Impacts of Climate Change on the Establishment, Distribution, Growth

Review Article - doi: 10.3832/ifor0537-003 ©iForest – Biogeosciences and Forestry

Collection: NFZ Summer School 2009 - Birmensdorf (Switzerland) tribution shifts of Swiss stone pine popula Long-term ecosystem research: understanding the present to shape the future tions in the future will be discussed. Guest Editor: Marcus Schaub (WSL, Switzerland) Seedling establishment Swiss stone pine is a monoecious, wind Impacts of climate change on the establish pollinated species which reaches reproduc tive maturity at 40-60 years of age (Ulber et ment, distribution, growth and mortality of al. 2004) with good seed production years occurring on average twice in ten years Swiss stone pine (Pinus cembra L.) (Mattes 1982). Seed production is especially sensitive to climate because important deve

(1) (2) (3) lopmental processes such as the initiation of Boden S , Pyttel P , Eastaugh CS flower and cone primordia, meiosis and the release of pollen depend to a large degree on Anticipated future climate changes are expected to significantly influence climatic variables (Pigott 1992). The tempo forest ecosystems, particularly in treeline ecotones. Climate change will have ral dynamics of seed production and the in both direct and indirect effects on the future distribution of alpine tree spe fluence of climate change on seed produc cies, some of which will be positive and others negative. Although increased tion of Swiss stone pine have however not temperatures are on the whole likely to have a positive impact on growth and been comprehensively investigated to date. distribution of Swiss stone pine (Pinus cembra L.), indirect effects that influ The wingless Swiss stone pine seeds are ence seed dispersal may threaten the population viability of species. The com mainly dispersed by the European nutcracker plexity of the interrelations between climatic and non-climatic factors de bird (Nucifraga caryocatactes L.). Swiss mands further research, which should include long-term monitoring. stone pine seeds are the main food source for European nutcrackers, and those birds are Keywords: Swiss stone pine, Treeline, Climate change, Distribution shift, Tree capable of gathering and transporting a large growth, Mortality amount of seeds for storage in their own ter ritory. Nutcrackers hide the seeds on the ground and prefer sites under sheltering trees Introduction biomes to climate variability is high and thus or stumps, ridges or rock ledges in open Future impacts of global climate change of special interest for understanding the ef areas (Mattes 1982), which in turn places such as predicted increases in annual air and fects of global change. Swiss stone pine seeds into microsites fa surface temperatures and variations in pre Swiss stone pine (Pinus cembra L.) is dis vourable for germination and seedling esta cipitation will cause significant alterations in tributed in timberline ecotones across Europe blishment. Gregory et al. (2009) determined forest ecosystems (Eastaugh 2008). Impacts from the Carpathian Mountains to the French that variation in observed population trend of these changes will be proportionally more Alps (Polunin & Walters 1986, Ulber et al. among European bird species is significantly perceptible at high elevations (Bensiton et al. 2004). During several hundred years of hu linked with model projections of change in 1997). man activities such as alpine farming or tim the extent of the species’ potential geogra In timberline ecotones near the upper limit ber extraction Swiss stone pine was often phical range associated with climate change. of closed forests tree growth, forest structure eliminated and therefore restricted to stands Their results show that the European and forest dynamics are mainly temperature- on inaccessible slopes exposed to the North nutcracker is one of the ten bird species to driven (Tranquillini 1979, Innes 1991, (Holtmeier 1966, Motta & Nola 2001, Höhn have most declined with global warming Körner 1998). The sensitivity of these et al. 2009). In recent decades, socio-eco during the period 1980-2005. nomic and silvicultural changes have fa Swiss stone pine germinates well on orga voured the establishment of Swiss stone pine nic soils with an accumulated layer of litter (1) Institute for Forest Growth, Albert- Ludwigs University Freiburg, Tennenbacher (Motta et al. 2006). This five-needled conifer and moss, but it can also germinate and es Straße 4, D-79106 Freiburg (Germany); (2) tree is well adapted to the harsh