The botanist effect: counties with maximal species richness tend to be home to universities and botanists

Aim  To investigate the distribution of local flowering plant species richness in areas surrounding American universities.
Methods  Species richness in university counties was compared with neighbouring counties. Data were derived from Synthesis of the North American Flora ( http://www.phylosystems.com/prepublication ). Probabilities of the resultant distribution were calculated, and the results were also simulated.
Results  In almost every case there were more species reported in the university county than in its neighbours. Several possible explanations were considered. We conclude that the key element is the presence of botanists in these counties who have, apparently, paid more attention to plants near at hand, and found more species of them there.
Main conclusions  Ecologists must be aware that numerical data that appear very solid, collected over many decades, may represent not only the qualities of 'nature' but also something of the collectors of the data.