In this alternate Earth, there is a clear ecological distinction between trees depending on altitude. The lowlands are exclusive to broad-leaved deciduous trees while conifers can be found only on the cooler, drier highlands. The sole--and MAJOR--exception to this distinction is the Taiga, its close proximity to the Arctic Circle making the crucial materials for forest growth--climate, sunlight and soil--unsuitable for the broad-leaves to take root.
There was a different kind of tree that likely occupied the same niche that the angiosperms would later take--Ginkgophyta, the ginkgo. They used to be a diverse, successful group, but over the millions of years, their numbers got cut and got cut and got cut until, today, only Ginkgo biloba remains.
But does it have to be this way? From what we know, do ginkgoes share the same environmental requirements and advantages as the conifers? Or would a highland coniferous-ginkgous mixed forest be unfeasible?