Dulan can be found on Google earth as Qagan Us @ 36 17 07 N, 98 04 21 E. Tree cover is interesting in the region. Mostly confined to higher mountain slopes, yet near the Dunde region more extensive on the northern slopes than southern.

This is a truly inhospitable region and from the general lack of greenery I would venture that precipitation would be THE deciding factor here. Sand deserts, rocky mountains, rocky plains abd many large salt flats, this region has it all.

It might not be about precipitation only but also about temperature and treelines etc etc..

Wasn’t the Sahara more “green” during Holcene optimum?

Maybee more desert today is a “sign” of a colder Earth?

Finally, here is the location map from Gou et al 2007, which twq proposed to us as evidence that Dulan junipers could be used as a temperature proxy, notwithstanding the explicit statements by Sheppard et al, Shao et al and Zhang et al that Dulan junipers had strongest correlations to temperature.

I assume you meant

Finally, here is the location map from Gou et al 2007, which twq proposed to us as evidence that Dulan junipers could be used as a temperature proxy, notwithstanding the explicit statements by Sheppard et al, Shao et al and Zhang et al that Dulan junipers had strongest correlations to precipitation.

notwithstanding the explicit statements by Sheppard et al, Shao et al and Zhang et al that Dulan junipers had strongest correlations to temperature.

Surely the last word here should be “precipitation”?