Quantitative analysis of sub-alpine grasslands in trans-Himalayan region of Manang, central Nepal

Species composition and richness of grassland vegetation were studied in trans-Himalayan region of Manang. Two south-facing sites, both at the similar altitude (3800-4200 m asl), were selected and a total of 40 plots (10 x 10 m) with 200 quadrates (1 m x 1 m) were sampled. Altogether, 97 plant species were recorded. The similarity index between two sites was 12.37%. There was significant negative correlation between species richness and altitude in site I. Species richness did not show significant relationship with altitude in site II. Various physical and biological factors interact differently in different sites to create habitat heterogeneity which determine the distribution pattern of plant species and influence variations in species composition and diversity. Key-words: alpine region; quantitative analysis; species diversity; vegetation.DOI: 10.3126/botor.v6i0.2910 Botanica Orientalis - Journal of Plant Science (2009) 6: 47-51

AEC Glacier alpine bluegrass

AEC Glacier alpine bluegrass, Poa alpina L., is a reclamation cultivar developed for use in reclaiming and revegetating disturbed sites at high elevations. It is the second alpine bluegrass cultivar released by the Alberta Environmental Centre, Vegreville, AB. This cultivar is expected to complement a prior release, AEC Blueridge alpine bluegrass. AEC Glacier is adapted to high elevations where it is capable of rapid growth and seed production. Key words: Alpine bluegrass, Poa alpina, cultivar description, reclamation

Pollination, capsule damage, and the production of seeds in Salix setchelliana (Salicaceae), an Alaskan glacial river gravel bar willow

Salix setchelliana, a clonal prostrate willow, is a dominant species of glacial river gravel bars in Denali National Park, Alaska. This habitat, which is located between migrating river channels, is unpredictable in time, patchy in space, and essentially alpine in nature. The species takes advantage of both entomophily and anemophily, thus perhaps improving its success under these conditions. It is dependent primarily on insect pollination, carried out by a variety of species, but wind pollination accounted for 7–25% of seed production. The number of seeds per capsule was much below the potential maximum. Seed prédation, and probably insufficient pollination, influenced seed production. Prédation accounted for a 70% reduction in seed production per capsule in an open pollination treatment (P = 0.005). There were significant differences in number of seeds per capsule between collection sites (P = 0.0022). An inverse relationship was observed between seed predation levels and seed numbers in both insect-damaged and undamaged capsules. Key words: alpine, clonal, pollination, seed prédation.

Seed germination, seedling demography, and growth of Salix setchelliana on glacial river gravel bars in Alaska

This study examines the recruitment from seed of Salix setchelliana Ball, a prostrate clonal willow, which grows in the gravel-bar habitat of glacial rivers in Denali National Park, Alaska. Seeds of this species did not exhibit any dormancy. Under laboratory conditions, seeds moistened immediately after collection showed 100% germination, and percent germination decreased with an increase in the length of dry storage. Since summer precipitation is generally frequent in this region, this is probably not a factor limiting recruitment. Most seedlings observed in the field were located on gravel bars with greater plant cover, as opposed to those with sparse plant cover. The survivorship of seedlings over their first winter averaged 11%; in comparison, yearly survivorship in years 1–6 averaged 69%. The most likely cause of mortality was insufficient carbohydrate accumulation. Seedling leaf area differed between years and locations. An inverse relationship was found between leaf area and age-class for seedlings of younger age-classes. Key words: alpine, clonal, recruitment.

Pollination in alpine Norway: flowering phenology, insect visitors, and visitation rates in two plant communities

Pollination studies in European alpine communities are few. The objective of this study was to describe the pollination ecology in two alpine plant communities at Finse, southwestern Norway. Because of late snowmelt and early winter at Finse, the time available for flowering and seed maturation is restricted. Flowering was concentrated at the beginning of the season in both communities, and large overlaps in flowering time were found for most species. In one of the communities, flowering peaks were significantly clumped, whereas in the other they were randomly distributed through the season. However, in this community, five insect-pollinated species flowered simultaneously early in the season. Diptera almost exclusively dominated the visitor assemblage. Most plant species pairs had high overlaps in flower visitor species. Species flowering simultaneously attracted the same visitor species. In one community, eight species pairs flowered sequentially and shared visitors. Visitation rates were highest at the lowest elevated site. The results are compared with those obtained in other alpine areas. It is argued that selection for an early flowering is probably stronger than selection pressures resulting from interspecific interactions. Key words: alpine, Diptera, flowering phenology, flower visitors, season length, visitation rate.

