Technical guidelines for genetic conservation and use Mountain Pinus mugo Pinus mugo Pinus mugo Pinus m A. H. Alexandrov1, G. von Wühlisch2, G. G. Vendramin3 1 Forest Research Institute, Bulgarian Academy of Sciences, Sofia, Bulgaria 2 Institute for Forest Genetics and Breeding, Grosshansdorf, Germany 3 Institute of Biosciences and Bioresources, National Research Council of Italy

These Technical Guidelines are intended to assist those who cherish the valuable mountain pine genepool and its inheritance, through conserving valuable seed sources or use in practical forestry. The focus is on conserving the genetic diversity of the at 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 available knowledge of the species and on widely accepted methods for conservation of forest genetic resources. Biology and ecology

Pinus mugo is a species of exposed subalpine and alpine sites, not suitable for other tree or species, for example on slopes with frequent snow slides, where only Alnus viridis could also occur. Mountain pine can be either monopodial with upright stem and narrow pyram- idal crown, or with one or sev- eral inclined stems with shrub- shaped crown. Some lateral branches reach up to 9–10 m in length, as the inclined stems rise in their ends and form a clump. On rocky and poor soils, moun- tain pine has mostly multi-stem and shrub-shape forms. Branch- es are relatively thick and very elastic, resistant to storms, snow- pressure, ice and avalanches in high mountains. The growth is very slow, only 2–3 cm during the first years, which ranks the species among the most slow- growing tree species in Europe. Shrub-shaped specimens reach MountainPinus pinePinus mugo Mountain mugo pinePinus mugo Mountain pinePinusPinus mugo Mountain pine mugoPinus mugo Mountain pinePinus Pinusmugo Mountain pinePinus mugomugo Mountain pinePinus mugo MountainPinus pinePinus mugo Mountain mugo pinePinus mugo Mountain pinePinuPinus mugo

up to 3–5 m height, while mono- Pinus mugo is often found Importance and use podial ones reach up to 20–25 mixed with limited participation m and 50–60 cm in diameter of Picea abies (L.) Karst., Pinus at the age of 150–200 years. sylvestris L., Larix decidua Mill., The role of Pinus mugo in The species’ maximum age is Pinus cembra L. (or, respec- water protection and soil erosion 250–300 years. tively, Pinus peuce Gris.), Bet- control is of primary importance The root system is horizon- ula pendula Roth., Alnus viridis in the high-mountain belt. The tal, usually without a central (Chaix) DC., species is quite suitable for root, and side roots are thick L. It also occurs in pure and cultivation on poor soils and in and branched with lengths up often dense, impenetrable as- windy places along the Baltic to 8–9 m. sociations; in peat bogs, where Sea coast. In many regions in The bark is thin, grey-brown the species is a glacial relict; Central and Northern Europe it to dark grey, and peels off in and mixed with Juniperus com- is used for landscape design. rectangular flakes on old in- munis L. It is tolerant to different soil dividuals. Shoots are smooth, conditions, growing well both on brown to grey-black, and peat bogs and dry stony soils, are conical, red-brown and very Distribution but requiring high atmospheric resinous. humidity. The resinous, durable Needles occur in pairs in a and elastic wood with specific fascicle, from 2-8 cm in length The geographic range of Pi- weight up to 0.83 g cm-3 and 1 to 2 mm in width, and are nus mugo includes mountains finds its application in making slightly tortuous, with a light to in the , Carpathians, the lasting wooden decorations, dark green colour. They remain Ore Mountains, Alps, Vosges for production of medicinal on the tree from 4–5 to 10–12 mountains, Apennines (to Abru- turpentine, fragrant bath oils, years. zzo) and Pyrenees, predomi- reduction coal and for fuel. The Mountain pine is mostly di- nantly in subalpine parts and species is frequently used for oecious but can be monoecious above the treeline. Separate landscape design in parks and as well, with cones growing on populations and solitary individ- gardens, where manifold horti- some and catkins on other indi- uals occur from 150–200 m cultural varieties are found. Its viduals. Male catkins are 10 mm above sea level in southern ecological role, however, long, with a yellow or red colour, Poland and southeast- is of primary importance. dispersing from May until ern Germany up to Especially its ability to the end of June. Female cones 2500 m in the Alps cover exposed sit singly or 2 to 4 together usu- and 2700 m in the sites continuously ally in a node, young ones being and makes it purple and mature ones dark mountains invaluable brown with a length up to 5–6 (Bulgaria). for the con- cm and width up to 3 cm. After Communities solidation 15–17 months of growth, the at low alti- of steep cones mature by October of the tudes in Cen- slopes following year. Their apophyse tral Europe with high is convex and surrounded by a occur in peat avalanche black ring. The seeds are black, bogs. risk. 3–4 mm in size with 10 mm long, yellow wings with dark nerves. MountainPinus pinePinus mugo Mountain mugo pinePinus mugo Mountain pinePinusPinus mugo Mountain pine mugoPinus mugo Mountain pinePinus Pinusmugo Mountain pinePinus mugomugo Mountain pinePinus mugo MountainPinus pinePinus mugo Mountain mugo pinePinus mugo Mountain pinePinuPinus mugo

