Climate change perils for dioecious plant species.

Climate change, particularly increased aridity, poses a significant threat to plants and the biotic communities they support. Dioecious species may be especially vulnerable to climate change given that they often exhibit spatial segregation of the sexes, reinforced by physiological and morphological specialization of each sex to different microhabitats. In dimorphic species, the overexpression of a trait by one gender versus the other may become suppressed in future climates. Data suggest that males will generally be less sensitive to increased aridity than co-occurring females and, consequently, extreme male-biased sex ratios are possible in a significant number of populations. The effects of male-biased sex ratios are likely to cascade to dependent community members, especially those that are specialized on one sex.