Sibirica Ledeb Research Articles

Наследственная обусловленность пигментного состава хвои представителей рода лиственница

The content and ratio of plastid pigments in the conifers of three species of the larch genus (Larix Mill.) were studied: Siberian larch (L. sibirica Ledeb.), Gmelin’s larch (L. Gmelinii (Rupr.) Rupr.), Sukachev’s larch (L. Sukaczewii Dylis). Their seed progeny is concentrated on a pilot site in the Sergachsky forestry of the Nizhny Novgorod region with geographical coordinates 55°32 ‘14,2” N 45°28’01,0” E and an absolute height of 160 m. The site is assigned to the zone of coniferous-broad-leaved forests (the third forest-growing zone) and is included in the area of coniferous-broad-leaved (mixed) forests of the European part of the Russian Federation. The content of chlorophyll a, chlorophyll b and carotenoids in the needles was determined by spectrophotometric method at wavelengths: 665 nm, 649 nm, 452,5 nm. Samples for research were prepared in accordance with the principle of a single logical difference and randomized sample formation. Phenotypic differences in the pigment composition of needles between representatives of these species were revealed. The pigment composition of Siberian larch is dominated by chlorophyll a (3,76 ± 0,12 mg/g), significantly less chlorophyll b (1,87 ± 0,07 mg/g) and even less carotenoids (0,59 ± 0,02 mg/g). The same is observed in the pigment composition of other larch species. The hereditary conditionality of the species specificity of Siberian larch, Gmelin’s larch and Sukachev’s larch was established for all the tested characteristics. The greatest influence (29,84 ± 1,61 %) on the formation of the total phenotypic dispersion was observed in the ratio of the content of chlorophyll-a to the content of carotenoids, the least (5,89 ± 2,16 %) — in the content of dry matter in the needles. Relatively high values were obtained for the proportion of carotenoids (26,74 ± 1,68 %) and the ratio of their content to the total of chlorophylls (26,39 ± 1,69 %). The studied species showed an unequal level of similarity or significant differences in the individual characteristics of the pigment composition of needles.

State of the relict species Abies sibirica Ledeb. in the natural monument «Sinegorskaya fir grove» (Koktau mountains)

The article presents the results of studies of Siberian fir (Abies sibirica Ledeb.) in the natural monument «Sinegorskaya fir grove». In order to study the current state and development of the relict population field expeditions were conducted. By route-reconnaissance method the main occupied areas of the population on Mountain Medvedka were observed: the eastern, northern and western slopes, as well as two peaks. The studied population is represented by all age groups. There are 3 main types of A. sibirica Ledeb. phytocenoses: birch-fir (Betula pendula Roth, A. sibirica Ledeb.), fir (A. sibirica Ledeb.) and fir-aspen (Populus tremula L., A. sibirica Ledeb.). Parameters such as the height of mature trees, annual growth, length of young needles and the amount of young undergrowth have been determined. It has been established that the regeneration of the species directly depends on the type of phytocenosis. Based on the results of observations of the state, re-newal and dispersal of Siberian fir only birch-fir communities are characterized by optimal conditions. In communities with aspen the species is severely oppressed. Diseases and pests were found in clean plantations. The limiting factors for the species are xerophytization of the habitat and the lack of sufficient soil layer. As additional protection measures to increase regeneration artificial re-sowing of seeds and planting of fir seed-lings were suggested. Constant monitoring of the state of the population was proposed.