The effectiveness of quadrats for measuring vascular plant diversity

摘要

Quadrats are widely used for measuring characteristics of vascular plant communities. It is well recognized that quadrat size affects measurements of frequency and cover. The ability of quadrats of varying sizes to adequately measure diversity has not been established. An exhaustive search of sixteen 40 by 40 m old field plots documented presence or absence of 88 vascular plant species (mean=58.8 per plot). Against these benchmarks, measurements of species richness were obtained from 50 samples in each plot and compared among three different sized quadrats (0.2 by 0.5 m, 0.5 by 0.5 m and 0.5 by 1.0 m).