Poa Alpina Research Articles

Native Grass Cultivars for Multiple Revegetation Goals on a Proposed Mine Site in Southcentral Alaska

AbstractNative grasses may be used for multiple, sometimes conflicting, goals in revegetation projects. Woody plants are frequently desired for moose browse and timber in Alaska, but naturally occurring Calamagrostis canadensis (bluejoint reedgrass) hinders the establishment of these desired species. Seven grass cultivars of Alaskan origin were evaluated for their ability (1) to stabilize the soil, (2) to reduce regeneration of C. canadensis, (3) to allow openings for natural colonization, and (4) to permit establishment of desirable rooted cuttings. Cultivars tested are “Arctared” Festuca rubra (red fescue), “Alyeska”Arctagrostis latifolia (polar‐grass), “Nugget”Poa pratensis (bluegrass) “Norcoast”Deschampsia beringensis (Bering hairgrass), “Nortran”Deschampsia caespitosa (tufted hairgrass), “Gruening” Poa alpina (alpine bluegrass), and “Sourdough” Calamagrostis canadensis. These were tested as single species and in multi‐species mixtures, with two seeding rates of the multi‐species mixture (0.5, 0.25 seeds/cm2). Experimental plots included unfertilized, unfertilized with rooted Salicaceae cuttings, and fertilized (350 kg/ha 20:20:10). A control plot was not seeded. After three growing seasons, Nortran D. caespitosa and Arctared F. rubra were the most successful cultivars. They provided 87% to 98% of the seeded‐species cover for soil stabilization and suppressed C. canadensis on the fertilized subplots without reducing species diversity. Gruening Poa alpina was less than 3 cm tall, and it helped stabilize the site without interfering with woody plant establishment. Although cuttings were shorter under some seed treatments compared to the nonseeded control, heights of cuttings were not related to cover of seeded cultivars (r = 0.09, p > 0.55) but were positively correlated with total vascular plant cover (r= 0.61, p < 0.001).

Effects of elevated carbon dioxide on three grass species from montane pasture II. Nutrient uptake, allocation and efficiency of use

Agrostis capillaris L. 4 , Festuca vivipara L. and Poa alpina L. were grown in outdoor open-top chambers at either ambient (340 μmol mol -1 ) or elevated (680 μmol mol -1 ) CO 2 for periods from 79 to 189 d. Under these conditions there is increased growth of A. capillaris and P. alpina, but reduced growth of F. vivipara. Nutrient use efficiency, nutrient productivity (total plant dry weight gain per unit of nutrient) and nutrient allocation of all three grass species were measured in an attempt to understand their individual growth responses further and to determine whether altered nutrient-use efficiencies and productivities enable plants exposed to an elevated atmospheric CO 2 environment to overcome potential limitations to growth imposed by soil fertility

Effects of elevated carbon dioxide on three montane grass species

Upland grasslands are a major component of natural vegetation within the UK. Such grasslands support slow growing relatively stable plant communities. The response of native montane grass species to elevated atmospheric carbon dioxide concentrations has received little attention to date. Of such studies, most have only focused on short-term (days to weeks) responses, often under favourable controlled environment conditions. In this study Agrostis capillaris L. 5 , Festuca vivipara L. and Poa alpina L. were grown under semi-natural conditions in outdoor open-top chambers at either ambient (340 μmol mol -1 ) or elevated (680 μmol mol -1 ) concentrations of atmospheric carbon dioxide (CO 2 ) for periods from 79 to 189 d, with a nutrient availability similar to that of montane Agrostis-Fescue grassland in Snowdonia, N. Wales

Salt stress tolerance in native Alberta populations of slender wheatgrass and alpine bluegrass

