Forbes, B.C., Fauria, M.M. and Zetterberg, P. 2010. Russian
Arctic warming and 'greening' are closely tracked by tundra
shrub willows. Global Change Biology 16: 1542-1554. Remote
sensing data suggest that tundra vegetation in North America may
be responding to recent warming via enhanced photosynthetic
activity (Goetz et al., 2005; Verbyla , 2008), and the authors
write that "at a circumpolar scale, the highest photosynthetic
activity and strongest growth trends are reported in locations
characterized by erect shrub tundra (Reynolds et al., 2006),"
noting that "live leaf phytomass from deciduous shrubs, shown to
have increased in northern Alaska during the second half of the
last century (Sturm et al., 2001; Tape et al., 2006), is
believed to be a key driver of the observed trends (Jia et al.,
2003; Goetz et al., 2005; Verbyla, 2008)." What was done Working
with Salix lanata L. (sensu latu) -- an abundant deciduous
dioecious willow with nearly circumpolar geographic distribution
from the northern boreal fores