Introgression between Betula tianshanica and Betula microphylla and its implications for conservation

Abstract

In rapidly changing environments species conservation can be hindered by uncertainties in distinguishing closely related species. Cryptic ongoing hybridization can add further uncertainty and could be beneficial or destructive. Here, we show that a declining birch tree species is hybridizing with a more widespread relative in the Junggar basin, NW China, and their hybrids have been previously named as rare sub‐species. Given the declining numbers of this birch tree, we suggest that conservation effort should aim to slow the rate of anthropogenic habitat loss at this hybrid zone and preserve its pure populations away from the hybrid zone.