Alpine bluegrass [Poa alpina L.] and slender wheatgrass [Elymus trachycaulus (Link.) Gould ex Shinners] accessions from alpine and subalpine regions of the Canadian Rocky Mountains and eastern foothills were tested for tolerance to salinity stress. Accessions with higher emergence (%) than salt-tolerant Orbit tall wheatgrass [Thinopyrum elongatum (Host) D. R. Dewey, comb, nov.], after 21 d in vermiculite saturated with a NaCl-salinized half-Hoagland solution (electrical conductivity 15 dS m−1) and nurtured in growth cabinets set to repeat 20/15 °C day (16-h)/night temperatures, were considered tolerant of salt-stress. This test identified 72 alpine bluegrass and 11 slender wheatgrass salt-tolerant accessions. Most of these accessions originated from two specific sites near the Alberta-British Columbia border. Slender wheatgrass accessions tolerant to NaCl were also tolerant to the other salts commonly found in Alberta soils. In slender wheatgrass, the ability to emerge in a salinized nutrient solution had moderate heritability (61–68%), suggesting the possibility of genetic improvement through selection.Key words: Salt tolerance, selection, heritability, alpine bluegrass, slender wheatgrass

Influence of maternal plant environment and provenance on alpine bluegrass seed germination

Adequate restoration of alpine disturbances requires seed material capable of germinating in high proportions and at a rapid rate. Germination of alpine bluegrass (Poa alpina L.) seeds of different provenances and produced under different environmental conditions was compared under uniform conditions of 16/8 h cycles of light/dark and 22/15 °C temperature. Seeds from nursery plots at the Alberta Environmental Centre, Vegreville, germinated in significantly higher proportions and faster than seeds from the same accessions grown in alpine environments. Alpine bluegrass clones grown in controlled environment chambers set at 22/15 °C and 15/8 °C light/dark with a 16-h photoperiod produced seeds with higher rates of germination and greater cumulative germination than seeds produced in an 8/1 °C regime. It is suggested that alpine blue-grass seeds with high germination percentage and rates are best produced under prairie nursery conditions.Key words: Alpine bluegrass, Poa alpina L., seed germination, maternal environment

Registration of ‘Gruening’ Alpine Bluegrass

Registration of ‘Gruening’ Alpine Bluegrass

Long day stimulation of dry matter production in Poa alpina along a latitudinal gradient in Norway

Photoperiod extension with weak include from 8 to 24 h stimulated relative growth rate (RGR) of Poa alpina up to 20%. The response was greatest in young plants at low temperatures. The leaf area ratio (LAR) increased by about 50% which more than compensated for a reduction in net assimilation rate (NAR) by about 20%. The effect of daylength extension on RGR was similar for an arctic ecotype of P. alpina from Svalbard, an alpine ecotype from southern Norway and a borealtemperate ecotype from southern Norway. The main changes in the growth parameters occurred over the 13 to 17 h photoperiod range in P. alpina from both Svalbard and Rondane, although plants at Svalbard are exposed to midnight sun throughout their growing season. The ecotype of P. alpina from southern Norway had fewer tillers and allocated less dry matter to the roots than the two other ecotypes.

Exposure of two upland plant species to acidic fogs

A system is described for exposing large numbers of plants to acidic fogs. The system allows low volumes of treatment solutions to be provided at particle sizes chiefly in the 5–30 μm range (equivalent to fog/cloud droplets). Plants of Poa alpina L. and Epilobium brunnescens were propagated from material collected in Snowdonia, North Wales and exposed to fog treatments at pH values of 2·5, 3·5, 4·5 and 5·6. There were 3 × 4 h exposures per week which provided a total of 6 mm deposition. Supplementary watering was with pH 4·5 simulated acid rain (24 mm per week). After 21 weeks, there was increased lowering and a greater dry weight for plants of E. brunnescens exposed to the pH 2·5 fog in comparison with other treatments. Also, the plants used assimilated material to form shoots rather than roots. A similar increase in dry weight accumulation in the pH 2·5 treatment was found in P. alpina after 63 weeks but this was not associated with changes in assimilate partitioning.

