STATE AND ECOLOGICAL STRUCTURE OF POPULATIONS OF PINUS PALLASIANA D. DON OF THE LOWER BELT OF THE SOUTHERN MACROSLOPE OF THE MAIN RIDGE OF THE CRIMEAN MOUNTAINS
Authors: Koba V. P. , Khromov A. F. , Sakhno T. M. 
Published: August 2020

The main area of the forests of P. pallasiana D. Don of the Mountain Crimea is located on the southern macroslope of the Main ridge of Crimean mountains at altitudes of 400–1200 m above sea level, stretching from Zaprudnoe village to the town of Simeiz. In some places, small areas of natural plantings of P. pallasiana occur in close proximity to the coastal edge, which indicates a wider distribution of this species in the lower belt of the southern macroslope of the Main ridge of the Crimean mountains in the past.

The reduction in the area of natural plantings of P. pallasiana in the lower belt is obviously due to anthropogenic pressure, since most of the residential areas of the Southern coast of the Crimea are located here. At present, there are isolated areas of natural forests of P. pallasiana in the coastal zone – this is primarily in «Cape Martyan» and «Cape Aya» nature reserves. One of the reasons for the decline in the life status and death of stands of P. pallasiana may be due to global climate change. In this regard, the study of the state of P. pallasiana is of particular interest in the regional territories of natural growth, where the effect of limiting factors is most pronounced.

The study of natural stands of P. pallasiana was carried out in the lower zone of the southern macroslope of the Main ridge of the Crimean mountains, using methods of dendrometry and forest taxation.

Under the conditions of the coastal territories of the reserve «Cape Aya», P. pallasiana forms open stands of trees, the average trunk height is 5.3 ± 0.8 m, while the trees have relatively large diameter sizes – up to 40 cm. The life span of individual plants reaches 150–180 years, with an average stand age of 80.1 ± 7.2 years. The ratio of dendrometric indicators and the age of plants indicate that the growing conditions of P. pallasiana in the ecotopes of the reserve «Cape Aya» are quite tough.

In another isolated area of natural plantings, which is located on the territory of the reserve «Cape Martyan», P. pallasiana is represented by widely spaced groups, less often – single trees in the oak-juniper communities. The average age of P. pallasiana here is 70.3 ± 6.5 years. Plants aged 40 and 60 years have the highest representation – 13.6 % and 13.1 %, respectively. Young and old individuals make up a small part of the structure of the stand. Plantings P. pallasiana on the territory of the reserve «Cape Martyan» have relatively low forest assessment rates, their structure is dominated by low-growing trees with a small trunk diameter. In terms of life quality, most of P. pallasiana trees (71.7 %) within the reserve are in poor state.

In the whole, the stands of P. pallasiana in the lower zone of the southern macroslope of the Main ridge of the Crimean mountains are characterized by relatively low taxational indicators. The ratio of age, height, and diameter of trees indicate that P. pallasiana grows under rather harsh conditions in the ecotopes of the coastal zone. Based on the analysis of the characteristics of seed renewal due to the influence of climatic factors, it was found that the most significant influence on the survival rate and population dynamics of P. pallasiana is the temperature regime of the first half of the growing season. Against the background of ever-increasing economic and recreational activities, negative climate change trends associated with global warming will increasingly limit the opportunities for successful growth and development, seed renewal of natural populations of P. pallasiana in the lower belt of the southern macroslope of the Main ridge of the Crimean mountains.