Genetic knowledge branches, forming a pyramidal Holocene expansion. Marginal P. crown. These hybrids are also uncinata populations from the partially interfertile, but the Iberian system are compatible The following can incidence of natural hybridization with elevational shifts and long- be identified: seems to be very low. term isolation. - Pinus mugo ssp mugo Turra The geographical pattern of Nucleotide polymorphisms occurring in central and eastern genetic diversity has recently in nuclear, chloroplast and parts of the species’ range, been described using chloroplast mitochondrial DNA fragments mainly in the Southern and microsatellites (cpSSRs) for P. were used to study the Eastern Alps, Apennines uncinata with a homogeneous speciation history of Pinus and Balkans. It is Pyrenean gene pool and mugo, P. uliginosa and P. shrub-shaped, strongly differentiated sylvestris. Overall, the genetic 3–6 m height, with populations in the Iberian data indicate that P. mugo and several stems, and Systems. A lack of genetic P. uliginosa share the same gene has symmetrical thin- differentiation between P. pool and that the phenotypic scaled cones. uncinata and P. mugo sensu differences (e.g. growth form) - Pinus mugo ssp stricto has been observed are most likely due to very uncinata (Raymond) in the Alps. A stronger limited areas of the genome. P. Domin occurring in differentiation between mugo and P. uliginosa are more western and northern geographical regions than divergent from P. sylvestris than parts of the species’ between morphologically from each other. The nucleotide range—in the Pyrenees identified taxa (P. mugo sensu patterns can best be explained and Vosges mountains and stricto, P. uncinata and P. by the divergence with migration southern Poland. It usually rotundata/P. pseudopumilio) speciation scenario, although the forms a monopodial tree with has been observed. Some hybrid speciation scenario with heights up to 20–25 m and authors identified a Pyrenean a small genomic contribution with asymmetrical, thick-scaled and an Alpine gene pool, along from P. sylvestris cannot be cones. with several smaller genetic completely excluded. Both subspecies can also clusters corresponding to hybridize, and in the western peripheral populations. The core Alps and northern Carpathians regions of the Pyrenees and Pinus mugo ssp rotundata Alps were probably recolonized, (Link) Janchen & Neumayer is respectively by P. uncinata and P. confirmed. uncinata/P. mugo sensu stricto, Pinus mugo subsp. pumilio from multiple glacial refugia is also distinguished as a that were well connected by subspecies. It occurs in the pollen flow within the mountain Alps, Carpathians and Jura chains. Pinus rotundata/P. and is shrub-shaped and has pseudopumilio populations symmetrical cones. from the Black Forest, Vosges Hybrids between Pinus mugo and Jura mountains were very Turra and L. have likely recolonized from various been recorded in various parts of glacial populations that kept the species’ range, which have their genetic distinctiveness an upright stem and short side despite late glacial and early MountainPinus pinePinus mugo Mountain mugo pinePinus mugo Mountain pinePinusPinus mugo Mountain pine mugoPinus mugo Mountain pinePinus Pinusmugo Mountain pinePinus mugomugo Mountain pinePinus mugo MountainPinus pinePinus mugo Mountain mugo pinePinus mugo Mountain pinePinuPinus mugo

