Tree species composition of forests and its age-related changes in suramens of the Kama region of the Republic of Tatarstan

Research findings featuring forest tree species structure pattern in the Pre-Kama region suramens of the Tatarstan Republic that is very specific in ecotopes with varying moisture degree. Forests growing in the forest growing condition type (FGCT) N2 account for the major share in the Pre-Kama region suramens. Woods in humid and wet suramens come short of them in area and growing stock dozen times. Pine mostly artificial plantations prevail in fresh suramens. Birch woods dominate in wet suramens. In occurrence aspen, lime and spruce woods are sufficiently inferior and in these conditions it'd be reasonable to substitute them with pine and larch woods with higher productivity. Older woods prevail in wet suramens. Forest tree species structure in the Pre-Kama region of the Tatarstan Republic drastically differs from one in the Marji El Republic. Forest tree species structure in the Pre-Kama region suramens affected by silvicultural operations as well as biocoenotic and abiotic factors varies greatly with age and goes on in every hygrotop very specifically. Thus spruce woods mainly as forest plantations prevail in young forests in fresh suramens. In the follow-up spruce wood share in forest structure arrangement in this FGCT is gradually reducing due to spruce drop related to its low drought resilience that are quite often in the Tatarstan Republic. Birch share in forests of this FGCT is the greatest at 41-60 years and lime wood - 80-100 years. Aspen wood share in forests of all ages is low and they don't occur after 80 years. In wet suramens within whole age range birch woods prevail reducing its share after 50 years gradually replaced with lime woods. Aspen wood share is the greatest at 21-40 years. At 20 years birch woods prevail in wet suramens where edificatory number is low. Forest structure in the Pre-Kama region in all age groups is far from commercial an ideal and needs sufficient adjustment especially in wet suramens.