Plant Diversity Sampling
Plant diversity sampling is used to describe the annual variation of the presence and abundance of plant species at NEON sites.  Plant diversity sampling at SRER is measured once or twice annually around peak flowering.  Plant species composition, presence and abundance data, and estimates of cover are collected within a subset of Tower (n = 3) and Distributed Plots (n=20).  The plot-based method yields plant species data at multiple scales that provides an understanding of changes in composition, distribution, and abundance, of native and non-native plant species.  Plant diversity data are comparable within and across NEON sites and to other continental vegetation efforts to allow for a comprehensive understanding of the impacts of the drivers of change on the diversity of plant species and the functional role they play in ecological systems.  Voucher specimens of twenty to forty of the common species found in the plots will be collected, pressed, mounted, and stored. Voucher specimens provide a permanent record of the NEON naming convention, use of authorities, validation, and a means to track taxonomic naming conventions through time.  Specimens will be collected during peak phenology, and will be pressed, dried, and mounted according to herbaria standards such that species identity can be evaluated in the future.