subalpine tablish itself on mineral soils or even rocky Institute of Silviculture, Albert-Ludwigs climate conditions in the Central European surfaces (Ulber et al. 2004). Seedlings profit University Freiburg, Tennenbacher Straße 4, Alps (Ulber et al. 2004) and is often asso from large endosperm reserves, are shade D-79106 Freiburg (Germany); (3) University ciated with mountain pine (Pinus montana tolerant and therefore able to persist as un of Natural Resources and Applied Life Miller), Scots pine (Pinus sylvestris L.), derstorey saplings (Hättenschwiler & Körner Sciences (BOKU), Department of Forest and European larch (Larix decidua Miller) and 1995). Seedling survival is enhanced by Soil Sciences, Institute of Silviculture, Peter Norway spruce (Picea abies L. Karst). In the early snow melt in warm spring months and Jordan Straße 82, 1190 Vienna (Austria) continental subalpine forests of the Central early snow falls at the beginning of winter Alps with relatively low rainfall and mean that limit deep freezing of the soil (Vittoz et @ Simon Boden ([email protected] annual temperatures below 1.5 °C (Ellenberg al. 2008). Increased soil warming is favou freiburg.de) 1996), stands develop from early-successio rable for cell activity and cell differentiation Received: May 25, 2010 - Accepted: May 31, nal stages dominated by mountain pine to a and thus for further root establishment 2010 late-successional stage dominated by Swiss (Gruber et al. 2009). Particularly at mountain stone pine and European Larch (Risch et al. sites tree seedlings are likely to benefit from Citation: Boden S, Pyttel P, Eastaugh CS, 2010. Impacts of climate change on the 2003, Höhn et al. 2009). microclimates created by dwarf shrubs, but establishment, distribution, growth and This review will summarize the evidence as they grow taller, there may be a microcli mortality of Swiss stone pine (Pinus cembra of Swiss stone pine responses to climate matological bottleneck in the development of L.). iForest 3: 82-85 [online: 2010-07-15] change at the timberline ecotone. The review the seedlings to mature tress (Grace et al. URL: http://www.sisef.it/iforest/show.php? will consider all life stages, and possible dis 2002). id=537

Growth change several factors are worth mentioning, scales. Besides local microclimates (Daniels The growing season at the timberline is besides drought periods. Long-lasting snow & Veblen 2003), the primary climatic limita very short and any extensions of the season cover may stress trees by significantly redu tion on vegetation establishment is the com due to small temperature differences at the cing the length of the growing period, but bined effects of growing-season length, sea beginning and the end of the snow-free pe snow also has mechanical effects on trees sonal temperatures and the duration of the riod have a large effect on the annual carbon (snowbreak damage). The branches of Swiss snowpack (e.g. Tranquillini 1979, Körner gain of evergreen conifers (Wieser et al. stone pine are relatively short and elastic, 1998). Several studies (e.g. Innes 1991, Pauli 2009). The maturation and hardening of tis therefore the crowns of adult Swiss stone et al. 1996, Walther et al. 2002, Pauli et al. sues, needles, shoots and buds are positively pine trees are less prone to snowbreak 2003, Daniels & Veblen 2003) have assessed influenced by an extended growing season damage from overloading than for example that the lengthening of the growing season, (Baig & Tanquillini 1980), as is resilience the crowns of Scots pine with less elastic higher spring and summer temperatures and against winter stress (e.g. frost desiccation) branches (McKinney et al. 2009). an earlier melting of the snowpack will lead in combination with the climate conditions The occurrence of the ascomycete Grem to an altitudinal upward movement of high during winter of the current year (Tran meniella abietina, the main pathogenic mountain vegetation and a consistent quillini 1963, Tranquillini 1979). Swiss fungus for Swiss stone pine, is positively re upslope advance of altitudinal timberlines. stone pine has a relative low photosynthetic lated to the mean duration of snow cover in This may be the case as well for Swiss stone capacity and a low daily and seasonal carbon spring (Senn 1999). Prolonged snow cover pine in the timberline ecotone and possibly gain (Wieser et al. 2009), the length of the allows the fungus to grow for a longer time lead to an upward distribution of this spe active growing period is thus of special im under favourably moist