Results of the 60-years experience of unique geographical larch plantings

The results of the comparative study on the growth of the four larch proveniences in geographic cultures of 60 years old on the territory of the Forest Experimental Garden of the Russian State Agrarian University (Moscow Timiryazev Agricultural Academy), including Scottish form of Larix decidua, Polish subspecies of L. decidua, L. sibirica and L. broad-scaly (L. decidua and L. kaempferi hybrid) are presented. The range of coverage of the geographical location of the most distanced provenience is more than 5.5 thousand km. It is established that the Polish larch takes a leading place in growth according to the complex growth indicators. The larch is somewhat inferior to it;it is a broad and scaly hybrid. The Siberian larch is significantly slower in its growth. The Scottish form of European larch slightly exceeds the Siberian larch by the height and stem diameter, though it has a noticeably higher density of the stand. At the same time, the presence of the large proportion (27 %) of shrinking trees in Scottish larch provenience, which is significantly higher than in other provinces, suggests that thinning process might occur in this population in the nearest future, thus bringing it closer to the aggregate growth indicators of Siberian larch. The Polish larch, which gives high rates of growth and productivity when planted in the middle belt of European Russia, is a promising breed for artificial reforestation. The range of the natural spread of the Polish larch species enters the region of the optimum in the area of the genus Larix.