BTW, the reason no trees of that size grow along the Kolmya river any longer is quite simple ~ IT GOT COLDER, the storms got stronger, the trees and the dirt they grew in was washed right off the sides of the hills, and new trees of the same type cannot thrive there.
thanks, found it.
Abstract
A 538-yr tree-ring chronology and reconstruction of June temperatures were developed from living and dead Larix dahurica trees. The samples were obtained near the lower Lena River in northern Siberia. Dendrochronological techniques were used to estimate the ages of establishment and mortality of Larix dahurica on the presently treeless uplands and to determine the establishment dates of living trees in the lowlands. The 20th century may have experienced the greatest prolonged period of high June temperatures over the past 538 yr. In contrast the greatest prolonged period of cold appears to have occurred during the first half of the 19th century. It was during the 19th century that the uplands lost much of their tree and soil cover. Recruitment of trees occurred in the lowlands during the 20th century, but trees have not been able to recolonize the uplands, possibly due to the lack of suitable soil.
http://www.jstor.org/pss/1552005