Technical guidelines for genetic conservation and use Swiss stone Pinus cembra

Marcus Ulber1, Felix Gugerli1 and Gregor Bozic2 1Section Ecological Genetics, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland EUFORGEN 2Slovenian Forestry Institute, Ljubljana,

These Technical Guidelines are intended to assist those who cherish the valuable Swiss genepool and its inheritance, through conserving valuable sources or use in practical forestry. The focus is on conserving the genetic diversity of the species at the European scale. The recommendations provided in this module should be regarded as a commonly agreed basis to be complemented and further developed in local, national or regional conditions. The Guidelines are based on the available knowledge of the species and on widely accepted methods for the conservation of forest genetic resources.

Biology and ecology Pinus cembra is often associated with Pinus mugo, L. decidua and/or P. abies. Pinus cembra L. is a five-needled Stone pine tends to be a cli- pine (subgenus Strobus, max species tolerating some section Cembra, subsection shade in the juvenile stage and Cembrae). The species rarely germinating well on organic soils exceeds heights of 25 m, its with an accumulated layer of lit- growth is very slow but long- ter and moss. However, it can lasting and between 500 germinate and establish itself on and 1000 years of age mineral soils or even rocky sur- are reported. Under faces as well. natural conditions, The slow juvenile growth of P. it may take 30 cembra makes the species vul- years to reach nerable to browsing for a long 1.30 m. Owing to time and susceptible to lethal its slow growth, P. fungus infestations occurring cembra is a weak under prolonged snow cover. For competitor com- the latter reason, P. cembra is pared with other not found in microhabitats or trees. However, it is regions with long-lasting snow better adapted to the cover (e.g. border zones of the harsh upper subalpine ). conditions than Stone pine is a wind- any other European tree pollinated species with male and species. Consequently, it female flowers on the same tree can compete in mixed stands (monoecious). Within natural where the performance of the stands, reproductive maturity is other subalpine trees (mainly not reached before are Picea abies and Larix decidua) is 40–60 years of age. Flowering reduced and establish pure and seed production occur every stands above their growth limit. 2–3 years, but only a single year PinusSwiss stone pinePinus cembra cembraSwiss stone pinePinus cembraSwiss stone Pin pinePinus cem

out of 4–10 is an abundant mast Distribution The altitudinal range of P. year. Self-fertilization is possible. cembra forests is from 1500 to The ripen in the year after 2400 m asl (single individuals pollination, but the cones The distribution range of 1200–2850 m) in the Alps and remain closed and do not the Swiss stone pine is from 1300 to 1700 m asl release the heavy, wingless small compared with oth- (900–1985 m) in the Carpathi- seeds. The seeds are most- er pine species. It is ans. The lower boundary is ly dispersed by the European restricted to the sub- determined by the competition of nutcracker (Nucifraga caryocat- alpine belt in the con- other tree species (mainly P. actes), a bird species with a tinental (i.e. central) abies), whereas the upper limit strong mutualistic relationship parts of the Alps seems to be a physiological (cli- with P. cembra. The nutcracker (, , Switzerland, matic) boundary. picks most of the cones from the , ) and to some The likely origin of P. cembra trees and caches those seeds it higher regions of the Carpathian seems to be in the Siberian does not immediately eat in Mountains (isolated patches region, where its closest relative, shallow underground deposits from Tatra Mountains in P. sibirica (treated as P. cembra as a food source for the winter. and to the Southern var. sibirica or P. cembra subsp. A single nutcracker may store Carpathians in and sibirica by some authors), covers more than 25 000 seeds every ). The total species' vast areas. It is supposed to year. Dispersal distances can be coverage was estimated as have survived the last glaciation as far as 15 km horizontally and about 30 000 hectares (density- period in the vicinity of the Alpine 700 m altitudinally. Most of the weighted area) in the 1970s. and Carpathian mountain deposits are retrieved and emp- ranges from where it tied by the bird during winter and could expand in an spring, but some are left, many early postglacial of them in sites suitable for phase to occupy germination and sur- large areas. At vival of P. cembra, lower alti- resulting in a sufficient tudes it was and regular regeneration subsequent- of the tree. Tree clusters ly replaced. (with either separated or fused trunks) originating from more than one germinated seed from one deposit are frequent and improve the stabil- ity of the sub- alpine forest. nusembraSwiss stone cembra pinePinus cembraSwiss stone pinePinus cembraPinusSwiss stone pinePin

