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 drawbacks, 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.