Size and shape of Carex meyeriana tussocks in an alpine wetland, northern Sichuan Province, China

To determine the morphological characteristics of Carex meyeriana tussocks, surveys were conducted in a large alpine-grassy marshland (3430 m elevation) in northern Sichuan Province, China. While tussocks did not exceed 26 cm in height, the basal area of tussocks continually expanded. Mature tussocks sometimes resulted in aggregation of tussocks. Carex meyeriana rarely developed long horizontal rhizomes and produced shoot rhizomes that led to the development of bell-shaped tussocks as a result of basal shoot (tiller) development patterns. Equisetum limosum invaded and grew in immature tussocks, while Potentilla anserina and Chamaesium paradoxum invaded the tussock summits. From the sequence of those cohabitants, the upper parts of tussocks were gradually invaded with various species. Key words: alpine wetland, Carex meyeriana, China, cohabitant, morphology, tussock.

Effect of snow-free duration on leaf life-span of four alpine plant species

Leaf life-spans and specific leaf weights of four plant species, Phyllodoce aleutica, Rhododendron aureum, Sieversia pentapetala, and Potentilla matsumurae were compared along a gradient of decreasing snow-free duration in alpine snow beds. Life-span was obtained by observation from emergence to senescence for deciduous plants and was estimated from leaf age distributions for evergreen plants. Along the gradient, the evergreen shrubs Ph. aleutica and R. aureum had extended leaf life-spans, whereas the deciduous shrubs S. pentapetala and the deciduous herb Po. matsumurae had reduced leaf life-spans. Specific leaf weights, obtained by dry weight per unit leaf area, increased in Ph. aleutica but decreased in S. pentapetala and Po. matsumurae along the gradient. These phenomena are considered adaptive adjustments for maintaining a positive carbon balance under the conditions of limited photosynthetic season. Key words: alpine snow bed, carbon balance, deciduous plants, evergreen plants, leaf life-span, specific leaf weight.

Endophytic fungi from the mycorrhizae of alpine ericoid plants

Strains of a slow-growing, sterile, darkly pigmented fungus were obtained from alpine mycorrhizae of the Alberta Rocky Mountains. Sporulating isolates of this fungus from the roots of Cassiope mertensiana and Arctostaphylos uva-ursi (Ericaceae) as well as from Luetkea pectinata (Rosaceae) were identified as Phialocephala fortinii. Axenic cultures of Menziesia ferruginea (Ericaceae) seedlings were grown with P. fortinii for characterization of the fungus–root association. Typically, dark, simple septate hyphae form extensive wefts on the root surface and produce intracortical sclerotia of compact, darkly pigmented and irregularly lobed, thick-walled hyphae. Intracellular coils are not produced. This association differs from the ericoid mycorrhizal type and represents a fungus–root association that is common in alpine plants. In addition, several isolates of Oidiodendron griseum, a species previously reported from mycorrhizae of ericaceous plants, were found to form intracellular coils within the cortical root cells of Loiseleuria procumbens (Ericaceae). Key words: alpine mycorrhizae, Ericaceae, Phialocephala fortinii, Oidiodendron griseum.

The frequency and relationship of flowering plants on the distribution pattern of Ophiocordyceps sinensis (Yarchagunbu) in the highlands of Dolpa district, Nepal

Ophiocordyceps sinensis (Berk.) G.H. Sung, J.M. Sung, Hywell-Jones & Spatafora is a highly valuable medicinal fungus. Biologically it is an entomopathogenic, entomophagous or entomophilous fungus. In order to investigate different floral associations with O. sinensis, and to know different threats to pasture biodiversity, research was conducted in three pastures of Raha and Majphal Village Development Committees of Dolpa district. The study revealed that Juncus thomsonii and Bistorta macrophylla were the principal plant associates with O. sinensis as they dominated the alpine pasture vegetation. This research also highlighted the need for some proactive solutions along with conservation awareness program as important management initiatives to ensure ecological balance of O. sinensis. Key words: Alpine zone, flora, Ophiocordyceps sinensis, pasture management, Yarsagumba doi: 10.3126/banko.v19i1.2180 Banko Janakari, Vol. 19, No. 1, 29-36