Ann. Bot. Fennici 47: 280–292 ISSN 0003-3847 (print) ISSN 1797-2442 (online) Helsinki 30 August 2010 © Finnish Zoological and Botanical Publishing Board 2010 Growth of Alpine lady-fern (Athyrium distentifolium) and plant species composition on a ski piste in the Hrubý Jeseník Mts., Czech Republic Marek Banaš1,*, Miroslav Zeidler1, Martin Duchoslav2 & Jan Hošek3 1) Department of Ecology and Environmental Science, Faculty of Science, Palacký University, Tř. Svobody 26, CZ-771 46 Olomouc, Czech Republic (*[email protected]) 2) Department of Botany, Faculty of Science, Palacký University, Šlechtitelů 11, CZ-783 71 Olomouc, Czech Republic 3) Areál ČOV, CZ-268 01 Hořovice, Czech Republic Received 15 Dec. 2008, revised version received 29 May 2009, accepted 9 June 2009 Banaš, M., Zeidler, M., Duchoslav, M. & Hošek, J. 2010: Growth of Alpine lady-fern (Athyrium dis- tentifolium) and plant species composition on a ski piste in the Hrubý Jeseník Mts., Czech Repub- lic. — Ann. Bot. Fennici 47: 280–292. This study was focused on identifying the impact of a ski piste on snow conditions, soil temperature, as well as phenological development and growth of Athyrium disten- tifolium, and examining differences in species composition between the ski piste and the natural environment. Longer snow-cover period and deeper snow were observed on the ski piste than in the natural surroundings. Lower soil temperature was found on the ski piste during the peak winter period and at the beginning of the growing period. Different environmental conditions on the ski piste caused a delay and shortening of the phenological development of A. distentifolium in the late spring. Individuals of that plant caught up the initial delay in phenological development within 36 days after the beginning of measurement. However, plants only grew to lower height on ski piste as compared with plants in control plots. Even relatively small differences in the time of snow melt and soil temperature development in stands examined on the ski piste resulted in significant changes in the species composition of the studied vegetation towards subalpine tall grasslands. Key words: alpine plant community, Athyrium distentifolium, habitat ecology, phenol- ogy, ski piste, species composition Introduction follow isolines of snow melt (Körner 1999). The snow cover protects plants from low tempera- Snow cover strongly determines the distribu- tures, drought and frost (Ellenberg 1988, Jones tion of plant species in the alpine zone (Billings & Pomeroy 2001). Snow distribution determines & Bliss 1959, Körner 1999). Patterns of snow the length of the growing season (Körner 1999, distribution and snow duration in alpine areas Sturm et al. 2001), and it influences soil devel- create rather stable mosaics of vegetation that opment and the soil environment including soil ANN. BOT. FeNNICI Vol. 47 • Growth of Alpine lady-fern and plant species composition on a ski piste 281 temperature, freeze-thaw cycles, microbial activ- so heat flow through the compacted snow cover ity, oxygen–CO2 balance (Meyer 1993, Körner is much higher than in areas with natural snow 1999, Jones & Pomeroy 2001), respiration of cover (Sturm et al. 1997). This results in more plants during the winter, nutrient transport and freezing of soil on ski pistes as compared with nutrient availability (Bilbrough et al. 2000, Fah- areas having a natural snow cover (Baiderin nestock et al. 2000, Lipson et al. 2002, Schimel 1982, Cernusca et al. 1990, Rixen et al. 2004), et al. 2004). There is also a close relationship subsequent reduction of soil microbial activity between snow duration, plant cover, phenology (Meyer 1993) and carbohydrate reserve changes of plants and plant productivity (Walker et al. in below-ground biomass (Zeidler et al. 2008). 1995, Heegaard 2002, Huelber et al. 2006, Kudo Changes in oxygen and carbon dioxide bal- & Hirao 2006). Experiments with altered snow ances, as a result of an increased number of ice depths and snow cover duration have shown layers in the snow, have also been observed at significant phenological and growth changes in sites with a compacted snow cover (Cernusca et alpine plants (Galen & Stanton 1993, 1995, al. 1990, Newesely 1997). The lack of oxygen Walker et al. 1999, Totland & Alatao 2002, causes an increased susceptibility of plants to Wahren et al. 2005). frost damage in their shoots and roots (Körner Skiing in ski areas exerts an important type 1999). As a result, plant species with insufficient of land-use that significantly influences the dis- cold hardiness and plants sensitive to mechani- tribution of snow cover and subsequently the cal stress may be damaged, resulting in a shift development of limiting factors in the mountain among functional groups (Wipf et al. 2005). environment (Titus & Tsuyuzaki 1998, Rixen et Shortening of the vegetation season on ski pistes al. 2003). Research focused on the impacts of can also have an impact on some plants, as has ski piste operation on the mountain environment been shown