Browsing by Subject "altitude"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Growth Strategy and Population Structure in a Threatened Herb (Neopicrorhiza scrophulariiflora) in Alpine Himalaya(Department of Botany, 2009) Devkota, BalakVariation in growth strategy, plant performance and population structure was studied in a threatened longlived clonal medicinal herb [(Neopicrorhiza scrophulariiflora (Pennell) .Y. Hong)] in relation to altitude and other environmental variables. Seven populations were selected from lower alpine and upper alpine habitats in Walangchung Gola and Ghunsa sectors within Kangchenjunga Conservation Area, East Nepal.The two sectors differ in terms of degree of protection at landscape level (Ghunsa sector being more protected than Walangchung Gola sector) and level of precipitation (higher precipitation in Ghunsa sector). The habitat of N. scrophulariiflora ranged from shrubland to open rocky/scree or grassy slopes on increasing altitude. There were strong geographical (sectorial) and altitudinal differences in the relative contribution of sexual and vegetative growth strategies in population persistence. Altitude was also related to the inter-population variation in other plant performance traits as well as in population size and structure.Sexual allocation and sexual reproductive effort were high in lower alpine populations. As compared to Ghunsa sector (moist sites); populations from alangchung Gola sector (drier sites) produced large-sized genets (except in highly disturbed site). hunsa populations on the other hand showed significantly Variation in growth strategy, plant performance and population structure was studied in a threatened longlived clonal medicinal herb [(Neopicrorhiza scrophulariiflora (Pennell) D.Y. Hong)] in relation to altitude and other environmental variables. Seven populations were selected from lower alpine and upper alpine habitats in Walangchung Gola and Ghunsa sectors within Kangchenjunga Conservation Area, East Nepal. The two sectors differ in terms of degree of protection at landscape level (Ghunsa sector being more protected than Walangchung Gola sector) and level of precipitation (higher precipitation in Ghunsa sector). The habitat of N. scrophulariiflora ranged from shrubland to open rocky/scree or grassy slopes on increasing altitude. There were strong geographical (sectorial) and altitudinal differences in the relative contribution of sexual and vegetative growth strategies in population persistence. Altitude was also related to the inter-population variation in other plant performance traits as well as in population size and structure. Sexual allocation and sexual reproductive effort were high in lower alpine populations. As compared to Ghunsa sector (moist sites); populations from Walangchung Gola sector (drier sites) produced large-sized genets (except in highly disturbed site). Ghunsa populations on the other hand showed significantly large number of flowering ramets per genet than did by Walangchung Gola populations. This shows that at high altitudes and at drier sites, plants tend to invest less in sexual fecundity and more in traits ensuring persistence of vegetative offshoots. Populations from Walangchung Gola sector showed higher proportions of juvenile and vegetative adult ramets, with poor representation of very young and reproductive adult ramets. In highly disturbed populations, proportion of reproductive adult was even greatly reduced. On the other hand, populations from Ghunsa sector showed almost equal proportions of young, juvenile and vegetative adult ramets. Proportion of adult reproductive ramets was also significantly high in Ghunsa populations than in Walangchung Gola populations. This showed that Ghunsa populations were stable in density and self-replacing. The strong relationship between environmental conditions and plant growth strategy, adult performance and population structure of N. scrophulariiflora has important implications for its in situ management. The lower performance of plants (in terms of growth-related traits), and low sexual reproductive efforts in higher alpine sites (especially Walangchung Gola sector) indicate that these populations need immediate action to protect them from illegal and premature harvesting. In such populations management should focus on increasing seedling recruitment and reducing damage to the reproductive adults. Thus long-term plan with a strong measure for sustainable utilization system is needed to manage the target species populations simultaneously respecting traditional access rights of the local users. Extremely low seedling recruitment makes this species highly vulnerable if harvesting is applied at fairly higher level, because in such condition population genetic diversity can be expected to be very low. Thus applying low level of harvesting with fairly long rotation is a good strategy for population persistence. Level of harvesting