Snow-bed Communities Research Articles

Phytosociological analysis of acidophytic alpine mat-grass swards in the Julian Alps and the Karawanks

Abstract Acidophytic alpine mat-grass swards are rare in the alpine belt of the predominantly calcareous Southeastern Alps of Slovenia, mostly occurring where limestone is admixed with marlstone or chert. Those for which we were able to make phytosociological relevés can be classified mainly into two syntaxa: Carici curvulae-Nardetum strictae vaccinietosum gaultherioidis and Sieversio-Nardetum strictae vaccinietosum. At slightly lower elevations, in the forest zone of the subalpine plateau Pokljuka, we found similar swards occupying small areas in frost hollows with luvisol on limestone. They include character species of various subalpine-alpine sward and snow bed communities and are classified into the syntaxon Homogyno alpinae-Nardetum scorzoneroidetosum croceae.

The orophilous relict High Campoese finely-toothed willow communities

This paper examines High Campoese orophilous snowbed dwarf communities of finely-toothed willow Salix breviserrata Flod. The acidophilous, rupicolous and temporihygrophilous character of this species results in a singular floristic composition that is very different from the Salix breviserrata s.l. Picoeuropean communities. Based on the relevés sampled, the authors describe the endemic High Campoese dwarf scrub association Alchemillo alpinae-Salicetum breviserratae, which we ascribe to the Salicetea herbaceae class, where the mildest ecological conditions are represented, accounting for its relict character. These are Sites of Community Importance as stipulated by the European Commission Habitats Directive, which, together with their sensitivity to global climate change stemming from their limited synchorology, underlines their threatened status and the need for conservation policy.

Класс Salicetea herbaceae Br.-Bl. 1948 в Алтае-Саянской горной области

Класс Salicetea herbaceae Br.-Bl. 1948 в Алтае-Саянской горной области

Snow-bed communities with dominant Salix herbacea in the Julian Alps

Abstract In the alpine belt of the Julian Alps (glacial cirque Na Jezerih under Mt. Veliki Rokav, Jarečica, the Mangart Saddle and Prodi under Mt. Mangart as well as Mt. Plešivec in the rock wall of Loška Stena) we studied the phytosociology and ecology of snow-bed vegetation with dominating flowering plants Salix herbacea, Luzula alpinopilosa, Gnaphalium supinum, Soldanella pusilla and Salix retusa, and numerous moss species. Based on the comparison with similar snow-bed communities in the Central, Eastern and Southern Alps we described a new association Salicetum retuso-herbaceae and classified it into the alliance Salicion herbaceae and class Salicetea herbaceae. We determined several successional stages of snow-bed vegetation on mixed calcareous-silicate bedrock that we treat as variants, in two relevés also the initial association Polytrichetum sexangularis.

Синтаксономия луговин тундрового пояса гор Мурманской области

Синтаксономия луговин тундрового пояса гор Мурманской области

A Baseline Study of Alpine Snowbed and Rill Communities On Mount Washington, Nh

Abstract Quantitative data on the abundance and frequency of vascular plants, bryophytes and lichens are lacking for alpine snowbed and rill communities in northeastern North America. Such data are needed to establish whether the communities are changing in response to climate warming, nitrogen deposition or shifts in the timing of precipitation and snowmelt. We surveyed nine sites (five snowbeds and four rills) on Mount Washington (White Mountain National Forest, New Hampshire), recording 54 vascular plant species, 42 bryophytes and 13 lichens. Although vascular plants were most abundant, bryophytes and lichens, which had not been completely surveyed in these communities previously, were important in terms of species richness (as many as eight bryophytes and four lichens in 1 m2 quadrats) and were occasionally abundant, particularly bryophytes in rills. We found that snowbeds and rills are separate communities. Some species are shared, but far higher numbers of vascular plants, bryophytes and lichens wer...

