phenetic STRUCTURE OF scots pine populations of the eluvial positions and mires of the west siberia*

¹Makhatkov I.D., ²Tarakanov V.V., ²Tyupina V.M.

¹Institute of Soil Science and Agrochemistry, SB RAS, Russia, makhatkov@mail.ru

² West-Siberian Office of the Institute of Forest, SB RAS, Russia, vvtarh@yandex.ru

One of the main issues in population biology of forests is the extent of genetic differentiation between mire and watershed forests of Scots pine (Pinus sylvestris L.). Due to the development of phenetic methods to estimate spatial population structure (Vidyakin 2006) and poor respective information about West-Siberian area of Scots pine we undertook the presented pilot study.

The 14 study sites were located in autumn 206 in the taiga ecosystems along the transect on the right bank of the Ob river from 59 to 63° NL, and described geobotanically and taxationally. On each study from 40-100 trees one typical cone was sampled. Then in the laboratory the cones and seeds were analyzed morphometrically according to Vidyakin (2006).

Analyses showed that the size of the cones and seeds, the number and weight of mature seeds correlated with each other and with environmental conditions, except for such variable as cone index that was constant in all cases.

Among the seed phenes the color type of the first layer displayed close correlation with size variables. The share of seed with brown first layer decreased with increasing sizes of cones and seeds, the coefficients of correlation ranging from -0.53 to -0.79. So this variable seems to be determined by habitat conditions.

The frequencies of phenes of the 2^nd and 3^rd color layers varied independently of each other of the size variables, the differences between eluvial and mire populations being statistically insignificant. However, factor analysis of phonetic variables showed differentiation of the populations (Fig.).

The mire and watershed populations were well differentiated by the 2^nd principal component, that had generally higher values for the eluvial populations as compared to the mire ones (except for one mire population). This exception may be due to the spreading of seeds from the neighboring alleviated populations.

Our study showed the complexity of population structure of mire tree stands, that seemed to be phenologically different, but at the same time experiencing certain “migration pressure” from the eluvially positioned populations. Further studies are needed to elucidate the issue.

*The study was financially supported by SB RAS Integration grant # 5.23.