should be even low in harsh higher alpine habitats of Walangchung Gola sector. Key words: altitude, disturbance, medicinal plant, plant performance, soil variable, sustainable management. large number of flowering ramets per genet than did by Walangchung Gola populations. This shows that at high altitudes and at drier sites, plants tend to invest less in sexual fecundity and more in traits ensuring persistence of vegetative offshoots. Populations from Walangchung Gola sector showed higher proportions of juvenile and vegetative adult ramets, with poor representation of very young and reproductive adult ramets. In highly disturbed populations, proportion of reproductive adult was even greatly reduced. On the other hand, populations from Ghunsa sector showed almost equal proportions of young, juvenile and vegetative adult ramets. Proportion of adult reproductive ramets was also significantly high in Ghunsa populations than in Walangchung Gola populations. This showed that Ghunsa populations were stable in density and self-replacing. The strong relationship between environmental conditions and plant growth strategy, adult performance and population structure of N. scrophulariiflora has important implications for its in situ management. The lower performance of plants (in terms of growth-related traits), and low sexual reproductive efforts in higher alpine sites (especially Walangchung Gola sector) indicate that these populations need immediate action to protect them from illegal and premature harvesting. In such populations management should focus on increasing seedling recruitment and reducing damage to the reproductive adults. Thus long-term plan with a strong measure for sustainable utilization system is needed to manage the target species populations simultaneously respecting traditional access rights of the local users. Extremely low seedling recruitment makes this species highly vulnerable if harvesting is applied at fairly higher level, because in such condition population genetic diversity can be expected to be very low. Thus applying low level of harvesting with fairly long rotation is a good strategy for population persistence. Level of harvesting should be even low in harsh higher alpine habitats of Walangchung Gola sector. Key words:, disturbance, medicinal plant, plant performance, soil variable, sustainable management.Item VEGETATION STATUS, COMPOSITION AND STRUCTURE OF MALIKA FOREST, BAGLUNG, WESTERN NEPAL(Amrit Campus, 2023-08-14) GAIRE, NISHAThere is the importance of structurally diverse forests for the conservation of biodiversity and provision of a wide range of ecosystem services. The frequency, diversity, density, IVI, Carbon stock and soil nutrient factors of two altitudinal range i.e 1600-2000m and 2000-2400m were quantify to investigate the vegetation diversity of Malika Community Forest. Systematic random sampling was applied for vegetation analysis. Circular quadrat method was used in the field for the observation. The altitude wise collected data was divided into two altitudinal range (1600-2400m). Altogether 70 main quadrats were studied from these two altitudes. For Tree species, altogether 140 quadrats (70X2) were laid for shrub species and 210 quadrats (70X3) for herb species were laid. Circular plot of 10m² radius were laid for the study. Number of seedlings and saplings were also recorded within main plot. Community structured was studies by using vegetation quantitative characters (frequency, density, IVI), carbon stock analysis and regeneration. Total 16 soil samples were prepared for laboratory analyses which were collected from center of each quadrat. For soil analysis both physical as well as chemical parameters like the N, P, K, soil pH, organic matter and soil texture of the soil were tested. In the present study, the tree species diversity decreased from lower to highest altitudes. Between two altitudinal range, the highest frequencies among shrubs was of Rubus ellipticus in lower altitude and of Prunus sp in upper altitude whereas Artemisia indica and Cynodon dactylon which was 34% in lower altitude whereas Stellaria media and Cyperus rotundus has highest frequencies (42%) in upper altitude among herbs and highest frequency was of Pinus among trees. The highest diversity was found among herbs species i.e H=2.97 in low altitudinal range whereas highest diversity in shrubs species in upper altitudinal range of 2000-2400m i.e, H=2.66. In the studied area the highest IVI for herbs was of Stellaria media, Arisaema toftuosum, Ageratina adenophora. Dicranopteris and for shrubs the highest IVI was of Lyonia ovalifolia and Rhus javanica. Among the tree species Pinus roxburghii scored highest IVI recorded as from 2000-2400m. The density of seedlings and saplings of P. roxburghii were highest in both altitudes. The highest carbon stock was reported in P. roxburghii. The tree and shrub species richness increased from lower to higher altitudes.