Fungal host shifts: bias or biology?

Heilmann-Clausen & Læssøe (2012) have commented that our recent paper (Gange et al. 2011) concerning Auricularia auricula-judae and its apparent expansion in host range, perhaps in response to climate change, is open to question. Instead they suggest that the changes observed may be due more to an alteration in the quality of fungal foraying over time. Here, we provide a comment on fungal foray quality and the problems of comparing results from one sampling regime with another. We follow their suggestion of standardising some of our data and show that A. auricula-judae has exhibited a remarkable change in abundance over time, coincidental with its apparent expansion in host range. Using the same method as Heilmann-Clausen & Læssøe (2012), we show that our host range estimates were reasonable and contend that our sampling regime was robust and as unbiased as possible. We do not claim that climate change is the only driver of the observed changes and agree that further studies need to be conducted which eliminate all bias from disparate datasets.