Characteristics of life-form and growth-form of plant species in an alpine ecosystem of North-West Himalaya

摘要

The present study was conducted in the alpine pastures of Tungnath (30° 14′N and 79° 13′ E) to observe life-form and growth-form patterns of alpine plant species under grazed and ungrazed conditions and to work out the plant life form spectrum.Species were categorized as plant habit,height and length of growth-cycle and life-form classes according to Raunkiaer's system.The results show that in total of 68 species at grazed site,hemicryptophytes (He) accounted for 50.00%species,followed by cryptophytes (26.47%),chamaephytes (16.18%),phanerophytes (4.41%) and therophytes (2.94%).At the ungrazed site in 65 plant species,hemicryptophytes (He) accounted for 49.23% species,cryptophytes (26.15%),chamaephytes (15.38%),phanerophytes (6.15%)and therophytes (3.08 % species).In general,hemicrptophyte are dominant in both sites i.e.graged and ungrazed.Growth form categories were classified as forbs,shrubs,grasses and sedges and undershrubs,according to plant habit and height.On the basis of length of the growth cycle,species were categorized as plant species of short growth cycle,intermediate growth cycle and long growth cycle.The short forbs of plant habit and height,had the highest emergence,and grasses and sedges had the lowest emergence in representative species.Percentage of species with long growth cycle was highest in both sites.