conditions. Infec cies, although in some cases soil water con portance for further growth increase. Motta tions of Swiss stone pine with Phacadium ditions may be a limiting factor (Anfodillo et & Nola (2001) detected a distinct increasing infestans, the second most important patho al. 1998). The upper tree line is the preferred trend in growth rates of Swiss stone pine genic fungus, are governed more by stand territory of the European nutcracker, and over the last century in the Eastern Italian density-dependent interactions (Burdon et al. thus possible altitudinal expansion of Swiss Alps. The radial growth of several Swiss 1992). stone pine populations at the treeline ecotone stone pine stands in the Central Swiss Alps Insects are the most important seed preda will depend in part on the response of has increased with increasing summer tem tors during the predispersal phase of seed de nutcrackers to environmental change (Motta peratures and longer growing seasons since velopment (Turgeon et al. 1994). Dormont & & Nola 2001). 1980 (Vittoz et al. 2008), although conti Roques (1999) speculate that the limited Variations in altitudinal timberline posi nuing periods of drought may have limited colonization of Swiss stone pine seeds by in tions and tree growth are explained by a radial growth (Oberhuber 2004, Vittoz et al. sects may also be due to the behaviour of the combination of a general thermal boundary 2008). Pietsch & Hasenauer (2005) show European nutcracker. The bird harvests most for tree growth and regional edaphic proper that stomatal conductance in Swiss stone of the mature cones by the end of the sum ties and disturbances (Körner 1998). These pine (necessary for CO2 uptake and tree mer (Mattes 1982) before the completion of regional to local scale factors may obscure or growth) is correlated to stem temperature, insect larval development within the cone, reverse vegetation patterns and trends expec which provides a physiological explanation which may help to limit seed damage by in ted from global climate change (Daniels & for these recent increasing growth rates. An sects. Veblen 2003). Anfodillo et al. (1998) for early initiation of growth may, however, in example reported for the Eastern Italian Alps crease trees’ susceptibility to late frost Discussion that soils at the timberline could become events (Cannell & Smith 1986). Radial An understanding of seedling recruitment physiologically dry during the growing growth of Swiss stone pine at the timber line dynamics and their climatic controls is indi period and that high temperatures and va is negatively correlated with cool summer spensable for predicting likely future chan pour pressure deficits limit the radial growth (June-August) and previous autumn (Sep ges in the distribution of Swiss stone pine in of Swiss stone pine. Severe climatic events tember-October) temperatures and low pre response to climate change. The quantity and such as drought or severe frost during the cipitation in late winter (Pfeifer et al. 2005). quality of seed production, dispersal, esta growing season are more likely than tempe Several other authors also mention a similar blishment and subsequent growth after esta rature changes to control tree population dy influence of precipitation in the previous au blishment are essential for the formation of namics in timberline ecotones (Wieser et al. tumn and winter as well as current summer new subalpine forest areas at higher alti 2009). An increase in stochastic disturbances temperatures (Carrer et al. 1998, Oberhuber tudes. due to for example fire or windthrow may 2004, Carrer et al. 2007, Oberhuber et al. Swiss stone pine may reestablish in alpine diminish the regeneration of the shade tole 2008, Gruber et al. 2009, Leonelli et al. areas even long after the reduction or cessa rant Swiss stone pine and may give pioneer 2009). tion of farming or other human activities, species the chance to establish (Hät Non-climatic aspects of global change such due to the seed dispersal accomplished by tenschwiler & Körner 1995). Vegetation as higher nitrogen deposition and the rise in the European nutcracker (Mattes 1982). Cli changes at the timberline ecotone may rather atmospheric CO2 concentration may also be mate change may have a deleterious effect occur abruptly, therefore long-term trends on considered as enhancing growth simulators on Swiss stone pine establishment due to ad large spatial distribution scales of Swiss (Nicolussi et al. 1995, Wieser et al. 2009). ded pressures on this seed dispersal vector. stone pine due