GERMINATION RESPONSE OF TWO ALPINE GRASSES FROM THE ROCKY MOUNTAINS OF ALBERTA

Germination studies on alpine bluegress (Poa alpina L.) and broad-glumed wheatgrass (Agropyron latiglume Scribn. and Smith [Rydb.]) were undertaken to determine optimum germination conditions, the presence of seed dormancy and the extent of variability among populations for rapid germination. Poa alpina seeds germinated best under darkness and 16/8 h cycles of 22/15 °C temperature, while A. latiglume needed a 29/22 °C regime and darkness for best germination. Rapid germination in both species occurred within a narrow range of temperature conditions. Light and suboptimal temperatures appeared to have an inhibitory effect on seed germination during the initial period of imbibition. Germination inhibition through external factors (secondary dormancy) and the presence of primary dormancy in the nursery-grown seeds may be a genetic adaptation to stressful alpine environments. This and the differences among populations for seed germination in both species are encouraging for our breeding program which is developing genotypes for alpine and subalpine reclamation.Key words: Alpine bluegrass, broad-glumed wheat grass, temperature effect, light, population, seed germination.

Environmental Control of Flowering and Viviparous Proliferation in Seminiferous and Viviparous Arctic Populations of Two Poa Species

Inflorescence initiation and development in viviparous Poa alpina L. and seminiferous and viviparous Poa alpigena (Fries) Lindman from Svalbard have been studied in controlled environments. A dual induction requirement was found in all plant types with pronounced effects of photoperiod and temperature. Floral primordia were initiated in short days (SD) at temperatures up to 18?C, while at low temperatures (3 to 6?C) long days (LD) were equally effective. Normal culm elongation and panicle development were dependent on LD (> 17 h), although a few abnormal or stunted panicles were formed in SD as well, with high temperature partially substituting for long photoperiods. In the seminiferous form of P. alpigena (ephemeral) proliferation was induced by marginal induction (primary and secondary) and it was especially stimulated by SD during inflorescence development. In the habitually viviparous plants mixed inflorescences with a high proportion of sexual flowers were induced by saturating induction, primary and secondary induction acting additively. Long days (LD) and high temperature during inflorescence development were especially conducive. Comparison with other temperate perennial grasses are made and the adaptive value of these responses in the arctic environment is discussed with the literature in the field.

Pollen assemblage–plant community relationships on the Storbreen glacier foreland, Jotunheimen Mountains, southern Norway

SUMMARYPresent‐day pollen assemblages from 38 sites within differing but closely juxtaposed plant communities from the Storbreen glacier foreland in southern Norway, provide evidence for the degree to which these plant communities can be characterized by distinctive pollen assemblages. Multivariate statistical analyses of the data demonstrate a broad, tripartite division in the pollen record which reflects the three major vegetation types: (i) Pioneer Poa alpina–Trisetum spicatum community; (ii) Snowbed Salix herbacea‐dominated community; (iii) Dwarf‐shrub heath community. Occasional overrepresentation of Salix, Oxyria and Cyperaceae pollen leads to assemblages that are difficult to characterize and remain outside all major groups. Four general pollen indices are derived, each of which provide maximum limiting estimates for the proportion of pollen derived from different potential source areas. Combined with isopollen mapping the indices suggest that in pioneer communities between 20–40% of pollen collected within the community could have derived locally i.e. within the 16 m2 quadrat, whereas in the dwarf‐shrub heath this figure rises to over 60%. The remaining pollen largely originates from long distance transport, i.e. < 1 km, with little movement of foreland‐derived pollen across the foreland itself. Thus the ‘extra‐local’ component appears to play a relatively insignificant role within the area of study. The ability to separate such local and long‐distance elements will prove of particular value in the reconstruction of the history of plant communities beyond the tree‐line.