Rate of microsuccessions: Structure and floristic richness recovery after turf transplantation in alpine plant communities

Reciprocal transplantations of sod pieces have been conducted in alpine plant communities of the northwestern Caucasus. During 25 years, the changes in floristic richness and successional rates have been registered. Study objects were chosen to be. plant communities located along the toposequence from ridges to hollows with gradient of snow. cover thickness increase and vegetation period decrease, namely alpine lichen heath (ALH), Festuca varia grasslands (FVG), Geranium-Hedysarum meadows (GHM), and snow bed communities (SBC). The results of the study confirm the hypothesis about floristic richness of transplanted pieces to come closer to that of a background acceptor community. It is shown that during succession the variability reduces if sod pieces from different communities are transplanted into a common one. In particular, this is evident in case of SBC, where floristic richness of sod pieces transplanted from ALH and GHM has reduced noticeably. Also, it is evident from the results that the more different are donor and acceptor communities the higher is the rate of their changing. However, the assumption of higher succession rate in more productive communities has not been affirmed. On the opposite, communities with initially low productivity turned out to change faster than those with high productivity. It is found out that sod pieces transplanted to upper areas of the toposequence have had higher rate of alteration in comparison with those transplanted to lower areas. The reason behind this, as it may be suggested, is a longer growth season, which means a more prolonged period of high functional activity, and, accordingly, more time for the effects of competition, bringing seeds over, etc. In whole, the rate of succession decreases as the time from the moment of transplantation.increases, especially in communities with low productivity.

Current vegetation changes in an alpine late snowbed community in the south-eastern Alps (N-Italy)

During the last decades, a significant warming was observed in the Alps, cascading into a decrease in snowfall and snow-cover duration. Within the alpine landscape, snowbed communities are regarded as especially vulnerable to the predicted warmer temperatures and earlier snowmelt time. Albeit snowbeds represent a prominent component of the tundra biome, the current vegetation dynamics of these habitats are not yet well understood. In this study, the changes of vascular species richness, co-occurrence, composition, and abundance were evaluated within a late snowbed in the south-eastern Alps. The study was based on a re-survey of 11 permanent plots after a 6-year period. Species richness and abundance significantly increased and species co-occurrence shifted toward higher species segregation. Moreover, the changes in species richness at different spatial scales were related to different environmental factors, and a change in the proportion between snowbed and non-snowbed plants was found. The results suggest an increasing importance of competitive interaction among species in determining the future structure and composition of this community. In conclusion, there is strong evidence that this snowbed community is not in equilibrium with the current climate, and that changes in floristic composition and functional processes of this habitat are underway.

Long-term vegetation dynamic in the Northwestern Caucasus: which communities are more affected by upward shifts of plant species?

We studied long-term (25–31 years) dynamics of alpine communities at the Teberda Reserve, NW Caucasus, Russia, to test the following hypotheses: (1) lower altitude species increase and high altitude species decrease their abundance as a consequence of climate warming; (2) such changes in abundance are more significant in communities with short growth season (due to persistent snow cover) compared to exposed communities; (3) species with similar changes in abundance have similar functional traits. Four alpine communities with different positions in relief were considered in order of winter snow cover: alpine lichen heaths (ALH), Festuca varia grasslands (FVG), Geranium-Hedysarum meadows (GHM), and snowbed communities (SBC).

Integral assessment of the regrow capacity of alpine plants

A method for the comparative assessment of the regrow capacity (the ability of plants to the after-mowing recovery of above-ground biomass) of herbs in natural plant communities has been proposed. The method is based on the combined use of biomass parameters and the data on the number of shoots for the cases of the single and double removal of the biomass. The regrow capacity of 42 alpine species from four different plant communities has been assessed. The average weighted regrow capacity score decreases in the following series: Geranium-Hedysarum meadows > alpine lichen heaths ≥ alpine snow-bed communities ≥ Festuca varia meadows.