Threats to to limited areas at higher Guidelines for genetic elevations. Some P. uncinata genetic diversity conservation and use populations from the Iberian The relatively wide Peninsula are in this situation. Large autochthonous moun- distribution range of mountain These populations are strongly tain pine populations are charac- pine in Europe gives no reason differentiated and, as southern terized by high genetic diversity to fear for its genetic diversity, ‘rear edge’ populations, they may and adaptability which suggest with the exception, for example, harbour important adaptations in situ conservation as the main of some isolated occurrences relevant to the conservation strategy. In situ conservation of in Central Spain, Southern of the species. In the Black mountain pine contributes to the France, Abruzzo (Italy), and the Forest, many P. rotundata/P. natural recovery of the treeline, western Balkan Range (Serbia pseudopumilio populations which is lowered in many places and Bulgaria). Clear cutting show considerable dieback and due to anthropogenic impact of fragmented stands and insufficient natural regeneration. (fires, felling, grazing, building particularly forest fires were a These seem to be delayed activities). National parks often danger in the second half of consequences of the drainage harbour large mountain pine the 20th century, and currently of bogs for peat collection. After formations and provide in situ risks are linked to climate at least 200 years of regular genetic conservation of this spe- changes and anthropogenic burning of peat bogs in the Black cies. However, it still needs pro- impact caused by construction Forest, fire disturbance has tection due to extension of natu- of ski slopes and accompanying ceased, reducing the availability ral and man-made disturbances. facilities. of open for bog pine Therefore it is recommended In general, the health status regeneration. At the same time, that genetic conservation pro- of mountain pine is stable, the lowering of water tables has grammes start with the following because it does not suffer from allowed the establishment of a objectives: conservation of en- dangerous fungal diseases and dense undergrowth and invasion dangered, marginal populations insect pests. Specific diseases of the drier bog margins by the and habitats of Pinus mugo; are white snow mould, caused shade-tolerant Picea abies (L.) sampling the genetic diversity; by Phacidium infestans P. Karst. Karst. Because global warming establishment of Dynamic Con- and black snow mould, caused is expected to aggravate the servation Units based on long by juniperi (Duby) dieback, and these populations term autochthony, high biodiver- Petrak, which affect needles are genetically distinct, sity value and location during snow cover and cause conservation measures in ecologically their gradual decay on separate are justified and diverse re- branches, without being lethal necessary. gions of large for the entire mountain pine A populations ecological system. combined (> 1000 indi- It is predicted that in the strategy viduals). Iberian Peninsula montane of in situ Whenever species such as P. conservation natural regenera- sylvestris and P. uncinata of the larger tion is unsatisfactory, will suffer intense and rapid bogs along with like for restoration of reduction of their distribution the establishment burnt and eroded ter- ranges because global warming of ex situ collections is rains in mountain pine will induce their migration recommended. zones, sowing and/or PinusMountain pinePinus mugo Mountainmugo pinePinus mugo Mountain Pinus pinePinus mugo Mountain pinemugoPinus mugo Mountain pine PinusPinus mugo Mountain pinePinus mugom Mou

Distribution range of mountain pine

planting need to be carried out. point to inferior quality or growth lifespan of mountain pine and When artificial regeneration is characteristics in the local pop- other forest tree species. carried out according to the prin- ulation. Local material usually - If there is no local material ciples of genetic conservation, guarantees retention of the evo- available or if there are signs of then the following requirements lutionary and adaptive character- inbreeding, then restoration may for the use of reproductive mate- istics that have developed at a rely on the introduction of mate- rial must be observed: given site under specific condi- rial from outside. Material from - Preference should always tions over generations. Lack of localities sharing the site condi- be given to local material, unless adaptability can lead to serious tions with the regeneration site results from provenance trials failures at any stage of the long should be preferred. PinusMountain pinePinus mugo Mountainmugo pinePinus mugo Mountain Pinus pinePinus mugo Mountain pinemugoPinus mugo Mountain pine PinusPinus mugo Mountain pinePinus mugom Mou

This series of Technical Guide- Selected bibliography lines and distribution maps were produced by members of the EUFORGEN Networks. The Benito Garzón, M., R. Sánchez de Dios and H. Sainz Ollero. 2008. Effects of climate change on the distribution of Iberian tree species. Applied Vegeta- objective is to identify minimum tion Science, 11: 169-178. requirements for long-term Christensen, K.I. 1987. A morphometric study of the Pinus mugo Turra com- genetic conservation in Europe, plex and its natural hybridization with P. sylvestris L. (). Feddes in order to reduce the overall Repertorium, 98: 623-635. conservation cost and to improve Dzialuk, A., E. Muchewicz, A. Boratyński, J.M. Montserrat, K. Boratyńska and quality standards in each country. J. Burczyk. 2009. Genetic variation of Pinus uncinata (Pinaceae) in the Pyrenees determined with cpSSR markers. Systematics and Evolu- tion, 277: 197-205. Heuertz, M., J. Teufel, S.C. Gonzàlez-Martìnez, A. Soto, B. Fady, R. Alìa Citation: Alexandrov, A., G. von and G.G. Vendramin. 2010. Geography determines genetic relationships Wühlisch, G. Vendramin. 2019. between species of mountain pine (Pinus mugo complex) in Western EUFORGEN Technical Guide- Europe. Journal of Biogeography 37: 541–556 lines for genetic conservation von Sengbusch, P. 2002. Untersuchungen zur Ökologie von Pinus rotundata LINK (Moor - Bergkiefer) im Südschwarzwald. Doctoral thesis, Albert- and use for mountain pine (Pinus Ludwigs-Universität, Freiburg. mugo). European Forest Genetic Wachowiak, W., A.E. Palmè and O. Savolainen. 2011. Speciation history of Resources Programme (EUFOR- three closely related Pinus mugo (T.), P. uliginosa (N.) and P. sylvestris GEN), European Forest Institute. (L.). Molecular Ecology 10: 1729-1753. 6 pages. The distribution map is based on: Caudullo, G., Welk, E., San-Miguel-Ayanz, J., 2017. Chorological maps for the main European woody species. Data in Brief 12, 662-666. https://doi.org/10.1016/j.dib.2017.05.007 Drawings: Pinus mugo, Claudio Giordano.

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