Importance and use Genetic knowledge Threats to genetic diversity

Wherever it occurs naturally, P. In concordance with the putative Owing to its ecological charac- cembra contributes to the upper- survival areas during the last teristics (weak competitiveness) most forest belt in the glaciation, isozyme and to negative anthropogenic mountains, forming mixed variation indicates impact (overuse, deforestation, or pure stands. Conse- a low degree of intentional burning for gaining quently, the species genetic differen- grassland), the occurrence of P. has a crucial tiation between a cembra today is highly fragment- protective stone pine population ed in parts of its distribution function for from the Carpathian range, and small population the surround- mountains and the popula- sizes are common. ing area. The tions from the Alps. Most of The fragmentation may inhibit presence of the genetic diversity found in gene flow among the populations. (evergreen) Carpathian stands resides Small populations are generally trees in the within populations. This also prone to elevated inbreeding and stone pine's altitudinal holds for the Alpine range, where genetic erosion, but they are zone helps to minimize the risk of the two main distribution areas in specifically threatened in an avalanches and soil erosion. the eastern and the western Alps unstable area such as subalpine Pinus cembra is, therefore, val- cannot be separated based on regions by avalanches, forest ued as a stabilizing factor and chloroplast diversity owing to fires, landslides or unusual cli- often used for afforestation at extended historical pollen flow. matic events which can lead to high elevations. However, there is a reduced further dramatic losses of genetic Stone pine forests (pure and genetic variation in isolated pop- information. mixed) have a high aesthetic and ulations at the northern margin of ornamental value for many the . Crown forms for- regions famous for summer and merly recognized as distinct winter tourism. races are considered Besides the protective and to be the result of aesthetic functions of the environmental effects species, the timber of P. cembra rather than deserving is highly valued, especially for of taxonomic status. paneling, carvings and traditional However, elevational furniture because of its special variation was observed wood characteristics (soft, light, with respect to growth resistant, warm reddish colour, response in common gar- perfume of ). However, the den experiments. Further- traded quantities are compara- more, it remains open tively small and mainly serve the whether the occurrence of local markets. green instead of violet cones has a genetic background. sPinus cembracembraSwiss stone pinePinus cembraSwiss stonePinus pinePinus cembraSwiss stonec p

A specific problem of many P. Guidelines for genetic ommended for both wood pro- cembra stands is the highly conservation and use duction and protection purpos- skewed age distribution owing to es. Where stone pine is naturally a lack of recruitment and young The main strategy of genetic mixed with other tree species it is trees (often as a result of brows- conservation of Swiss stone pine advisable to retain the mixture. ing or other damages by ungu- should be a dynamic in situ con- The crucial point in any case lates or grazing livestock). If servation. However, complemen- for a dynamic in situ gene con- those stands cannot be regener- tary dynamic or static ex situ servation is the regeneration of ated, these populations risk conservation may be appropriate the stand. Natural regeneration is losing some of their genetic in some cases. considered to be the best way information in the short term and In situ conservation can be for gene conservation. extinction in the long term. Fur- done within natural forest If there are suitable germina- thermore, high ozone loads reserves, in gene conservation tion sites and seed trees within seem to cause a decline of P. units specifically managed for the nutcracker's dispersal range, cembra, whereas the species the purpose, as well as in forests regeneration of P. cembra has shown a higher degree of managed mainly for other pur- occurs naturally. Sometimes a resistance to other air pollutants poses. Generally, abundant and very dense cover of grasses or than do sympatric pine species. large stands of interfertile Alpine roses can be an obstacle An altitudinal cline of growth autochthonous stone pine for seedling growth, and the characteristics has been trees are best to assure removal of patches of this vege- observed in provenance genetic adaptability and tation can be useful. If necessary, tests showing that P. adaptedness in the long animals affecting the young cembra performs best in term. However, small and plants have to be excluded or the altitudinal zone from isolated populations of P. individual protection measures which it originates. Once cembra can be of special must be taken. Forest gaps the growth belt of stone interest if particular adapta- smaller in diameter than the pine is reduced to a nar- tions can be assumed. height of the surrounding stand row altitudinal strip and the Normally, gene conser- tend to accumulate snow during genepool is depleted, the vation can be matched the winter and become snow- capability of the species to with other goals of the free only late in spring. Therefore, spread out again is therefore stand management. As the dimensions of regeneration limited. many of the P. cem- gaps should be 1–4 times the bra forests are stand height depending on the expected to fulfil site conditions. protection and/or For artificial regeneration in aesthetic functions, a continuous existing stands or for high- tree cover is needed. A suffi- elevation afforestations with P. ciently dense, multilayered, cembra, reproductive material uneven-aged forest with a clus- must be chosen carefully owing tered structure meets these to extreme site conditions. Only demands best. Small-scale silvi- well-adapted and sufficiently cultural practices such as the variable material originating from group selection method or the similar sites ensures a long-term cluster selection method are rec- success for both production and PinusSwiss stone pinePinus cembra Swisscembra stone pinePinus cembraSwiss stone P pineP