Lateglacial vegetation and palaeoenvironment in W Norway, with new pollen data from the Sunnmøre region

Kruger, L. C., Paus, A., Svendsen, J. I. & Bjune, A. E. 2011: Lateglacial vegetation and palaeoenvironment in W Norway, with new pollen data from the Sunnmore region. Boreas, 10.1111/j.1502-3885.2011.00213.x. ISSN 0300-9483. Two sediment sequences from Sunnmore, northern W Norway, were pollen-analytically studied to reconstruct the Lateglacial vegetation history and climate. The coastal Dimnamyra was deglaciated around 15.3 ka BP, whereas Lokjingsmyra, further inland, became ice-free around 14 ka BP. The pioneer vegetation dominated by snow-bed communities was gradually replaced by grassland and sparse heath vegetation. A pronounced peak in Poaceae around 12.9 ka BP may reflect warmer and/or drier conditions. The Younger Dryas (YD) cooling phase shows increasing snow-bed vegetation and the local establishment of Artemisia norvegica. A subsequent vegetation closure from grassland to heath signals the Holocene warming. Birch forests were established 500–600 years after the YD–Holocene transition. This development follows the pattern of the Sunnmore region, which is clearly different from the Empetrum dominance in the Lateglacial interstadial further south in W Norway. The Lateglacial oscillations GI-1d (Older Dryas) and GI-1b (Gerzensee) are hardly traceable in the north, in contrast to southern W Norway. The southern vegetation was probably closer to an ecotone and more susceptible to climate changes.

Experimental comparison of competition and facilitation in alpine communities varying in productivity

AbstractQuestion. Competitive and facilitative interactions among plant species in different abiotic environments potentially link productivity, vegetation structure, species composition and functional diversity. We investigated these interactions among four alpine communities along an environmental productivity gradient in a generally harsh climate. We hypothesised that the importance of competition would be higher in more productive sites.Location. Mt. M. Khatipara (43°27′N, 41°41′E, altitude 2750 m), NW Caucasus, Russia. Communities ranged from low‐productivity alpine lichen heath (ALH) and snowbed communities (SBC), to intermediate productivity Festuca grassland (FVG), and high‐productivity Geranium‐Hedysarum meadow (GHM).Methods. We quantified the relative influence of competition and facilitation on community structure by expressing biomass of target species within each natural community proportionally to biomass of the species in a “null community” with experimental release from interspecific competition by removing all other species (for 6 years). An overall index of change in community composition due to interspecific interactions was calculated as the sum of absolute or proportional differences of the component species.Results. Species responses to neighbour removal ranged from positive to neutral. There was no evidence of facilitation among the selected dominant species. As expected, competition was generally most important in the most productive alpine community (GHM). The intermediate position for low‐productivity communities of stressful environments (ALH, SBC) and the last position of intermediately productive FVG were unexpected.Conclusions. Our results appear to support the Fretwell‐Oksanen hypothesis in that competition in communities of intermediate productivity was less intense than in low‐ or high‐productive communities. However, the zero net effect of competition and facilitation in FVG might be the result of abiotic stress due to strong sun exposure and high soil temperatures after neighbour removal. Thus, non‐linear relationships between soil fertility, productivity and different abiotic stresses may also determine the balance between competition and facilitation.

Безлесные растительные сообщества побережья Восточного Мурмана (Кольский полуостров, Россия)

A phytosociological survey of the Barents Sea coastal plant communities according to Braun-Blan­quet approach is presented. Ass. Honckenyo diffusae—Elymetum arenarii (Regel 1928) R. Tx. 1966. is des­cribed on the sand beach. Halophillous vegetation is fragmented and ascribed to the community type Stellaria humifusa—Triglochin palustre. Tall herb mea­dows on the shore are described as ass. Tripleuro­spermo—Festucetum arenariae ass. nov. Mesic and moist meadows on the sea-exposed slopes are described as ass. Polygono vivipari—Thalictretum alpini (Kalliola 1939) stat. nov. Ass. Geranietum sylvatici Nordh.1943 includes meadows along springs and brooks, ass. Rumici—Salicetum lapponi Dahl 1957 combines mea­dows with willow shrub layer. Heath vegetation of the marine terrains and low hills is presented by ass. Arctostaphylo alpinae—Empetretum hermaphroditi (Zinserling 1935) Koroleva 1994, and heathlands on the hilltops belong to the Loiseleurio—Diapensietum (Fries 1913) Nordh. 1943 subass. typicum и salicetosum nummulariae subass. nov. Stands of ass. Phyllodoco—Vaccinietum myrtilli Nordh. (1928) 1943 are common in the snow-protected habitats. Snow-bed communities are described as ass. Veratro lobeliani—Salicetum herbaceae ass. nov. Paludified heathlands are described as ass. Rubo chamaemori—Caricetum rariflorae (Regel 1923) stat. nov. Sloping fens belong to ass. Drepa­noclado revolventis—Trichophoretum cespitosi Nordh. 1928. The syntaxa spectrum of the area investigated shows close affinities to the low arctic tundra subzone as well as to the coastal vegetation of the subarctic region.

