Observation bias and its causes in botanical surveys on high-alpine summits

摘要

QuestionTo determine long-term vegetation changes in revisitation studies, it is crucial to know how much of measured species turnover over time can be attributed to pseudo-turnover (i.e. turnover caused by imperfect data acquisition), and which factors contribute to observation bias and pseudo-turnover. Independent simultaneous surveys provide a powerful tool to quantify pseudo-turnover and to indentify factors causing it, which may vary strongly between lowland and mountain areas.