imberhe. Uiihiis Cluinuiniionis. liithiis (ircUciis. (jinltiiiniic iiKiirdiilnilhi. Lcihiin jxiluslrr. 

 Drosera rolundifolid. Mt'tu/dnlhrs Iri/blidld. Eriophoium ixu/iiKildiii. Aiulniiiicda polijolia. 

 Ranunculus nuUcans. mikI riricuhirid minor. 



In sloiiy places and on dry sloping; clills I liavc collec-lcd as tlie most cliaiac- 

 lerislic plan Is: 



Agrimonid pilasd. (icnuiiuni lidhcrlidnuni. Asplcniuni sriilfnliioimlr. Wnndsid 

 ilvensis, and Asplenium linla nuiniiia. 



Fig. '6b. ('.liarMilerislic view sout]i of llic Algiiu- Pnss near Ust 



Alginc Picca olnwata and Ihtiiln imhcscciis. with a dense i^round 



vegetation consistinf^ of various licrbs (see text). 



Towards the limit of tree vegetation the hireh is generally first seen to remain 

 hehind, soon followed by the aspen. About 100 m. below the tree limit proper, the 

 spruce and the silver-fir also come to an end, only the cedar, the larch, and rareh. 

 the fir reaching it. The climatic conditions, especially the moisture, seem to be the chief 

 factors in determining which of tliese trees are to reach highest. In drier localities, as 

 for instance on the Tannu-Ola, the larch seemed to be the most persevering one, the 

 fir and above all the cedar, on the contrary, predominating in moister places, for in- 

 stance in the <v,Altaian». The height of the tree limit seemed, for the rest, to vary even in 

 rather neighbouring localities. It is also worth noticing that the tree limit descends east- 

 wards from the Yenisei from a height of about 2200 m. above sea-level to about 1700 lo 

 1800 m. above sea-level near the Algiac Pass, a characteristic trail that has nol ye( been 

 accounted for. Moreover, the tree limit, of course, reaches higher on tlu' south side of 

 the mountains than on the north when upon level terms in other re.spect.s. In the moister 

 parts of the Sayansk district the cedar is, as we have seen, the tree thai climbs higiie.st 

 up on the mountains, some stunted, weather-beaten specimens reaching high up to liic 



Tlic vej^etation 

 al)out tlie tree 

 limit. 