Растительность южной части острова Большевик (архипелаг Северная Земля)

Bolshevik Isl. is the one of the largest islands within the Severnaya Zemlya archipelago. It is situated in the southern part of the polar desert zone. In the course of three field work trips in 1997, 1998 and 2000 years 252 relevees were made in its southern part on three geomorphologic surfaces: coastal plain, inner upland close to glacier and ancient high river terraces. As the result 27 syntaxonomical units of different rank (15 associations, 2 subassociations, 2 variants, and 8 community types) were described using Braun-Blanquet approach. All syntaxa, except one, are new and mostly similar to communities described on Franz Josef Land. The problems were to put new syntaxa into the higher level units (including class) within the syntaxonomical hierarchy. The main bulk of syntaxa, both zonal and intrazonal ones, has to be preliminary placed into Salicetea herbaceae class although there is a lot of reasons to consider zonal syntaxa as a new class that is specific for the polar desert zone. In any case, there are no one syntaxon that can be referred to Loiseleurio-Vaccinietea class that combines zonal vegetation in the tundra zone. The wide ecological range of great majority of species as well as the changes of their intralandscape distribution compare to the tundra zone made additional difficulties in finding character and differential species. 340 species (vascular plants — 52, mosses — 97, liverworts — 41, lichens — 150), that compiles 73 % of the whole island flora and 84 % of its southern part, were recorded within the all relevees. Almost half of these (182) are very rare on the island and 127 species were met 1—2 times. There are 70 species with wide ecological range throughout all landscape types with such commonly distributed herbs as Saxifraga cernua, S. hyperborea and Stellaria ed­ward­sii, mosses Polytrichastrum alpinum and Sanionia uncinata and lichen Stereocaulon rivulorum among these. Phippsia algida, the character species for snow bed communities, occurs in about 70 % of syntaxa. Useful for differentiation of syntaxa have been appeared 87 species. Few species with wide distribution within a landscape demonstrate their preference to a certain syntaxon by higher abundance (preferential character species). These are mostly bryophytes: mosses Bryum cryophilum and Grimmia torquata, and liver­worts Gymnomitrion corallioides, Marsupella arctica and Scapania crassiretis. Cryptogam species predo­minate in the whole flora as well as in each syntaxon. The number of species varies from 12 to 70 per sample plots 5÷5 m and from 20 to 195 in different syntaxa. The richest in species (70 per community and about 190 for association) are zonal plant communities on the accumulative coastal plain in the region of Sol­nechnaya Bay, the poorest one, with 10 and 20 species consequently, is ass. Hygrohypno polari—Saxifragetosum hyperboreae that was described on the upland, close to glacier in the inner part of island.