Distribution range of Swiss stone pine

protection purposes. For - venances can facilitate a more Static ex situ conservation of ations near the tree limit, the regular supply of seeds. reproductive material of P. cem- provenance of the material Seed orchards can serve as a bra for gene conservation pur- should lie within a 100-metre alti- means of dynamic ex situ con- poses is advisable only in case of tude range relative to the plant- servation of P. cembra if the emergency and the material ing site. It is suggested to breed number of progenies is suffi- should be recultivated as soon the plants in montane altitudes ciently high (at least 50 trees pro- as possible. and to transplant them into a posed per origin population), nursery located above 1500 m especially in the case of en- asl to ensure hardy acclimatiz- dangered small or relic popula- ation. Direct seeding has proven tions. However, it is preferable to to be a satisfactory alternative to conduct dynamic ex situ conserv- planting. As a consequence of ation in the vicinity of the original the erratic seed production and site and to use the local material. the slow growth process, the This is what the nutcracker tends planning of a plantation should to do when it "salvages" the start well in advance. Seed species from accessible spots to orchards at lower altitudes con- rocky outcrops where the taining high-elevation pro- seedlings may survive. PinusePinus cembraSwiss stone cembrapinePinus cembraSwiss stone pinePinus cembraPinSwiss ston

EUFORGEN

These Technical Guidelines were Selected bibliography produced by members of the EUFORGEN Network. The objective of the Network is to Contini, L. and Y. Lavarello. 1982. Le Pin Cembro (Pinus cembra L.) – Réparti- tion, écologie, sylviculture et production. INRA. 197 p. identify minimum genetic conser- vation requirements in the long Gugerli, F., M. Anzidei, A. Madaghiele, U. Büchler, C. Sperisen, J. Senn and G.G. Vendramin. 2001. Chloroplast microsatellites and mitochondrial nad1 term in , in order to reduce intron 2 sequences indicate phylogeographic relationship of Swiss stone the overall conservation cost and pine (Pinus cembra), Siberian stone pine (P. sibirica), and Siberian dwarf pine (P. pumila). Molecular Ecology 10:1489–1497 to improve the quality of stan- dards in each country. Holzer, K. 1975. Genetics of Pinus cembra L. Annales Forestales 6/5:139-158. Rikli, M. 1909. Die Arve in der Schweiz – Ein Beitrag zur Waldgeschichte und Waldwirtschaft der Schweizer Alpen. N. Denkschr. Schweiz. nat. forsch. Ges. XLIV. 455 p. Schmidt, W.C. and F.-K. Holtmeier, compilers. 1994. Proceedings of the Inter- national Workshop on Subalpine Stone and Their Environment: the Citation: Ulber, M., F. Gugerli and Status of Our Knowledge. St. Moritz, Switzerland, 5–11 September 1992. G. Bozic. 2004. EUFORGEN Gen. Tech. Rep. INT-GTR-309. U.S. Department of Agriculture, Forest Ser- vice, Intermountain Research Station, Ogden, UT. 321 p. Technical Guidelines for genetic conservation and use for Swiss Schütt, P. 2000. Pinus cembra Linné, 1753. In Schütt P., H. Weisgerber, H.J. Schuck, U. Lang and A. Roloff, eds. Enzyklopädie der Holzgewächse. 16th stone pine (Pinus cembra). Inter- volume, ecomed-Verlag, Landsberg/Lech, 18 p. national Plant Genetic Resources Institute, Rome, Italy. 6 pages.

Drawings: Pinus cembra, Claudio Giordano. © IPGRI, 2003.

ISBN 92-9043-619-0

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