摘要：Recovery of tall alpine herbfields from livestock grazing and drought were examined using 30, 0.6 × 0.9 m permanent quadrats photographed in 1959, 1964, 1968, 1978, and 2001 in Kosciuszko National Park, southeastern Australia. Cover attributes were assessed using a 130-point grid superimposed over each slide/photograph. For the 18 permanent quadrats near Mount Gungartan, where grazing ceased in 1958, there was a pattern of increasing vegetation cover. Bare areas were initially colonized by herbs, with native grasses, the lateral expansion of existing shrubs, and other herb species eventually replacing the colonizing herbs. For the 12 quadrats near Mount Kosciuszko, where grazing ceased 15 years before the survey, vegetation cover was high (around 94%) in all surveys except at the end of a long drought. The drought caused an increase in litter at both locations as graminoids died back. Graminoid cover recovered relatively rapidly and had reached pre-drought levels by 1978 and remained high. Herb cover was dynamic after the initial recovery from grazing, with a trend for reduced herb cover after 1964. The pattern of recovery from these two types of landscape level disturbances differed due to the different responses of the major life forms to bare ground, litter, and existing vegetation cover. The study also highlights the benefits of existing long-term monitoring programs.
