Suitability of methods for recording species numbers and cover in alpine long-term vegetation monitoring
Friedmann, Barbara; Pauli, Harald; Gottfried, Michael; Grabherr, Georg
Methods of vegetation recording - subplot frequency, point-framing and visual cover estimation - were assessed in terms of their usefulness in high alpine environments, with a focus on their suitability for long-term monitoring programmes. Two of the methods for estimating cover (point-framing and visual estimation) were comparable only for covers above 0.7% in 1 m². For detecting the exact species number, point-framing was unsuitable while the other two methods yielded similar results. The time taken to complete a quadrat varied for each method, with point-framing being the quickest and most unaffected by species number or vegetation cover. When trying to detect change over time and conducting long-term vegetation monitoring, the exact species number of a plot, and similarly the cover of rare and small species are especially important. We suggest therefore that, despite its draw-backs, visual estimation is the most suitable method in alpine vegetation, because it gives a reliable species number, the cover estimation is comparable to point-framing, and it takes less time than subplot frequency.