Leaf anatomy of alpine plants as related to altitudinal stress

Alopecurus gerardi, Poa alpina, and Carex curvula are spontaneous, perennial forage plants distributed in the high elevation (2300–3200 m) pasture lands of Piedmont and Valle d'Aosta (Italy). Sedum atratum is an annual succulent which grows at elevations up to 3200 m. The three monocotyledons have, in comparison with corresponding plants from the low‐land, peculiar organographic and anatomic structures such as curling leaf lamina, vascular bundle sheath layer with chloroplasts arranged in a centrifugal fashion, low stomatal density (stomata number/cm2: upper epidermis x̄= 0–11.9; lower epidermis x̄= 7.66–11.55), thick cuticles, as well as higher values of S (H2O; g/dm2; x̄= 0.6–0.32), Sm (H2O g/mg Chi.; x̄= 0.11–0.16), SLW (g f. wt/dm2; x̄= 0.86–1.36), but lower SLA values (cm2/g f. wt; x̄= 75.07–116.77). All these data are correlated to water stress. Even though the leaf lamina anatomy possesses some features typical of C4 plants, the presence of starch grains in the mesophyll chloroplasts indicates that these plants are probably C3 ones.In spite of high values of thylacoid grana/thylacoid intergrana ratios, typical of shade plants (mesophyll chloroplasts: x̄ up to 3.81; bundle sheath chloroplasts: x̄ up to 5.3), and Chi a/Chl b ratios (x̄ up to 4.23 in C. curvula), the apparent absence of peroxisomes seem to indicate a very efficient dark phase of photosynthesis. S. atratum, in comparison with the typical CAM succulents, which live in dryer and warmer habitats, has a higher values of stomatal density (upper epidermis, x̄= 2.59; lower epidermis, x̄= 3.15) and of SLA (x̄= 24.98), but lower S (x̄= 3.83), Sm (x̄= 1.19) and SLW (x̄= 4.15).

Reproductive Response to three Temperature Regimes of four Poa Alpina Populations from The Rocky Mountains of Alberta, Canada

The effects of temperature and population origin on the reproductive response of Poa alpina L. tussocks from the Rocky Mountains of Alberta were investigated. Clones from four tussocks (samples) collected from two alpine and two subalpine environments were tested simultaneously in growth chambers using three temperature regimes (8/1°C, 15/8°C, 22/15°C, light/dark) with a 16-h photoperiod. Eight reproductive traits were observed on each clone. Normal panicles were present in all the clones tested at the 8/1°C temperature, while at the 15/8°C and 22/15°C temperatures the reproductive structures were mainly abnormal, viviparous, or nonexistent. At the low temperature regime the clones from the high alpine environment (elevation 2700 m) had more florets and seeds per panicle than the clones from the low subalpine environment (elevation 1480 m). In the 15/8°C and 22/15°C regimes this relationship was reversed, suggesting temperature-specific adaptation in the tested samples. The effects of sample and sample-te...

Reproductive Response to Three Temperature Regimes of Four Poa alpina Populations from the Rocky Mountains of Alberta, Canada

Reproductive Response to Three Temperature Regimes of Four Poa alpina Populations from the Rocky Mountains of Alberta, Canada

Natural Reestablishment of Mycorrhizae in Disturbed Alpine Ecosystems

Vesicular-arbuscular mycorrhizal fungi were surveyed in several successional areas of the Beartooth Mountains in Montana. Roots were examined for percentage of mycorrhizal infection, and spores were counted in rhizosphere soils from undisturbed, - 25-yr-old seral, and 3- and 7-yr-old revegetated areas in 1983 and 1984. The three most abundant grasses of early seral areas, Deschampsia caespitosa, Agropyron trachycaulum, and Poa alpina, showed similar patterns: spore counts and percent infection of these species were generally higher in undisturbed than seral and revegetated areas in 1983, but in 1984 the spore numbers and infection were similar because the values dropped in undisturbed areas and increased in the other areas. Patterns of mycorrhizal infection varied for the other species, and Geum rossii, a late seral dominant, was heavily colonized by an unidentified nonendogonaceous fungus. Plant colonization is slow in the alpine, but once plants are established, mycorrhizal fungi apparently colonize quickly. Even the 3-yr-old revegetated area had infection equal to some of the undisturbed areas. However, only a single mycorrhizal fungal species was obtained from the revegetated areas, in contrast to more than 11 species from older areas.

Ecological characteristics of 35-year-old crude-oil spills in tundra plant communities of the Mackenzie Mountains, N.W.T.