Spatial Analysis of Soils, Vegetation, Productivity, and Carbon Stored in Mountain Tundra Ecosystems, Khibiny Mountains, Russia

Data on the distribution of plant communities, their productivity, and major carbon stores held in mountain tundra vegetation and soils are presented. Extreme snow-bed communities had the lowest total biomass (662 g/m2), primarily in the main root portion in mineral soil horizons. Dwarf shrub-dominated heath on a gentle mountain slope had the highest total biomass (2406 g/m2), with woody perennial stems prevailing in the above-ground portion, and the main root portion concentrated in the organic horizon. Grass and sedge meadows situated in a hollow had the greatest total net primary production (215 g/m2), and roots were evenly distributed throughout the soil profile. The total amount of carbon stored in the ecosystem included carbon stored in above- and below-ground biomass, in the organic horizon, and in mineral soil horizons to a depth of 30 cm. Total carbon was lowest in snow-bed and lichen-dominated tundra (6183 g/m2 and 6337 g/m2, respectively), and highest in dwarf shrubs and grass-dominated tundra (25,261 g/m2 and 20,407 g/m2, respectively), the latter being comparable to total carbon stored in boreal forest ecosystems. Most of the carbon (95-97%) in tundra ecosystems was stored in soils (organic and mineral soil horizons).

Vegetation, climate and ice‐front oscillations in the Tromsø area, northern Norway during the Allerød and Younger Dryas

Sediments from two small lakes distal to the Tromsø–Lyngen moraine at Tromsø, northern Norway, indicate that the area was deglaciated prior to c. 11.7 14C ka BP. The earliest vegetation was dominated by calciphilous and heliophilous pioneer plants on unstable soils; this changed to a vegetation reflecting a dry continental climate until c. 10.7 14Cka BP. A phase (10.7–10.5 14Cka BP) with snow‐bed communities was followed by one with a mosaic of plant communities. This was succeeded by Empetrum heaths c. 10.3 14Cka BP, then by an open forest with Betula pubescens after 10.0 14Cka BP. Ice‐front oscillations in the Tromsø area are evaluated. The main part of the Younger Dryas glacial readvance, the Tromsø–Lyngen event, probably occurred between 10.7 and 10.3 14Cka BP.

The spider genera Robertus, Enoplognatha, Steatoda and Crustulina (Araneae: Theridiidae) from Japan

Keys and brief descriptions of 17 species of the genera Robertus, Enoplognatha, Steatoda and Crustulina are given. A new species, Robertus yasudai, is described from the alpine snow-bed communities of Mts. Daisetsu, Hokkaido. A Chinese species, Enoplognatha lordosa Zhu & Song 1992, is recorded for the first time from Japan. Enoplognatha abrupta (Karsch 1879) and Clubiona parvula (S. Saito 1933) are newly transferred from Steatoda. Six species names are newly synonymized: Enoplognatha submargarita Yaginuma & Zhu 1992 with E. margarita Yaginuma 1964; E. japonica Bosenberg & Strand 1906, E. dorsinotata Bosenberg & Strand 1906 and Steatoda albimaculosa (S. Saito 1934) with E. tecta (Keyserling 1884); and E. transversifoveata (Bosenberg & Strand 1906) and E. hangzhouensis Zhu 1998 with E. abrupta (Karsch 1879). Two species names, S. japonica (Donitz & Strand 1906) and S. minus (Donitz & Strand 1906), are nomina dubia.

Winter and early spring CO2 efflux from tundra communities of northern Alaska

Carbon dioxide concentrations through snow were measured in different arctic tundra communities on the North Slope of Alaska during winter and early spring of 1996. Subnivean CO2 concentrations were always higher than atmospheric CO2. A steady state diffusion model was used to generate conservative estimates of CO2 flux to the atmosphere. The magnitude of CO2 efflux differed with tundra community type, and rates of carbon release increased from March to May. Winter CO2 efflux was highest in riparian and snow bed communities and lowest in dry heath, upland tussock, and wet sedge communities. Snow generally accrues earlier in winter and is deeper in riparian and snow bed communities compared with other tundra communities, which are typically windswept and do not accumulate much snow during the winter. These results support the hypothesis that early and deep snow accumulation may insulate microbial populations from very cold temperatures, allowing sites with earlier snow cover to sustain higher levels of activity throughout winter compared to communities that have later developing snow cover. Extrapolating our estimates of CO2 efflux to the entire snow‐covered season indicates that total carbon flux during winter in the Arctic is 13–109 kg CO2‐C ha−1, depending on the vegetation community type. Wintertime CO2 flux is a potentially important, yet largely overlooked, part of the annual carbon cycle of tundra, and carbon release during winter should be accounted for in estimates of annual carbon balance in arctic ecosystems.