to global climate change may Other non-climatic aspects such as tropo Although a further increase in summer tem be difficult to detect or predict. spheric ozone are suspected on the other peratures might shorten the interval between Besides the possible upward shift Hät hand as contributing factors for growth de good seed years (Holtmeier & Broll 2007), tenschwiler & Körner (1995) considered that cline of Swiss stone pine (Dalstein et al. the recruitment of Swiss stone pine popula in recent decades reduced forest pasturing 2002). tions is likely to be reduced if the population and increased nitrogen input may have led to of the European nutcracker is significantly denser ground and understorey vegetation in Mortality impacted (Mattes 1982). some parts of Central Switzerland, which At high elevations, the survival of trees is The Alpine climate system is very com may result in a possible downward move mainly affected by environmental factors plex, with complex patterns of variation and ment of Swiss stone pine due to its shade (Tranquillini 1979). In the context of climate dynamics on interannual and decadal time tolerance as a climax species. Under pre

iForest (2010) 3: 82-85 83 © SISEF http://www.sisef.it/iforest/ Impacts of climate change on Swiss stone pine dicted warmer climatic conditions however Zurich forest network (http://www.nfz- mate change: A multidisciplinary review. IUFRO this downward shift of Swiss stone pine is forestnet.org/) for their invitation to the con Occasional Paper 21, International Union of likely to be limited by the competitive ad ference and in particular to thank Dr Marcus Forest Research Organisations, Vienna. vantage of other tree species. Anfodillo et al. Schaub and his colleagues for their organisa Ellenberg H (1996). Vegetation Mitteleuropas und (1998) speculate that for example European tion of the summer school and the staff of der Alpen in ökologischer, dynamischer und his larch is favoured in competition against the Swiss National Park for their leading of torischer Sicht. UTB, Stuttgart, pp. 1056. Swiss stone pine in the case of an increase of the associated field trip. The authors are also Grace J, Berninger F, Nagy L (2002). Impacts of air temperature due to a higher water uptake grateful for language revision by Dr Silvia Climate Change on the Tree Line. Annals of Bo capacity. Dingwall and technical comments from two tany 90: 537-544. - doi: 10.1093/aob/mcf222 Although tree mortality is a highly random anonymous reviews, all of which served to Gregory RD, Willis SG, Jiguet F, Vorisek P, process that is difficult to predict (Monserud greatly improve the paper. Klavanova A, Van Strien A, Huntley B, Colling 1976), it seems that environmental factors ham YC, Couvet D, Green RE (2009). An indi such as snowbreak or pathogenic insects and References cator of the impact of climatic change on fungi are not the major influences on large Anfodillo T, Rento S, Carraro V, Furlanetto L, Ur European Bird Populations. PloS One 4 (3): tree mortality of Swiss stone pine. Frequent binati C, Carrer M (1998). Tree water relations e4678. - doi: 10.1371/journal.pone.0004678 drought periods or late frost events however and climatic variations at the alpine timberline: Gruber A, Baumgartner D, Zimmermann J, Ober may be more significant drivers of mortality seasonal changes of sap flux and xylem water huber W (2009). Temporal dynamic of wood rates. potential in Larix decidua Miller, Picea abies formation in Pinus cembra along the alpine Longer observation periods will be neces (L.) Karst and Pinus cembra L.. Annals of Forest treeline ecotone and the effect of climate va sary to confirm and predict distribution Science 55: 159-172. - doi: 10.1051/ riables. Trees 23: 623-635. - doi: 10.1007/ shifts, growth increase and mortality of forest:19980110 s00468-008-0307-7 Swiss stone pine in the Central Alps, and Baig MN, Tanquillini W (1980). The effects of Hättenschwiler S, Körner C (1995). Responses to long-term data collection of multiple para wind and temperature on cuticular transpiration recent climate warming of Pinus sylvestris and meters will be necessary to distinguish the of Picea abies and Pinus cembra and their signi Pinus cembra within their montane transition relative influence of climate on the develop ficance in desiccation damage at the alpine tree zone in the Swiss Alps. Journal of Vegetation ment of Swiss stone pine. line. Oecologia 47: 252-256. - doi: 10.1007/ Science 6: 357-368. - doi: 10.2307/3236235 BF00346828 Holtmeier FK (1966). Die ökologische Funktion