in the Alps and Russia. There can be began to be carried out in the 1970s and 1980s phenological changes in early-flowering species, with the expansion of these activities, especially or they can even disappear from communities in the European Alps (Weiss et al. 1998). Most (Baiderin 1982, Wipf et al. 2005). of those studies focused on direct impacts, espe- Only a few studies have dealt with the rela- cially on the impacts of mechanical disturbances tion between snow cover and alpine vegetation on the soil cover, plant phenology and plant of the Hercynian Mountains of central Europe communities (e.g. Bayfield 1980, 1996, Watson (sensu Grabherr et al. 2003), particularly from 1985, Tsuyuzaki 1993). They also dealt with the High Sudeten Mts. (Jeník 1958, Štursa et al. an evaluation of vegetation succession in areas 1973, Klimešová 1993, Hejcman et al. 2006). where grass had been seeded artificially (e.g. Data concerning the impact of ski pistes on Delarze 1994, Urbanska et al. 1999, Fattorini alpine vegetation of these mountains is lack- 2001, Gros et al. 2004). Fewer studies dealt ing. In addition, the alpine tundra of Hercy- with indirect impacts of downhill skiing, i.e. the nian Mts., including the studied territory in the impact of altered snow conditions on the soil Hrubý Jeseník Mts., covers only about 10.48 environment and vegetation on ski pistes (Baid- km2 and is therefore threatened by the develop- erin 1982, Rixen et al. 2003, 2004, Keller et al. ment of anthropogenic activities (Jeník 1998, 2004, Wipf et al. 2005). Grabherr et al. 2003). An important community Manipulation of snow (displacing and com- of the alpine belt of the Hrubý Jeseník Mts. is pacting the snow cover) on ski pistes and skiers’ the Athyrium distentifolium community [asso- activities results in a considerable snow compac- ciation Adenostyli-Athyrietum alpestris (Zlatník tion (Keller et al. 2004). Snow compaction is 1928) Jeník 1961]. Within the Hercynian Mts. of reflected in changes of its thermal and hydrologi- central Europe, this is a rare alpine community cal properties. Snow density, hardness, heat con- (Kočí 2001), potentially endangered by down- ductivity, water content and duration increase, hill skiing development. Nevertheless, potential while porosity and permeability decrease (Sturm changes of the community under influence of ski et al. 1997, Rixen et al. 2003, Keller et al. 2004). piste have been neglected up until now. Heat conductivity is a function of snow density, This study of the alpine plant community 282 Banaš et al. • ANN. BOT. FeNNICI Vol. 47 dominated by A. distentifolium is focused on (1) alliance Dryopterido-Athyrion Holub ex Sýkora identifying the difference in snow conditions et Štursa 1973) occur in protected, shaded and and soil temperature between the ski piste and moist places with long-lasting snow cover at the natural environment, (2) examining if the ski and around the alpine timberline. The stands are piste causes a delay of phenological develop- dominated by A. distentifolium, but Adenostyles ment and decrease of growth in A. distentifolium, alliariae, Rumex arifolius, Silene dioica, Stel- as the community’s dominant species, and (3) laria nemorum, Oxalis acetosella occur as well. examining if there are differences in species In lower areas, the vegetation gradually changes composition between stands of the community into a mountain spruce forest of the association on the ski piste and the natural environment. Athyrio alpestris–Piceetum Hartmann 1959. The study region has the highest situated downhill ski pistes in the Hercynian Mts., reach- Material and methods ing into the alpine zone. The ski piste examined has been used for skiing since the first half of Study site the 20th century, and snow grooming has been performed since the 1980s. There is no artificial The study area (about 10 000 m2) is situated snow-making on the ski piste and natural snow in northeastern Czech Republic, in the Hrubý accumulation is supported only by 1-m-heigh Jeseník Mts., which is the second highest moun- snowfences. The relief and vegetation on the ski tain range within the Hercynian Mts. of cen- piste and surroundings are of natural character. tral Europe (sensu Grabherr et al. 2003). The Use as a pasture ceased in the 1940s, and there research locality is situated on the northeastern have been no important mechanical disturbances leeward hillside of Petrovy Kameny Mt. (1448 m — particularly because the location is part of a a.s.l., 50°04´N, 17°14´E) in the alpine belt above national nature reserve. The mechanical distur- timberline (Jeník 1972, Treml & Banaš 2008). bance of plants on the ski run is prevented by The relief of the slope of Petrovy Kameny operating rules. Skiing activities are suspended Mt. has been shaped by cryogenic and perigla- when snow depth drops below 80 cm. cial processes (Křížek et al. 2005). The study area is formed of crystalline bedrock and gneiss (Demek 1987) with podzolic soils (Kubiena Measurement of snow conditions 1953).