Shifts in Mycorrhiza and Microbial Activity along an Oroarctic Altitudinal Gradient in Northern Fennoscandia

Roots of 42 plant species, collected in northern Finland from Carex bigelowii and Salix herbacea rich snowbed communities at four altitudes (600-900 m) above treeline in low and middle oroarctic belts, were examined for mycorrhiza and soil microbial activity. Eight plant species were common and characteristic across the gradient, all together 58 plant species were identified. Colonization percentage was 100 in the four ectomycorrhizal species, of which only S. herbacea characterizes snowbed communities. There was a trend in ericoid mycorrhizal species (all rare) of increased colonization with altitude. Twenty-three species had arbuscular mycorrhiza (AM), nine being heavily colonized, including Gnaphalium supinum and Sibbaldia procumbens, which were typical for snowbed communities. Veronica alpina, also a typical species, was moderately colonized. Average AM colonization varied little from 600 to 800 m, but at 900 m root colonization dropped significantly. This was due to weakly mycorrhizal Cardamine bellidifolia and Festuca ovina, which grew only at higher altitudes. If these two species were excluded, there were no differences in average AM colonization among altitudes, e.g. colonization in G. supinum, S. procumbens, and V. alpina did not differ among altitudes. Seven AM fungal species were identified, none of which has been reported before from the Kiblen mountains in Scandinavia; Acaulospora scrobiculata was the most common. Seven species were nonmycorrhizal (NM), Carex bigelowii and Oxyria digyna being typical for snowbed communities. In addition, there were nine unexamined species which were most obviously NM, judged by related examined species. Basal respiration rate and microbial biomass as well as the metabolic quotient were highest at 700 m altitude, where also AM spore density was highest, and were only about one third at two highest altitudes compared to those at 700 m. Microbial parameters and mycorrhizal colonization did not show any relation with each other.

Shifts in Mycorrhiza and Microbial Activity along an Oroarctic Altitudinal Gradient in Northern Fennoscandia

Roots of 42 plant species, collected in northern Finland from Carex bigelowii and Salix herbácea rich snowbed communities at four altitudes (600-900 m) above treeline in low and middle oroarctic belts, were examined for mycorrhiza and soil microbial activity. Eight plant species were common and characteristic across the gradient, all together 58 plant species were identified. Colonization percentage was 100 in the four ectomycorrhizal species, of which only S. herbácea characterizes snowbed communities. There was a trend in ericoid mycorrhizal species (all rare) of increased colonization with altitude. Twenty-three species had arbuscular mycorrhiza (AM), nine being heavily colonized, including Gnaphalium supinum and Sibbaldia procumbens, which were typical for snowbed communities. Veronica alpina, also a typical species, was moderately colonized. Average AM colonization varied little from 600 to 800 m, but at 900 m root colonization dropped significantly. This was due to weakly mycorrhizal Cardamine bellidifolia and Festuca ovina, which grew only at higher altitudes. If these two species were excluded, there were no differences in average AM colonization among altitudes, e.g. colonization in G. supinum, S. procumbens, and V. alpina did not differ among altitudes. Seven AM fungal species were identified, none of which has been reported before from the Kiölen mountains in Scandinavia; Acaulospora scrobiculata was the most common. Seven species were nonmycorrhizal (NM), Carex bigelowii and Oxyria digyna being typical for snowbed communities. In addition, there were nine unexamined species which were most obviously NM, judged by related examined species. Basal respiration rate and microbial biomass as well as the metabolic quotient were highest at 700 m altitude, where also AM spore density was highest, and were only about one third at two highest altitudes compared to those at 700 m. Microbial parameters and mycorrhizal colonization did not show any relation with each other.