Conclusions Bensiton M, Diaz HF, Bradley RS (1997). Climate des Tannenhähers im Zirben-Lärchenwald und Climatic influences on treeline ecosystems change at high elevation sites: an overview. Cli an der Waldgrenze des Oberengadins. Journal of are a complex mix of direct and indirect ef mate Change 36: 233-251. - doi: 10.1023/ Ornithology 107: 337-345. - doi: 10.1007/ fects, which individually may either posit A:1005380714349 BF01677905 ively or negatively influence tree growth and Burdon JJ, Wennstöm A, Ericson L, Müller WJ, Holtmeier FK, Broll G (2007). Treeline advance - distribution. Although individual aspects of Morton R (1992). Density-dependent mortality in driving processes and adverse factors. Landscape these effects have been studied, the overall Pinus sylvestris caused by the snow blight patho Online 1: 1-33. - doi: 10.3097/LO.200701 likely consequences of new climatic condi gen Phacidium infestans. Oecologia 90: 74-79. - Innes JL (1991). High-altitude and high-latitude tions for the establishment, distribution, doi: 10.1007/BF00317811 tree growth in relation to past, present and future growth and mortality of Swiss stone pine are Cannell MGR, Smith RI (1986). Climatic warm global climate change. The Holocene 1: 168-173. still poorly understood. Continued warming ing, spring budburst and frost damage on trees. - doi: 10.1177/095968369100100210 is likely to lead to an altitudinal or latitudinal Journal of Applied Ecology 23: 177-191. - doi: Höhn M, Gugerli F, Abran P, Bisztray G, Buo population shift and increased growth, but 10.2307/2403090 namici A, Cseke K, Hufnagel L, Quintela-Sabar extreme events such as drought or wildfires Carrer M, Anfodillo T, Urbinati C, Carraro V is C, Sebastiani F, Vendramin GG (2009). Vari may however cause growth declines or mor (1998). High-altitude forest sensitivity to global ation in the chloroplast DNA of Swiss stone pine tality. The distribution of Swiss stone pine warming: results from long-term and short-term (Pinus cembra L.) reflects contrasting post-gla populations in the future is however inescap analyses in the Eastern Italian Alps. In: “The Im cial history of populations from the Carpathians ably related to the adaptability of the primary pacts of Climate Variability on Forests”. Spring and the Alps. Journal of Biogeography 36: 1798- seed dispersal vector (the European nut er, Berlin, Heidelberg, pp. 318. 1806. - doi: 10.1111/j.1365-2699.2009.02122.x cracker bird) to environmental change. Fu Carrer M, Nola P, Eduard J, Motta R, Urbinati C Körner C (1998). A re-assessment of the high el ture research on Swiss stone pine should use (2007). Regional variability of climate-growth evation treeline positions and their explanation. long-term monitoring on large spatial scales relationships in Pinus cembra high elevation Oecologia 115: 445-459. - doi: 10.1007/ to better understand the ongoing changing forests in the Alps. Journal of Ecology 95: 1072- s004420050540 dynamic processes during the lifespan of 1083. - doi: 10.1111/j.1365-2745.2007.01281.x Leonelli G, Pelfini M, Battipaglia G, Cherubini P Swiss stone pine in the timberline ecotone Daniels LD, Veblen TT (2003). Regional and local (2009). Site-aspect influence on climate sensitiv and the contributing factors that influence effects of disturbance and climate on altitudinal ity over time of a high-altitude Pinus cembra the dynamics. Combined studies involving treelines in northern Patagonia. Journal of Veget tree-ring network. Climatic change 96: 185-201. both forest growth researchers and avian ation Science 14: 733-742. - doi: 10.1111/j.1654- - doi: 10.1007/s10584-009-9574-6 ecologists would help to better understand 1103.2003.tb02205.x Mattes H (1982). Die Lebensgemeinschaft von seed dispersal and seedling establishment Dalstein L, Torti X, LeThiec D, Dizengremel P Tannenhäher, Nucifraga caryocatactes (L.), und processes. (2002). Physiological study of declining Pinus Arve, Pinus cembra L., und ihre forstliche cembra (L.) trees in southern France. Trees 16: Bedeutung in der oberen Gebirgswaldstufe. Acknowledgements 299-305. - doi: 10.1007/s00468-001-0160-4 Berichte Eidgenössische Forschungsanstalt This paper was produced as a result of the Dormont L, Roques A (1999). A survey of insects Wald, Schnee und Landschaft WSL 241, pp. 74. 2009 5th annual NFZ summer school in attacking seed cones of Pinus cembra in the Alps, Monserud RA (1976). Simulation of forest tree Zurich, held in conjunction with the LWF the Pyrénées and Massif Central. Journal of Ap mortality. Forest Science 22 (3): 438-444. [on Long-Term Forest Ecosystem research con plied Entomology 123: 65-72. - doi: 10.1046/ line] URL: http://www.ingentaconnect.com/con ference, 8-9 September 2009. The authors j.1439-0418.1999.00318.x tent/saf/fs/1976/00000022/00000004/art00015 would like to thank the Nancy / Freiburg / Eastaugh C (2008). Adaptations of forests to cli Motta R, Nola P (2001). Growth trends and dy