In June 1945 the CANOL Crude Oil Pipeline No. 1 from Norman Wells, Northwest Territories, to Whitehorse, Yukon Territory, was abandoned. During its short history, approximately 17 838 500 L of oil was lost through spills and 9 864 400 L was left in the line and storage tanks. Although some burning was done during salvage operations, most residual oil was drained onto the soil surface. Studies in alpine tundra indicate that this oil penetrated up to 60 cm in dry, coarse-textured soils and 8 cm in wet, clay-rich soils. Oil decomposition ranged from complete utilization of n-alkanes to selective metabolism of n-alkanes C12 to C19. Contaminated soils were drier than control soils. This, plus surface blackening and thinning or organic surface layers, resulted in subsurface warming. Floristic similarity coefficients comparing control sites and 27 crude-oil spills varied from 19 to 52. Plant cover was substantially lower on oil spills and in only one community was floristic diversity greater on oil spills than on associated control sites. Dominant colonizers included Cladonia pocillum, Cladonia pyxidata, Rinodina roscida, Carex aquatilis, Carex membranacea, Carex scirpoidea, Epilobium angustifolium, Eriophorum angustifolium, Festuca altaica, Juncus albescens, Poa alpina, Salix planifolia, Solidago multiradiata, and Trisetum spicatum.

Vivipary, a Reproductive Strategy in Response to Environmental Stress?

The occurrence of vivipary as a reproductive strategy in arctic and alpine plants is discussed with special reference to the viviparous grasses, and in particular to the ecology of Festuca vivipara (L.) Sm. There are considerable differences between the seeds and plantlets of closely related species of seminiferous and viviparous grasses apart from those of morphology and weight. F. vivipara plantlets had a higher nutrient capital than F. ovina L. seeds, and in contrast to seeds, contained predominantly low molecular weight organic reserves. 25% of the dry weight was in the form of soluble carbohydrates. On germination, the content of the soluble carbohydrate and amino acids changed little, unlike the large changes observed in seeds. Developing plantlets of F. vivipara increased in dry weight throughout the season until culm collapse. In the early stages of growth, the plantlets were non-viable as independent propagules, but 89% of plantlets were non-dormant and capable of germination immediately prior to culm collapse. In contrast Poa bulbosa L. plantlets reached a stable dry weight, and the bulbils were dormant at dehiscence. The establishment of F. ovina and F. vivipara propagules from neighbouring populations in the English Lake District was compared in experiments not involving competition between the two species. Despite the larger weight of the plantlets, a slower initial growth rate of F. vivipara plants resulted in larger plants of F. ovina at the end of the experiments. No such slow initial growth rate was observed with Poa alpina L. var. vivipara L. In a competition experiment the growth of the viviparous species Deschampsia alpina (L.) R + S, Poa alpina var. vivipara and F. vivipara was less adversely affected than that of closely related seminiferous species. F. vivipara plantlets became water-stressed in the field as demonstrated by a large increase in proline content, whereas the leaves of the parent plants did not. Developing plantlets of other viviparous grasses showed similar large increases in proline content, and it is proposed that a major cause of the restriction of these species is the desiccation of both developing and dehisced plantlets. The success of vivipary in arctic and alpine habitats is discussed in terms of the variety of dispersal mechanisms and the problems of establishment and growth in the short, cold growing seasons of these regions.

Determinants of Spatial Distribution of Rocky Mountain Bighorn Sheep

Determinants of Spatial Distribution of Rocky Mountain Bighorn Sheep

The Effect of Cell Elongation on Leaf Anatomy of Poa alpina

The hypothesis (Slade 1957) that the larger cells and intercellular spaces in the spongy mesophyll and the wider spacing of veinlets in leaves grown in deep shade might be due to differences in cell extension rather than in meristematic growth has been tested on leaves from Poa alpina plants in which cell extension has been stimulated by shade and/or gibberellin. Increase in leaf length in treated plants was always associated with increases in cell length and in distance between commissural veins and with greater longitudinal extension of the cells and intercellular spaces in the mesophyll. These changes occurred at the expense of increase in girth of both cells and intercellular spaces, the overall effect being reduction in thickness of the leaf blade. There were no significant differences in the number of cells separating successive commissural veins in treated and untreated leaves; so the greater spacing of these veins in shaded or gibberellin-treated leaves is due to greater extension of cells and int...

Accessory chromosomes in Poa alpina

Accessory chromosomes in Poa alpina