Spatial knowledge deficiencies drive taxonomic and geographic selectivity in data deficiency

Abstract The uncertain threat status of species inevitably influences their focus on conservation. Just as in extinction risk, the non-randomness phenomenon related to uncertainty (also referred to as selectivity ), which is a certain character cluster in some groupings, also exists in data deficiency of species' knowledge. In order to illustrate this kind of non-random phenomenon and explain the uncertainties it caused, we performed a hypergeometric test on taxonomic and geographic groupings of China's spermatophyte species and quantified two factors— frequency of collections and spatial accessibility — to indicate the primary causes of spatial knowledge deficiencies. We found that selectivity in data deficiency exists both taxonomically and geographically. Fifteen of the families were more deficient than expected, which included 30.0% of species and 56.3% ranked data deficient (DD). Among these, eight families were statistically highly significant with p I  = 0.58, z-score = 27.0, p 2  = 0.879, p