namics in sub-alpine forest stands in the Varaita Pauli H, Gottfried M, Grabherr G (2003). Effects water relations of plants” (Rutter AJ, Whitehead Valley (Piedmont, Italy) and their relationships of Climate change on the alpine and nival veget FH eds). Blackwell, Oxford, UK, pp. 153-166. with human activities and global change. Journal ation of the Alps. Journal of Mountain Ecology Tranquillini W (1979). Physiological ecology of of Vegetation Science 12: 219-230. - doi: 7: 9-12. the alpine timberline. Springer-Verlag, New 10.2307/3236606 Pfeifer K, Kofler W, Oberhuber W (2005). Cli York, USA. Motta R, Morales M, Nola P (2006). Human land- mate related causes of distinct radial growth re Turgeon JJ, Roques A, De Groot P (1994). Insect use, forest dynamics and tree growth at the ductions in Pinus cembra during the last 200 yr. fauna of coniferous seed cones. Diversity, host- treeline in the western Italian Alps. Annals of Vegetation History and Archaeobotany 14: 211- plant interactions, and management. Annual Re Forest Science 63: 739-747. - doi: 10.1051/ 220. - doi: 10.1007/s00334-005-0001-2 view of Entomology 39: 179-212. - doi: forest:2006055 Pietsch SA, Hasenauer H (2005). Modeling cem 10.1146/annurev.en.39.010194.001143 McKinney ST, Fiedler CE, Tomback DF (2009). bran pine ecosystems in Austria. Austrian Journ Ulber M, Gugerli F, Bozic G (2004). EUFORGEN Invasive pathogen threatens bird-pine mutualism: al of Forest Science 122 (1): 37-54. Technical Guidelines for genetic conservation implications for sustaining a high-elevation eco Pigott CD (1992). Are the distributions of species and use for Swiss stone pine (Pinus cembra L.). system. Ecological Applications 19 (3): 597-607. determined by failure to set seed? In: “Fruit and International Plant Genetic Resources Institute, - doi: 10.1890/08-0151.1 seed production” (Marshall J, Grace J eds). Cam Rome, Italy, pp. 6. Nicolussi K, Bortenschlager S, Körner C (1995). bridge University Press, Cambridge, UK, pp. Vittoz P, Rulence B, Largey T, Freléchoux F Increase in tree-ring width in subalpine Pinus 256. (2008). Effects of climate and land-use change

cembra from the Central Alps that may be CO2 Polunin O, Walters M (1986). A guide to the ve on the establishment and growth of Cembran related. Trees 9: 181-189. - doi: 10.1007/ getation of Britain and Europe. Oxford Univ. pine (Pinus cembra L.) over the altitudinal BF00195270 Press, Oxford, UK, pp. 238. treeline ecotone in the central Swiss Alps. Arctic, Oberhuber W (2004). Influence of climate on radi Risch AC, Nagel LM, Schütz M, Krüsi BO, Antarctic and Alpine Research 40: 225-232. - al growth of Pinus cembra within the alpine tim Kienast F, Bugmann H (2003). Structure and doi: 10.1657/1523-0430(06-010)[VITTOZ]2.0. berline ecotone. Tree Physiology 24: 291-301. - long-term development of subalpine Pinus CO;2 doi: 10.1093/treephys/24.3.291 montana Miller and Pinus cembra L. forests in Walther GR, Post E, Convey P, Menzel A, Oberhuber W, Kofler W, Pfeifer K, Seeber A, the central European Alps. Forstwissenschaft Parmesan C, Beebee TJC, Fromentin O, Hoegh- Gruber A, Wieser G (2008). Long-term changes liches Centralblatt 122: 219-230. Guldberg JM, Bairlein F (2002). Ecological re in tree-ring climate relationships at Mt. Senn J (1999). Tree mortality caused by Grem sponses to recent climate change. Nature 416: Patscherkofel (Tyrol, Austria) since the mid- meniella abietina in a subalpine afforestation in 389-395. - doi: 10.1038/416389a 1980s. Trees 22: 31-40. - doi: 10.1007/s00468- the central Alps and its relationship with duration Wieser G, Matyssek R, Luzian R, Zwerger P, Pin 007-0166-7 of snow cover. European Journal of Forest dur P, Oberhuber W, Gruber A (2009). Effects of Pauli H, Gottfried M, Grabherr G (1996). Effects Pathology 29: 65-74. - doi: 10.1046/j.1439- atmospheric and climate change at the timberline of climate change on mountain ecosystems - up 0329.1999.00131.x of the Central European Alps. Annals of Forest ward shifting of alpine plants. World Resource Tranquillini W (1963). Climate and water rela Science 66: 402. - doi: 10.1051/forest/2009023 Review 8 (3): 382-390. tions of plants in the sub-alpine region. In: “The