Seed Germination of Coniferous Introduced Species in the Environment of Central Kazakhstan with Various Stratification and Inclusion of Needle Litter into Substrate

Abstract

This study observes the issues of the possible usage of wastes from timber industry in the sprouting of seeds of coniferous plants in the arid climate of Central Kazakhstan. Such treatment of coniferous seeds is easily implementable and cost-effective, compared to the other methods. However, the complex chemical composition of needle litter in the soil substrate has the multifactorial and controversial effects on such indicators as germination energy, seed germination capacity and rest energy. In addition, the article discusses the use of long-term natural seed stratification as an alternative method of planting seeds in forest nurseries. The other studies have shown that natural stratification has a more significant effect on the indicators of seed rest energy and germination energy. However, it should be said that these parameters mostly correlate with the generic assignment of the objects. Thus, representatives of the genera Picea and Abies have more significant rates of germination during spring stratification. Whereas, representatives of the genera Pinus and Pseudotsuga – with natural stratification. This may be the result of their ecological and biological adaptation. The conditions of Central Kazakhstan are characterized by a sharply continental climate, which includes not only a sharp climate change, but also a rather low snow cover and low temperatures. Under these conditions, the seeds of the genera Pinus and Pseudotsuga may have higher adaptive abilities, which may become a further subject of research. At the same time, it was determined that despite the rather convincing data obtained during autumn stratification, the highest results of seed germination in most experimental species were noted during spring stratification, including variation with the use of needle litter. Again, it is not entirely advisable to introduce the use of this method based only on the indicators of seed germination in arid conditions of Central Kazakhstan, since the favorable period for seed germination in this area is unstable from year to year. Thus, based on the results of the study, it was concluded that the most suitable method for germinating seeds of conifers, with some exceptions, is natural stratification. The use of needle litter affects insignificantly the rates of seed germination, and in some cases even suppresses this process.