Why we still need permanent plots for vegetation science

The use of permanent plots has a long tradition in ecology (Callahan, 1984; Wildi and Schültz, 2000; Lindenmayer et al., 2012; Hughes et al., 2017) and vegetation science (Bakker et al., 1996a). Recently, permanent‐plot studies were considered among the six most important developments in vegetation science (Chytrý et al., 2019). As the present Special Feature demonstrates, the value of permanent plots is becoming ever more evident as a growing number of available time series highlights the variability inherent in plant communities and the non‐linear ways in which community composition and function respond to global change. In a previous Special Feature in Journal of Vegetation Science edited by Bakker et al. (1996a), different contributors showed the importance of permanent plots in understanding the mechanisms underlying vegetation changes, particularly following succession. Bakker et al. (1996a) used the term ‘permanent plots’ broadly to ‘include studies in which a series of randomly located plots or transects have been described at certain time intervals within a fixed area’. Such permanent plots are thus based on regular observation of the temporal dynamics of vegetation using sampling units with a fixed location in time, while the sampling approach is kept consistent.