collection effort, is a good measure.
- Parent tree grower: Keep records of the trees you grow, when did you plant them, where did your seedlings come from, and, if possible, where the original seed came from. Keep a book for your trees.The lineage of your trees matters, as it will affect the performance of their progeny, and the progeny of their progeny both in the case you use that seed as your own stock for propagation and in the case you allow its harvest for release to third parties.
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By their fruits ye shall know them
Small tips on Eucalyptus Identification
Gustavo Iglesias Trabado 
GIT Forestry Consulting - Consultoría y Servicios de Ingeniería Agroforestal - www.git-forestry.com
Eucalyptus species determination is not just a matter of botanical interest. It can be quite important for its implications in regard to the different genetic pools (be them species, subspecies, provenances, or races) in cultivation. Important issues as cold hardiness (tolerance to winter frosts), growth rates (timber productivity) and physical and chemical properties of wood (timber quality) can depend on this variability, and hence be subject of forestry engineering.
Fig. 1: Two types of Ash ("Fraxinus wood-like") Eucalyptus: Tasmanian Oak
However, bark based identification can also be misleading. Pictured above (Fig. 1) you have two different types of eucalypts. If based on "bark only" criteria, maybe the first thought is they are two different species. But in fact, we are seeing two types of eucalypt belonging to the same species, but different gene pools. Both are Alpine Ash, a type of Tasmanian Oak (Roble de Tasmania).
To the left (Fig. 1), the classical form, rough stringy bark in the lower portion of the main stem, clean withish bark in the upper portion and in the main branches. In mainland Southeastern Australia it has also received the vernacular name of "White Top". To the right, a variant, rough stringy persistant bark almost to the very top and on the main branches too. The latter type is restricted to natural habitats in Tasmania.
So, what the botanists say about this? Let's read Dean Nicolle:
- Eucalyptus delegatensis subsp. delegatensis (mainland Australia Alpine Ash) "Single stemmed tree 30 to 60 metres tall (...) Bark rough on the trunk up to 10 to 30 metres above ground level, moderately fissured and hard-fibrous, grey-brown; smooth above, ribbony, grey to pale grey over white"
- Eucalyptus delegatensis subsp. tasmaniensis (also known as E. tasmaniensis) "Single stemmed tree 20 to 90 metres tall (...) Bark rough over most of the entire trunk, moderately fissured and stringy-fibrous, grey brown to red-brown, smooth on branches, pale grey over cream"
An encouraging bark-based diagnosis indeed. But, back to the initial point, given the high chances of confusing both these types of eucalypt with others of the Ash type (E. obliqua, E. fastigata, E. regnans sometimes), and the extra options given by the possibility for some of these species to produce hybrid seed when grown in close spatial relationship, bark can help in some cases.Fig. 4: Example of botanical sample gathering methodology for accurate Eucalyptus species identification (Click to enlarge) But the most important information to work out what Eucalyptus we are seeing and defining geographically the original gene pools is to be sourced from comparison of flower buds and seed pods (fruit capsules) (Fig. 4) for the case of adult trees.
Fig. 5: Example of mature Eucalyptus specimen bearing flower buds and seed pods (capsules), essential organs for accurate Eucalyptus species identification. (Click image to enlarge).
Fig. 7: Different simultaneous stages of the reproductive cycle and eucalypt seed maturation process in a standing Snow Gum Eucalyptus tree.(Click to enlarge) Fig. 8: Maturation stages for eucalypt fruits collected on Corymbia calophylla trees in a single visit, showing some of the internal organs within Eucalyptus infrutescences in each phase. (Click to enlarge)
Fig. 9: Examples of Eucalyptus seedling nursery stock for afforestation Find a local expert to ID your Eucalyptus
If you have an unknown eucalypt around and you are able to collect and photograph samples of the key organs needed for identification,
do not hesitate contacting GIT Forestry Consulting.
Contact GIT Forestry Consulting - Eucalyptologics If you are in the USA and find it easier to post fresh samples to a local expert, you can also contact
Dr. Matt Ritter, resident
eucalypt hunter at the
California Polytechnic State University.
GIT's Eucalyptology Topics 
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Eucalyptus fastigata & Eucalyptus sieberi in Galicia: Siblings of Tasmanian Oak
We bring you today two rare examples of Ash ("Fraxinus wood like") Eucalyptus growing in Galicia (Northwestern Spain).
Fig.1: Eucalyptus fastigata and Eucalyptus sieberi in Galicia, Northwestern Spain. (Click to enlarge)
To the left, E. fastigata, the Brown Barrel, with natural habitat ranging from the highlands of Gippsland (Victoria) through the Great Dividing Range to New England (New South Wales) in Australia. To the right, E. sieberi, the Silvertop Ash or Black Ash, with natural habitat in NSW, Victoria and Tasmania.
Both species belong to series Obliquae, being close relatives of other relatively cold hardy Monocalyptus as E. pauciflora and its remarkable frost tolerant subspecies niphophila and debeuzevillei, E. delegatensis and its subspecies, E. regnans, E. gregsoniana, E. fraxinoides, E. lacrimans and, of course, E. obliqua.
The Brown Barrel received its botanical name after its columnar and stylised growth habit ("fastigatum") and the Black Ash honours Franz Wilhelm Sieber (1789-1844), a Czech-German botanist that, among other travels around the world and plant collections, visited New South Wales by 1823 and collected and later named E. pauciflora. So responsible of a funny eucalyptic fact.
Two groups of eucalypts are commonly cultivated worldwide within this
Monocalyptus /
Obliquae part of taxonomy. One one hand, the
Snow Gums, that have spread to temperate areas of the world because of their extreme tolerance to cold, ability to resist frost and snow.
Fig. 2: Giant specimen of Eucalyptus obliqua (Tasmanian Oak) in Galicia, Northwestern SpainOn the other hand and thinking now in timber terms, the
Tasmanian Oaks or
Robles de Tasmania, not all of them really Tasmanian, but that could be grouped within that commercial name for lumber considerations. These are known all over the world for their
excellent wood properties and noble uses as splendid furniture or beautiful flooring.
Fig. 3: Eucalyptus delegatensis ssp. tasmaniensis (Tasmanian Oak) timber plantation in Galicia, Northwestern Spain. (Click to enlarge)With suitable silviculture including pruning and thinning, appropriate genetic background for the seedlings used in reafforestation and some patience using longer rotation cycles, Tasmanian Oak can be an interesting alternative for high value timber production in cold temperate areas of Northwestern Spain. Its fast growth compared to conifers and other broadleaved species and higher tolerance to frost than E. globulus make it suitable for farm forestry in the highlands.
- Brooker, M.I.H. (1977) Internal bud morphology, seedling characters and classification of the ash group of euclaypts. Australian Forest Research 7(3):197-207
- Wilcox, M.D. (1979) The ash group of eucalypts. New Zealand Journal of Forestry Science 9(2):133–144.
- Revell, D.H. (1981) Silviculture of eucalypts: New Zealand experience. In "Wood: Future Growth and Conversion". Workshop Proceedings, Canberra, Australia. Bachelard E. P. & Hillis W. E. (eds.)
- Wilcox, M.D. (1982) Genetic variance in frost tolerance, early height growth and incidence of forking among and within provenances of Eucalyptus fastigata. New Zealand Journal of Forestry Science 12(3):510–524.
- Haslett, A.N. (1988) A guide to handling and grade-sawing plantation-grown eucalypts. New Zealand Forest Research Institute. FRI Bulletin Nº 142.
- Barr, N. (1996) Growing Eucalypt Trees for Milling on New Zealand Farms. New Zealand Farm Forestry Association Inc.
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